Juan C. Braga

University of Granada | UGR · Department of Stratigraphy and Paleontology

In Brazil, studies on fossil crustose coralline algae (CCA) are scarce and limited to a few taxonomic accounts and to palaeoenvironmental interpretation of deposits with abundant CCA. Here, the most relevant reports on fossil and recent CCA bioconstructions and rhodolith beds are summarized from the oldest records to Holocene and living examples. T...

The occurrence of rhodolith beds in the stratigraphic record from the Cretaceous to the Pleistocene was analysed from published papers. Most data refer to low–mid latitude records of rhodolith beds described in the Tethyan–Paratethyan–Mediterranean domain. The first putative rhodolith beds are from Albian (uppermost Lower Cretaceous) deposits. Thes...

Neogoniolithon is a widespread genus of non‐geniculate coralline algae in the Mediterranean Sea. Three vaguely differentiated species have been reported in the region. This study examined the diversity of Neogoniolithon in the Mediterranean by inferring phylogenies using psb A and COI‐5P markers, applying delimitation algorithms and comparing morph...

The Río Alías Strait developed in the Early Pliocene as a narrow marine corridor at the connection of the microtidal Mediterranean Sea and the north‐eastern margin of the Almería‐Níjar Basin in the eastern Betic Cordillera (South‐East Spain). The orientation and topography of the strait were controlled by the transpressive Carboneras and Polopos/So...

The export of neritic material from the top of carbonate platforms is a key process in the construction of their slopes. However, our knowledge of the supply pattern of materials from platforms is dominantly based on platforms lying in the euphotic zone during the present sea‐level highstand. This is a somewhat biased perspective as through geologi...

Rhodoliths are nodules mainly composed of crustose coralline algae with subordinate encrusting organisms, formed by successive overlapping encrustation. The subspheroidal rhodoliths from the Vitória-Trindade Seamount Chain (Jaseur Seamount and Trindade Island shelf; Brazil, southwestern Atlantic), sampled at water depths from 65 to 74 m, were built...

The Guadalquivir Basin is the foreland basin of the Betic Cordillera (S Spain). Closest to the orogen, several thrust‐top basins evolved during the Late Miocene in the central part of the cordillera. Here, we study the Upper Miocene deposits in five of these satellite basins: Montefrío, Iznájar‐Cuevas de San Marcos, Antequera, Bobadilla Estación an...

Sea surface temperatures (SST) have been identified as a main controlling factor on larger benthic foraminifera (LBF) living in tropical to sub-tropical shallow-water carbonate and mixed siliciclastic‑carbonate platforms. Changes in SST, along with those in ocean acidification and nutrient content recorded in the global oceans throughout their hist...

The Los Guájares valley is located about 35 km south of Granada in the Internal Zones of the Betic Cordillera. The Miocene deposits in this area consist of six sedimentary units separated by unconformities, which are exposed in small and laterally discontinuous outcrops overlying metamorphic rocks of the Alpujárride Complex. The lowest unit compris...

Fibrous aragonite crusts occur in two consecutive Pleistocene successions in the Danakil Depression (Afar, Ethiopia). Lateral transitions between pristine and altered fibrous aragonite crusts document changes in texture associated with diagenesis. Crusts formed as essentially abiotic seafloor precipitates at the transition from marine to evaporitic...

Reef communities at intermediate (10 to 30 m) and mesophotic (~ 30 to 150 m) depths occupy large areas of sea floor but little is known about their potential to accrete vertically, their response to sea-level change and other environmental perturbations. In this study, the authors have examined cores from two holes, M0040A and M0041A, drilled by th...

New sedimentological data of facies and diagenesis as well as chronological data including strontium (87Sr/86Sr)-isotope ratios and uranium (U)-series dating, radiocarbon (14C) accelerator mass spectrometry (AMS) dating and biostratigraphy from elevated reef terraces (makatea) in the southern Cook Islands of Mangaia, Rarotonga and Aitutaki contribu...

The Abrolhos shelf, in the eastern Brazilian margin, encompasses the largest reef province in the South Atlantic, characterised by low coral diversity and a high level of endemism. Knowledge gaps about how the Abrolhos coastal reefs evolved, during the post LGM and MIS 6/MIS 5, favoured a paradigm that is revisited in the light of new data. Here, n...

Understanding of global sea-level changes and coral reef development is poorly constrained during Marine Isotope Stage 3 (MIS 3; ~ 60 to 30 ka). Australia’s North West Shelf (NWS), at depths of ~ 50 to 120 m below present sea-level (mbsl), represents an ideal natural laboratory to address these knowledge gaps. In this study, the authors investigate...

Corals, coralline algae and vermetid gastropods are indirect (marine limiting) relative sea-level (RSL) indicators. The precision in sea-level reconstruction based on fossils of those organisms depends on the probable palaeodepth in which they grew. Constraining such palaeodepth depends, in turn, on the available information about the habitats of t...

Mixed siliciclastic-carbonate deposits accumulated in several satellite sub-basins at the southern margin of the Guadalquivir Basin, the foreland basin of the Betic Cordillera (S. Spain). The prevailing coarse-grained sediments and deposition in shallow-water settings make it difficult to establish the precise age of the complete successions. For t...

Rhodolith limestones occur in the upper part of the Miocene infill of the Ronda Basin in southern Spain. This basin was an embayment at the southern margin of the Atlantic-linked Guadalquivir Basin, the foreland basin of the Betic Cordillera. Messinian rhodolith limestones crop out in the mesa of the Roman settlement Acinipo. They mostly consist of...

Serravallian (middle Miocene) coralline algal assemblages at the southern margin of the Guadalquivir Basin (southern Spain) occur as rhodoliths preserved in situ or very close to their growth habitats (autochthonous–parautochthonous assemblages) and also as reworked remains (allochthonous assemblages). The former assemblages consist of spherical rh...

Mesophotic reefs, hardgrounds and current‐controlled pelagic to hemipelagic carbonates are facies marking carbonate platform drowning successions, irrespective of the factors controlling this evolution. A modern analogue of a carbonate platform in a state of drowning, where these facies occur has not been properly reported on to date. In the presen...

Carbonate contourite drifts are poorly documented in the onshore record because of the difficulty of implementing diagnostic criteria for their recognition. Accordingly, little is known about the relative position of carbonate drifts with respect to ancient carbonate platforms, seaways and shallow passages within the context of palaeoceanography. T...

During the Paleocene/Eocene Thermal Maximum, ~55.6 Ma, the Earth experienced the warmest event of the last 66 Ma due to a massive release of CO2. This event lasted for ~100 thousands of years with the consequent ocean acidification (estimated pH = 7.8-7.6). In this paper, we analyze the effects of this global environmental shift on coralline algal...

Shallow-water rhodolith beds are rare in the Mediterranean Sea and generally poorly known. The Punta de la Mona rhodolith bed extends for 16,000 square meters in shallow and oligotrophic waters at the southern coast of Spain, off Almuñecar in the Alborán Sea. We present a detailed analysis of the structure (rhodolith cover and density, rhodolith si...

Rhodolith beds are biogenic benthic habitats mainly formed by unattached, non-geniculate coralline algae, which can be inhabited by many associated species. The Brazilian continental shelf encompasses the largest continuous rhodolith bed in the world. This study was based on samples obtained from seven sites and videos taken by a Remotely Operated...

Only two alveolinoid genera, Borelis de Montfort, 1808 and Alveolinella H. Douvillé, 1907 thrive in present-day Indo-Pacific coral-reef settings. The former is widespread from the Western (Red Sea) to the Central Indo-Pacific and Caribbean Sea coasts, whereas the latter occurs in the Central and Eastern Indo-Pacific area. A third Indo-Pacific alveo...

While spatial facies patterns can be observed in modern systems, only vertical facies successions can usually be examined in ancient deposits. Lateral facies relationships (depositional models) and relative sea-level changes throughout time are traditionally deduced from correlation of vertical facies successions along transects perpendicular to in...

The geomorphology of the Amazon Continental Margin (ACM) is highly heterogeneous and includes a variety of reef-like formations found in deep-water along the shelf-slope transition. The ACM has been divided into three Sectors (Northern, Central and Southern) according to the distribution of the carbonate producers and the 'reefs', influenced by the...

Well-preserved oyster shells from mixed heterozoan carbonates and terrigenous sediments of Miocene age in the La Chanata area (southern Spain) show varying luminescence and covarying δ18O and δ13C compositions > –2‰ VPDB. Temperature and salinity modeling based on the δ18O give temperatures ranging from 13 to 33 °C (average 22.4 °C) and normal-mari...

The approximately 350 m-thick stratigraphic succession of the Zagra Strait records an important oceanographic phase of basin interconnection between the Atlantic Ocean (Guadalquivir Basin) and the Mediterranean Sea through the Betic Cordillera (southern Spain) during the early Tortonian. The Zagra Strait developed as a narrow structurally-controlle...

Marine straits and seaways are known to host a wide range of sedimentary processes and products, but the role of marine connections in the development of large river systems remains little studied. This study explores a hypothesis that shallow marine waters flooded the lower Colorado River valley at ∼ 5 Ma along a fault-controlled former tidal stra...

Miocene, Austrotrillina Parr, 1942 is the only genus showing a non-homogeneous shell structure. This consists of a parakeriotheca, coated by a thin, dense tectum. Four Austrotrillina species (A. brunni, A. eocaenica, A. howchini, A. striata) have been often used as biostratigraphical markers in the Mediterranean and Indo-Pacific areas. New material...

Marine straits and seaways are known to host a wide range of sedimentary processes and products, but the role of marine connections in the development of large river systems remains little studied. This study explores a hypothesis that shallow marine waters flooded the lower Colorado River valley at ~ 5 Ma along a fault-controlled former tidal stra...

Drilling of the eastern Brazilian continental shelf in the 1980’s identified several main factors controlling Holocene reef growth in the South Atlantic. However, this model is limited by few fossil reef cores, sparse uncalibrated dates (< 10) and basic sedimentary and coralgal descriptions. Here we integrate 62 recently published C¹⁴-AMS ages with...

Despite the abundance of seagrass-related deposits in the geological record, seagrass macrofossils are scattered in time and space, due to the low preservation potential of marine angiosperms. Fossil seagrass impressions, mainly rhizomes occur in Messinian (late Miocene) marl beds intercalated in cross-bedded bioclastic limestones in the Guadalquiv...

Carbonate platforms are built mainly by corals living in shallow light-saturated tropical waters. The Saya de Malha Bank (Indian Ocean), one of the world’s largest carbonate platforms, lies in the path of the South Equatorial Current. Its reefs do not reach sea level, and all carbonate production is mesophotic to oligophotic. New geological and oce...

Macroids and rhodoliths, made by encrusting acervulinid foraminifera and coralline algae, are widely recognized as bioengineers providing relatively stable microhabitats and increasing biodiversity for other species. Macroid and rhodolith beds occur in different depositional settings at various localities and bathymetries worldwide. Six case studie...

Past shallow-water carbonate environments of the main island of New Caledonia (NC) have been subject to high terrigenous influx derived from the erosion of ultramafic obducted nappes and are therefore a relevant case study for characterizing neritic carbonate production in mixed carbonate-siliciclastic systems under a tropical climate. More particu...

Coralline red algae with protuberances in their thalli are common and instructive examples of fabricational effects on fossil preservation. The body (thallus) of non-geniculate coralline algae is a coherent mass of cell filaments. All vegetative cells, except the epithallial ones at the tip of each filament are enclosed by a high-Mg calcite wall. M...

The subclass Corallinophycidae is the only group of red algae characterized by the presence of calcite crystals in their cell walls. Except for the Rhodogorgonales, the remaining orders - collectively called corallines - are diverse and widely distributed, having calcified cell walls and highly variable morphology. Corallines constitute the group w...

During the greenhouse conditions prevailing in the early-middle Eocene, larger benthic foraminifers (LBF) spread out on carbonate platforms worldwide while rhodolith beds were scarcely represented. This reduction in rhodolith beds coincided with a relative decrease in coralline algal diversity and with a drastic decline of coral reef abundance. Mid...

The fossil record provides valuable data for improving our understanding of both past and future reef resilience and vulnerability to environmental change. The spatial and temporal pattern of the initiation of the Holocene Great Barrier Reef presents a case study of reef response to rapid sea-level rise. Past studies have been limited by the lack o...

Bioerosion traces preserved in coral reef framework provide insight into past environmental conditions and reef health. However, few studies have explored the relationship between bioerosion, reef growth history and environmental changes. The International Ocean Drilling Program (IODP) Expedition 325 sampled late glacial to deglacial reef sequences...

In this review we assess the state of knowledge for the coralline algae of the Mediterranean Sea, a group of calcareous seaweeds imperfectly known and considered highly vulnerable to long-term climate change. Corallines have occurred in the Mediterranean area for ~140 My and are well-represented in the subsequent fossil record; for some species cur...

The study of the Miocene carbonate platform of the Maldives allows understanding the controlling factors triggering the stepwise drowning of carbonate platforms. This research presents high-resolution seismic profiles and sediment cores retrieved from Sites U1465, U1469, and U1470 drilled during International Ocean Discovery Program (IODP) Expediti...

The palaeobiogeography of the alveolinoid Borelis species reveals the evolutionary patterns leading to the two extant representatives, which occur in shallow‐water tropical carbonate, coral reef‐related settings. Type material and new material of fossil Borelis species, along with Recent specimens were studied to assess their taxonomic status, spec...

The development history of an oligo-mesophotic, early Miocene, isolated carbonate system (>160 m in thickness), forming the uppermost part of the Oligo-Miocene Yadana buildup (northern Andaman Sea), has been evidenced from the integration of sedimentological core studies from 4 wells (cumulated core length: 343 m), well correlations, seismic interp...

The Miocene is an essential period in the configuration of the present-day relief of the Betic Cordillera and the South Iberian continental margin, which determined the structure and evolution of the Neogene sedimentary basins (Fig. 3.1). The crustal thinning processes that occurred during the early and middle Miocene, after the main metamorphic ev...

Integrated Ocean Drilling Program (IODP) Expedition 325 cored submerged reefs along the shelf edge of the Great Barrier Reef (GBR) to study sea-level and environmental changes and their impacts on reef communities and reef growth since the Last Glacial Maximum (LGM). Previous work defined five reef sequences (Reef 1–5) that span the last 30,000 yea...

The structure and composition of rhodoliths in two regions of the Brazilian shelf, Abrolhos Continental Shelf (ACS) and South Espírito Santo State (SES) were examined and compared. Rhodoliths were sampled at depth ranges of 10–20 m and 50–60 m in SES, and 20–30 m and 50–75 m in ACS. Rhodoliths in SES are algal boundstones, built mainly of melobesio...

Microbialites are volumetrically abundant components in Last Glacial Maximum and deglacial reefs in the Australian Great Barrier Reef sampled by IODP Expedition 325 in 34 holes from 17 sites (M0030–M0058), along four transects on the shelf edge. Detailed radiometric datings show that four distinct reef phases developed between 28and 10 ka, displayi...

Adeylithon gen. nov. with one species, A. bosencei sp. nov., belonging to the subfamily Hydrolithoideae is described from Pacific coral reefs based on psbA sequences and morpho‐anatomy. In contrast with Hydrolithon, A. bosencei showed layers of large polygonal “cells”, which resulted from extensive lateral fusions of perithallial cells, intersperse...

To date, there is hardly any knowledge of facies and age of Pleistocene reef limestone in the Maldives. Likewise, there are no robust estimates of Quaternary subsidence in this major shallow-water carbonate platform and reef area. In a core recovered on the windward margin of Rasdhoo Atoll in the central part of the archipelago, Pleistocene coralga...

Holocene fringing reef development around Bora Bora is controlled by variations in accommodation space (as a function of sea‐level and antecedent topography) and exposure to waves and currents. Subsidence ranged from 0 to 0.11 m/kyr, and did not create significant accommodation space. A windward fringing reef started to grow 8.7 kyr BP, retrograded...

The approximately 10,000-year-long Last Glacial Maximum, before the termination of the last ice age, was the coldest period in Earth's recent climate history1. Relative to the Holocene epoch, atmospheric carbon dioxide was about 100 parts per million lower and tropical sea surface temperatures were about 3 to 5 degrees Celsius lower2,3. The Last Gl...

In major modern reef regions, either in the Indo-Pacific or the Caribbean, scleractinian corals are described as the main reef framework builders, often associated with crustose coralline algae. We used underwater cores to investigate Late Holocene reef growth and characterise the main framework builders in the Abrolhos Shelf, the largest and riche...

The Betic Cordillera (Southern Spain) constitutes the westernmost segment of the Alpine Chains. The Alpujárride Complex, from the the Internal Zone of the Betic Cordillera, exhibits a thick (up to 2000 m in thickness), Alpine-type, Middle-Upper Triassic marine-carbonate sequence. Stratigraphic correlations and facies-belt distributions reveals that...

The link between the Mediterranean Sea and the Atlantic Ocean through the Betic Cordillera (southern Spain) was reduced to a few seaways in the Miocene as the mountain belt uplifted during the Alpine orogeny. The North-Betic Strait, located in the Prebetic Zone, was the first one to close in the early Late-Miocene. During the Tortonian, there were...

Previous drilling through submerged fossil coral reefs has greatly improved our understanding of the general pattern of sea-level change since the Last Glacial Maximum, however, how reefs responded to these changes remains uncertain. Here we document the evolution of the Great Barrier Reef (GBR), the world's largest reef system, to major, abrupt en...

Pleistocene fibrous aragonite fabrics, including crusts and spherules, occur in the Danakil Depression (Afar, Ethiopia) following the deposition of two distinctive Middle and Late Pleistocene coralgal reef units and pre‐dating the precipitation of evaporites. Crusts on top of the oldest reef units (Marine Isotope Stage 7) cover and fill cavities wi...

Calcareous coralline algae (Rhodophyta; Corallinales, Hapalidiales, and Sporolithales; corallines hereafter) constitute one of the most widespread and successful groups of marine macrophytes. They occur as crusts partially coating hard or soft substrates, as laminar thalli growing directly on the seabed, or forming structures rolling freely on the...

Rhodoliths are common components in Neogene shallow-water marine deposits from the Mediterranean and Paratethys regions. Rhodolith-rich deposits (rhodolith beds) appear to be most widespread in the Langhian (middle Miocene) and late Tortonian-early Messinian (late Miocene) intervals and their occurrences decline in the Piacenzian (late Pliocene). N...

Fossil coral reefs are valuable recorders of glacio-eustatic sea-level changes, as they provide key temporal information on deglacial meltwater pulses (MWPs). The timing, rate, magnitude, and meltwater source of these sea-level episodes remain controversial, despite their importance for understanding ocean-ice sheet dynamics during periods of abrup...

A submarine landslide, the Alhama de Almería Slide, influenced late Tortonian and early Messinian (late Miocene) sedimentary processes in the vicinity of Alhama de Almería in southeast Spain. Its 220-m-high headscarp and deposits are now subaerially exposed. The landslide occurred at the northern slope of the antecedent relief of the present-day Si...

Eleven marine terraces, locally faulted and southward-tilted, can be recognized in the Promontorio de Cabrera, at the eastern end of the Cordillera Septentrional in the northern Dominican Republic. The lower terraces (T1-T7) are reefal platforms belonging to the La Isabela Formation, whereas the upper ones (T8-T11) are abrasion platforms sculpted i...

The geological record of Hispaniola documents a continuous increase in island surface since the Early Pleistocene due to the emergence of marine deposits. In eastern Hispaniola, the Llanura Costera del Caribe and the Los Haitises regions formed by the emergence in the Early-Middle Pleistocene of limestone of the Los Haitises Formation, and marls an...

The genus Aethesolithon was established by Johnson (1964) based on Miocene fossil of coralline algae from Guam, Mariana Islands. The type species, A. problematicum J.H.Johnson, was described in the Bonya Limestone, dated as Tertiary f, which now is known to extend from the early Miocene (Burdigalian) to the late Miocene. According to the protologue...

Este volumen de la SJP está dedicado a nuestro compañero, amigo y maestro Pascual Rivas Carrera, con motivo de su jubilación en septiembre de 2015. Pascual Rivas nació en Santander en 1945 y llegó a Granada en los años 60 para estudiar Ciencias Geológicas. Continuó en la Universidad de Granada haciendo su Tesis Doctoral bajo la dirección de la Dra....

The temporal dimension of the most recent Corallinaceae (order Corallinales) phylogeny was presented here, based on first occurrence time estimates from the fossil record. Calibration of the molecular clock of the genetic marker SSU entailed a separation of Corallinales from Hapalidiales in the Albian (Early Cretaceous ~ 105 mya). Neither the calib...