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Plastic debris forms: Rock analogues emerging from marine pollution
Abstract and Figures
Continuous input of plastic litter in ocean and coastal environments achieved alarming levels that are exposing new settings in natural systems. While novel plastic debris pollution, with rock-like appearance, has been reported worldwide, fundamentally geological analyses are still lacking. We surveyed the first occurrence of multiple associated plastic debris on a single outcrop located in a remote site (Trindade Island, SE Atlantic Ocean). Even though all plastic debris forms consisted of polypropylene and polyethylene, through a sedimentary approach (cross section, macro, and micro analyses) distinct types were identified. We detected plastiglomerates, geogenic analogous to conglomerates, divided into in situ and clastic types, and formed over beach sediment. We identified plastistones as a new type with homogeneous composition (lacking incorporated materials), geogenic-looking igneous rocks, divided into in situ and clastic types, and formed over rock surfaces. We linked pyroplastics, geogenic analogous to clasts, to clastic plastiglomerates/plastistones, therefore representing clastic types of plastic debris forms. This association was correlated in a depositional system model, which suggests that plastic debris forms are rock synthetic equivalents in which humans act as depositional and post-depositional agents.
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... Recentemente, foram descobertas as primeiras ocorrências de análogos de rochas com detritos plásticos na Ilha de Trindade, arquipélago brasileiro a sudeste do Oceano Atlântico (Santos et al., 2022). O sistema deposicional da associação de rochas encontradas sugere que as formas de detritos plásticos são equivalentes sintéticos de rochas nas quais os seres humanos atuam como "agentes deposicionais e pósdeposicionais" (Santos et al., 2022). ...
... Recentemente, foram descobertas as primeiras ocorrências de análogos de rochas com detritos plásticos na Ilha de Trindade, arquipélago brasileiro a sudeste do Oceano Atlântico (Santos et al., 2022). O sistema deposicional da associação de rochas encontradas sugere que as formas de detritos plásticos são equivalentes sintéticos de rochas nas quais os seres humanos atuam como "agentes deposicionais e pósdeposicionais" (Santos et al., 2022). Embora tenham sido identificados tipos distintos de rochas, todas as formas de detritos plásticos consistiram em polipropileno e polietileno. ...
... Ainda que as garrafas PET -utilizadas no presente estudo como material para fabricação da fibra de reforço do solo -tenham em sua composição outro material plástico, o politereftalato de etileno, essa descoberta atenta para a entrada contínua de lixo plástico em ambientes oceânicos e costeiros. Como alertam Santos et al. (2022), a poluição alcançou níveis alarmantes que estão expondo novos ambientes em sistemas naturais. ...
RESUMO. Com o crescimento acelerado em obras de infraestrutura, o aumento das atividades industriais e a constante geração de resíduos, faz-se necessário o desenvolvimento de medidas sustentáveis para minimizar os impactos ao meio ambiente. Da conjugação desses fatores, surge uma interessante perspectiva para a utilização de materiais alternativos para aterro em obras geotécnicas, atentando-se para a redução do impacto causado pelo descarte de resíduos sólidos. Nesse sentido, é possível aliar geotecnia experimental e ambiental a métodos e práticas alternativas e sustentáveis para sua abordagem em obras civis geotécnicas. No âmbito da estabilização de solos, por exemplo, a utilização de materiais alternativos ainda é muito incipiente. No intuito de ampliar a área de conhecimento em referência ao aproveitamento de materiais para reforço de solos compactados, o presente trabalho teve como objetivo uma análise experimental simplificada do comportamento de um solo laterítico reforçado com fibras de garrafas PET como base de pavimentação. O comportamento foi simulado por meio de ensaios laboratoriais de compactação, de resistência à penetração e de cisalhamento direto. Os resultados obtidos mostraram a influência das fibras de garrafas PET no aumento da resistência à penetração do solo. Sugere-se, entretanto, o aprofundamento na avaliação do comportamento das fibras para conclusões definitivas. ABSTRACT - With the accelerated growth in infrastructure works, the increase in industrial activities and the constant generation of waste, it is necessary to develop sustainable practices to minimize impacts on the environment. From the combination of these factors, an interesting perspective arises for the use of alternative materials for landfill in geotechnical works, paying attention to the reduction of the impact caused by the disposal of solid waste. In this sense, it is possible to combine experimental and environmental geotechnics with alternative and sustainable methods and practices for its approach in geotechnical civil works. In the scope of soil stabilization, for example, the use of alternative materials is still very incipient. In order to expand the area of knowledge in reference to the use of materials to reinforce compacted soils, the present work aimed at a simplified experimental analysis of the behavior of a lateritic soil reinforced with PET bottle fibers as a paving base. The behavior was simulated through laboratory tests of compaction, resistance to penetration and direct shear. The results obtained showed the influence of PET bottle fibers in increasing soil penetration resistance. It is suggested to deepen the evaluation of the behavior of the fibers for definitive conclusions.
... Our study provides the first records and characterizations of plasticoncrete (plastic hardened in concrete), plastimetal (plastic rusted with metal) and plastisessiles (plastic attached to benthic substrates by sessile invertebrates) worldwide. These plastic forms did not consist of the same components as plastiglomerate (plastic, rock, inorganic and/or organic materials; Corcoran et al., 2014), pyroplastic (plastic, Turner et al., 2019), plasticrusts (plastic, intertidal rock; Gestoso et al., 2019), anthropoquinas (plastic, beachrock; Fernandino et al., 2020), plastistone (plastic; Santos et al., 2022) and plastitar (plastic, tar / crude oil; Gregory, 1983;Wilber, 1987;Turner and Holmes, 2011;Domínguez-Hernández et al., 2022). They also did not show any signs of plastic melting (as in plastiglomerate, pyroplastic and plastistone; Corcoran et al., 2014;Turner et al., 2019;Ehlers and Ellrich, 2020;De-la-Torre et al., 2022;Furukuma et al., 2022;Santos et al., 2022;Rakib et al., 2023), plastic abrasion (as in plasticrusts; Gestoso et al., 2019;Ehlers and Ellrich, 2020;Ehlers et al., 2021;Ellrich et al., 2023) or plastic interactions with beachrock (as in anthropoquinas; Fernandino et al., 2020) or tar (as in plastitar; Gregory, 1983;Wilber, 1987;Turner and Holmes, 2011;Domínguez-Hernández et al., 2022). ...
... These plastic forms did not consist of the same components as plastiglomerate (plastic, rock, inorganic and/or organic materials; Corcoran et al., 2014), pyroplastic (plastic, Turner et al., 2019), plasticrusts (plastic, intertidal rock; Gestoso et al., 2019), anthropoquinas (plastic, beachrock; Fernandino et al., 2020), plastistone (plastic; Santos et al., 2022) and plastitar (plastic, tar / crude oil; Gregory, 1983;Wilber, 1987;Turner and Holmes, 2011;Domínguez-Hernández et al., 2022). They also did not show any signs of plastic melting (as in plastiglomerate, pyroplastic and plastistone; Corcoran et al., 2014;Turner et al., 2019;Ehlers and Ellrich, 2020;De-la-Torre et al., 2022;Furukuma et al., 2022;Santos et al., 2022;Rakib et al., 2023), plastic abrasion (as in plasticrusts; Gestoso et al., 2019;Ehlers and Ellrich, 2020;Ehlers et al., 2021;Ellrich et al., 2023) or plastic interactions with beachrock (as in anthropoquinas; Fernandino et al., 2020) or tar (as in plastitar; Gregory, 1983;Wilber, 1987;Turner and Holmes, 2011;Domínguez-Hernández et al., 2022). Plasticoncrete and plastimetal are the first plastic forms that each consists of two man-made materials (plastic and concrete, plastic and metal) whereas all previously reported plastic forms contained only plastic as artificial component. ...
... To date, most plastic form records stem from marine coastal habitats (Fig. S1). Aside from plastitar (i.e., benthic plasto-tar crusts and pelagic plasto-tarballs on/off Bermuda; Wilber, 1987), only pyroplastic and plasticoncrete have been reported in marine coastal (Turner et al., 2019;Ehlers and Ellrich, 2020;Furukuma, 2021;De-la-Torre et al., 2022;de Vos et al., 2022;Ellrich and Ehlers, 2022;Furukuma et al., 2022;James et al., 2022;Lozoya et al., 2022;Santos et al., 2022;Sewwandi et al., 2022a;Sewwandi et al., 2022b;Fig. 1A-G) and terrestrial habitats (Cyvin et al., 2021;Fig. ...
Plastic forms, including plastiglomerate, pyroplastic, plasticrusts, anthropoquinas, plastistone and plastitar, were recorded worldwide. These plastic forms derive from geochemical or geophysical interactions such as heat-induced plastic fusion with rock in campfires, incomplete plastic combustion, water motion-driven plastic abrasion in the rocky intertidal zone, plastic deposition in hardened sediments and plastic bonding with tar. Thereby, these interactions can profoundly influence the fate of plastics in the environment. This study characterized three novel plastic forms (plasticoncrete, plastimetal and plastisessiles) discovered on Helgoland island (North Sea). Plasticoncrete consisted of common polyethylene (PE) and polypropylene (PP) fibers hardened in concrete. Plastimetal included PE fibers rusted with metal. Plastisessiles consisted of PE fibers attached to benthic substrates by sessile invertebrates (oysters and polychaetes). Plasticoncrete and plastimetal constitute the first plastic forms composed of two man-made materials. Plastisessiles show that plastic forms not only result from human- or environment-mediated interactions but also from biological interactions between invertebrates and plastic. All plastic forms (bulk density ≥ 1.4 g/cm3) sunk during floating tests and hardly changed their positions during a 13-day field experiment and 153- to 306-day field monitorings, confirming their local formation, limited mobility and longevity. Still, experimentally detached plastic fibers floated, confirming that the formation of these plastic forms influences the fate of plastic fibers in the environment. The experiment also showed that plasticoncrete got deposited in beach sand under wavy and windy conditions, indicating that coastal waves and onshore winds drive plasticoncrete deposition in coastal sediments. We also provide first records of plasticoncrete on Mallorca island (Mediterranean Sea) and plastimetal on Hikoshima island (Sea of Japan), respectively, which show that these plastic forms are no local phenomena. Thereby, our study contributes to the growing fundamental knowledge of plastic forms that is essential to understand the role and fate of these pollutants in coastal habitats worldwide.
... The study of Plastics as a part of the geologic record is recent, still in initial development. Existing information has been described by diverse authors (i.e., Turner et al., 2019;Fernandino et al., 2020;Avelar Santos et al., 2022;De la Torre et al., 2022;Furukuma et al., 2022, among others). The leading example is Plastiglomerate, which were first reported by Corcoran et al. (2014). ...
... After compaction, the precipitation of quartz and the plastic cements between the grains (gravel) binds the sediment into rock. Plastiglomerates found along the study area can be compared with those found on the coast of Hawaii (Corcoran et al., 2014), Spain (Irabien et al., 2015), Peru (De la Torre et al., 2021), Portugal , and Brazil (Avelar Santos et al., 2022). ...
... Gracia et al. (2018) and Gracia and Rangel-Buitrago (2020) described both species as invasive in the study area. Similar secondary forms have been reported in England, Scotland, Ireland, Spain, and Canada by Turner et al. (2019), Italy (Ehlers and Ellrich, 2020), Peru (De la Torre et al., 2021), Japan (Furukuma, 2021;Furukuma et al., 2022), Portugal (Ellrich and and Brazil (Avelar Santos et al., 2022). ...
This study presents the first report of plastics in the geological record (rocks and formations composed of plastics) along the central Caribbean Coast of Colombia, northern coast of South America. These novel records of pollution include two rock types (plastiglomerates and quartz plastisandstones), two altered plastic types (pyroplastics and plasticrusts), two soil types (plasticlasts and anthrosols), and a series of artifacts (fossils) found near human settlements. All of them were analyzed using Fourier Transform Infrared (FTIR) spectroscopy. Polyester, high-density polyethylene, and copolymers of alkyl acrylates or methacrylates were identified as the principal polymers forming these rocks. This research provides new insights into the petrology of these emerging new forms of pollution, for which humans are primarily responsible for their generation and distribution. Similarly, the results presented emphasize that plastics are generating a deluge of pollutants in terms of variety and volume, overwhelming natural environments globally. Controlling or even eliminating their use has become one of the most significant challenges of the 21st Century.
... In this scenario, plastic pollution stands out as plastic debris forms, i.e., materials containing plastic with a rock-like appearance (see Santos et al., 2022). ...
... (a) In situ occurences, on a wave-cut platform occuping at least part of the intertidal zone. The deposits cover massive nephelinites (seaward) and beach sediment (landward); (b) Sample varying vertically from plastiglomerate into plastistone towards the top of the deposits (afterSantos et al., 2022). ...
... Beach sediments composed of natural and human-made components (plastic fragments, red arrows) (afterSantos et al., 2022). ...
Anthropocene is still not formally included in the Geological Time Scale, and the scientific community is discussing what it represents stratigraphically. However, the Anthropocene is considered by many in the scientific community as currently happening and highlights humans as active global-scale geological agents. In this sense, geoscientists have the opportunity to understand how we influenced the past and are influencing the present, which is key to the future from an archaeological perspective. In this scenario, plastic pollution stands out as
plastic debris forms, i.e., materials containing plastic with a rock-like appearance. We have described the first outcrop composed of plastic forms on a remote oceanic island (Tartarugas beach, Trindade Island, SE Atlantic Ocean). We have identified plastiglomerates composed of melted plastic cement, a framework of volcanic lithoclasts, and a matrix ranging from fine to coarse sand (approximately 0.125 mm to 1 mm) of lithic fragments, heavy minerals, plastic, and bioclasts. In addition, we introduced the term plastistones, characterized by the homogeneous composition of melted plastic. We verified that occurrences were compatible with that of pure polyethylene (PE) and polypropylene (PP) via Fourier Transform Infrared
Spectroscopy (FTIR). We have found microplastics in the beach sediment. Therefore, the outcrop eroded has become a sediment supply for the beach. In this sense, due to Trindade Island’s location in a region with intense carbonate precipitation and beach rock formation, these plastic fragments have the potential to be preserved among the natural material during these rocks formation. This scenario suggests that these human-influenced rock-like materials show a high fossilization susceptibility (e.g., ichnofossils, anthropoquinas). In this sense,
plastic debris forms are relevant in the Anthropocene background. The Earth Sciences should increasingly deal with these novel sedimentary scenarios, where plastic and other types of marine pollution are the main components in deposits.
... Classification and origin of the new types of plastic pollution. Several new terms were introduced to classify the types of plastic pollution studied [9][10][11][12][13]16,18 . However, the distinction between plastiglomerate and its variants is sometimes subtle or imprecise. ...
... Previous studies on plastiglomerate and its variants have mentioned PE, PP, and PET as polymers 11,13,15,17,18,40 . This study reports acrylates/polyurethane/varnish and a styrene-acrylonitrile copolymer as additional polymer type in plastiglomerates (Table 1, Fig. 4). ...
This study reports on plastiglomerate and other new forms of plastic pollution in the tropical marine continent of Indonesia. Twenty-five samples were collected from an island beach in the Java Sea where plastiglomerate, plasticrusts, and pyroplastic were formed by the uncontrolled burning of plastic waste. The most common plastic types were polyethylene and polypropylene (PE/PP), as shown by ATR-FTIR spectroscopy. However, acrylates/polyurethane/varnish (PU) and a copolymer of styrene and acrylonitrile were found as well. This suggests that plastiglomerates can form from a wider variety of plastic polymers than previously reported. FTIR analysis also indicates thermo-oxidative weathering, making the charred plastic more brittle and susceptible to microplastic formation. A subset of the samples was analyzed for associated chemical contaminants. One plastiglomerate with a PU matrix showed high concentrations of phthalates. All samples had high concentrations of polycyclic aromatic hydrocarbons (PAHs), likely due to the burning of the plastic in open fires. The burning leads to a change in the physical and chemical properties of the plastics contained in the plastiglomerates. Plastiglomerate and plastic waste of similar origin are therefore often more weathered and contaminated with organic pollutants than their parent polymers. The highest PAH concentration was found in a plastitar sample. Plastitar is defined as an agglomerate of tar and plastics that adheres to coastal rocks. In contrast, our study documents a more mobile, clastic plastitar type. This clastic plastitar could pose an additional ecological risk because of its mobility. These new types of plastic pollution could be an important vector for chemical contamination of nearby coastal habitats such as coral reefs, seagrass meadows, and mangroves.
... c o m / l o c a t e / s c i t o t e n v passing through cities, and suspended in the atmosphere. Since its creation, plastic has been dispersed and can now be found in our water (Kirstein et al., 2021), food (Kapukotuwa et al., 2022), blood (Leslie et al., 2022), and more recently as forming rocks Avelar Santos et al., 2022). Plastics are now so omnipresent on planet Earth that their amounts, distribution, and impacts are used to delimit the Anthropocene Epoch or Age (Crutzen and Soermer, 2000). ...
... Plastics can now be used as a stratigraphic tool to define a new time-rock unit (i.e., stage or substage) within the Anthropocene: the Plasticene . The Plasticene, as part of the geological record, started with the surge of plastic production after World War II, and can be defined as the time within the Anthropocene when plastics became part of sedimentary processes and were deposited, buried, and now serve as clear stratigraphic markers in deposits and rocks of all sizes, shapes, and compositions Avelar Santos et al., 2022). The leading example is plastiglomerate, first reported in Kamilo Beach, Hawaii (Corcoran et al., 2014). ...
The Anthropocene, the most recent geologic time division, marks humanity's profound impact on Earth. Amidst debates, the Anthropocene Working Group recommended its inclusion in the International Chronostratigraphic Chart (ICC). This period is characterized by the mid-20th century Great Acceleration Event Array (GAEA), which includes widespread presence of pollutants such as radionuclides, organochlorine pesticides, PCBs, and plastic production. The Anthropocene concept should raise public awareness of these threats, with plastic pollution being a primary concern. Plastics are now pervasive and serve as a marker for the Anthropocene Epoch or Age. Understanding their entry into the geological record requires considering the "Plastic Geological Cycle," which encompasses extraction, production, use, disposal, degradation, fragmentation, accumulation, and lithification. This cycle reveals the transformation of plastics into new forms of pollution characteristic of the Anthropocene. With 91 % of discarded plastics never recycled, they accumulate in the environment and enter the geological record through processes like photodegradation, thermal stress, and biodegradation. The proposed Plasticene stage within the Anthropocene is defined by the post-World War II surge in plastic production and their incorporation into sedimentary processes and rocks. The study of plastics in the geologic record serves as a warning of their negative impacts and highlights the urgency of addressing plastic pollution for a sustainable future.
... We suspect that the shells were present where the plastic materials were illegally burned and became incrusted in the molten plastic by accident. On the other hand, various sessile organisms have been reported on the surface of weathered pyroplastics, such as calcareous worm tubes(Turner et al., 2019), snail egg capsules, and barnacles(Furukuma et al., 2022), and various macroinvertebrates(Santos et al., 2022). Interestingly, the colonization of plastic litter by live organisms has been widely investigated and reported worldwide(Mantelatto et al., 2020;Póvoa et al., 2022;Rech et al., 2018), and is recognized as a possible driver of biological invasions due to the ability of J o u r n a l P r e -p r o o f Journal Pre-proof plastics to be transported for long distances(De-la-Torre et al., 2023;García-Gómez et al., 2021). ...
... It has been observed that, unlike HDPE, LDPE displays a weak band at around 1377 cm -1 indicating a CH 3 bending deformation(Chércoles Asensio et al., 2009), which allowed distinguishing between these two polymers using FTIR spectra.The four polymers identified in the novel plastic forms from Cox"s Bazar are commonly reported in other parts of the world. For instance,Santos et al. (2022) and found the same polymer types in different plastic forms from Brazil and Peru, respectively. These are some of the most massively produced and consumed plastic polymers worldwide(Geyer et al., 2017). ...
The identification and description of novel plastic forms, such as pyroplastics and plastiglomerates, in coastal areas raised several concerns in the field of plastic pollution. Under the growing literature in the field, the present study preliminarily reports the occurrence of novel plastic forms on Cox"s Bazar beach, Bangladesh. The description of the novel plastic forms agrees with the literature, mostly consisting of lithic and biogenic elements within a synthetic polymer matrix (HDPE, LDPE, PP, and PET identified). Several knowledge gaps regarding the interaction between the novel plastic forms and colonizing organisms, as well as the leaching rates of plastic additives, remain to be addressed as crucial points to understand their implications. Illegal waste dumping and burning were identified as the primary catalysts for the emergence of new plastic forms in Cox's Bazar. Overall, researchers must reach a baseline consensus regarding the methodologies and next steps in the field.
... Therefore, it is unclear whether these findings constitute plasticrusts or plastiglomerates ('agglutinations of rock and molten plastic'; Corcoran et al., 2014). Other Peruvian plasticrusts (large and homogenous plastic surfaces covering a smooth boulder; Fig. 3A in De-la-Torre et al., 2022) strongly resembled plastiglomerates from sandy and rocky intertidal habitats (Furukuma et al., 2022;Santos et al., 2022). These plastic surfaces were concentrated in shallow surface depressions of the boulder (as in plastiglomerates; Corcoran et al., 2014) and contained pores (as in plastiglomerates and pyroplastics; Corcoran et al., 2014;Turner et al., 2019;De-la-Torre et al., 2022;Furukuma et al., 2022;Santos et al., 2022) which indicates heat-induced formation (Salasinska et al., 2020;Luo et al., 2022) of these plastic surfaces. ...
... Other Peruvian plasticrusts (large and homogenous plastic surfaces covering a smooth boulder; Fig. 3A in De-la-Torre et al., 2022) strongly resembled plastiglomerates from sandy and rocky intertidal habitats (Furukuma et al., 2022;Santos et al., 2022). These plastic surfaces were concentrated in shallow surface depressions of the boulder (as in plastiglomerates; Corcoran et al., 2014) and contained pores (as in plastiglomerates and pyroplastics; Corcoran et al., 2014;Turner et al., 2019;De-la-Torre et al., 2022;Furukuma et al., 2022;Santos et al., 2022) which indicates heat-induced formation (Salasinska et al., 2020;Luo et al., 2022) of these plastic surfaces. Furthermore, these plastic surfaces were completely absent from boulder surface protrusions which distinguished them from all previous plasticrust records (Fig. 1A-E in Gestoso et al., 2019;Fig. ...
Plasticrusts are a plastic form that consists of plastic encrusting intertidal rocks. To date, plasticrusts have been reported on Madeira Island (Atlantic Ocean), Giglio Island (Mediterranean Sea) and in Peru (Pacific Ocean) but information on plasticrust sources, generation, degeneration and fate is largely missing. To address these knowledge gaps, we combined plasticrust field surveys, experiments and monitorings along the Yamaguchi Prefecture (Honshu, Japan) coastline (Sea of Japan) with macro-, micro- and spectroscopic analyses in Koblenz, Germany. Our surveys detected polyethylene (PE) plasticrusts that derived from very common PE containers and polyester (PEST) plasticrusts that resulted from PEST-based paint. We also confirmed that plasticrust abundance, cover and distribution were positively related to wave exposure and tidal amplitude. Our experiments showed that plasticrusts are generated by cobbles scratching across plastic containers, plastic containers being dragged across cobbles during beach clean-ups, and waves abrading plastic containers on intertidal rocks. Our monitorings found that plasticrust abundance and cover decreased over time and the macro- and microscopic examinations indicated that detached plasticrusts contribute to microplastic pollution. The monitorings also suggested that hydrodynamics (wave occurrence, tidal height) and precipitation drive plasticrust degeneration. Finally, floating tests revealed that low density (PE) plasticrusts float whereas high density (PEST) plasticrusts sink suggesting that polymer type floatability influences the fate of plasticrusts. By tracking the entire lifespan of plasticrusts for the first time, our study contributes fundamental knowledge of plasticrust generation and degeneration in the rocky intertidal zone and identified plasticrusts as novel microplastic sources.
... From herein, we excluded from Results those eight grey documents that had their information regarding waterbirds-plastic interactions fully published and a book chapter that has the same results published in a peer-reviewed journal (Colabuono and Vooren, 2006;Colabuono and Vooren, 2007), totalling 87 documents at the end. Four studies were published in 2022, up to May, although they were not included in the analyses (Azevedo- Santos et al., 2022;Costa et al., 2022;Nascimento et al., 2022;Robuck et al., 2022). Noteworthy, Azevedo-- Santos et al. (2022) reported on a duck (Anseriformes) entangled in a ghost fishing net. ...
... Four studies were published in 2022, up to May, although they were not included in the analyses (Azevedo- Santos et al., 2022;Costa et al., 2022;Nascimento et al., 2022;Robuck et al., 2022). Noteworthy, Azevedo-- Santos et al. (2022) reported on a duck (Anseriformes) entangled in a ghost fishing net. ...
Plastic pollution is an increasing global problem, especially in aquatic environments. From invertebrates to vertebrates, many aquatic species have been affected by plastic pollution worldwide. Waterbirds also interact with plastics, mainly by ingesting them or using them as nest material. Brazil has one of the largest aquatic environment areas, including the most extensive wetland (the Pantanal) and biggest river (the Amazon), and a ∼7500 km long coastline, which hosts a remarkable waterbird diversity with more than 200 species from 28 bird families. Here, we synthesise published and grey literature to assess where, how, and which waterbirds (marine and continental) interact with plastics in Brazil. We found 96 documents reporting interaction between waterbirds and plastics. Only 32% of the occurring species in the country had at least one individual analysed. Plastic ingestion was reported in 67% of the studies, and seabirds were the study subject in 79% of them. We found no reports in continental aquatic environments, unveiling entire regions without any information regarding interactions. Consequently, this geographic bias drew a considerable taxonomic bias, with whole families and orders without information. Additionally, most studies did not aim to search for plastic interactions, which had a twofold effect. First, studies did not report their findings using the proposed standard metric, hampering thus advances in understanding trends or defining robust baselines. Second, as it was not their main objective, plastics were not mentioned in titles, abstracts, and keywords, making it difficult to find these studies. We propose means for achieving a better understanding of waterbird-plastic interactions in space and time, and recommend searching for sentinel species and for allocating research grants.
... More recently, plastic was proposed as a marker of the upper subdivision of a new geological stage: the Plasticene (Rangel-Buitrago et al., 2022). Plastics are indeed interacting with the geological cycle in many ways, and new geological formations are being increasingly reported in the scientific literature (e. g., De-la-Torre et al., 2021Santos et al., 2022;Goswami and Bhadury, 2023). The so-called "Detriplastic rocks" (cf. ...
A new geological formation consisting of plastic debris admixed to petroleum oil residue, termed “plastitar”, has been recently described in the Canary Islands. Here, we report its widespread occurrence across the Mediterranean coast and new insights into its biogeochemical composition. Specifically, we found marked differences in the diagenetic stable indicator profiles, suggesting a heterogeneous seeps provenance. Moreover, the 801 plastic
particles found in the 1372 g of tar surveyed, with a maximum concentration of 2.0 items/g, showed interesting patterns in the tar mat, with nurdles predominantly layered in the external of the tar mat and lines in the inner core. Overall, the collected bservation suggests that tar entraps plastics through a stepwise process and is a sink
for them.
... 120 Moreover, the integration of microplastics as part of the geological cycle through the burning (e.g., bushfires or campfires) and/or burial have been found to create favorable conditions for the formation of plastic geomaterials such as plastistones or plastiglomerates. 121 3.2. Physical Infrastructure Resilience. ...
... More recently, plastic was proposed as a marker of the upper subdivision of a new geological stage: the Plasticene (Rangel-Buitrago et al., 2022). Plastics are indeed interacting with the geological cycle in many ways, and new geological formations are being increasingly reported in the scientific literature (e.g., De-la-Torre et al., 2021Santos et al., 2022;Goswami and Bhadury, 2023). The so-called "Detriplastic rocks" (cf. ...
... Finally, anthropoquinas were originally sedimentary rocks that included Anthropocene markers, such as plastic (Fernandino et al., 2020;De-la-Torre et al., 2022). These plastic formations are an intriguing (and under-studied) issue in plastic pollution because they behave differently from typical plastic litter in the environment (Santos et al., 2022). These recently identified plastic types appear to be typical findings and might represent an under-utilized source of plastics. ...
One of the most significant environmental issues confronting our world is plastic trash, which is of particular concern to the marine environment. The sedimentary record of the planet may likely one day contain a horizon of plastic that can be potentially identified as an Anthropocene marker. Here we report the presence of 'plas-tiglomerate' from coastal habitats located in the Aves Island, Andaman Sea, India. This novel form of plastic pollution forms with the incineration of plastic litter in the environment and then mixing of organic/inorganic composite materials in the molten plastic matrix. The plastic pollutants were collected from the Aves Island beach during marine litter surveys. Micro-Raman (μ-Raman) spectroscopy was used to evaluate and confirm all putative plastic forms. Plastiglomerates were made of a polyethylene (PE) and polyvinyl chloride (PVC) matrix with inclusions of rock and sand. Therefore, our research offers new insight into the intricate process of plas-tiglomerates formation.
Plastics, “yesterday's hero... today's villain” or “the contemporary symbol of modernity,” were invented in the early 20th century by Leo Hendrik Baekeland from macromolecules (resins, elastomers, and artificial fibres) of formaldehyde and phenol. This synthetic organic polymer took hold of daily human life and transformed the modern world with an ever-widening range of applications. Plastics are the third most-widely manufactured material in the world after cement and steel, and they have become widespread in our society with excessive production and consumption to meet demand. Plastics use is so dominant that they are inappropriately considered essential in the world consumers marketplace. Plastics are a clear indicator of the Anthropocene and can be considered the marker of the upper subdivision of this stage: the Plasticene.
Beaches in the Anthropocene carry the heavy burden of human-derived pollution, like that induced by plastic litter. For decades, plastic debris has been classified based on its source or physical size. In recent years, studies described and documented new forms of plastic formations, including plastiglomerates, plasticrusts, and pyroplas-tics. However, reports of these newly described formations are substantially lacking. Therefore, in the present study, we reported the first evidence of plasticrusts (plastic encrusting rock surfaces), plastiglomerates (organic/ inorganic composite materials in a plastic matrix), and pyroplastics (burned and weathered plastics) in Peru. The plastic pollutants were recovered from the field through marine litter surveys on four beaches where illegal litter burning and campfires take place. All the suspected plastic formations were analyzed and confirmed using Fourier transformed infrared (FTIR) spectroscopy, and one of each type was analyzed by X-Ray fluorescence (EDX) spectrometry. Plastiglomerates consisted of a high-density polyethylene (HDPE) or polypropylene (PP) matrix with rock and sand inclusions. Pyroplastics were found in various stages of weathering and consisted of various polymers, including HDPE, PP, polyethylene terephthalate (PET), and polyamide (PA). Interestingly, our field observations suggest a new plasticrust formation pathway based on plastic burning and filling of rock crevices with molten plastic. The latter was identified as either PP or HDPE. Elements typically found in the sand and seawater (e.g., Na, Cl, Ca, Si, Fe) were identified on the surface of the plastic formations, as well as others that could potentially be associated with the leaching of additives (e.g., Ti, Br). Although the present study contributed to the knowledge concerning the occurrence of the new types of plastic formations, as well as possible formation pathways, there are still many questions to answer. Hence, we encourage future studies to focus on the toxicity that new plastic formations may induce in contrast with conventional plastics, the release of secondary contaminants (e.g., microplastics, additives), and their degradation in the environment. Lastly, standardized sampling and data treatment protocols are required.
Over the course of the last decade the concept of the Anthropocene has become widely established within and beyond the geoscientific literature but its boundaries remain undefined. Formal definition of the Anthropocene as a chronostratigraphical series and geochronological epoch following the Holocene, at a fixed horizon and with a precise global start date, has been proposed, but fails to account for the diachronic nature of human impacts on global environmental systems during the late Quaternary. By contrast, defining the Anthropocene as an ongoing geological event more closely reflects the reality of both historical and ongoing human–environment interactions, encapsulating spatial and temporal heterogeneity, as well as diverse social and environmental processes that characterize anthropogenic global changes. Thus, an Anthropocene Event incorporates a substantially wider range of anthropogenic environmental and cultural effects, while at the same time applying more readily in different academic contexts than would be the case with a rigidly defined Anthropocene Series/Epoch.
Ecuador’s Galapagos Islands and their unique biodiversity are a global conservation priority. We explored the presence, composition and environmental drivers of plastic contamination across the marine ecosystem at an island scale, investigated uptake in marine invertebrates and designed a systematic priority scoring analysis to identify the most vulnerable vertebrate species. Beach contamination varied by site (macroplastic 0 - 0.66 items.m⁻², microplastics 0 - 448.8 particles.m⁻² or 0 – 74.6 particles.kg⁻¹), with high plastic accumulation on east-facing beaches that are influenced by the Humboldt Current. Local littering and waste management leakages accounted for just 2% of macroplastic. Microplastics (including anthropogenic cellulosics) were ubiquitous but in low concentrations in benthic sediments (6.7 - 86.7 particles.kg⁻¹) and surface seawater (0.04 - 0.89 particles.m⁻³), with elevated concentrations in the harbour suggesting some local input. Microplastics were present in all seven marine invertebrate species examined, found in 52% of individuals (n = 123) confirming uptake of microplastics in the Galapagos marine food web. Priority scoring analysis combining species distribution information, IUCN Red List conservation status and literature evidence of harm from entanglement and ingestion of plastics in similar species identified 27 marine vertebrates in need of urgent, targeted monitoring and mitigation including pinnipeds, seabirds, turtles and sharks.
The term Anthropocene initially emerged from the Earth System science community in
the early 2000s, denoting a concept that the Holocene Epoch has terminated as a consequence of human activities. First associated with the onset of the Industrial Revolution, it was then more closely linked
with the Great Acceleration in industrialization and globalization from the 1950s that fundamentally modified physical, chemical, and biological signals in geological archives. Since 2009, the Anthropocene has been evaluated by the Anthropocene Working Group, tasked with examining it for potential
inclusion in the Geological Time Scale. Such inclusion requires a precisely defined chronostratigraphic and geochronological unit with a globally synchronous base and inception, with the mid-twentieth century being geologically optimal. This reflects an Earth System state in which human activities have become predominant drivers of modifications to the stratigraphic record, making it clearly distinct
from the Holocene. However, more recently, the term Anthropocene has also become used for different conceptual interpretations in diverse scholarly fields, including the environmental and social sciences and humanities. These are often flexibly interpreted, commonly without reference to the geological record, and diachronous in time; they often extend much further back in time than the mid-twentieth century. These broader conceptualizations encompass wide ranges and levels of human impacts and interactions with the environment. Here, we clarify what the Anthropocene is in geological terms and compare the proposed geological (chronostratigraphic) definition with some of these broader interpretations and applications of the term “Anthropocene,” showing both their overlaps and differences.
Growth in fundamental drivers—energy use, economic productivity and population—can provide quantitative indications of the proposed boundary between the Holocene Epoch and the Anthropocene. Human energy expenditure in the Anthropocene, ~22 zetajoules (ZJ), exceeds that across the prior 11,700 years of the Holocene (~14.6 ZJ), largely through combustion of fossil fuels. The global warming effect during the Anthropocene is more than an order of magnitude greater still. Global human population, their productivity and energy consumption, and most changes impacting the global environment, are highly correlated. This extraordinary outburst of consumption and productivity demonstrates how the Earth System has departed from its Holocene state since ~1950 CE, forcing abrupt physical, chemical and biological changes to the Earth’s stratigraphic record that can be used to justify the proposal for naming a new epoch—the Anthropocene.
In: Communications Earth & Environment (Open Access Nature Research Paper)
A review of 80 papers on microplastic (MP) particles in marine sediments was conducted for different sedimentary environments. The papers were assessed for data on average MP concentration, MP morphotype (fibres, fragments, films, etc.), MP particle size distribution, sediment accumulation rates and correlations with total organic carbon (TOC) and sediment grain size. The median concentration of MP particles is highest in fjords at 7000 particles kg⁻¹ dry sediment (DS) followed by 300 in estuarine environments, 200 in beaches, 200 in shallow coastal environments, 50 on continental shelves and 80 particles kg⁻¹ DS for deep sea environments. Fibres are the dominant MP type and account for 90% of MP on beaches (median value) and 49% of particles in tide-dominated estuaries. In order to advance our understanding of the fate of MP in the ocean, quantitative assessments are needed of MP flux rates (g m⁻² year⁻¹) in a range of sedimentary environments.
Plastic marine pollution in the Arctic today illustrates the global distribution of plastic waste of all sizes traveling by wind and waves, entering food chains, and presenting challenges to management and mitigation. While currents move plastics from lower latitudes into the Arctic, significant waste is also generated by remote communities, as well as maritime activities, such as shipping, fishing and tourism, which are increasing their activities as seasonal sea ice diminishes. Mitigation strategies may include monitoring programs of plastic waste abundance and distribution, improved waste management in Arctic communities, Extended Producer Responsibility (EPR) to reverse the transport of waste plastics and packaging from remote communities, incentivized gear recovery of abandoned, lost and discarded fishing gear (ALDFG), gear tagging and tracking, and restricting tourism and employing “leave no trace” policies. Here we report how these mitigation strategies are employed in the Arctic to minimize plastic waste impacts, and move Arctic communities toward better materials management and circular economic practices. The evidence of harm from waste plastics exacerbated by the ubiquity of plastic marine pollution in all biomes, and the rapid reporting of ecological and social costs, together suggest that we know enough to act quickly to manage and mitigate plastics from all sources to the Arctic.
The threat posed by plastic pollution to marine ecosystems and human health is under increasing scrutiny. Much of the macro- and microplastic in the ocean ends up on the seafloor, with some of the highest concentrations reported in submarine canyons that intersect the continental shelf and directly connect to terrestrial plastic sources. Gravity-driven avalanches, known as turbidity currents, are the primary process for delivering terrestrial sediment and organic carbon to the deep sea through submarine canyons. The ability of turbidity currents to transport and bury plastics is poorly understood, however. Using flume experiments, we investigate how turbidity currents transport microplastics, and their role in differential burial of microplastic fragments and fibers. We show that microplastic fragments become relatively concentrated within the base of turbidity currents, whereas fibers are more homogeneously distributed throughout the flow. Surprisingly, the resultant deposits show an opposing trend, as they are enriched with fibers, rather than fragments. We explain this apparent contradiction by a depositional mechanism whereby fibers are preferentially removed from suspension and buried in the deposits as they are trapped between settling sand-grains. Our results suggest that turbidity currents potentially distribute and bury large quantities of microplastics in seafloor sediments.
As plastic pollution in the environment has increased rapidly in the last half century, so too has the study of the effects of plastic on marine, aquatic and terrestrial ecosystems. From this research, a series of new terms has emerged to describe the phenomena unique to the presence of plastic-based materials in nature. In this short note, we bring together disparate neologisms into a single lexicon with the aim to encourage use of a unified vocabulary to describe the new reality of ecological, chemical, and geological systems in the age of plastics.
Plastic litter is an ever-increasing global issue and one of this generation’s key environmental challenges. Microplastics have
reached oceans via river transport on a global scale. With the exception of two megacities, Paris (France) and Dongguan
(China), there is a lack of information on atmospheric microplastic deposition or transport. Here we present the observations
of atmospheric microplastic deposition in a remote, pristine mountain catchment (French Pyrenees). We analysed samples,
taken over five months, that represent atmospheric wet and dry deposition and identified fibres up to ~750 µm long and frag-
ments ≤300 µm as microplastics. We document relative daily counts of 249 fragments, 73 films and 44 fibres per square
metre that deposited on the catchment. An air mass trajectory analysis shows microplastic transport through the atmosphere
over a distance of up to 95 km. We suggest that microplastics can reach and affect remote, sparsely inhabited areas through
atmospheric transport.
Plastics is all the rage, and mitigating marine litter is topping the agenda for nations pushing issues such as ocean acidification, or even climate change, away from the public consciousness. We are personally directly affected by plastics and charismatic megafauna is dying from it, and it is something that appears to be doable. So, who cares about the issue of ocean acidification anymore? We all should. The challenge is dual in the fact that is both invisible to the naked eye and therefore not felt like a pressing issue to the public, thereby not reaching the top of the agenda of policy makers; but also that it is framed in the climate change narrative of fear-whereby it instills in a fight-or-flight response in the public, resulting in their avoidance of the issue because they feel they are unable to take action that have results. In this article, we argue that the effective global environmental governance of ocean acidification, though critical to address, mitigate against and adapt to, is hindered by the both this lack of perception of urgency in the general public, fueled by a lack of media coverage, as well as a fight-or-flight response resulting from fear. We compare this to the more media friendly and plastics problem that is tangible and manageable. We report on a media plots of plastics and ocean acidification coverage over time and argue that the issue needs to be detangled from climate change and framed as its own issue to reach the agenda at a global level, making it manageable to assess and even care about for policy makers and the public alike?
Millions of metric tons of plastics are produced annually and transported from land to the oceans. Finding the fate of the plastic debris will help define the impacts of plastic pollution in the ocean. Here, we report the abundances of microplastic in the deepest part of the world’s ocean. We found that microplastic abundances in hadal bottom waters range from 2.06 to 13.51 pieces per litre, several times higher than those in open ocean subsurface water. Moreover, microplastic abundances in hadal sediments of the Mariana Trench vary from 200 to 2200 pieces per litre, distinctly higher than those in most deep sea sediments. These results suggest that manmade plastics have contaminated the most remote and deepest places on the planet. The hadal zone is likely one of the largest sinks for microplastic debris on Earth, with unknown but potentially damaging impacts on this fragile ecosystem.
Polymer identification of plastic marine debris can help identify its sources, degradation, and fate. We optimized and validated a fast, simple, and accessible technique, attenuated total reflectance Fourier transform infrared spectroscopy (ATR FT-IR), to identify polymers contained in plastic ingested by sea turtles. Spectra of consumer good items with known resin identification codes #1-6 and several #7 plastics were compared to standard and raw manufactured polymers. High temperature size exclusion chromatography measurements confirmed ATR FT-IR could differentiate these polymers. High-density (HDPE) and low-density polyethylene (LDPE) discrimination is challenging but a clear step-by-step guide is provided that identified 78% of ingested PE samples. The optimal cleaning methods consisted of wiping ingested pieces with water or cutting. Of 828 ingested plastics pieces from 50 Pacific sea turtles, 96% were identified by ATR FT-IR as HDPE, LDPE, unknown PE, polypropylene (PP), PE and PP mixtures, polystyrene, polyvinyl chloride, and nylon.
Esta dissertação representa uma abordagem teórico-metodológica, a partir do campo da geoarqueologia, para o estudo dos processos de formação (culturais e naturais) do sambaqui Jabuticabeira II. Este sambaqui monumental tem sido o mais estudado do litoral sul do Estado de Santa Catarina devido à alta quantidade de sepultamentos humanos que contém e à sua intrincada estratigrafia. A complexidade observada nas seções verticais do sítio não foi satisfatoriamente explicada pelas abordagens arqueoestratigráficas tradicionais. Por isso, realizou-se nesta pesquisa uma adaptação da análise de fácies sedimentares para desenvolver um método que permita realizar a descrição, caracterização e interpretação destes sedimentos arqueológicos.
Understanding the global mass inventory is one of the main challenges in present research on plastic marine debris. Especially the fragmentation and vertical transport processes of oceanic plastic are poorly understood. However, whereas fragmentation rates are unknown, information on plastic emissions, concentrations of plastics in the ocean surface layer (OSL) and fragmentation mechanisms is available. Here, we apply a systems engineering analytical approach and propose a tentative 'whole ocean' mass balance model that combines emission data, surface area-normalized plastic fragmentation rates, estimated concentrations in the OSL, and removal from the OSL by sinking. We simulate known plastic abundances in the OSL and calculate an average whole ocean apparent surface area-normalized plastic fragmentation rate constant, given representative radii for macroplastic and microplastic. Simulations show that 99.8% of the plastic that had entered the ocean since 1950 had settled below the OSL by 2016, with an additional 9.4 million tons settling per year. In 2016, the model predicts that of the 0.309 million tons in the OSL, an estimated 83.7% was macroplastic, 13.8% microplastic, and 2.5% was < 0.335 mm 'nanoplastic'. A zero future emission simulation shows that almost all plastic in the OSL would be removed within three years, implying a fast response time of surface plastic abundance to changes in inputs. The model complements current spatially explicit models, points to future experiments that would inform critical model parameters, and allows for further validation when more experimental and field data become available.
Plastics in the marine environment have become a major concern because of their persistence at sea, and adverse consequences to marine life and potentially human health. Implementing mitigation strategies requires an understanding and quantification of marine plastic sources, taking spatial and temporal variability into account. Here we present a global model of plastic inputs from rivers into oceans based on waste management, population density and hydrological information. Our model is calibrated against measurements available in the literature. We estimate that between 1.15 and 2.41 million tonnes of plastic waste currently enters the ocean every year from rivers, with over 74% of emissions occurring between May and October. The top 20 polluting rivers, mostly located in Asia, account for 67% of the global total. The findings of this study provide baseline data for ocean plastic mass balance exercises, and assist in prioritizing future plastic debris monitoring and mitigation strategies.
Significance
The isolation of remote islands has, until recently, afforded protection from most human activities. However, society’s increasing desire for plastic products has resulted in plastic becoming ubiquitous in the marine environment, where it persists for decades. We provide a comprehensive analysis of the quantity and source of beach-washed plastic debris on one of the world’s remotest islands. The density of debris was the highest recorded anywhere in the world, suggesting that remote islands close to oceanic plastic accumulation zones act as important sinks for some of the waste accumulated in these areas. As global plastic production continues to increase exponentially, it will further impact the exceptional natural beauty and biodiversity for which remote islands have been recognized.
The "Anthropocene Epoch" has been proposed as a new post-Holocene geological time interval-a period characterized by the pervasive impact of human activities on the geological record. Prior to the influence of human technologies, the diversity and distribution of minerals at or near Earth's surface arose through physical, chemical, and/or biological processes. Since the advent of human mining and manufacturing, particularly since the industrial revolution of the mid-eighteenth century, mineral-like compounds have experienced a punctuation event in diversity and distribution owing to the pervasive impact of human activities. We catalog 208 mineral species approved by the International Mineralogical Association that occur principally or exclusively as a consequence of human processes. At least three types of human activities have affected the diversity and distribution of minerals and mineral-like compounds in ways that might be reflected in the worldwide stratigraphic record. The most obvious influence is the widespread occurrence of synthetic mineral-like compounds, some of which are manufactured directly for applications (e.g., YAG crystals for lasers; Portland cement) and others that arise indirectly (e.g., alteration of mine tunnel walls; weathering products of mine dumps and slag). A second human influence on the distribution of Earth's near-surface minerals relates to large-scale movements of rocks and sediments-sites where large volumes of rocks and minerals have been removed. Finally, humans have become relentlessly efficient in redistributing select natural minerals, such as gemstones and fine mineral specimens, across the globe. All three influences are likely to be preserved as distinctive stratigraphic markers far into the future.
In recent decades, several seabird populations have declined globally due to anthropogenic activities. In Brazil, 14 seabird species breed at four oceanic islands and one atoll: the Abrolhos, Fernando de Noronha, and São Pedro and São Paulo (SPSPA) archipelagos; the Trindade/Martin Vaz Islands; and the Atol das Rocas. Seven species are listed as nationally threatened by extinction. This study aimed to present new information on breeding seabird populations in Brazilian oceanic islands, compile all available data previously published and, when possible, to provide updated information on population estimates from censuses carried out sporadically at different islands between 2006 and 2013. Based on new data and the thorough review provided here,
of the 35 seabird breeding populations analysed, 14% were increasing (as Red-billed Tropicbird Phaethon aethereus, Magnificent Frigatebird Fregata magnificens and Brown Noddy Anous stolidus in Abrolhos), 11% were decreasing (as Brown Booby Sula leucogaster in Atol das Rocas and Great Frigatebird Fregata minor in Trindade island), 23% were stable (as White-tailed Tropicbird Phaethon lepturus in Fernando de Noronha and Brown Noddy and Black Noddy Anous minutus in São Pedro and São Paulo Archipelago), and the remaining 49% were unknown or not possible to evaluate. The Red-footed Booby (Sula sula) is locally extinct in Trindade Island, however there are colonies of only a few individuals of other species, such as the Audubon's Shearwater Puffinus lherminieri and Redbilled Tropicbird in Noronha, Black Noddy in Martin Vaz, and Great (Fregata ariel trinitatis) and Lesser (F. m. nicolli) Frigatebirds in Trindade, that may become extinct soon. Censuses at distinct periods of the breeding cycles and protocols were highly variable, making temporal comparisons difficult. These results indicate an urgent need for long-term studies to improve the scenario to assess seabird population trends based on comparable methodologies, in order to determine trends in the future.
Plastiglomerate and pyroplastic are two novel plastic debris forms that were originally discovered on sandy beaches in Hawaii and the UK, respectively. While plastiglomerate consists of plastic melted together with rocks or pebbles, pyroplastic is melted plastic. Although both plastic debris forms were related to campfires, it is unclear whether they are related to each other. Also, plastiglomerate and pyroplastic records from other shore types are missing. Therefore, we surveyed pebble beach habitats in Madeira Island (Atlantic Ocean) for plastiglomerate and pyroplastic. We detected one plastiglomerate (PG 1 , including a pebble) and four pyroplastics (PP 1-4). While PP 2-4 consisted of polypropylene, PG 1 and PP 1 consisted of polyethylene and polypropylene. Furthermore, PG 1 and PP 1 included previously undescribed pebble shaped clasts that unequivocally linked plastiglomerate to pyroplastic. Thereby, our findings provide the first record of plastiglomerate and pyroplastic from pebble beach habitats worldwide and establish the link between these two novel plastic debris forms.
Rivers polluted by anthropogenic litter are major transport routes of litter from inland to the coastal zone and the ocean. However, litter studies have primarily focused on marine environments, and the litter dynamics in rivers are still poorly understood. Herein, we explored the abundances, composition and sources of litter at the riversides and in surface waters of mountain rivers from continental Chile in two different years. Additionally, we evaluated whether different temporal, geographic, topographic, hydrologic or anthropogenic factors influence the abundances of litter. Anthropogenic litter was prevalent in Chilean rivers, both at the riversides and in surface waters. Average abundances of riverside litter, floating macrolitter, and small floating plastics were 1.8 items m⁻², 10.1 items h⁻¹ and 5.8 items h⁻¹, respectively, and abundances were generally higher in northern Chile. Plastics dominated in all compartments, comprising 29% of riverside litter and more than 70% of small floating litter, but other litter categories were also present at riversides. Sources of litter in Chilean rivers were mostly local, such as recreational visitors, residents, and illegal dumping, and there were no clear effects of the different tested factors on the abundances of litter. Litter densities in surface waters were low compared to those in lowland slow-flowing rivers in other countries, suggesting that retention of litter is limited in the highly dynamic and rapidly flushing mountain rivers, and thus most litter (primarily plastics) is transported directly to the sea. The results suggest that to adequately address this problem in Chile, prevention measures should be aimed at the identified local sources, by means of education, public policies, legislation, and enforcement.
Plasticrusts are a novel form of plastic debris which has only recently been discovered in Madeira Island, NE Atlantic Ocean. Plasticrusts consist of plastic encrusting wave-exposed rocky intertidal habitats and are presumably generated by waves smashing plastic debris against intertidal rocks. However, direct observations of this process are lacking and it is unknown which type of plastic debris the plasticrusts derive from. Therefore, we examined the Madeira rocky intertidal for signs of plasticrust formation and collected plasticrust and co-occurring plastic debris pieces of matching colors. We examined all collected materials using digital micro-scopy and Fourier-transform infrared spectroscopy. We found that plasticrusts can result from maritime ropes being scoured across raspy intertidal rocks and that the plasticrusts and the corresponding ropes consisted of polypropylene (PP) and high-density polyethylene (HDPE). Furthermore, we show that high temperatures contribute to plasticrust formation. Thereby, our study provides first insights into the complex plasticrust formation process.
Plastic contamination of the environment is a global problem whose magnitude justifies the consideration of plastics as emergent geomaterials with chemistries not previously seen in Earth’s history. At the elemental level, plastics are predominantly carbon. The comparison of plastic stocks and fluxes to those of carbon reveals that the quantities of plastics present in some ecosystems rival the quantity of natural organic carbon and suggests that geochemists should now consider plastics in their analyses. Acknowledging plastics as geomaterials and adopting geochemical insights and methods can expedite our understanding of plastics in the Earth system. Plastics also can be used as global-scale tracers to advance Earth system science.
Marine plastic pollution is a global concern because of continuous release into the oceans over the last several decades. Although recent studies have made efforts to characterize the so-called plastisphere, or microbial community inhabiting plastic substrates, it is not clear whether the plastisphere is defined as a core community or as a random attachment of microbial cells. Likewise, little is known about the influence of the deep-sea environment on the plastisphere. In our experimental study, we evaluated the microbial colonization on polypropylene pellets and two types of plastic bags: regular high density polyethylene (HDPE) and HDPE with the oxo-biodegradable additive BDA. Gravel was used as control. Samples were deployed at three sites at 3300 m depth in the Southwest Atlantic Ocean and left for microbial colonization for 719 days. For microbial communities analysis, DNA was extracted from the biofilm on plastic and gravel substrates, and then the 16S rRNA was sequenced through the Illumina Miseq platform. Cultivation was performed to isolate strains from the plastic and gravel substrates. Substrate type strongly influenced the microbial composition and structure, while no difference between sites was detected. Although several taxa were shared among plastics, we observed some groups specific for each plastic substrate. These communities comprised taxa previously reported from both epipelagic zones and deep-sea benthic ecosystems. The core microbiome (microbial taxa shared by all plastic substrates) was exclusively composed by low abundance taxa, with some members well-described in the plastisphere and with known plastic-degradation capabilities. Additionally, we obtained bacterial strains that have been previously reported inhabiting plastic substrates and/or degrading hydrocarbon compounds, which corroborates our metabarcoding data and suggests the presence of microbial members potentially active and involved with degradation of these plastics in the deep sea.
The quantity of floating plastic debris (FPD) is continuously being increased in the oceans. To assess their size, structure, and composition along the eastern Arabian Sea (EAS), FPD samples were collected by using a surface plankton net. The microplastic size fraction (0.5–5mm) was the most prevalent accounting for >50% of the total, followed by mesoplastics (5–25mm; ~40%) and macroplastics (>25mm; ~10%). The collected FPDs were categorized into five different types and eight colours. Attenuated Total
Reflectance-Fourier Transform Infrared Spectrometry (ATR-FTIR) analysis of the plastics revealed that polypropylene, polyethylene, and nylon were the most dominant polymers, and these comprised mostly
of fibre/fishing line. The abundance of FPD in the EAS (0.013 ± 0.012 no.s/m 3) was found to be very low compared to elsewhere. The prevalent microplastics presence in the oceans might have occurred mainly by the degradation of larger items. It increases bioavailability, and hence, is a risk to marine ecosystems.
Marine plastic litter is ubiquitous and knowledge about its impact on coasts, open waters, the deep-sea, and the biota found in those habitats is increasing. However, studies of how it affects terrestrial environments such as islands are not as common. Over time, macroplastics in marine, as well as terrestrial environments, will fragment into microplastics. A toxic level of microplastic is defined by characteristics of the specific organisms and the habitat it affects, but also of the plastic itself. Plastic litter is being collected from wilderness areas through beach-cleanups by volunteers, schools and professionals. A question that needs to be addressed is whether macroplastic that is partially weathered and buried under vegetation should be taken out of the topsoil layer or left untouched to further degrade with the risk of negative impacts on soil organisms or removed from the topsoil layer. A quantification of the amount of plastic found within the topsoil layer is therefore of great interest. In this study, a survey was conducted in spring/autumn 2020 at Mausund and Froan landscape conservation area in Frøya municipality, Norway (N63°). Thirteen samples of vegetated soil from above the storm tide limit from eight remote and uninhabited islands were collected, quantified and analyzed, and the results showed high amounts of plastic. Potential future concentrations of microplastic in the samples if left untouched are estimated, based on a formula from existing literature.
As an emerging marine environmental issue, marine plastic debris pollution has attracted worldwide attention. Studies have covered more and more areas of the world's oceans. To further understand the sources and variation of marine plastic debris in the surface water of the Bohai Sea, in this study, plastic debris was collected during the four seasons of 2016–2017. The results showed the mean density of plastic debris over these seasons was 0.49 ± 0.18 particles/m³. Macro-, meso-, and micro- plastics accounted for 5%, 26%, and 69% of the total number of plastic debris, respectively. The density of the microplastics was 0.35 ± 0.13 particles/m³. The highest density was found in spring, followed by summer and winter, and the lowest in autumn. High distribution densities were observed in the Liaodong Bay and the Bohai Strait, which were attributed to the dynamics of the rim current, terrain, and fishery activities.
Capsule abstract
Riverine input, dynamics of the rim current, terrain, and fishery activities contribute to the variations in marine plastic debris in the surface water of the Bohai Sea.
In search of an effective method to evaluate plastic contamination, macrolitter (>25 mm), mesolitter (5-25 mm), large microlitter (2-5 mm), large and small microplastics (2-5 mm and 0.5-2 mm) abundances in surface beach sands were simultaneously determined by two methods in four beach zones at six locations along the 100-km-long marine coast of the Curonian Spit National Park and the neighboring cities. Mean (median) content of plastic items per m 2 is 0.85 (0.33) for macro-, 1.48 (0.40) for meso-, 3.35 (0.68) for large microlitter, and 3235 (1800) for microplastics (0.5-5 mm). The distribution of litter and microplastics (0.5-5 mm) is highly variable along and across the beach. The abundance of small-microplastics (0.5-2 mm) at the beach face is similar for all the locations and replicates. Swash-zone mixing, water percolation, importance of sediment pore size (rather than grain size), natural sorting of plastic particles at the beach face are considered.
Plastic waste has become ubiquitous in ecosystems worldwide. Few, recent studies report evidence of coastal vegetated habitats acting as sink for plastics, yet assessments have been completed either for macro or microplastics and focussing on just one type of vegetated habitat. Here, we investigated the role of marine coastal vegetated habitats as sinks for macro (≥5 mm) and microplastics (<5 mm) through a comprehensive, multi-habitat approach. We assessed the occurrence, abundance and physical properties of macro and microplastics in the canopy and superficial sediment of two intertidal (seagrass Zostera noltei, saltmarsh Sporobolus maritimus) and two subtidal (mixed seagrass meadows of Cymodocea nodosa and Zostera marina, rhizophytic macroalga Caulerpa prolifera) habitats in the Ria Formosa lagoon (Portugal). Our results showed that coastal vegetated habitats trapped macro and microplastics in the sediment at variable degrees (1.3–17.3 macroplastics 100 m⁻², and 18.2–35.2 microplastics kg⁻¹). Macroplastics accumulated in all vegetated habitat but not in nearby unvegetated areas, but only S. maritimus habitat presented a significant trapping effect. Microplastics occurred in the sediment of all vegetated and unvegetated areas with similar abundances and high variability. Microplastics, all of type fibre, were recorded on all canopies except for S. maritimus. Overall, the trapping capacity of microplastics in the sediment and on the canopy was higher for subtidal than for intertidal vegetated habitats. We conclude that generalizations in the trapping effect of coastal vegetated areas should be done with caution, since it may be highly variable and may depend on the plastic size, habitat and tidal position. Since these habitats support a high biodiversity, they should be included in assessments of plastic debris accumulation and impacts in coastal areas. Further research, including experimental studies, is needed to shed more light on the role of coastal vegetated habitats as plastic sinks.
The occurrence of plastic waste in the environment has become a central topic on the global agenda. Recently, significant attention has been paid to this issue, with a particular focus on small plastic particles, microplastics, in the marine environment. This has resulted in a large volume of scientific research and public and media attention to the presence and risks associated with plastic in the ocean. Yet, the majority of plastics are produced, consumed, and disposed of on land. This indicates that solutions for tackling global plastic contamination lie in better understanding the processes leading to the environmental release of plastic in the terrestrial environment. Studies have also begun to uncover significant contamination of soil, atmospheric, and freshwater systems with a wide range of plastic waste through diverse and complex release pathways. Nevertheless, several questions remain regarding the sources, dynamics, associated risks, and potential solutions for limiting plastic waste emissions in the terrestrial environment.
Plastic, as a “flagship species”, represents how deeply humans impact the environment. Although scarce, the presence of plastic and other anthropogenic materials in rocks has already been reported in the literature, however, so far, not in the Southern Hemisphere. Thus, the objective of the present study was to report and describe samples of sedimentary rocks containing anthropogenic items cemented with biogenic and siliciclastic material – anthropoquinas – and to discuss implications to the establishment of the Anthropocene and geodiversity conservation. Six samples of anthropoquinas were evaluated, presenting different technofossils (metal bottle caps, ship nail, plastic earring and plastic fragment) and composition (lithic and biogenic fragments). Energy Dispersive X-ray Spectroscopy was conducted on two samples, reflecting differences regarding their genesis. The description of these rocks is concerning and reflects how deeply human behavior influences various natural compartments. Therefore, studies on the effects of marine litter on geodiversity are strongly encouraged.
The designation of the Anthropocene formalizes the end of the 11,700-yearlong Holocene and the beginning of a new epoch. In the technical debates governing this transition, the stability of previous disciplinary conventions is under question, and new modes of expression and expertise are solicited to ground answers. In our examination of Anthropocene origin stories, we analyze science communication about geological designations with an emphasis on how internal and external rhetorical processes of casuistic stretching frame the Holocene-Anthropocene transition. We argue that external stretching challenges scientists to distinguish an epoch of previous human influence from one of humans’ environmental impact. The resulting frames of influence-complexity and impact-collapse characterize the Anthropocene’s formalization and offer implications beyond geology. By taking up an analysis of the scientific sources governing this transition, we identify ways that rhetorical scholarship might help navigate the contemporary paradigm debates determining the Anthropocene’s designation.
We report the presence of ‘plasticrusts’ and ‘pyroplastic’ from coastal habitats in Giglio island, Tyrrhenian Sea, Italy. These novel plastic debris types have only recently been described for the first time from Madeira island (NE Atlantic Ocean) and the United Kingdom, respectively. While ‘plasticrusts’ are generated by sea waves smashing plastic debris against intertidal rocks, ‘pyroplastic’ derives from (un)deliberately burnt plastic waste. Using Fourier-transform infrared (FTIR) spectroscopy, we identified the ‘plasticrust’ material as polyethylene (PE) and the ‘pyroplastic’ material as polyethylene terephthalate (PET). These polymers are widely used in everyday products and, therefore, contribute heavily to plastic pollution in aquatic and terrestrial environments worldwide. Furthermore, our field surveys suggest that ‘plasticrust’ abundance is related to wave-exposure and that the ‘pyroplastic’ derived from beverage bottles which we frequently found along the Giglio coast. Overall, our findings corroborate the notion that ‘plasticrusts’ and ‘pyroplastic’ are common debris types in marine coastal habitats.
First documented in 2014, plastiglomerate continues to proliferate across the Earth’s surface. While these materials represent long-lasting symbols of anthropogenic impacts on the environment, they also highlight the need to address the global plastic crisis.
Items of marine plastic litter are conventionally classified as primary or secondary, depending on whether they are distinct objects or angular fragments, respectively. "Pyroplastic" is an additional type of plastic litter that is described here, based on observations made on beached samples from south west England. Pyroplastics are derived from the informal or more organised burning of manufactured plastics and may be angular "plastiglomerates", comprising pieces of plastic debris within a matrix, or rounded plastic "pebbles", where agglomerated material has been weathered and smoothed into more brittle and neutrally-coloured geogenic-looking clasts. Beached pyroplastics are usually positively buoyant because of a polyethylene or polypropylene matrix, and exhibit a bimodal mass distribution attributed to the breakage of larger clasts (>20 mm) into smaller fragments (<5 mm). XRF analysis reveals variable quantities of Pb in the matrix (up to 7500 μg g-1), often in the presence of Cr, implying that material in many samples pre-dates restrictions on the use of lead chromate. Low concentrations of Br and Sb relative to pieces of manufactured plastics in the marine environment suggest that pyroplastics are not directly or indirectly derived from electronic plastic. Calcareous worm tubes on the surfaces of pyroplastics dense enough to be temporarily submerged in the circalittoral zone are enriched in Pb, suggesting that constituents within the matrix are partly bioavailable. Evading ready detection due to their striking visual similarity to geogenic material, pyroplastics may contribute to an underestimation of the stock of beached plastics in many cases.
Plastic debris is one of the most extensive pollution problems our planet is facing today and a particular concern for marine environment conservation. The dimension of the problem is so large that it is possible our current era will generate an anthropogenic marker horizon of plastic in earth's sedimentary record. Here we present a new type of plastic pollution, the 'plasticrusts', plastic debris encrusting the rocky surface, recently discovered in the intertidal rocky shores of a volcanic Atlantic island. The potential impact that these new 'plasticrusts' may have needs to be further explored, as e.g. potential ingestion by intertidal organisms could suppose a new pathway for entrance of plastics into marine food webs. Consequently, its inclusion as a potential new marine debris category in management and monitoring actions should be pondered.
A stratigraphic framework can be constructed through lithofacies description and interpretation. The application of this method in volcanic systems is a fundamental tool for understanding their evolution and eruptive dynamics and for establishing hazard assessments in active volcanic areas. This work presents and discusses a detailed stratigraphy of the Paredão Volcano, allowing the understanding of the lateral and vertical distribution of volcanic facies and the 3D geometry of the deposits, generating a model for the volcanism and discussing the erupting mechanisms. The Paredão Volcano is a scoria cone located in the southeast of Trindade Island and represents the youngest subaerial volcanic episode (Pleistocene) recorded in Brazil. Its stratigraphic organization indicates nephelinitic flows alternate with lapillistones and lapilli-tuffs of same composition at the base and a pyroclastic cone with nearly 200 m high above the sea level. Through lithofacies description and association 4 stratigraphic columns were constructed in scale 1:50, three of them at the Tartarugas beach (TRV-01, TRV-02, TRV-03) and the other one at the pyroclastic cone (TRV-04). The petrographic characterization of facies was carried through conventional optical microscopy. The stratigraphic analysis resulted in the distinction of seven lithofacies, divided into two coherent and five volcaniclastic (one autoclastic and four pyroclastic). The coherent lithofacies are of massive (Npm) and vesicular porphyritic nephelinite (Npv). Texturally, the lavas are holocrystalline and vesicular, composed by olivine phenocrysts in a very fine matrix of clinopyroxene, nepheline, zeolite and titanomagnetite, at times with phlogopite. The autoclastic lithofacies of nephelinitic breccia (Nb) is composed of fragments (2 mm–15 cm) of vesicular nephelinite and the pyroclastic ones are composed mainly of lapillitic scoria fragments with subordinate bombs and volcanic ash. The pyroclastic lithofacies are of massive lapillistone (Lm) and lapilli-breccia (LBm), planar stratified lapilli-tuff (LTp), and reverse grading lapillistone (Lrg). The lithofacies associations characterize ‘A’a, rubbly pahoehoe and pahoehoe flow types, distal and proximal pyroclastic deposits. The interpretation of the vertical and lateral facies distribution leads to the conclusion that the volcanism occurred with an initial phreatomagmatic stage, succeeded by a Strombolian stage (pyroclastic with primary fragments domain) and a final Hawaiian stage (lava flows domain).
Microplastic (MP) contaminates terrestrial, aquatic and atmospheric environments. Although the number of river sampling studies with regard to MP concentrations is increasing, comprehension of the predominant transport processes of MP in the watercourse is still very limited. In order to gain a better process understanding, around 500 physical experiments are conducted to shed more light on the effects of particle shape, size and density on the rise and settling velocities of MP. The determined velocities ranged between 0.39 cm/s for polyamide fibres (settling) and 31.4 cm/s for expanded polystyrene pellets (rise). Subsequently, the determined velocities were compared with formulae from sediment transport and, as there were large differences between theoretically and experimentally determined velocities, own formulae were developed to describe settling and rise velocities of MP particles with a large variety of shapes, sizes and densities. This study shows that MP differs significantly from sediment in its behavior and that a transfer of common sediment transport formulae should be treated with caution. Furthermore, the established formulae can now be used in numerical simulations to describe the settling and rising of MP more precisely.
Marine debris is widespread in oceans worldwide, including the most remote locations. Here, for the first time, we report macro-debris accumulation on beaches of Trindade Island, a remote island 1160 km from mainland Brazil. High debris density was recorded on windward, east-coast beaches, which are exposed to wind-driven currents. Small-sized plastic fragments were the most abundant debris. Polyethylene (67%), polypropylene (30%) and polyamide (3%) were the most prevalent polymeric materials identified by ATR-FTIR. Identified debris show that interaction with Trindade fauna, mainly with seabirds and endangered terrestrial crabs, exists and already has some impact. This study provides baseline information on Trindade macro-debris demonstrating that the island, located on the edge of the South Atlantic Gyre, acts as a sink for gyre debris, exposing the island fauna to the threats related to plastic contamination.
The present work presented the first dated paleosealevel indicators and new paleogeographic reconstructions of the Island of Trindade. All evidence for Holocene sealevels point to the elevations higher than the present in the age interval between 5.06 ka and 0.55 ka. The altitude and ages of the reconstructions are in good agreement with hindcast model curves and the empirical sealevel envelope for the mainland eastern and northeastern Brazilian coast. However, the position of paleo vermetid-reef indicates that sealevel was lower than eustatic elevation, suggesting an effect of island subsidence. In contrast to the Brazilian mainland coastal zone, where conspicuous evidences of Pleistocene highstands were recorded, no evidence of sealevels predating the Holocene has ever been observed on the island. This could be attributed to intense coastal erosion and log-term island subsidence. A volcanic edifice rising more than 5500 m above the ocean floor was built by magmatic activity that extended over the late Pliocene and early Pleistocene. After the cessation of volcanic build up, the island started to shrink due to subaerial and marine erosion. During Pleistocene sealevel lowstands, alluvial fans were formed beyond the present limits of emerged areas. They were enclosed within and preserved from erosion by the Middle to Late Pleistocene lava flows and pyroclastic deposits. During Late Pleistocene sealevel highstand, intense coastal erosion removed the distal parts of the alluvial fans. It is very likely that at that time the entire coast of the island experienced intense erosion and subsidence as deduced from the absence of Pleistocene coastal deposits, which are widespread along mainland Brazilian coast. The east coast of the island was dominated by high sea cliffs sculpted into volcanic rocks. A volcanic cone was subsequently formed, when the sealevel was lower than present during the Late Pleistocene to early Holocene. During the mid to late Holocene sealevel highstand the volcanic cone was partially eroded and a bay formed, where vermetid-reefs grow and sand beach deposits prograded until the bay was infilled. During the sealevel maximum, wave-cut terraces were formed and sea cliffs were active. During the lowering of the sealevel, cliffs became inactive and vermetid-reefs were eroded. Beach erosion and aeolian deflation presently prevails, indicating a low sediment supply.
Concrete is the most abundant anthropogenic sedimentary rock on the planet, the production process requiring the transport of component cement and aggregates on scales far greater than natural geological processes. A building material for over two millennia, the scale of production and mineralogical and geochemical distinctiveness of concrete since the mid-20th century makes it a prominent signal for the Anthropocene within terrestrial, and increasingly subterranean, environments. It will be robust over millennial scales, but over millions of years will recrystallize to common natural minerals and disaggregate, losing mineralogical evidence of human origin, though commonly retaining aspects of human-made texture and form.
The West Antarctic Ice Sheet is one of the largest potential sources of rising sea levels. Over the past 40 years, glaciers flowing into the Amundsen Sea sector of the ice sheet have thinned at an accelerating rate, and several numerical models suggest that unstable and irreversible retreat of the grounding line-which marks the boundary between grounded ice and floating ice shelf-is underway. Understanding this recent retreat requires a detailed knowledge of grounding-line history, but the locations of the grounding line before the advent of satellite monitoring in the 1990s are poorly dated. In particular, a history of grounding-line retreat is required to understand the relative roles of contemporaneous ocean-forced change and of ongoing glacier response to an earlier perturbation in driving ice-sheet loss. Here we show that the present thinning and retreat of Pine Island Glacier in West Antarctica is part of a climatically forced trend that was triggered in the 1940s. Our conclusions arise from analysis of sediment cores recovered beneath the floating Pine Island Glacier ice shelf, and constrain the date at which the grounding line retreated from a prominent seafloor ridge. We find that incursion of marine water beyond the crest of this ridge, forming an ocean cavity beneath the ice shelf, occurred in 1945 (±12 years); final ungrounding of the ice shelf from the ridge occurred in 1970 (±4 years). The initial opening of this ocean cavity followed a period of strong warming of West Antarctica, associated with El Niño activity. Thus our results suggest that, even when climate forcing weakened, ice-sheet retreat continued.
Terminal settling velocity of around 600 microplastic particles, ranging from 0.5 to 5 mm, of three regular shapes was measured in a series of sink experiments: Polycaprolactone (material density 1131 kg m− 3) spheres and short cylinders with equal dimensions, and long cylinders cut from fishing lines (1130–1168 kg m− 3) of different diameters (0.15–0.71 mm). Settling velocities ranging from 5 to 127 mm s− 1 were compared with several semi-empirical predictions developed for natural sediments showing reasonable consistency with observations except for the case of long cylinders, for which the new approximation is proposed. The effect of particle's shape on its settling velocity is highlighted, indicating the need of further experiments with real marine microplastics of different shapes and the necessity of the development of reasonable parameterization of microplastics settling for proper modeling of their transport in the water column.
Many polyethylene (PE) films used in various packaging applications are based on multi-layer systems and are fabricated by using the coextrusion techniques that can combine different raw materials. The identification of the comonomer type (octene - C8, hexene - C6 and butene - C4) in films, where two or more different linear low density polyethylene (LLDPE) resins are present, is becoming a frequent request. This report presents a novel approach where multivariate classification techniques are used in combination with FTIR for the identification of the comonomer type in coextruded films. A set of different LLDPE coextruded samples have been measured by FTIR, and the resulting spectra processed by Principal Component Analysis (PCA). By projecting the samples to the scores plots a difference is observed as a function of comonomer composition. This approach, compared with others is much faster, as just the time of measuring a film by direct infrared analysis is required.
The Trindade Island is located in the South Atlantic Ocean, 1170 km from the Brazilian coast and represents the eastern end of the submarine E–W Vitória–Trindade Chain. This is interpreted as the Trindade plume track beneath the South American plate during the Cenozoic. Almeida (1961) recognized five volcanogenic successions at Trindade in decreasing age: the Trindade Complex (TC) and the Desejado (DF), Morro Vermelho (MV), Valado (VF) and Paredão (PF) formations, composed of nephelinitic to phonolitic effusive–pyroclastic deposits, dykes and necks. Here, we present new 40Ar/39Ar ages and re–evaluation of available 40K/40Ar* data that, coupled with previous petrological information, allowed us to reconstruct the volcanic history of the island (i.e., 3.9–0.25 Ma) distinguishing near synchronous volcanic episodes and solving
several stratigraphic uncertainties reported in the literature.
The geochronological dataset show that the nephelinitic–phonolitic volcanism at Trindade was discontinuous throught time, being marked by periods of high volcanic activity and periods of quiescence, which suggests variable melt production and eruption rates. The peak of the volcanic activity occurred between 3.9–2.5 Ma (i.e., Lower Pliocene to Lower Pleistocene) that is represented by the TC, which correspond to the largest volume of volcanic deposits preserved in the island. The volcanic activity
slows down progressively from 2.5 Ma to cease at ca. 1.6 Ma, period that is represented by the DF. This volcanism was followed by a quiescent period that lasted until the ephemeral nephelinitic volcanism of the MV (no age), VA (no age) and PF (ca. 0.25 Ma). Thus, the volcanic activity in Trindade was ceased completely at ca. 0.25 Ma, event registered in the uppermost volcanic deposits of the PF and that represents the last volcanic activity in the Brazilian territory.
Rocks are naturally occurring aggregates of one or more minerals. In the case of porosity or fracturing, they also contain fluid phases. With respect to their geological genesis and processes, rocks are divided into three major groups:. -igneous rocks (magmatites),-metamorphic rocks (metamorphites), and-sedimentary rocks (sediments).Rocks are characterized by their composition (minerals, fluids), texture, and structure.Of specific interest are sedimentary rocks with respect to their reservoir properties. Clastic (sandstone) and carbonate (limestone, dolomite) rocks are the most common reservoir rocks. Clay and shale have a strong influence upon rock properties and are discussed.Some core measurement techniques for laboratory determination are compiled.