Checklist, assemblage composition, and biogeographic assessment of Recentbenthic foraminifera (Protista, Rhizaria) from São Vincente, Cape Verdes

We describe for the first time subtropical intertidal foraminiferal assemblages from beach sands on São Vincente, Cape Verdes. Sixty-five benthic foraminiferal species were recognised, representing 47 genera, 31 families, and 8 superfamilies. Endemic species were not recognised. The new checklist largely extends an earlier record of nine benthic foraminiferal species from fossil carbonate sands on the island. Bolivina striatula, Rosalina vilardeboana and Millettiana milletti dominated the living (rose Bengal stained) fauna, while Elphidium crispum, Amphistegina gibbosa, Quinqueloculina seminulum, Ammonia tepida, Triloculina rotunda and Glabratella patelliformis dominated the dead assemblages. The living fauna lacks species typical for coarse-grained substrates. Instead, there were species that had a planktonic stage in their life cycle. The living fauna therefore received a substantial contribution of floating species and propagules that may have endured a long transport by surface ocean currents. The dead assemblages largely differed from the living fauna and contained redeposited tests deriving from a rhodolith-mollusc carbonate facies at <20 m water depth. A comparison of the Recent foraminiferal inventory with other areas identified the Caribbean and Mediterranean as the most likely source regions. They have also been constrained as origin points for littoral to subtidal macroorganisms on other Cape Verdean islands. Micro-and macrofaunal evidences assigned the Cape Verde Current and North Equatorial Current as the main trajectories for faunal immigrations. The contribution from the NW African coast was rather low, a pattern that cannot be explained by the currently available information

The Middle to Late Miocene “Carbonate Crash” in the Equatorial Indian Ocean

We integrate benthic foraminiferal stable isotopes, X‐ray fluorescence elemental ratios, and carbonate accumulation estimates in a continuous sedimentary archive recovered at International Ocean Discovery Program Site U1443 (Ninetyeast Ridge, Indian Ocean) to reconstruct changes in carbonate deposition and climate evolution over the interval 13.5 to 8.2 million years ago. Declining carbonate percentages together with a marked decrease in carbonate accumulation rates after ~13.2 Ma signal the onset of a prolonged episode of reduced carbonate deposition. This extended phase, which lasted until ~8.7 Ma, coincides with the middle to late Miocene carbonate crash, originally identified in the eastern equatorial Pacific Ocean and the Caribbean Sea. Interocean comparison reveals that intense carbonate impoverishment at Site U1443 (~11.5 to ~10 Ma) coincides with prolonged episodes of reduced carbonate deposition in all major tropical ocean basins. This implies that global changes in the intensity of chemical weathering and riverine input of calcium and carbonate ions into the ocean reservoir were instrumental in driving the carbonate crash. An increase in U1443 Log (Ba/Ti) together with a change in sediment color from red to green indicate a rise in organic export flux to the sea floor after ~11.2 Ma, which predates the global onset of the biogenic bloom. This early rise in export flux from biological production may have been linked to increased advection of nutrients and intensification of upper ocean mixing, associated with changes in the seasonality and intensity of the Indian Monsoon

The Middle to Late Miocene “Carbonate Crash” in the Equatorial Indian Ocean

金沢大学理工研究域地球社会基盤学系We integrate benthic foraminiferal stable isotopes, X-ray fluorescence elemental ratios, and carbonate accumulation estimates in a continuous sedimentary archive recovered at International Ocean Discovery Program Site U1443 (Ninetyeast Ridge, Indian Ocean) to reconstruct changes in carbonate deposition and climate evolution over the interval 13.5 to 8.2 million years ago. Declining carbonate percentages together with a marked decrease in carbonate accumulation rates after ~13.2 Ma signal the onset of a prolonged episode of reduced carbonate deposition. This extended phase, which lasted until ~8.7 Ma, coincides with the middle to late Miocene carbonate crash, originally identified in the eastern equatorial Pacific Ocean and the Caribbean Sea. Interocean comparison reveals that intense carbonate impoverishment at Site U1443 (~11.5 to ~10 Ma) coincides with prolonged episodes of reduced carbonate deposition in all major tropical ocean basins. This implies that global changes in the intensity of chemical weathering and riverine input of calcium and carbonate ions into the ocean reservoir were instrumental in driving the carbonate crash. An increase in U1443 Log (Ba/Ti) together with a change in sediment color from red to green indicate a rise in organic export flux to the sea floor after ~11.2 Ma, which predates the global onset of the biogenic bloom. This early rise in export flux from biological production may have been linked to increased advection of nutrients and intensification of upper ocean mixing, associated with changes in the seasonality and intensity of the Indian Monsoon. ©2019. American Geophysical Union. All Rights Reserved.Embargo Period 6 month

Secular and orbital-scale variability of equatorial Indian Ocean summer monsoon winds during the late Miocene

In the modern northern Indian Ocean, biological productivity is intimately linked to near-surface oceanographic dynamics forced by the South Asian, or Indian, monsoon. In the late Pleistocene, this strong seasonal signal is transferred to the sedimentary record in the form of strong variance in the precession band (19–23 kyr), because precession dominates low-latitude insolation variations and drives seasonal contrast in oceanographic conditions. In addition, internal climate system feedbacks (e.g. ice-sheet albedo, carbon cycle, topography) play a key role in monsoon variability. Little is known about orbital-scale monsoon variability in the pre-Pleistocene, when atmospheric CO2 levels and global temperatures were higher. In addition, many questions remain open regarding the timing of the initiation and intensification of the South Asian monsoon during the Miocene, an interval of significant global climate change that culminated in bipolar glaciation. Here, we present new high-resolution (<1 kyr) records of export productivity and sediment accumulation from International Ocean Discovery Program Site U1443 in the southernmost part of the Bay of Bengal spanning the late Miocene (9 to 5 million years ago). Underpinned by a new orbitally tuned benthic isotope stratigraphy, we use X-ray fluorescence-derived biogenic barium variations to discern productivity trends and rhythms. Results show strong eccentricity-modulated precession-band productivity variations throughout the late Miocene, interpreted to reflect insolation forcing of summer monsoon wind strength in the equatorial Indian Ocean. On long timescales, our data support the interpretation that South Asian monsoon winds were already established by 9 Ma in the equatorial sector of the Indian Ocean, with no apparent intensification over the latest Miocene

Rotaliida Delage & Herouard 1896

Order Rotaliida Delage &amp; H&eacute;rouard 1896 Superfamily Discorboidea Ehrenberg 1838Published as part of &lt;i&gt;Schönfeld, Joachim &amp; Lübbers, Julia, 2020, Checklist, assemblage composition, and biogeographic assessment of Recent benthic foraminifera (Protista, Rhizaria) from São Vincente, Cape Verdes, pp. 151-192 in Zootaxa 4731 (2)&lt;/i&gt; on page 158, DOI: 10.11646/zootaxa.4731.2.1, &lt;a href="http://zenodo.org/record/3637801"&gt;http://zenodo.org/record/3637801&lt;/a&gt

Adelosina d'Orbigny 1826

Genus &lt;i&gt;Adelosina&lt;/i&gt; d&rsquo;Orbigny 1826 &lt;p&gt; &lt;i&gt;Adelosina carinata-striata&lt;/i&gt; Wiesner 1923, p. 77, pl. 14, figs. 190&ndash;191 [Plate 1, Fig. 19]. Cimerman &amp; Langer (1991), p. 28, pl. 20, figs. 1&ndash;4. &rdquo; &lt;i&gt;Quinqueloculina carinatastriata&lt;/i&gt; &rdquo; Bouchet &lt;i&gt;et al.&lt;/i&gt; (2007), p. p. 205, pl. 1, figs. 1&ndash;6. Yokes &lt;i&gt;et al.&lt;/i&gt; (2014), fig. 7.1. Note: this species was common in the Mediterranean and recently has invaded the Atlantic coast of Europe (Bouchet &lt;i&gt;et al.&lt;/i&gt; 2007).&lt;/p&gt;Published as part of &lt;i&gt;Schönfeld, Joachim &amp; Lübbers, Julia, 2020, Checklist, assemblage composition, and biogeographic assessment of Recent benthic foraminifera (Protista, Rhizaria) from São Vincente, Cape Verdes, pp. 151-192 in Zootaxa 4731 (2)&lt;/i&gt; on page 155, DOI: 10.11646/zootaxa.4731.2.1, &lt;a href="http://zenodo.org/record/3637801"&gt;http://zenodo.org/record/3637801&lt;/a&gt

Epistominella Husezima & Maruhasi 1944

Genus: &lt;i&gt;Epistominella&lt;/i&gt; Husezima &amp; Maruhasi 1944 &lt;p&gt; &lt;i&gt;Epistominella&lt;/i&gt; sp. Note: the specimen is very similar to the deep-water species &lt;i&gt;Epistominella exigua&lt;/i&gt; (Brady 1884), but the earlier parts of the test comprise more than half of the test diameter on the dorsal side, which otherwise is a character of the shelf-dwelling species &lt;i&gt;Epistominella vitrea&lt;/i&gt; Parker 1953. None-the-less, our specimen is missing the inflated chambers, depressed sutures and rounded periphery of the latter species.&lt;/p&gt;Published as part of &lt;i&gt;Schönfeld, Joachim &amp; Lübbers, Julia, 2020, Checklist, assemblage composition, and biogeographic assessment of Recent benthic foraminifera (Protista, Rhizaria) from São Vincente, Cape Verdes, pp. 151-192 in Zootaxa 4731 (2)&lt;/i&gt; on page 161, DOI: 10.11646/zootaxa.4731.2.1, &lt;a href="http://zenodo.org/record/3637801"&gt;http://zenodo.org/record/3637801&lt;/a&gt

Buliminella Cushman 1911

Genus Buliminella Cushman 1911 Buliminella elegantissima (d’Orbigny) = Bulimina elegantissima d’Orbigny 1839a, p. 51, pl. 7, figs. 13, 14 [Plate 2, Fig. 31, 32]. Höglund (1947), p. 215, pl. 18, fig. 1a, b. Barrick (1989), p. 263, fig. 3.1. Rodrigues et al. (2014), fig. 11.4 e.Published as part of Schönfeld, Joachim & Lübbers, Julia, 2020, Checklist, assemblage composition, and biogeographic assessment of Recent benthic foraminifera (Protista, Rhizaria) from São Vincente, Cape Verdes, pp. 151-192 in Zootaxa 4731 (2) on page 161, DOI: 10.11646/zootaxa.4731.2.1, http://zenodo.org/record/363780