Article

A new terrestrial plant-rich Fossil-Lagerstätte from the middle Cenomanian (Late Cretaceous) of the Apennine Carbonate Platform (Magliano Vetere, southern Italy): Depositional and palaeoenvironmental settings

Authors:
To read the full-text of this research, you can request a copy directly from the authors.

Abstract

We describe a new terrestrial, plant-rich Fossil-Lagerstätte discovered at Magliano Vetere (Campania region, S Italy) in the middle Cenomanian of the Apennine Carbonate Platform. The deposit, 1.42 m thick, is made up of a thin-bedded interlayering of evenly laminated dolomicrites, lenticular dolorudites and carbonaceous seams, which contain well-preserved remains of terrestrial plants yielding cuticles and minor fishes. This study focuses on plant remains, to provide systematical, taphonomical and palaeoenvironmental considerations; nevertheless, a preliminary analysis carried out on fossil fishes has led to the identification of pycnodontids and teleosts. The Fossil-Lagerstätte retains sterile foliage-bearing shoots with epidermal features belonging to the genus Frenelopsis of the extinct conifer family of the Cheirolepidiaceae. Plant remains possibly represent a stable biotope, as floral composition displays no variation along the deposit. Nevertheless, episodes of harsh environmental conditions occurred as demonstrated by a fish mortality event and Ca-sulphate evaporite precipitation. Taphonomical considerations and sedimentological evidence from the encasing sediments suggest a parautochthonous deposition of fossil plants in a supratidal/intertidal mudflat, including a salt-marsh that was characterised by a restricted sea-water circulation, deposition of primary dolomite and episodical wildfires. The presence of xeromorphic features in Frenelopsis from Magliano Vetere could represent an adaptation to haline environment which was subjected to microtephra supply from a distant, orogenic volcanism. The facies evolution of the studied Fossil-Lagerstätte records a rapid regressive and a following slower transgressive trend, and constitutes the lowermost portion of a ~20 m thick interval characterised by several dolomitic plattenkalk, up to 1.50 m thick, which are separated by cyclically stacked peritidal limestones. We infer that: 1) the ~20 m thick, Plattenkalk-bearing interval represents a Sequence Boundary Zone in the stratigraphical record of the middle Cenomanian ApCP; 2) Frenelopsis thrived at the verge of an arid–semiarid climatical phase during a major pulse of relative sea-level fall.

No full-text available

Request Full-text Paper PDF

To read the full-text of this research,
you can request a copy directly from the authors.

... Finally, several middle to upper Cenomanian paleofloras have been described from Veneto and Campania regions (Italy; Gomez et al., Table 2 Similarity comparison of the JCO palynological assemblage with 12 Cenomanian assemblages from western France. For location of the sites, references and species list, see Fig. 1 Bartiromo et al., 2019), but these are mostly composed of Frenelopsis remains, and no associated palynoflora was presented. The association of the Jaunay-Clan continental palynoflora and paleoflora is thus considered to be the most diversified Cenomanian combined paleobotanical and palynological assemblage described from Western Europe so far. ...
Article
Full-text available
Several mesofossil fl oras discovered in the Early Cretaceous rocks from the Lusitanian Basin of western Portugal comprise numerous well-preserved conifer remains. Here we report the occurrence of four conifer types in the mesofossil flora from the Catefi ca locality, about 4 km south of Torres Vedras in the Estremadura region on the western Portuguese Basin. The specimens were recovered from rocks belonging to the Almargem Formation, interpreted to be of late Aptian – early Albian age. It includes three Cheirolepidiaceae genera Frenelopsis SCHENK, Pseudofrenelopsis NATH. and Watsoniocladus V.SRINIV., and one conifer twig of Pagiophyllum-type. These conifers, which co-occurred in the same depositional bed with a well-diversifi ed early angiosperm assemblage including fl owers, seeds, fruits and dispersed stamens with pollen in situ, provide new insights into Early Cretaceous palaeoecology.
Article
Full-text available
Over recent decades, diverse structures ascribed to angiosperms, bennettitaleans, conifers, cycads, ginkgophytes and pteridosperms have been reported from the Cretaceous deposits of the Aquitaine Basin (southwestern France). However, Albian macrofloras remain uncommon in Aquitania as well as in France. The clay from the Archingeay-Les Nouillers quarries is one of the rare deposits of the Aquitaine Basin to yield Albian plant meso- and macro-remains. Although Albian plant-bearing beds are not accessible any more in these quarries, samples collected from excavations conducted at the end of the XXth century were deposited in the collections of the University of Rennes 1. This paper provides a synthesis of the meso- and macro-remains contained in these collections, including angiosperm leaves and leafy conifer axes, dated as Late Albian. Providing here an inventory of the Cretaceous meso- and macro-remains from the Aquitaine Basin, we compare the Albian flora from Archingeay-Les Nouillers with pre-Albian, Albian, Cenomanian, and Turono-Coniacian floras from other localities in southwestern France.
Article
Full-text available
Several highly effective fire-adaptive traits first evolved among modern plants during the mid-Cretaceous, in response to the widespread wildfires promoted by anomalously high atmospheric oxygen (O2) and extreme temperatures. Serotiny, or long-term canopy seed storage, is a fire-adaptive strategy common among plants living in fire-prone areas today, but evidence of this strategy has been lacking from the fossil record. Deposits of abundant fossil charcoal from sedimentary successions of the Chatham Islands, New Zealand, record wildfires in the south polar regions (75°–80°S) during the mid-Cretaceous (ca. 99–90 Ma). Newly discovered fossil conifer reproductive structures were consistently associated with these charcoal-rich deposits. The morphology and internal anatomy as revealed by neutron tomography exhibit a range of serotiny-associated characters. Numerous related fossils from similar, contemporaneous deposits of the Northern Hemisphere suggest that serotiny was a key adaptive strategy during the high-fire world of the Cretaceous.
Article
Full-text available
We investigated the onset and development of Cretaceous Oceanic Anoxic Event 2 (OAE2) in a newly drilled core (SN°4) from the Tarfaya Basin (southern Morocco), where this interval is unusually expanded. High-resolution (cm-scale equivalent to centennial) analysis of bulk organic and carbonate stable isotopes and of carbonate and organic carbon content in combination with XRF scanner derived elemental distribution reveal that the ocean-climate system behaved in a highly dynamic manner prior to and during the onset of OAE2. Correlation with the latest orbital solution indicates that the main carbon isotope shift occurred during an extended minimum in orbital eccentricity (~400 kyr cycle). Shorter term fluctuations in carbonate and organic carbon accumulation and in sea level related terrigenous discharge were predominantly driven by variations in orbital obliquity. Negative excursions in organic and carbonate δ13C preceded the global positive δ13C shift marking the onset of OAE2, suggesting injection of isotopically depleted carbon into the atmosphere. The main δ13C increase during the early phase of OAE2 in the late Cenomanian was punctuated by a transient plateau. Maximum organic carbon accumulation occurred during the later part of the main δ13C increase and was associated with climate cooling events, expressed as three consecutive maxima in bulk carbonate δ18O. The extinctions of the thermocline dwelling keeled planktonic foraminifers Rotalipora greenhornensis and Rotalipora cushmani occurred during the first and last of these cooling events and were likely associated with obliquity paced, ocean-wide expansions and intensifications of the oxygen minimum zone, affecting their habitat space on a global scale.
Article
Full-text available
This study provides new structural, stratigraphic, and geochemical data and a literature review of the Cretaceous–Paleogene stratigraphy, biostratigraphy, tectonics, and magmatism in the southern Apennines belt, Italy, with the aim to demonstrate the occurrence of an Albian to Eocene abortive rifting stage in the southern Adria domain. During this time, the tectono‐stratigraphic evolution of the Adria domain is characterized by episodes of coeval uplift and drowning. Different sectors of the Apennine and Apulian platforms were so characterized by changes in the paleoenvironments, leading to different stratigraphic records (from shallow‐water to slope and basin), as well as the development of thick bauxitic levels. Contemporaneously, a large amount of calciclastic sediments supply from the emerging sectors was deposited in the basins surrounding the carbonate platforms (i.e., Ligurian and Lagonegro–Molise basins). The Albian–Eocene interval was also characterized by the occurrence of anorogenic magmatism and synsedimentary extensional faulting that, along with the changed sedimentary facies distribution, points out for a crustal‐scale extensional tectonics. We suggest that such tectonics is the result of a rifting episode, characterized by limited anorogenic magmatism, starting in the Albian and reaching its climax in the uppermost Cretaceous–Eocene times. In this scenario, the extensional tectonics recorded in the Adria domain was the product during an event of a single abortive rift system, which extended toward the south, from the southern margin of the Ligurian Ocean to the Hyblean (Sicily), Pelagian (Tunisia), and Sirte Basin Province Rift (Libya).
Article
Full-text available
A new exceptionally preserved marginal marine biota is reported from the Late Ordovician Big Hill Formation of Stonington Peninsula in Michigan’s Upper Peninsula. The new Lagerstätte hosts a moderately diverse fauna of medusae, linguloid brachiopods, non-mineralized arthropods and orthocone nautiloids, alongside dasycladalean green algae. The biota is similar to those of Lagerstätten from the Late Ordovician of Canada, revealing an extensive distribution of a distinctive marginal marine palaeocommunity in Laurentia at this time. The Big Hill biota extends the geographical range of exceptionally preserved Late Ordovician faunas in Laurentia and indicates that further examples remain to be discovered.
Article
Full-text available
The functional morphology of the jaw apparatus and the skull and the feeding habits of the extinct pycnodont fishes are reconstructed in comparison with some extant halecostomes. For this a short review of the functional units of the pycnodont head is given. The feeding mechanisms of pycnodonts exhibit a transition from simple stereotypic feeding kinematics, which are characteristic for primitive actinoptergians, to the modulating feeding kinematics of advanced teleosts and is called limited modulating feeding kinematics herein. Two structural specialisations which are found in halecostomes (operculum with distinct m. levator operculare and the interopercular bone with the interopercular ligament) are supposed to be absent in pycnodonts, whereas they maintain the two primitive couplings for direct mandibular depression (epaxial muscles – neurocranium, hypaxial muscles -cleithrum-m. sternohyoideus – hyoid apparatus). Advanced pycnodonts developed a new structure (upper jaw protrusion, resulting in an enlargment of the buccopharyngeal cavity), that is absent in halecomorphs (e.g., Amia calva) and basal pycnodonts (e.g., Anduafrons, Mesturus). The premaxillae and maxillae are firmly fixed in basal pycnodonts, whereas the premaxillae and maxillae are free and movable in advanced pycnodonts. Pycnodonts were benthic foragers with a combination of biting or nipping and suction feeding based on the "truncated cone morphology" of the buccopharyngeal cavity. It is concluded, that pycnodonts certainly were omnivorous feeders with a general broad range of prey. But they were also a highly specialised group on generic level in respect to their prey. This is indicated by gut contents, as far as they are known, which comprise only monospecific remains of shelled invertebrates (e.g., spines of echinoderms, shells of bivalves). The ecological demands of pycnodonts are discussed. Die funktionelle Anatomie des Nahrungsaufnahmeapparates sowie das Fressverhalten der seit dem Eozän ausgestorbenen Neopterygier-Gruppe der Pycnodontier wird im Vergleich zu einigen rezenten Halecostomen (Amia calva, verschiedene Teleosteer) untersucht und diskutiert. Dazu wird eine kurze Übersicht über die funktionellen Einheiten des Pycnodontierschädels gegeben. Die Kinematik des Nahrungsaufnahmeapparates der Pycnodontier stellt einen Übergang von der einfachen, stereotypischen Kinematik primitiver Actinopterygier zu der modulierenden Kinematik fortschrittlicher Teleosteer dar und wird hier als limitierte, modulierende Kinematik bezeichnet. Zwei structurelle Spezialisationen, die bei Halecostomi entwickelt sind (Operculum mit distinkten m. levator operculare und das Interoperculare mit dem interoperculare Ligament) fehlen bei Pycnodontiern, wogegen sie die zwei primitiven Verbindungen zwischen den epaxialen Muskeln und dem Neurocrani-um und zwischen den hypaxialen Muskeln, dem Cleithrum und dem Sternohyoidmuskel für die direkte Unterkieferabsenkung beibehalten. Fortschrittliche Pycnodontier entwickeln aber eine neue Struktur (bewegliches Maxillare und Premaxillare zur Erweiterung des buccopharyngealen Raumes), die bei Halecomorphen als auch ursprünglichen Pycnodontiern (z. B. †Ardua-frons, †Mesturus) fehlt: Maxillare und Prämaxillare werden aus dem Schädelverband gelöst und beide werden gegeneinander beweglich Während der Mandibulardepression schwingt das nun freie Maxillare um einen vorderen Artikulationszapfen antero-ventrad und drückt das Prämaxillare nach vorne in Richtung Beute. Die ökomorphologische Untersuchung zeigt, dass der Rachenraum als „truncated-cone”, wie er für Teleosteer mit ausgeprägtem Schnappsaugmechanismus typisch ist, rekonstruiert werden kann. Die Kinematik des Kieferapparates der Pycnodontier repräsentiert somit eine Kombination aus reinem Beißen und Schnappsaugen. Pycnodontier ernährten sich vermutlich omnivor sowohl von schalentragenden als auch schalenlosen Invertebraten ernährten. Vermutlich waren die einzelnen Gattungen aber hochspezialisierte Beutegreifer. Dies lässt sich mithilfe der überlieferten Mageninhalte zeigen, die monospezifisch für jede Gattung sind. doi:10.1002/mmng.20010040110
Article
Full-text available
Oceanic Anoxic Event 2 (Cenomanian–Turonian: ca 94 Ma) represents a major palaeoceanographic phenomenon that took place during an interval of extreme global warmth when large amounts of organic matter entered the marine burial record, probably triggered by increased availability of nutrients for planktonic biota. Three sections (Eastbourne, Sussex, UK; Raia del Pedale, Campania, Italy; and Tarfaya, Morocco) recording this event illustrate the influence on marine geochemistry of mafic volcanic rock–seawater interaction, anoxia to euxinia, and re-oxygenation and cooling during the so-called ‘Plenus Cold Event’. The Eastbourne section represents the organic-lean epicontinental pelagic deposits of the English Chalk; the Raia del Pedale section represents a shallow-water platform carbonate on the Tethyan continental margin, also largely devoid of organic matter; and the Tarfaya core represents an Atlantic margin site where cyclically bedded organic-rich sediments were well-developed. Correlation between all three sections is readily achieved by biostratigraphy and carbon-isotope stratigraphy (δ13Ccarb and δ13Corg) over the Oceanic Anoxic Event 2 interval, represented by a characteristic broad positive carbon-isotope excursion. The stratigraphic range of the Plenus Cold Event, defined by the presence, in two discrete levels, of boreal fauna and an excursion to heavier oxygen-isotope values in the English Chalk, can be identified in Raia del Pedale and Tarfaya by using the carbon-isotope curve as a correlative tool. Similarly, a section in southern France allows its co-existing osmium-isotope excursion to relatively unradiogenic values to be placed in the context of the Oceanic Anoxic Event in all three analyzed sections. A fall to lower osmium-isotope values clearly pre-dated the onset of Oceanic Anoxic Event 2, as defined by the initial rise in carbon-isotope values, allowing the putative magmatic/mafic event as a trigger for the Oceanic Anoxic Event. An initial drop in sulphur-isotope ratios (δ34Scas) at Eastbourne correlates with the Os-isotope curve, suggesting that isotopically light sulphur could have been derived from a mafic igneous source. Re-oxygenation of sediments of all three investigated sections during the Plenus Cold Event is variably illustrated by change in Ce:Ca, I:Ca, Mo:Ca and U:Ca ratios, according to the redox behaviour of the elements in question and whether controls on seawater chemistry were local or global in nature. Changes in Mo-isotope ratios from Tarfaya and portions of the S-isotope curve from Eastbourne and Raia del Pedale also indicate the probable presence of more oxygen-rich bottom waters during the Plenus Cold Event. Oxidation by such waters of previously deposited organic-rich shales, as well as loss of anoxic/euxinic sinks, is credited with temporarily enriching global seawater in a range of other redox-sensitive trace metals (for example, V, Cr, Co, Ni, Cu, Zn and Cd) during ongoing basalt–seawater interaction indicated by persistent relatively non-radiogenic Os-isotope seawater values. However, early diagenetic enrichment of Mn in the English Chalk over much of the Oceanic Anoxic Event interval is broadly correlative in time with relatively low Os-isotope values in sections elsewhere: a relationship that may be due to the lack of affinity of Mn with carbon-rich shales, hence allowing relatively elevated concentrations of the element in marine waters to persist during leaching of mafic rocks, unlike other redox-sensitive species. The Ca-isotope and Li-isotope ratios from Eastbourne and Raia del Pedale indicate an increase in global weathering during the initial phase of Oceanic Anoxic Event 2, and the shift in Sr isotopes and Os isotopes to more unradiogenic values during the event suggests that not only construction but also destruction of one or more Large Igneous Provinces was probably a proximal cause of this major palaeoceanographic phenomenon by elevating nutrient levels and planktonic productivity in large tracts of the world ocean. Globally widespread carbon burial and silicate weathering are both identified as important mechanisms for drawing down atmospheric CO2 that, in the absence of overwhelming volcanogenic replenishment of this greenhouse gas during the early phase of Oceanic Anoxic Event 2, caused the Plenus Cold Event. This article is protected by copyright. All rights reserved.
Article
Full-text available
The taphonomy of fishes living in lacustrine environments has been extensively studied in both the laboratory and the fossil record; the taphonomy of marine fishes, however, is poorly known. Triassic marine fishes with heavy ganoid and cosmoid scales, which provided protection from rapid taphonomic loss, offer a means to examine marine fish taphonomy in the fossil record. Four genera of Early Triassic fishes (the ray-finned actinopterygians Albertonia, Bobasatrania, Boreosomus, and the lobe-finned coelacanth (sarcopterygian), Whiteia) from the Wapiti Lake, British Columbia locality of the Lower Triassic Sulphur Mountain Formation were examined in order to gain a better understanding of the taphonomy of fish in marine environments, determine ambient environmental conditions in the region during the Early Triassic, and ascertain the habitat and mode of life of the fish. Results indicate that environmental conditions that contributed to the preservation of the fossil fishes of the current study included deposition in deep, quiet waters, which reduced the odds of disarticulation, colder waters under higher pressure, which slowed decay and limited postmortem floatation, and waters that were anoxic, which discouraged predators and scavengers. In addition, the thickness of the primitive ganoid and cosmoid scales of the fossil fishes also increased their preservation potential. Taphonomic, physiological and environmental indicators suggest that Whiteia, Albertonia, and possibly Bobasatrania lived in deep, cold waters near the oxygen minimum zone, while Boreosomus lived higher in the water column. While the anatomical and physiological characteristics of modern fishes will likely continue to inhibit marine taphonomy studies, examination of ancient fish, particularly those with ganoid or cosmoid scales, may provide future avenues of research to gain a better understanding of marine fish taphonomy and provide a powerful tool to examine ancient fish behavior and their environment.
Article
Full-text available
Abstract Although ocean circulation plays a vital role in the climate system, its response to major carbon-cycle perturbations during the mid-Cretaceous, including mid-Cenomanian event I (MCE I) and the Cenomanian-Turonian oceanic anoxic event (OAE 2), is poorly constrained. Here we present Nd isotope evidence for episodic increases in the influence of boreal seawater in the European epicontinental sea during MCE I. The start of this circulation reorganization lagged the onset of the δ13C positive excursion defining MCE I. This sequence of change is similar to that observed during OAE 2 in the same area, showing a consistent response of regional circulation to changes in the global carbon cycle. Brief intervals of invasion of boreal fauna to mid-latitude seas, two during MCE I and one during OAE 2 (Plenus cold event), all started after the influence of boreal seawater was enhanced, implying a slower biological response to climate cooling rather than passive transport of fauna by boreal waters. The lack of an Nd isotope positive excursion in our record across MCE I supports a volcanic origin for prominent increases in seawater Nd isotope values found in the European epicontinental sea and the tropical Atlantic during OAE 2. The observed tight circulation-carbon cycle coupling may help the upper ocean replenish nutrients from deep waters and/or volcanic sources, providing a critical feedback allowing continuation of MCE I and OAE 2 over long durations.
Article
Full-text available
Accurate interpretations of facies in ancient reefs requires both proper “classification” of the reef and an understanding of the sedimentologic and biologic processes active during the formation of the reef. Study of modern reefs provides evidence for the processes affecting facies in reef complexes with a rigid organic framework and steep fore-reef wall, but generally reveals only the incipient products of these processes because most Holocene reefs have been growing for only a few thousand years following the Holocene transgression. Only where underlying topography approximates the profile of a mature reef complex can well developed examples of the sedimentologic facies of a mature reef complex be found in modern reefs. Study of these pseudo-mature reef complexes reveals a sequence of sedimentologic facies (from basin toward land) consisting of: 1. distal talus, 2. proximal talus, 3. reef-slope, 4. reef framework, 5. reef-crest, 6. reef-flat, and 7. back-reef sand. Knowledge of the characteristics and distribution of these facies should facilitate facies interpretation in comparable ancient reef complexes. Reef framework forms only a few percent of the volume of a mature reef complex, whereas the vast majority of the complex consists of debris in fore-reef and back-reef facies; the debris being derived largely from the framework. This has particular significance in hydrocarbon exploration because most wells drilled toward the top of a seismicly defined ancient reef complex would penetrate only the back-reef carbonate sand facies. However, this is as it should be because the reef framework facies generally has little preserved primary porosity due to sediment infilling of cavities and extensive marine cementation. The facies of modern reef complexes discussed here exist due to the presence of a significant marginal (as opposed to centrally located) shallow water, wave resistant, rigid organic framework composed largely of scleractinian corals. Similar facies may be expected in those fossil reef complexes with a more or less comparable organic framework such as the Devonian stromatoporoid/tabulate coral reefs, the Permian algal/sponge/marine cement reefs, and the Neogene coral reefs. However, different facies must occur in ancient reefs that lacked rigid organic frameworks such as the Paleozoic bryozoan and/or crinoid mounds, Late Paleozoic phylloid algal mounds, Cretaceous rudistid banks, and early Tertiary Nummulites banks.
Article
Full-text available
This short paper by Leonardi G. and Teruzzi, G. (1994) is the very first record of the discovery of the first dinosaur skeleton in Italy, a small, juvenile Maniraptora. This very interesting specimen was discovered near the Pietraroja village (Province of Benevento, Campania, Italy) in Lower Cretaceous - Aptian, Albian terrains, on a limestone slab of the Lower Albian "Calcari ad Ittioliti" Formation. A nearly complete, articulated skeleton of a very small dinosaur was found at this site. The tail is mostly lacking as are the distal portions of the hind limbs. It was described and identified herein as a juvenile theropod belonging to the Maniraptora clade. As these authors emphasized, the most striking feature is the preservation of a number of soft parts such as muscle fibers, the intestine, its content, and possibly the liver. For this specimen the taxon Scipionyx samniticus was later instituted, and it was described in detail by C. Dal Sasso and M. Signore in Nature, March 1998. (This paper is little known and, unfortunately, in spite of the importance of the discovery it represents, it is too little quoted. Note by G. Leonardi 2017) (This article was published in the journal Paleocronache, 1 (1993): 1-14. Museo Civico di Storia Naturale di Milano, Italy. This journal is not in the search-list of journals automatically proposed by this file.
Article
Full-text available
We report exceptionally well-preserved plant remains ascribed to the extinct conifer Glenrosa J. Watson et H.L. Fisher emend. V. Srinivasan inside silica-rich nodules from the Cenomanian of the Font-de-Benon quarry, Charente-Maritime, western France. Remains are preserved in three dimensions and mainly consist of fragmented leafy axes. Pollen cones of this conifer are for the first time reported and in some cases remain connected to leafy stems. Histology of Glenrosa has not previously been observed; here, most of internal tissues and cells are well-preserved and allow us to describe a new species, Glenrosa carentonensis sp. nov., using propagation phase-contrast X-ray synchrotron microtomography, a non-destructive technique. Leafy axes consist of characteristic helically arranged leaves bearing stomatal crypts. Glenrosa carentonensis sp. nov. differs from the other described species in developing a phyllotaxy 8/21, claw-shaped leaves, a thicker cuticle, a higher number of papillae and stomata per crypt. Pollen cones consist of peltate, helically arranged microsporophylls, each of them bearing 6-7 pollen sacs. The new high resolution tomographic approach tested here allows virtual palaeohistology on plants included inside a dense rock to be made. Most tissues of Glenrosa carentonensis sp. nov. are described. Lithological and palaeontological data combined with xerophytic features of Glenrosa carentonensis sp. nov. suggest that this conifer has been adapted to survive in harsh and instable environments such as coastal area exposed to hot, dry conditions.
Article
A palynological analysis of 45 samples from six mid-Cretaceous amber-bearing outcrops from Charentes has been carried out. A total of 227 taxa have been recorded in the studied palynofloras. Palynological data support earlier evidence and indicate an early Cenomanian age for the assemblages. The heterogeneous compositions of the palynofloral assemblages indicate the existence of different coastal depositional settings with a variable but usually weak marine influence. The local vegetation was subdivided in various types including herbaceous formations integrating ferns and eudicots which may have colonised frequently-disturbed, fluvial, open environments and xeric arboreal communities dominated by Cheirolepidiaceae and probably integrating drought- and/or salt-tolerant angiosperms and ferns (Anemiaceae and Gleicheniaceae) and other gymnosperms (Araucariaceae, Ginkgoales and scarce Cycadales and Gnetales). The existence of riparian and freshwater wetland communities integrating taxodioids, aquatic and/or hygrophilous angiosperms, ferns, lycopods, mosses and clubmosses is proposed. Coastal/?lagoonal counterparts including plants tolerant to periodical floods by saline or brackish waters is suggested by palynological evidence. Conifer forests mainly integrating Pinaceae and Podocarpaceae in raised hinterlands may also be interpreted on the basis of taphonomical considerations. The wide variety of depositional settings inferred by the palynological data support enhanced transport capabilities for amber and/or a widespread occurrence of producers in local vegetation during the early Cenomanian.
Article
Extensive evaporites in Lower Mississippian successions from palaeoequatorial regions are commonly used as evidence for an arid to semi-arid palaeoclimate. However, in this study, detailed studies of evaporites and their context refute this interpretation. Detailed sedimentological and petrographical analysis of the Lower Mississippian of northern Britain, is combined with archived log data from more than 40 boreholes across southern Scotland, northern England and Northern Ireland, and published literature from Canada. Two key cores from the Tweed Basin and the northern margin of the Northumberland – Solway Basin contain 178 evaporite intervals and reveal twelve distinct forms of gypsum and anhydrite across seven facies that are associated with planar laminated siltstone and intercalated thin beds of ferroan dolostone. Nodular gypsum and anhydrite, typically in intervals less than 1 to 2 m thick, are integral components of the succession. Nodular evaporite occurs within about 1 m of a palaeosurface, but most evaporite deposits represent ephemeral brine pans to semi-permanent hypersaline lakes or salinas on a floodplain that was subjected periodically to storm surges introducing marine waters. Formation of evaporites under a strongly seasonal climate in a coastal wetland is supported by palaeosol types and geochemical proxies, and from palaeobotanical evidence published previously. Although 65% of modern equatorial areas experience a strongly seasonal climatic regime, salinas and sabkhas are a minor component today in comparison with the evidence from these Lower Mississippian successions. This implies that the earliest terrestrial environments were complex and dynamic providing a diverse range of habitats in which the early tetrapods became terrestrialized and represent a setting that is rarely preserved in the geological record.
Article
Stem fragments identified as Frenelopsis varions Fontaine have been found in the Lower Cretaceous (Albian) of central Texas. The cuticle is extremely thick and characterized by 5–6 subsidiary cells with papillae overarching the stomatal chamber. Guard cells are deeply sunken below the epidermis. Stomatal complexes are arranged in axial rows extending from the base of an internode to its apex. The rows of stomata continue into the sheathing leaf where the rows curve towards the leaf apex. The epidermis of F. varions was apparently long persistent and underwent prolonged growth. Axial rows of stomata are frequently disrupted resulting in a random pattern of stomata. A single, highly reduced, sheathing leaf is present at each node. The margin of the leaf has numerous unicellular trichomes and extends to form a slightly triangular blade.
Article
A 325 m long continuous succession of uppermost Albian to lower Turonian pelagic (outer shelf) deposits was recovered from a new drill site in the central part of the Tarfaya Basin (southern Morocco). Natural gamma ray wireline logging, carbonate and organic carbon content, bulk carbonate and organic carbon stable isotopes and X-ray fluorescence (XRF)-scanner derived elemental distribution data in combination with planktonic foraminiferal biostratigraphy indicate complete recovery of the Cenomanian Stage. This exceptional sediment archive allows to identify orbitally driven cyclic sedimentation patterns and to evaluate the pacing of climatic events and regional environmental change across the Albian-Cenomanian boundary (ACB), the mid-Cenomanian Event (MCE) and Oceanic Anoxic Event 2 (OAE2) in the latest Cenomanian. The deposition of organic-rich sediments in the Tarfaya Basin, likely driven by upwelling of nutrient-rich water masses, started during the latest Albian and intensified in two major steps following the MCE and the onset of OAE2. The duration and structure of the MCE and OAE2 carbon isotope excursions exhibit striking similarities, suggesting common driving mechanisms and climate-carbon cycle feedbacks. Both events were also associated with eustatic sea level falls, expressed as prominent sequence boundaries in the Tarfaya Basin. Based on the 405 kyr signal imprinted on the Natural Gamma Ray (NGR) and XRF-scanner derived Log(Zr/Rb) records, we estimate the duration of the Cenomanian Stage to be 4.8 ± 0.2 Myr.
Chapter
At the northeastern extremity of the Abu Dhabi sabkha, less than 1 m below the surface, a lithified lenticular dolomitic body immediately overlies Holocene regressive mangrove deposits. The persistent association of this dolomite lens with the palaeosol appears to have a genetic significance. Field measurements of salinities, pH and Eh of interstitial waters clearly indicate lateral interstitial input of water from the lagoon. This movement is favoured by the porosity created by the dense network of buried mangrove roots and by the diagenetic evolution of the sediment. There is no indication of a control of the chemistry of the interstitial waters by flood recharge through the sabkha surface. pH and Eh profiles also indicate the influence of organic matter on the circulating fluids. In the lower part of the section, decay of the organic matter in the mangrove palaeosol results in an anoxic environment with slightly acidic conditions, probably responsible for the dissolution of aragonite observed in the palaeosol and overlying white mud. The evaporative processes, especially active in the upper microbial mat and sabkha deposits, favour reoxidation by diffusion of ions, resulting in slightly basic, oxic conditions. Dolomite occurs in the transitional zone between these anoxic and oxic environments. The carbon isotopic signature of the dolomite-rich layer is less (down to 0‰) than that of aragonite in the same location (3‰). As proposed by McKenzie (1981), a contribution of carbon from the decaying organic matter to the carbonate pool is indicated.
Book
Aquacultural, oceanographic, and fisheries engineering, as well as other disciplines, require gas solubility data to compute the equilibrium concentration. These calculations, for example, can affect the output of aquacultural production or assist in environmental consulting. Until now, published solubility information has not been available in a consistent and uniform manner in one location. This book presents solubility concentrations of major atmospheric gases (oxygen, nitrogen, argon, carbon dioxide), noble gases (helium, neon, krypton, xenon), and trace gases (hydrogen, methane, nitrous oxide) as a function of temperature, salinity, pressure, and gas composition in a variety of formats. Data, equations, and theory are explained so that the user is able to understand the calculations and problems. Furthermore, data and solubility information are presented in a range of units to make them accessible across disciplines. This book will help the reader to look at a problem from a quantitative viewpoint and better understand carbonate chemistry. Revised from the earlier edition to include more accurate carbon dioxide tables and separate sections on the solubility of noble gases, trace gases, and oxygen in brines to provide a single resource for gas solubility data. This book is essential for all students and practitioners working in aquatic fields. A single source for highly accurate and comprehensive tables for gas solubility in aquatic systems Information provided in tables, equations, and computer programmes Theory is presented to better understand the equations and calculations.
Article
Lower Maastrichtian plant fossils were newly collected from the base of the Xullí unit, Tremp Group, in Isona, Tremp Basin, southern Pyrenees. They consist of conifers, monocot and eudicot angiosperms. Palynology shows algal oospores, fern spores, gymnosperm and angiosperm pollen grains. Sedimentological and taphonomic analyses indicate that this assemblage is parautochthonous and allochthonous. The plant fragments probably came from a nearby exposed area and were deposited in the distal floodplain. These taphonomic data shed light on the exact location and sampling biases of the palaeobotanical collection from Isona gathered by Vicente i Castells in the 1980s. Angiosperms and ferns dominated the plant community, which grew inland in freshwater environments. Cheirolepids inhabited coastal freshwater lakes in the same basin (the Posa unit) and in the geographically close basin of Vallcebre.
Book
The first edition of Evolution of Fossil Ecosystems was widely praised for its coverage and approach in describing and illustrating 14 well-known fossil sites from around the world. The authors have now updated the text and added 6 new chapters with many new color illustrations. Following a general introduction to fossil Lagerstätten, each chapter deals with a single site and follows the same format: its evolutionary position and significance; its background sedimentology, stratigraphy and palaeoenvironment; a description of the biota and palaeoecology; a comparison with other similar Lagerstätten; and a list of relevant museums and suggestions for visiting the sites. This study of exceptionally well-preserved fossil sites from different periods in geological time provides a picture of the evolution of ecosystems through the ages. Covers several sites that are not listed in other Lagerstatten books making this the most comprehensive book on the topic; Beautifully illustrated throughout with more than 450 color photographs and diagrams; Provides value to a wide range of students and professionals in palaeontology and related sciences. © 2012 Manson Publishing Ltd. Published by Elsevier Inc. All rights reserved.
Article
Previous researches, based on the analysis of satellite imagery of Southern Apennines, have pointed out the presence of tectonic features that can be referred to a shear zone named Cilento-Pollino. In this paper we analysed the Landsat imagery of the Cilento Peninsula, so that we could highlight the occurrence of rather long and frequent tectonic features, striking about N120. These features are mainly contained in a long and narrow area, corresponding to the Alburni, Cervati and Soprano-Vesole-Chianello Mountains. We have also carried out an intensive meso-structural analysis all along these mountains, where there was still a lack of recent data about tectonics. This analysis has revealed that the above-mentioned tectonic features are high angle faults, with left-lateral transtensional kinematics. Considering their length, the intensity of deformation and the morphological evidence, they have to be referred to a regional geological feature such as the Cilento-Pollino Shear Zone. The present structural analysis contributed to better determine the structural setting of the Soprano-Vesole-Chianello and Cervati Mountains. Here it is possible to recognise the effects of Miocene compressive tectonics, partially cloaked by the Plio-Pleistocene transtensional activity of the faults bordering the carbonate mountains. Such recent tectonics controlled the structural and morphological setting of this area generating negative flower structures characterised by great vertical upthrows.
Article
This study reports an integrated facies analysis carried out on a new section from the Upper Aptian of the SE Matese Mts. (Civitella Licinio, northern Campania, S. Italy), which includes several decimeter-to-meter scale lacustrine intervals straddling a meter-scale plant-rich Plattenkalk. These intervals are assigned to the late Gargasian–early Clansayesian by their stratigraphic relationship with the upper Salpingoporella dinarica acme as well as lithologic and biostratigraphic supra-regional key-markers found in the Apennine Carbonate Platform (ApCP), including the Orbitolina Level. We infer that the monogeneric parautochthonous plant remains (Frenelopsis sp.) were deposited in a supratidal-to-paralic coastal mudflat close to a restricted, shallow-marine lagoon, at the verge of an arid–semiarid climatic phase. The Plattenkalk was rapidly replaced by persistent lacustrine lithofacies at the onset of a major climatic turnover (Glacial Trigger). The overlying shallow-marine deposits are capped by a deeply incised palaeokarstic surface and, in turn, by unconformable middle Clansayesian transgressive shallow-marine deposits.
Chapter
Salt marsh systems are important in sustaining the ecology of coastal zones. In modern ecological terminology, the processes that occur within an ecosystem that can be judged as beneficial to man are known as “Ecosystem Services”. The major ecosystem services that salt marshes provide include: a habitat that serves as a nursery ground for birds and fish; a buffering system that mediates the erosive force of the ocean; and a site of carbon fixation that sustains the coastal food web. Salt marsh systems are very obviously dominated by halophytic angiosperms but the sediment between their stems serves as a rich substratum for microbial growth and development. This environment may appear harsh and uncompromising since the fine sediments of the marsh are often anaerobic within a few millimetres of the sediment surface and are subject to periods of tidal exposure and desiccation. Nevertheless, a wide diversity of microbial forms have become adapted to exploiting this harsh environment. The upper layers of sediment are inhabited by an assemblage of oxygenie phototrophs, which are replaced by anoxygenic phototrophs, and then heterotrophic forms with increasing depth in the sediment. This layering of microbial assemblages may take place over a few millimetres and establishes a microbial system characterised by extreme gradients. These microbial assemblages provide vital “services” of carbon fixation and nitrogen fixation while also acting to mediate the physical dynamics of the sediment through enhancing sediment capture and retention among the marsh plants. The microbial assemblages of salt marshes are therefore key to the overall meta-bolism and ecosystem services of the system. However, the study of these highly spatially-constrained assemblages presents real logistic difficulties and the final part of this review introduces a number of modern techniques employed to measure their properties while retain their natural structure and formation.
Chapter
Salt marshes are fascinating yet frustrating places in which to study ecology—fascinating because of the wealth of physical and biological interactions present in this blend of terrestrial, aquatic, and marine communities, yet frustrating because of the many methodological problems peculiar to tidal communities. Quantitative measurement of flows of energy and matter, simple and straightforward in many other ecosystems, becomes more difficult in a complex tidal estuary. Perhaps these common problems fostered in us a greater spirit of cooperation than is common among other ecologists. At any rate, our group at Sapelo Island developed a deep appreciation of the value of each other’s approach to scientific problems. In particular, we quickly came to realize the artificiality of separating ecosystem ecology from population ecology. Instead of perpetuating a sterile argument over the wisdom of measuring the whole or its parts, we adopted the more logical and scientifically defensible maxim that any explanation, as opposed to an observation, of the behavior of an entire system is impossible without some knowledge of its parts, and, in turn, any observed behavior of a single part can only be explained within the context of the system in which that part is functioning. This has been our philosophical approach to understanding ecological processes in the salt marshes.
Chapter
For decades, ecologists have considered bacteria to be responsible, directly or indirectly, for much of the recycling of inorganic nutrients in nature and have regarded them as an important source of food for small animals. Apart from such important roles, these unseen but ubiquitous organisms perform many other activities. They can alter the chemistry of water and sediments, influence the distribution of plants and animals, and provide conditions for massive mineral deposition.
Chapter
Salt marshes, which represent the final stage in the leveling of marine delta plains or the filling of depressions, embayments, and other irregularities along coasts, are to some extent a measure of coastal stability or equilibrium. The overall sedimentary sequence is therefore a potential record of coastal history; it may reveal complete successions from original estuary, delta, lagoon, or bay floors to the highest intertidal flat, including lateral variations in contemporaneous facies or subfacies. Associated mineral suites are equally important indicators of both sources and possible recycling of coastal sediments. As habitable dwelling space for numerous organisms, some of which are uniquely adapted to stressful conditions, salt marsh substrates record many details of significance in paleoecology, ichnology, and environmental reconstruction.
Article
Dolomite, despite its thermodynamic stability and abundance in the ancient rock record, is rarely found forming in Holocene environments. This enigma is frequently called the Dolomite Problem. The recent discovery of modern dolomite formation in Lagoa Vermelha, a shallow-water isolated coastal lagoon east of Rio de Janeiro, Brazil, provides a new environment to investigate the factors promoting dolomite precipitation under earth surface conditions. Lagoa Vermelha serves as a natural laboratory in which the dolomite formation process was studied using an integrated hydrologic, geochemical, and sedimentological approach. The results of this study indicate that Ca-dolomite precipitation occurs under anoxic hypersaline conditions within a black sludge layer directly overlying the water/se iment interface. With deposition, the dolomite undergoes an "ageing" process, whereby increased ordering of the crystal structure occurs. Both the initial precipitation and subsequent early diagenesis are strongly mediated by microbial activity. In fact, using sulfate-reducing bacteria cultured from Lagoa Vermelha samples, a highly ordered dolomite has been produced in the laboratory at low temperatures. These experimental results combined with the study of the natural environment mandate that a microbial factor be added to the list of factors capable of causing dolomite precipitation. Considering the Lagoa Vermelha system, we propose a new actualistic model for dolomite formation, which we call the microbial dolomite model.
Article
The Fossil-Lagerstätte of Pietraroja (Benevento province, Southern Italy) is a paleontological site of international relevance mostly known for the discovering of the theropod dinosaur Scipionyx samniticus. The site has been recently dated to the early (basal) Albian on the grounds of the microfossils yields. The fossil fern described in this paper has been collected at "Le Cavere" (a quarry close to the Pietraroja village). It is preserved as a fossil plant impression and is at present stored at the Museo di Paleobotanica (Orto Botanico di Napoli). General and fine morphology of the fossil, a pinna fragment, allow us to ascribe it to the family Matoniaceae and probably to the genus Phlebopteris.
Article
The flora of the Cenomanian–Turonian (ca. 96–90 Ma) Tupuangi Formation, Chatham Islands, New Zealand, was inhabiting a region well within the south polar circle (~70–80° S) during the early Late Cretaceous, an interval characterised by extreme global greenhouse conditions. The Tupuangi flora offers a unique perspective into an ecological and environmental setting which has no extant analogue, whilst providing proxies of polar palaeoclimatic conditions during a phase of extreme global warming. Ginkgoites waarrensis Douglas, 1965 (emended herein), a species known previously from a single occurrence in Australia, is an abundant element of the Tupuangi flora. Forty-five leaf samples from three localities are reported, and a systematic treatment of this species revealed a wide morphological range. In contrast to the exclusively riparian niche of more recent members of Ginkgoales, associated sedimentological and palaeoecological data suggest that this species had an ecological preference for regularly disturbed, coastal deltaic settings. Herein, we review the geographic and strat-igraphic distributions of Cretaceous Gondwanan ginkgoalean leaf taxa. An increasing diversity of this group from the Early Cretaceous to the early Late Cretaceous supports a broader trend of floral provincialisation throughout this interval, most likely driven by concurrent global transgression and active tectonic extension across southern Gondwana. Carbon dioxide has been inferred as a primary proximate cause of the mid-Cretaceous global greenhouse. The leaf cuticles of Ginkgoites waarrensis were utilised to approximate atmospheric carbon dioxide (pCO 2) during the Cenomanian. Stomatal index (SI) data were collected from ten specimens, and the stomatal ratio method yielded a semi-quantitative pCO 2 estimate of 1150–1350 ppmv, which is consistent with modelled and proxy estimates of the Cenomanian. The present study explores the inherent limitations of the transfer function method for estimating CO 2 when applied to taxa with very low SI values, such as G. waarrensis. In addition to pCO 2 , temperature and irradiance are identified as environmental variables which may have systematically promoted the low SI of G. waarrensis, but their combined influence is likely mitigated by the relatively high temperature of this region during the mid-Cretaceous and the high summer insolation at polar latitudes. Crown