Evolution of a major oceanographic pathway: the equatorial atlantic

Jones, E. J. W.; Cande, S. C.; Spathopoulos, Fivos

doi:10.1144/gsl.sp.1995.090.01.12

Cited by 34 publications

(17 citation statements)

References 40 publications

(37 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Transoceanic dispersal cannot be discarded a priori in stygobiont groups exhibiting a presumed Tethyan distribution but with shallow genetic divergences. Thus, to lend credence to the ancient vicariant origin hypothesis, divergence times between phylogenetic sister lineages placed at opposite sides of the Atlantic should be older than the establishment of deep-water conditions between Iberia and North America at about 95-110 million years ago (mya) [13,14].…”

Section: Resultsmentioning

confidence: 99%

Mitogenomic Phylogenetic Analysis Supports Continental-Scale Vicariance in Subterranean Thalassoid Crustaceans

et al. 2012

View full text Add to dashboard Cite

Many continental subterranean water crustaceans ("stygobionts") display extreme disjunct distributions, where different species in the same genus are isolated on continents or islands separated by broad oceanic expanses. Despite their freshwater habitat, most of these taxa appear to be most closely related to typical marine groups ("thalassoid" origin). Among the hadzioids-thalassoid amphipods including the stygobiont families Hadziidae, Pseudoniphargidae, and Metacrangonyctidae-several genera are restricted to inland groundwaters ranging from the Caribbean region to the Mediterranean and Middle East, including interspersed oceanic islands. This distribution might have arisen from Tethyan vicariance triggered by the sequential occlusion of the former Tethys Sea, a vast circumtropical ocean existing from the Middle Jurassic up to 20 million years ago (mya). Previous studies have been based on morphological analyses or limited DNA sequence data, making it difficult to test this hypothesis. We used complete mitochondrial protein-coding gene sequences, mainly obtained by next-generation sequencing methods and a nuclear ribosomal gene to resolve the phylogeny and to establish a time frame for diversification of the family Metacrangonyctidae (Amphipoda). The results were consistent with the plate tectonics vicariance hypothesis, with major diversifications occurring between 96 and 83 mya.

show abstract

Section: Resultsmentioning

confidence: 99%

Mitogenomic Phylogenetic Analysis Supports Continental-Scale Vicariance in Subterranean Thalassoid Crustaceans

et al. 2012

View full text Add to dashboard Cite

show abstract

“…The North Atlantic was a substantial basin at that time, but may have had limited connections to adjacent ocean basins (Figure 12). Rifting between South America and Africa during the Early Cretaceous created initially discontinuous marine basins with thick accumulations of siliciclastic sediments and evaporites [ Natland , 1978; Rabinowitz and LaBrecque , 1979; Tucholke and Vogt , 1979; Jones et al , 1995]. As rifting continued the basins widened, deepened and became permanently interconnected with the North Atlantic between the late Aptian and early Albian [ Moullade et al , 1998; Pletsch et al , 2001; Moulin et al , 2010].…”

Section: Discussionmentioning

confidence: 99%

Paleotemperature and paleosalinity inferences and chemostratigraphy across the Aptian/Albian boundary in the subtropical North Atlantic

et al. 2011

View full text Add to dashboard Cite

Geochemical analyses of extraordinarily well preserved late Aptian–early Albian foraminifera from Blake Nose (Ocean Drilling Program Site 1049) reveal rapid shifts of δ18O, δ13C, and 87Sr/88Sr in the subtropical North Atlantic that may be linked to a major planktic foraminifer extinction event across the Aptian/Albian boundary. The abruptness of the observed geochemical shifts and their coincidence with a sharp lithologic contact is explained as an artifact of a previously undetected hiatus of 0.8–1.4 million years at the boundary contact, but the values before and after the hiatus indicate that major oceanographic changes occurred at this time. 87Sr/88Sr increase by ∼0.000 200, δ13C values decrease by 1.5‰ to 2.2‰, and δ18O values decrease by ∼1.0‰ (planktics) to 0.5‰ (benthics) across the hiatus. Further, both 87Sr/88Sr ratios and δ18O values during the Albian are anomalously high. The 87Sr/88Sr values deviate from known patterns to such a degree that an explanation requires either the presence of inter‐basin differences in seawater 87Sr/88Sr during the Albian or revision of the seawater curve. For δ18O, planktic values in some Aptian samples likely reflect a diagenetic overprint, but preservation is excellent in the rest of the section. In well preserved material, benthic foraminiferal values are largely between 0.5 and 0.0‰ and planktic samples are largely between 0.0‰ to −1.0‰, with a brief excursion to −2.0‰ during OAE 1b. Using standard assumptions for Cretaceous isotopic paleotemperature calculations, the δ18O values suggest bottom water temperatures (at ∼1000 –1500 m) of 8–10°C and surface temperatures of 10–14°C, which are 4–6°C and 10–16°C cooler, respectively, than present‐day conditions at the same latitude. The cool subtropical sea surface temperature estimates are especially problematic because other paleoclimate proxy data for the mid‐Cretaceous and climate model predictions suggest that subtropical sea surface temperatures should have been the same as or warmer than at present. Because of their exquisite preservation, whole scale alteration of the analyzed foraminifera is an untenable explanation. Our proposed solution is a high evaporative fractionation factor in the early Albian North Atlantic that resulted in surface waters with higher δ18O values at elevated salinities than commonly cited in Cretaceous studies. A high fractionation factor is consistent with high rates of vapor export and a vigorous hydrological cycle and, like the Sr isotopes, implies limited connectivity among the individual basins of the Early Cretaceous proto‐Atlantic ocean.

show abstract

“…[32] The proposition of a short-living but larger-scale belt of PZE along west Africa may not have been expected taking into account that the opening of the Cretaceous equatorial Atlantic gateway was far advanced during Coniacian-Santonian times, probably as wide as $550 km at its narrowest point between western Ivory Coast and northeastern Brazil [Jones et al, 1995]. During the Coniacian-Santonian a free exchange of deep and surface water masses between the South and North Atlantic basins has to be considered Pletsch et al, 2001], somehow comparable to the modern ocean circulation.…”

Section: Discussionmentioning

confidence: 99%

Euxinia and primary production in Late Cretaceous eastern equatorial Atlantic surface waters fostered orbitally driven formation of marine black shales

et al. 2004

View full text Add to dashboard Cite

Oceanic anoxic events (OAE) in the Cretaceous represent major perturbations in the global climate and ocean system characterized by widespread deposition of organic carbon in the ocean. The causes and effects of these events are poorly constrained, mainly because of the lack of high‐resolution marine records. Here we report the distribution of molecular markers from a millennial‐scale record of Coniacian‐Santonian black shale (OAE‐3) from Ocean Drilling Program Site 959 in the Deep Ivorian Basin in the eastern equatorial Atlantic. Highly branched isoprenoids and alkenone‐derived organic compounds indicate that diatoms and calcareous nanoplankton were important primary producers. Changes in redox sensitive trace metal accumulation and biomarkers of green sulfur bacteria provide evidence for extreme variations in redox conditions, with intervals of lower photic zone euxinia (PZE). Accordingly, oxygen in the Coniacian‐Santonian tropical Atlantic was absent as during the Cenomanian‐Turonian boundary OAE‐2 but over more restricted geographic area and more limited time intervals. We hypothesize that PZE was a common phenomenon typical in large areas of tropical continental margins. These conditions fostered sequestration of atmospheric CO2 and thus helped cause the positive excursion in δ13C of carbonate documented in higher latitude marine records.

show abstract

Evolution of a major oceanographic pathway: the equatorial atlantic

Cited by 34 publications

References 40 publications

Mitogenomic Phylogenetic Analysis Supports Continental-Scale Vicariance in Subterranean Thalassoid Crustaceans

Mitogenomic Phylogenetic Analysis Supports Continental-Scale Vicariance in Subterranean Thalassoid Crustaceans

Paleotemperature and paleosalinity inferences and chemostratigraphy across the Aptian/Albian boundary in the subtropical North Atlantic

Euxinia and primary production in Late Cretaceous eastern equatorial Atlantic surface waters fostered orbitally driven formation of marine black shales

Contact Info

Product

Resources

About