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The Late Cretaceous-Danian of the northwest European shelf represents one of the largest and longest-lived cool-water carbonate shelves in the stratigraphic record. The palaeolatitude of the Danish basin was 45°N during that time. The heterozoan faunas are dominated by bryozoans, echinoids, molluscs, brachiopods, serpulids, and, to varying degree, by azooxanthellate corals. During the Late Maastrichtian, rare soft-substrate-dwelling solitary scleractinians occur, including Parasmilia cylindrical, P. excavata, Caryophyllia sp. as well as octocorals, especially Moltkia minuta . Contemporaneous bryozoan mound complexes below the photic zone, which provided hard substrates for the settlement of larvae, were not colonized by azooxanthellate corals. Neither environmental nor faunal changes among the corals across the Cretaceous-Tertiary (K/T) boundary were significant. After the K/T boundary, the first solitary corals (moulds of Parasmilia biseriata, P. cincta, Trochocyathus hemisphaericus, Caryophyllia sp.) and octocorals appeared in the Cerithium Limestone, which lies above the Fish Clay. Similar to their Late Maastrichtian counterparts, these corals formed level-bottom communities. The Early Danian post-Cerithium Limestone represents the peak of bryozoan mound development. Corals are present but rare. The Middle Danian is characterized by reduced bryozoan mound growth and by the mound-forming dendroid scleractinians Dendrophyllia candelabrum, Oculina becki and Faksephyllia faxoensis , which flourished predominantely in the vicinity of the Ringkøbing-Fyn High. Nine species of solitary scleractinians, stylasterinid hydrocorals, and octocorals contributed to reef building. Important criteria for the interpretation of “cold and deep-water coral bioherms” are (1) absence of algae, (2) low-diverse azooxanthellate coral communities, (3) dominance of dendroid growth forms in the corals, (4) surrounding pelagic sediment adjacent to the coral mounds, (5) occurrence of pelagic organisms (globigerinid foraminifers, coccoliths) in the lime mud, (6) breakdown of coral colonies predominantly by bioerosion instead of mechanical destruction waves, (7) mound- or bank-like morphology of the buildups and (8) occurrence at a high palaeolatitude. Mound morphology and growth direction were traced by variations in the abundance of colonial corals. Gross morphology of scleractinian corals, stylasterinid hydrocorals and octocorals suggests an azooxanthellate character of the reefbuilders: the scleractinians developed dendroid growth forms, while stylasterinids and octocorals formed fan-like colonies oriented perpendicular to the nutrient-rich currents. Strong bioerosion was responsible for the breakdown of the skeletons, and the resulting bioclasts formed the substrate for larvae. Modern azooxanthellate Oculina coral reefs along the shelf edge off central eastern Florida, USA show similarities in position, morphology, environment, water depth and current orientation with the coral mounds of the Paleocene and suggest a palaeodepth for the counterparts from the Danish basin of 100-300 m.

In general, fossils of corals are rare within Eocene and Oligocene marine strata that accumulated in a deep-water, convergent-margin setting and are now exposed in western Oregon and Washington, northwestern USA. At some localities, however, specimens of a few coral taxa are relatively abundant and associated with authigenic limestone deposits. Recently, these highly-localized limestone deposits were recognized as having precipitated due to the microbial oxidation of methane at seeps, areas where hydrocarbon-rich fluids were vented to the sea floor because of the tectonic compression and faulting of underlying sediments. As at modern methane-seeps, the ancient seeps supported dense invertebrate communities, in most cases dominated by tube-dwelling worms and bivalve mollusks, but they can also include gastropods, polyplacophorans, sponges, and corals. A few methaneseep assemblages in Eocene and Oligocene rocks of the Lincoln Creek Formation include the corals Caryophyllia wynoocheensis Durham, and an undescribed Flabellum ( Ulocyathus ) species. A new species of Deltocyathus appears to be restricted to a single methane-seep site. The corals Stephanocyathus holcombensis Durham, and Flabellum hertleini Durham have been reported from what may be methane-seeps sites in the Lincoln Creek Formation near Holcomb, Washington, and associated with an unusual crinoid-rich bioherm in the Keasey Formation near Mist, Oregon. Other corals, Flabellum ( Ulocyathus ) n. sp., Archohelia ? sp., Caryophyllia wynoocheensis , and Dendrophyllia hannibali Nomland, are reported from a Lincoln Creek Formation locality that includes methane-seep related assemblages near Knappton, Washington. Although widespread in the deep sea today, none of the genera found in the ancient seeps in Washington and Oregon have yet been reported from modern seeps, and corals have rarely been reported from pre-Tertiary methane-seep deposits. It is unlikely that any of these corals, like the bivalves and tubeworms found at methane-seeps, hosted and derived nutrients from endosymbiotic chemotrophic bacteria that were capable of metabolizing some of the reduced compounds in the seeping fluids. More likely, the corals probably were attracted to the greater amount of food at seeps relative to the surrounding deep sea, or to the attachment sites provided by hardgrounds of methane-derived carbonate deposits on the muddy seafloor.

Modern and widespread deep-water coral ecosystems have become a major target of research during the last decades. So far, only a few fossil counterparts of such carbonate-secreting deep-water communities have been described. This scarcity might be a result of either, a possible miss-identification as a tropical deposit and/or the rare case of tectonic uplift and subsequent access to these deepwater deposits. The early Pleistocene St. Paul’s Bay Limestone on the island of Rhodes (Greece) represents one of the few known examples of the bathyal ‘white coral community’ dominated by Lophelia pertusa which are exposed on land. This occurrence relates to a convergent tectonic setting with large-scale uplifts in the vicinity of the European-African plate boundary that is responsible for the exposure of these early Pleistocene deep-water deposits. The geometry of the St. Paul’s Bay Limestone significantly differs from the mound-forming Lophelia occurrences as known, e.g., from the NE-Atlantic or the Florida Strait. Instead, it appears similar to the modern ‘white coral community’ of the western Mediterranean Sea that is usually associated with submarine cliffs. Much like the latter, the St. Paul’s Bay Limestone demonstrates that the growth and final deposition of the ‘white coral community’ was strongly influenced by the complex relief with steep submarine basement cliffs generated by horst-graben systems. These submarine cliffs not only provided the main habitat for the ‘white coral community’, they also explain recurrent instability and redeposition by debris falls along the submarine cliffs. Such a debris fall mechanism is strongly suggested by: (1) the steep slope angles (>30°), (2) the short transport distance (<20 m), (3) the wedge-like geometry, (4) the lack of grading, (5) the fabric complexity with incorporated fragments of hardgrounds, intraclasts and slightly consolidated sediment, (6) geopetal structures of various directions, thus indicating multiple resedimentation events, and (7) the variety of fragmentation and bioerosion. This resulted in the final deposition of the ‘white coral community’ (1) at the foot of submarine cliffs and (2) in neptunian dykes and, to a minor extent (3) in erosional depressions of the basement rock. In conclusion, the basic characters of the St. Paul’s Bay Limestone in terms of the initial facies, fabric and fauna largely match those described for lithoherms (Florida Strait). The enhanced complexity in terms of the final fabric and the wedge-like geometry appear due to multiple resedimentation events via debris falls along submarine cliffs.

The Early Pleistocene fault plane of Furnari, that outcrops in northeastern Sicily (southern Italy), provided a primary hard substrate for the settling and growth of large coral colonies. Even though the corals did not form frameworks, they influenced the composition and distribution of the benthic communities. Corals and associated fauna produced organogenic debris, which was deposited along the fault scarp, within its fractures or at its base. Bulk-samples from coarse debris sediments along the palaeoescarpment and from silty sediments at the scarp foot have been studied, with focus on corals, molluscs, serpulids, bryozoans and ostracods. The fossil assemblages examined can be related to original coral and mud-communities from a shallow epibathyal palaeoenvironment, 400 to 500 m deep. High values in species richness and diversity were recorded, especially for the deep-coral communities. Owing to the inferred elevated biodiversity, the Furnari coral communities show similarities with those flourishing in the present day North Atlantic and appear congruent with the scenario of cold stenothermic Pleistocene deep Mediterranean waters.

Large carbonate mound structures have been discovered in the northern Porcupine Seabight (Northeast Atlantic) at depths between 600 and 1000 m. These mounds are associated with the growth of deep-sea corals Lophelia pertusa and Madrepora oculata . In this study, three sediment cores have been analysed. They are from locations close to Propeller Mound, a 150 m high ridge-like feature covered with a cold-water coral ecosystem at its upper flanks. The investigations are concentrated on grain-size analyses, carbon measurements and on the visual description of the cores and computer tomographic images, to evaluate sediment content and structure. The cores portray the depositional history of the past ∼31 kyr BP, mainly controlled by sea-level fluctuations and the climate regime with the advance and retreat of the Irish Ice Sheet onto the Irish Mainland Shelf. A first advance of glaciers is indicated by a turbiditic release slightly older than 31 kyr BP, coherent with Heinrich event 3 deposition. During Late Marine Isotope Stage 3 (MIS 3) and MIS 2 shelf erosion prevailed with abundant gravity flows and turbidity currents. A change from glaciomarine to hemipelagic contourite sedimentation during the onset of the Holocene indicates the establishment of the strong, present-day hydrodynamic regime at intermediate depths. The general decrease in accumulation of sediments with decreasing distance towards Propeller Mound suggests that currents (turbidity currents, gravity flows, bottom currents) had a generally stronger impact on the sediment accumulation at the mound base for the past ∼31 kyr BP, respectively.

We present combined ^230Th/U and ^14C dating on deep-water corals from the northeastern North Atlantic in order to investigate coral growth and sedimentation on carbonate mounds, as well as past changes of intermediate water ventilation. Within European projects GEOMOUND and ECOMOUND reef forming Lophelia pertusa deep-water corals were raised from intermediate depth (∼610 to 888 m bsl) from top of carbonate mounds at southeast Rockall Bank and at Porcupine Seabight. XRD analyses, δ^234U, and ^230Th/^232Th indicate negligible alteration of the investigated corals, i.e. open system U-series behavior. ^230Th/U ages from coral specimens of the uppermost coral sequence of the investigated mounds range from today to 10,950 CAL yr BP, i.e. coral growth during the Holocene. A modern Lophelia gave a ^230Th/U age of 1983±6 AD, close to the date of collection in 2001 AD. Deep-water coral growth is the driving process of sediment accumulation on the summit of carbonate mounds, with sediment accumulation rates in the order of ∼0.3 mm yr^−1. However, coral growth is discontinuous and irregular, and complete coral sequences are frequently altered (dissolved) likely due to organic matter consumption by oxidizing pore fluids. Mound top sediments indicate the presence of corals over several glacial/interglacial cycles, but corals of glacial origin could not be identified on the investigated mounds. Upper intermediate water Δ^14C and reservoir ages (R) were reconstructed on 11 deep-water corals. Δ^14C of −13±7 ‰ obtained on the coral dated to 1983 AD shows a significant lower value than the ones previously reported for the late 90’s (+27 ‰), but in agreement with seawater measurements performed in the early 80’s. Between 10,950 CAL yr BP and 420 CAL yr BP, R exhibit variations between as low as 240±110 yrs (at 5,440 CAL yr BP) to up to 750±230 yrs (at 10,450 CAL yr BP). However, most of the data (8 out of 10 corals) yield R between 400 and 600 yrs similar to previously reported pre-anthropogenic R values. Thus, the overall hydrographical pattern and surface to intermediate water CO_2 exchange in the eastern North Atlantic was similar to the present day one.

The Mediterranean basin represents an excellent biological archive of past and modern deep coral growth whose study may help to understand taxonomic, biogeographic, ecological, and evolutionary patterns of modern deep coral bioconstructions, best embodied by the Lophelia -reefs and mounds of the Atlantic Ocean. In fact, the occurrence of extant deep coral genera in the Mediterranean basin is documented, although not continuously, since the Miocene. Following the Messinian crisis the re-colonisation of the basin by deep coral is likely to have started with the Pliocene but little is known about deep coral biota linked to hard substrates during this epoch. It is certain that Atlantic-type deep-sea corals including the scleractinian triad Lophelia-Madrepora-Desmophyllum have been established in the basin since the latest Pliocene-Early Pleistocene as proven by outcrop evidence in southern Italy, especially Sicily and Calabria, and in Rhodes. Still-submerged dead coral assemblages are widespread in the entire basin between c. 250—2500 m depth; the majority is aged at the last glacial by AMS, C14 and U/Th dating. The present situation (post-glacial) is a general decline of such deep corals in the Mediterranean, and this is especially true for Lophelia which appears to be more severely affected by local extinctions. To date, the only exception to this general rule is represented by the recent discovery of prosperous Lophelia populations in the Eastern Ionian Sea.

Deep-water corals are widespread in the North Atlantic. Colonial azooxanthellate scleractinians sustain ecosystems mostly in the bathyal zone down the slopes and oceanic banks off the Iberian Peninsula to as far north as the Scandinavian shelf off northern Norway. Estimates of the geological age of 37 deepwater corals exposed at the seabed from major reef areas in the North Atlantic were based on U/Th datings. In contrast to the purely Holocene ages of deep-water corals in Scandinavian waters, the Faroe area and the Rockall Trough, deep-water corals from lower latitudes like the seamounts off NW-Africa, the Mid-Atlantic Ridge and the western Mediterranean Sea seemed to have grown continuously over the last 50 ka. Overall, deep-water corals showed U/Th ages between 0.09 and 53.5 ka.

Acesta excavata is the largest known bivalve associated with the Lophelia pertusa communities along the northeast Atlantic continental margin, but has also been found along steep cliffs, devoid of bathyal corals, and on more subdued topographies. During the Pleistocene, including the last glacial, A. excavata was widespread in the Mediterranean, but is in the Recent fauna known only from four Mediterranean sites. A new possible live-record from the Canyon du Var off Nice is presented. Radiocarbon dating (AMS ^14C-method) on an A. excavata assemblage from the Strait of Sicily yielded a Late Pleistocene age of 39.9 ka. Biometric parameters indicate that Pleistocene Mediterranean shells achieved about the same maximum sizes as their Recent Atlantic counterparts, but individuals have been slightly smaller on average. The subspecies Acesta excavata sublaevis Nordsieck, based on a subfossil juvenile Mediterranean shell, is not considered a valid taxon. Mineralogical composition and ultrastructure of A. excavata have been analyzed using thin-sections, Feigel staining, x-ray diffractometry (XRD) and SEM-imaging. Its wide distribution, large size (15 cm) and simple shell architecture makes it a prime candidate for palaeoenvironmental studies in cold-water coral settings.

This study reports for the first time on the occurrences of deep-water coral species in the Spanish territorial waters of the Strait of Gibraltar. Based on an extensive dataset of 334 grab samples, 16 species of calcareous corals have been identified in water depths between 13–443 m. Scleractinian corals form the dominant benthic community between 140–330 m water depth. The corals appear on the seabed both as solitary individuals and as patches on small biological topographic build-ups. The most common coral species Lophelia pertusa and Madrepora oculata are associated with coarse-grained calcareous sediments and mound structures. In the shallowest part of the study area (<150 m) algae and bryozoans are dominant and only a few coral species are observed. This zonation and the occurrence of the azooxanthellate corals in the Strait of Gibraltar relates to light availability and perhaps also to the complex interaction between the outflow of Mediterranean water and surficial inflow of Atlantic water into the Mediterranean Sea.