Bioactive metal releases in ocean surface water, such as those by ash falls during volcanic super... more Bioactive metal releases in ocean surface water, such as those by ash falls during volcanic super-eruptions, might have a potentially toxic impact on biocalcifier planktic microorganisms. Nano-XRF imaging with the cutting-edge synchrotron hard X-ray nano-analysis ID16B beamline (ESRF) revealed for the first time a specific Zn-and Mn-rich banding pattern in the test walls of Globorotalia menardii planktic foraminifers extracted from the Young Toba Tuff layer, and thus contemporaneous with Toba's super-eruption, 74,000 years ago. The intra-test correlation of Zn and Mn patterns at the nanoscale with the layered calcareous microarchitecture, indicates that the incorporation of these metals is syngenetic to the wall growth. The preferential Mn and Zn sequestration within the incipient stages of chamber formation suggests a selective incorporation mechanism providing a resilience strategy to metal pollution in the test building of planktic foraminifers. Planktic foraminifers are one of the major constituents of calcium carbonate accumulated in pelagic seafloor sediments (30-80% of total deep-marine calcite budget), playing a crucial role in the carbon cycle and climate regulation 1,2. Their calcitic tests with intricate and beautiful morphologies are easily preserved in marine sedi-mentary records and constitute an invaluable archive of past environmental and climatic conditions. The trace metal contents of these tests are widely used as palaeoceanographic and palaeoclimatic proxies, since metal incorporation is strongly affected by the environmental conditions in which the organisms grew 3. Differences in trace element contents between calcitic foraminifer tests and inorganic calcite precipitated in the same seawater conditions show that biological processes play an important role in metal incorporation 4. A detailed examination of trace metal distribution within the shell walls may help in identifying the biological processes controlling their incorporation. The most studied and emblematic example is the Mg/Ca paleothermometer proxy, whose intra-test micro-distribution displays a typical banding pattern in calcareous perforate foraminifers, which include planktic and benthic species. Different biological processes have been proposed to explain it 5-8. It has been shown that Mg incorporation for some planktic foraminifer species is diurnally paced and modulated by light-dark cyclicity 7,8 and is assumed to be related to physiological processes, such as symbiont photosynthesis or respiration, that affect the carbonate chemistry at the site of calcification 5 , or to a mitochondrial uptake of Mg 7. In addition to Mg, banding patterns of other minor and trace elements (Na, Sr, K, S, P, N, B, Mn) have also been displayed from culture experiments or found in live calcareous perforate foraminifers retrieved from natural seawater environments 9-13. This study aims to unravel the intra-test multi-intake of trace metals, such as Mn and Zn, into planktic foraminifera tests. As Mn and Zn contents in foraminifers reflect the availability of free Mn 2+ and Zn 2+ in open
<p><strong&a... more <p><strong>Biogeochemical disruptions across the Cretaceous-Paleogene boundary : insights from sulfur isotopes</strong></p><p> </p><p>Arbia JOUINI<sup>1*</sup>, Guillaume PARIS<sup>1</sup>, Guillaume CARO<sup>1</sup>, Annachiara BARTOLINI<sup>2</sup></p><p><sup>1 </sup>Centre de Recherches Pétrographiques et Géochimiques, CRPG-CNRS, UMR7358, ,15 rue Notre Dame des Pauvres, BP20, 54501Vandoeuvre-lès-Nancy, France, email:Arbia.jouini@univ-lorraine.Fr</p><p><sup>2</sup> Muséum National D’Histoire Naturelle, Département Origines & Evolution, CR2P MNHN, CNRS, Sorbonne Université, 8 rue Buffon CP38, 75005 Paris, France</p><p> </p><p>The Cretaceous–Paleogene (KPg) mass extinction event 66 million years ago witnessed one of the ‘Big Five’ mass extinctions of the Phanerozoic. Two major catastrophic events, the Chicxulub asteroid impact and the Deccan trap eruptions, were involved in complex climatic and environmental changes that culminated in the mass extinction including oceanic biogenic carbonate crisis, sea water chemistry and ocean oxygen level changes. Deep understanding of the coeval sulfur biogeochemical cycle may help to better constrain and quantify these parameters.</p><p>Here we present the first stratigraphic high resolution isotopic compositions of carbonate associated sulfate (CAS) based on monospecific planktic and benthic foraminifers' samples during the Maastrichtian-Danian transition from IODP pacific site 1209C. Primary δ34SCAS data suggests that there was a major perturbation of sulfur cycle around the KPg transition with rapid fluctuations (100-200kyr) of about 2-4‰ (±0.54‰, 2SD) during the late Maastrichtian followed by a negative excursion in δ34SCAS of 2-3‰ during the early Paleocene.</p><p>An increase in oxygen levels associated with a decline in organic carbon burial, related to a collapse in primary productivity, may have led to the early Paleocene δ34SCAS negative shift via a significant drop in microbial sulfate reduction. Alternatively, Deccan volcanism could also have played a role and impacted the sulfur cycle via direct input of isotopically light sulfur to the ocean. A revised correlation between δ34SCAS data reported in this study and a precise dating of the Deccan volcanism phases would allow us to explore this hypothesis.</p><p>Keywords : KPg boundary, Sulphur cycle, cycle du calcium, Planktic and benthic foraminifera</p><p> </p>
The Early Jurassic (late Pliensbachian to early Toarcian) was a period marked by extinctions, cli... more The Early Jurassic (late Pliensbachian to early Toarcian) was a period marked by extinctions, climate fluctuations, and oceanic anoxia. Although the causes of the early Toarcian Oceanic Anoxia Event (OAE) have been fairly well studied, the events that lead to the Toarcian OAE, i.e. the events in the late Pliensbachian, have not been well constrained. Scenarios of the driving mechanism of biotic and environmental changes of the late Pliensbachian have ranged from LIP volcanism (the Karoo-Ferrar LIP), ocean stagnation, and changing ocean circulation, to orbital forcing. The temporal relationship between the Karoo LIP and the late Pliensbachian (Kunae-Carlottense ammonite Zones) are investigated in an effort to evaluate a causal relationship. We present the first absolute timescale on the Kunae and Carlottense Zones based on precise high-precision U-Pb geochronology, and additional geochemical proxies, for a range of environmental proxies such as bulk organic carbon isotope composition...
<i>Sindhochelys ragei</i> n. gen., n. sp. (Figs 2-9) urn:lsid:zoobank.org:act: EC548A... more <i>Sindhochelys ragei</i> n. gen., n. sp. (Figs 2-9) urn:lsid:zoobank.org:act: EC548A31-BD5A-478D-83D7-266EE85C9186 TYPE MATERIAL. — Holotype, a shell, CPAG-RANKT-V-3. The final repository of the fossil material reported here is the Centre for Pure and Applied Geology (CPAG), University of Sindh, Jamshoro, Pakistan. High-resolution casts are housed at the Muséum national d'Histoire naturelle, Paris. DIAGNOSIS. — For monotypic genus and species. A bothremydid turtle defined by the ornamentation of the shell consisting of raised well protruding polygons but, unlike other ornamented forms such as Taphrosphyini and <i>Carteremys leithii</i>, in having conjoined rather larger irregular polygons without a clear net of granulations, polygons clearly but irregularly protruding and either elongated or regularly polygonal, or open in dichotomic sulci at places. Sharing with <i>Elochelys perfecta</i>, <i>Carteremys</i> group, " <i>Carteremys</i> " <i>pisdurensis</i>, and Taphrosphyini the generalized plastral anterior lobe scute pattern of a long intergular, separating narrower and shorter gulars, and widely reaching the pectorals, intergular also separating the thus narrowed humerals; but: humero-intergularo-pectoral sulcus crossing the entoplastron at the 2nd anterior third of its length, its humero-pectoral part posterior to the epi-hyoplastral suture in its median width, but close to it and laterally joining it, contrarily to <i>E. perfecta</i> where it is completely anterior to the suture, contrarily to " <i>C.</i> " <i>pisdurensis</i> where it is medially anterior to the suture and lateroposteriorly inclined much posteriorly to the suture, and contrarily to Taphrosphyini and the <i>Carteremys</i> group where it does not cross the suture; intergularo-pectoral sulcus relatively transverse on the entoplastron, as in the <i>Carteremys</i> group, not being medially inclined in a marked V contrarily to <i>E. perfecta</i>, " <i>C.</i> " <i>pisdurensis</i> and Taphrosphyini. Bothremydid carapace low with well-inclined bridges [...]
FIG. 10. — Fragmentary part of a carapace of an undetermined Bothremydidae, from the Paleocene of... more FIG. 10. — Fragmentary part of a carapace of an undetermined Bothremydidae, from the Paleocene of Ranikot, locality K18-12, CPAG-RANKT-V4, Southern Pakistan: A, B, ventral and dorsal views; C, detail of the dorsal decoration. Abbreviations: cost3, costal 3; cost5, costal 5; pcs, suture of the peripheral border with the border of plastral processes; per 5-8, peripherals 5, 6, 7, 8; perf, pholad perforations. Scale bars: A, B, 4 cm; C, 1 cm.
FIG. 8. — Sindhochelys ragei n. gen., n. sp., holotype CPAG-RANKT-V-3, from the Paleocene of Rani... more FIG. 8. — Sindhochelys ragei n. gen., n. sp., holotype CPAG-RANKT-V-3, from the Paleocene of Ranikot, locality K18-12, Southern Pakistan. A-D, decoration in various parts of the shell: A, isolated piece with the imprint of the mesoplastral external surface; B, marginal part of peripheral 10, dorsal view; C, left costal 1 part, posterior border at mid-width, dorsal view; D, a costal lateral border, in dorsal view; E, right hyoplastral part, ventral view. Scale bar: 5 cm.
FIG. 7. — Sindhochelys ragei n. gen., n. sp., holotype CPAG-RANKT-V-3, from the Paleocene of Rani... more FIG. 7. — Sindhochelys ragei n. gen., n. sp., holotype CPAG-RANKT-V-3, from the Paleocene of Ranikot, locality K18-12, Southern Pakistan. Medioanterior part of the shell, the nuchal being removed, showing a part of the dorsal face of the anterior lobe with the sulci limiting the overlapping scales. Scale bar: 5 cm.
FIG. 4. — Sindhochelys ragei n. gen., n. sp., holotype CPAG-RANKT-V-3, from the Paleocene of Rani... more FIG. 4. — Sindhochelys ragei n. gen., n. sp., holotype CPAG-RANKT-V-3, from the Paleocene of Ranikot, locality K18-12, Southern Pakistan: A, B, shell drawings, in dorsal (A) and ventral (B) views. Scale bars: 10 cm.
FIG. 5. — Sindhochelys ragei n. gen., n. sp., holotype CPAG-RANKT-V-3, from the Paleocene of Rani... more FIG. 5. — Sindhochelys ragei n. gen., n. sp., holotype CPAG-RANKT-V-3, from the Paleocene of Ranikot, locality K18-12, Southern Pakistan: A, anterolateral part of the carapace after removal of a part of the costal 1 with part of the neural l and the costal 2, to show the imprints of the thoracic ribs 1 and 2, and axillary buttress, in dorsal view; B, same removed part in ventral view. Abbreviations: ax b, axillary buttress; cost 1, costal 1; n1, neural 1; nu, nuchal; per 2, peripheral 2; rib 1, rib 2, medial part of thoracic ribs 1 and 2. Scale bar: 4 cm.
From the Guajira Desert to the Apennines, and from Mediterranean Microplates to the Mexican Killer Asteroid: Honoring the Career of Walter Alvarez, 2022
The reduced Jurassic sedimentary sequences deposited on a structural high in the Umbria-Marche Ap... more The reduced Jurassic sedimentary sequences deposited on a structural high in the Umbria-Marche Apennines, as well their relationships with adjacent expanded basinal sequences, have been reconstructed through detailed, interdisciplinary study of the Sasso di Pale and Monte Serrone areas near Foligno, Italy. The physiographic features of the basin originated in the Early Jurassic (latest early Pliensbachian), when extensional tectonic activity broke up a shallow water platform where the Calcare Massiccio had been deposited, and the area evolved from an edge-stepped structural high to a distally steepened ramp. The biostratigraphic framework of this paper is mainly based on calcareous nannofossils, which are a useful tool for dating condensed Jurassic successions. Although the sections studied have limited thickness and much lateral facies variation, the sedimentary evolution can be traced and interpreted within a wider Jurassic environmental perspective. In the upper Pliensbachian–low...
FIG. 5. — Comparison of extant and extinct Neocallichirus chelipeds:A, major male P1 chela of Neo... more FIG. 5. — Comparison of extant and extinct Neocallichirus chelipeds:A, major male P1 chela of Neocallichirus karumba (Poore & Griffin,1979) (A1), N. lakhraensis Hyžný & Charbonnier, n. sp., holotype CPAG.RAN.I.64 (A2) and N. khadroensis Hyžný & Charbonnier, n. sp., holotype CPAG.RAN.I.55 (A3); B, major P1 carpus of N. karumba (B1) and N. lakhraensis Hyžný & Charbonnier, n. sp., paratype CPAG.RAN.I.69 (B2); C, major P1 merus of N. karumba (C1), N. khadroensis Hyžný & Charbonnier, n. sp., paratype CPAG.RAN.I.63 (C2) and N. lakhraensis Hyžný & Charbonnier, n. sp., paratype CPAG.RAN.I.69 (C3); D, major female P1 chela of N. karumba (D1), N. lakhraensis Hyžný & Charbonnier, n. sp., paratype CPAG.RAN.I.66 (D2) and N. khadroensis Hyžný & Charbonnier, n. sp., paratype CPAG.RAN.I.59 (D3); E, minor P1 cheliped of N. karumba (E1) and N. lakhraensis Hyžný & Charbonnier,n. sp., paratype CPAG.RAN.I.72 (E2). Specimens of N. karumba are deposited under NHMW 21937 (male) and NHMW 21938 (female). Pho...
FIG. 6. — A-C, Neocallichirus borensis Beschin, De Angeli, Checchi & Mietto, 2006; A, B, holotype... more FIG. 6. — A-C, Neocallichirus borensis Beschin, De Angeli, Checchi & Mietto, 2006; A, B, holotype MCZ 2423; C, MCZ 2427; D-G, Neocallichirus tuberculatus (Lőrenthey in Lőrenthey & Beurlen, 1929) n. comb.; D-F, syntypes MFGI E.9465; H, Neocallichirus lakhraensis Hyžný & Charbonnier, n. sp., holotype CPAG. RAN.I.64; I, Neocallichirus khadroensis Hyžný & Charbonnier, n. sp., holotype CPAG.RAN.I.55; J-L, Neocallichirus maximus (A. Milne-Edwards, 1870). Photographs: M. Hyžný (A-F), and L. Cazes and P. Loubry (H-I). Scale bar: A-I, 10 mm. J-L, not to scale.
Logging data are measurements of physical properties of the formation surrounding a borehole, acq... more Logging data are measurements of physical properties of the formation surrounding a borehole, acquired in situ after completion of coring (wireline logging) or during drilling (Logging-While-Drilling, LWD). The range of data (resistivity, gamma radiation, velocity, density, borehole images,…) in any hole depends on the scientific objectives and operational constraints.
Bioactive metal releases in ocean surface water, such as those by ash falls during volcanic super... more Bioactive metal releases in ocean surface water, such as those by ash falls during volcanic super-eruptions, might have a potentially toxic impact on biocalcifier planktic microorganisms. Nano-XRF imaging with the cutting-edge synchrotron hard X-ray nano-analysis ID16B beamline (ESRF) revealed for the first time a specific Zn- and Mn-rich banding pattern in the test walls of Globorotalia menardii planktic foraminifers extracted from the Young Toba Tuff layer, and thus contemporaneous with Toba’s super-eruption, 74,000 years ago. The intra-test correlation of Zn and Mn patterns at the nanoscale with the layered calcareous microarchitecture, indicates that the incorporation of these metals is syngenetic to the wall growth. The preferential Mn and Zn sequestration within the incipient stages of chamber formation suggests a selective incorporation mechanism providing a resilience strategy to metal pollution in the test building of planktic foraminifers.
Bioactive metal releases in ocean surface water, such as those by ash falls during volcanic super... more Bioactive metal releases in ocean surface water, such as those by ash falls during volcanic super-eruptions, might have a potentially toxic impact on biocalcifier planktic microorganisms. Nano-XRF imaging with the cutting-edge synchrotron hard X-ray nano-analysis ID16B beamline (ESRF) revealed for the first time a specific Zn-and Mn-rich banding pattern in the test walls of Globorotalia menardii planktic foraminifers extracted from the Young Toba Tuff layer, and thus contemporaneous with Toba's super-eruption, 74,000 years ago. The intra-test correlation of Zn and Mn patterns at the nanoscale with the layered calcareous microarchitecture, indicates that the incorporation of these metals is syngenetic to the wall growth. The preferential Mn and Zn sequestration within the incipient stages of chamber formation suggests a selective incorporation mechanism providing a resilience strategy to metal pollution in the test building of planktic foraminifers. Planktic foraminifers are one of the major constituents of calcium carbonate accumulated in pelagic seafloor sediments (30-80% of total deep-marine calcite budget), playing a crucial role in the carbon cycle and climate regulation 1,2. Their calcitic tests with intricate and beautiful morphologies are easily preserved in marine sedi-mentary records and constitute an invaluable archive of past environmental and climatic conditions. The trace metal contents of these tests are widely used as palaeoceanographic and palaeoclimatic proxies, since metal incorporation is strongly affected by the environmental conditions in which the organisms grew 3. Differences in trace element contents between calcitic foraminifer tests and inorganic calcite precipitated in the same seawater conditions show that biological processes play an important role in metal incorporation 4. A detailed examination of trace metal distribution within the shell walls may help in identifying the biological processes controlling their incorporation. The most studied and emblematic example is the Mg/Ca paleothermometer proxy, whose intra-test micro-distribution displays a typical banding pattern in calcareous perforate foraminifers, which include planktic and benthic species. Different biological processes have been proposed to explain it 5-8. It has been shown that Mg incorporation for some planktic foraminifer species is diurnally paced and modulated by light-dark cyclicity 7,8 and is assumed to be related to physiological processes, such as symbiont photosynthesis or respiration, that affect the carbonate chemistry at the site of calcification 5 , or to a mitochondrial uptake of Mg 7. In addition to Mg, banding patterns of other minor and trace elements (Na, Sr, K, S, P, N, B, Mn) have also been displayed from culture experiments or found in live calcareous perforate foraminifers retrieved from natural seawater environments 9-13. This study aims to unravel the intra-test multi-intake of trace metals, such as Mn and Zn, into planktic foraminifera tests. As Mn and Zn contents in foraminifers reflect the availability of free Mn 2+ and Zn 2+ in open
&amp;amp;amp;amp;lt;p&amp;amp;amp;amp;gt;&amp;amp;amp;amp;lt;strong&amp;amp;amp;a... more &amp;amp;amp;amp;lt;p&amp;amp;amp;amp;gt;&amp;amp;amp;amp;lt;strong&amp;amp;amp;amp;gt;Biogeochemical disruptions across the Cretaceous-Paleogene boundary : insights from sulfur isotopes&amp;amp;amp;amp;lt;/strong&amp;amp;amp;amp;gt;&amp;amp;amp;amp;lt;/p&amp;amp;amp;amp;gt;&amp;amp;amp;amp;lt;p&amp;amp;amp;amp;gt;&amp;amp;amp;amp;amp;#160;&amp;amp;amp;amp;lt;/p&amp;amp;amp;amp;gt;&amp;amp;amp;amp;lt;p&amp;amp;amp;amp;gt;Arbia JOUINI&amp;amp;amp;amp;lt;sup&amp;amp;amp;amp;gt;1*&amp;amp;amp;amp;lt;/sup&amp;amp;amp;amp;gt;, Guillaume PARIS&amp;amp;amp;amp;lt;sup&amp;amp;amp;amp;gt;1&amp;amp;amp;amp;lt;/sup&amp;amp;amp;amp;gt;, Guillaume CARO&amp;amp;amp;amp;lt;sup&amp;amp;amp;amp;gt;1&amp;amp;amp;amp;lt;/sup&amp;amp;amp;amp;gt;, Annachiara BARTOLINI&amp;amp;amp;amp;lt;sup&amp;amp;amp;amp;gt;2&amp;amp;amp;amp;lt;/sup&amp;amp;amp;amp;gt;&amp;amp;amp;amp;lt;/p&amp;amp;amp;amp;gt;&amp;amp;amp;amp;lt;p&amp;amp;amp;amp;gt;&amp;amp;amp;amp;lt;sup&amp;amp;amp;amp;gt;1 &amp;amp;amp;amp;lt;/sup&amp;amp;amp;amp;gt;Centre de Recherches P&amp;amp;amp;amp;amp;#233;trographiques et G&amp;amp;amp;amp;amp;#233;ochimiques, CRPG-CNRS, UMR7358, ,15 rue Notre Dame des Pauvres, BP20, 54501Vandoeuvre-l&amp;amp;amp;amp;amp;#232;s-Nancy, France, email:Arbia.jouini@univ-lorraine.Fr&amp;amp;amp;amp;lt;/p&amp;amp;amp;amp;gt;&amp;amp;amp;amp;lt;p&amp;amp;amp;amp;gt;&amp;amp;amp;amp;lt;sup&amp;amp;amp;amp;gt;2&amp;amp;amp;amp;lt;/sup&amp;amp;amp;amp;gt; Mus&amp;amp;amp;amp;amp;#233;um National D&amp;amp;amp;amp;amp;#8217;Histoire Naturelle, D&amp;amp;amp;amp;amp;#233;partement Origines &amp;amp;amp;amp;amp; Evolution, CR2P MNHN, CNRS, Sorbonne Universit&amp;amp;amp;amp;amp;#233;, 8 rue Buffon CP38, 75005 Paris, France&amp;amp;amp;amp;lt;/p&amp;amp;amp;amp;gt;&amp;amp;amp;amp;lt;p&amp;amp;amp;amp;gt;&amp;amp;amp;amp;amp;#160;&amp;amp;amp;amp;lt;/p&amp;amp;amp;amp;gt;&amp;amp;amp;amp;lt;p&amp;amp;amp;amp;gt;The Cretaceous&amp;amp;amp;amp;amp;#8211;Paleogene (KPg) mass extinction event 66 million years ago witnessed one of the &amp;amp;amp;amp;amp;#8216;Big Five&amp;amp;amp;amp;amp;#8217; mass extinctions of the Phanerozoic. Two major catastrophic events, the Chicxulub asteroid impact and the Deccan trap eruptions, were involved in complex climatic and environmental changes that culminated in the mass extinction including oceanic biogenic carbonate crisis, sea water chemistry and ocean oxygen level changes. Deep understanding of the coeval sulfur biogeochemical cycle may help to better constrain and quantify these parameters.&amp;amp;amp;amp;lt;/p&amp;amp;amp;amp;gt;&amp;amp;amp;amp;lt;p&amp;amp;amp;amp;gt;Here we present the first stratigraphic high resolution isotopic compositions of carbonate associated sulfate (CAS) based on monospecific planktic and benthic foraminifers&amp;amp;amp;#39; samples during the Maastrichtian-Danian transition from IODP pacific site 1209C. Primary &amp;amp;amp;amp;amp;#948;34SCAS data suggests that there was a major perturbation of sulfur cycle around the KPg transition with rapid fluctuations (100-200kyr) of about 2-4&amp;amp;amp;amp;amp;#8240; (&amp;amp;amp;amp;amp;#177;0.54&amp;amp;amp;amp;amp;#8240;, 2SD) during the late Maastrichtian followed by a negative excursion in &amp;amp;amp;amp;amp;#948;34SCAS of 2-3&amp;amp;amp;amp;amp;#8240; during the early Paleocene.&amp;amp;amp;amp;lt;/p&amp;amp;amp;amp;gt;&amp;amp;amp;amp;lt;p&amp;amp;amp;amp;gt;An increase in oxygen levels associated with a decline in organic carbon burial, related to a collapse in primary productivity, may have led to the early Paleocene &amp;amp;amp;amp;amp;#948;34SCAS negative shift via a significant drop in microbial sulfate reduction. Alternatively, Deccan volcanism could also have played a role and impacted the sulfur cycle via direct input of isotopically light sulfur to the ocean. A revised correlation between &amp;amp;amp;amp;amp;#948;34SCAS data reported in this study and a precise dating of the Deccan volcanism phases would allow us to explore this hypothesis.&amp;amp;amp;amp;lt;/p&amp;amp;amp;amp;gt;&amp;amp;amp;amp;lt;p&amp;amp;amp;amp;gt;Keywords : KPg boundary, Sulphur cycle, cycle du calcium, Planktic and benthic foraminifera&amp;amp;amp;amp;lt;/p&amp;amp;amp;amp;gt;&amp;amp;amp;amp;lt;p&amp;amp;amp;amp;gt;&amp;amp;amp;amp;amp;#160;&amp;amp;amp;amp;lt;/p&amp;amp;amp;amp;gt;
The Early Jurassic (late Pliensbachian to early Toarcian) was a period marked by extinctions, cli... more The Early Jurassic (late Pliensbachian to early Toarcian) was a period marked by extinctions, climate fluctuations, and oceanic anoxia. Although the causes of the early Toarcian Oceanic Anoxia Event (OAE) have been fairly well studied, the events that lead to the Toarcian OAE, i.e. the events in the late Pliensbachian, have not been well constrained. Scenarios of the driving mechanism of biotic and environmental changes of the late Pliensbachian have ranged from LIP volcanism (the Karoo-Ferrar LIP), ocean stagnation, and changing ocean circulation, to orbital forcing. The temporal relationship between the Karoo LIP and the late Pliensbachian (Kunae-Carlottense ammonite Zones) are investigated in an effort to evaluate a causal relationship. We present the first absolute timescale on the Kunae and Carlottense Zones based on precise high-precision U-Pb geochronology, and additional geochemical proxies, for a range of environmental proxies such as bulk organic carbon isotope composition...
<i>Sindhochelys ragei</i> n. gen., n. sp. (Figs 2-9) urn:lsid:zoobank.org:act: EC548A... more <i>Sindhochelys ragei</i> n. gen., n. sp. (Figs 2-9) urn:lsid:zoobank.org:act: EC548A31-BD5A-478D-83D7-266EE85C9186 TYPE MATERIAL. — Holotype, a shell, CPAG-RANKT-V-3. The final repository of the fossil material reported here is the Centre for Pure and Applied Geology (CPAG), University of Sindh, Jamshoro, Pakistan. High-resolution casts are housed at the Muséum national d'Histoire naturelle, Paris. DIAGNOSIS. — For monotypic genus and species. A bothremydid turtle defined by the ornamentation of the shell consisting of raised well protruding polygons but, unlike other ornamented forms such as Taphrosphyini and <i>Carteremys leithii</i>, in having conjoined rather larger irregular polygons without a clear net of granulations, polygons clearly but irregularly protruding and either elongated or regularly polygonal, or open in dichotomic sulci at places. Sharing with <i>Elochelys perfecta</i>, <i>Carteremys</i> group, " <i>Carteremys</i> " <i>pisdurensis</i>, and Taphrosphyini the generalized plastral anterior lobe scute pattern of a long intergular, separating narrower and shorter gulars, and widely reaching the pectorals, intergular also separating the thus narrowed humerals; but: humero-intergularo-pectoral sulcus crossing the entoplastron at the 2nd anterior third of its length, its humero-pectoral part posterior to the epi-hyoplastral suture in its median width, but close to it and laterally joining it, contrarily to <i>E. perfecta</i> where it is completely anterior to the suture, contrarily to " <i>C.</i> " <i>pisdurensis</i> where it is medially anterior to the suture and lateroposteriorly inclined much posteriorly to the suture, and contrarily to Taphrosphyini and the <i>Carteremys</i> group where it does not cross the suture; intergularo-pectoral sulcus relatively transverse on the entoplastron, as in the <i>Carteremys</i> group, not being medially inclined in a marked V contrarily to <i>E. perfecta</i>, " <i>C.</i> " <i>pisdurensis</i> and Taphrosphyini. Bothremydid carapace low with well-inclined bridges [...]
FIG. 10. — Fragmentary part of a carapace of an undetermined Bothremydidae, from the Paleocene of... more FIG. 10. — Fragmentary part of a carapace of an undetermined Bothremydidae, from the Paleocene of Ranikot, locality K18-12, CPAG-RANKT-V4, Southern Pakistan: A, B, ventral and dorsal views; C, detail of the dorsal decoration. Abbreviations: cost3, costal 3; cost5, costal 5; pcs, suture of the peripheral border with the border of plastral processes; per 5-8, peripherals 5, 6, 7, 8; perf, pholad perforations. Scale bars: A, B, 4 cm; C, 1 cm.
FIG. 8. — Sindhochelys ragei n. gen., n. sp., holotype CPAG-RANKT-V-3, from the Paleocene of Rani... more FIG. 8. — Sindhochelys ragei n. gen., n. sp., holotype CPAG-RANKT-V-3, from the Paleocene of Ranikot, locality K18-12, Southern Pakistan. A-D, decoration in various parts of the shell: A, isolated piece with the imprint of the mesoplastral external surface; B, marginal part of peripheral 10, dorsal view; C, left costal 1 part, posterior border at mid-width, dorsal view; D, a costal lateral border, in dorsal view; E, right hyoplastral part, ventral view. Scale bar: 5 cm.
FIG. 7. — Sindhochelys ragei n. gen., n. sp., holotype CPAG-RANKT-V-3, from the Paleocene of Rani... more FIG. 7. — Sindhochelys ragei n. gen., n. sp., holotype CPAG-RANKT-V-3, from the Paleocene of Ranikot, locality K18-12, Southern Pakistan. Medioanterior part of the shell, the nuchal being removed, showing a part of the dorsal face of the anterior lobe with the sulci limiting the overlapping scales. Scale bar: 5 cm.
FIG. 4. — Sindhochelys ragei n. gen., n. sp., holotype CPAG-RANKT-V-3, from the Paleocene of Rani... more FIG. 4. — Sindhochelys ragei n. gen., n. sp., holotype CPAG-RANKT-V-3, from the Paleocene of Ranikot, locality K18-12, Southern Pakistan: A, B, shell drawings, in dorsal (A) and ventral (B) views. Scale bars: 10 cm.
FIG. 5. — Sindhochelys ragei n. gen., n. sp., holotype CPAG-RANKT-V-3, from the Paleocene of Rani... more FIG. 5. — Sindhochelys ragei n. gen., n. sp., holotype CPAG-RANKT-V-3, from the Paleocene of Ranikot, locality K18-12, Southern Pakistan: A, anterolateral part of the carapace after removal of a part of the costal 1 with part of the neural l and the costal 2, to show the imprints of the thoracic ribs 1 and 2, and axillary buttress, in dorsal view; B, same removed part in ventral view. Abbreviations: ax b, axillary buttress; cost 1, costal 1; n1, neural 1; nu, nuchal; per 2, peripheral 2; rib 1, rib 2, medial part of thoracic ribs 1 and 2. Scale bar: 4 cm.
From the Guajira Desert to the Apennines, and from Mediterranean Microplates to the Mexican Killer Asteroid: Honoring the Career of Walter Alvarez, 2022
The reduced Jurassic sedimentary sequences deposited on a structural high in the Umbria-Marche Ap... more The reduced Jurassic sedimentary sequences deposited on a structural high in the Umbria-Marche Apennines, as well their relationships with adjacent expanded basinal sequences, have been reconstructed through detailed, interdisciplinary study of the Sasso di Pale and Monte Serrone areas near Foligno, Italy. The physiographic features of the basin originated in the Early Jurassic (latest early Pliensbachian), when extensional tectonic activity broke up a shallow water platform where the Calcare Massiccio had been deposited, and the area evolved from an edge-stepped structural high to a distally steepened ramp. The biostratigraphic framework of this paper is mainly based on calcareous nannofossils, which are a useful tool for dating condensed Jurassic successions. Although the sections studied have limited thickness and much lateral facies variation, the sedimentary evolution can be traced and interpreted within a wider Jurassic environmental perspective. In the upper Pliensbachian–low...
FIG. 5. — Comparison of extant and extinct Neocallichirus chelipeds:A, major male P1 chela of Neo... more FIG. 5. — Comparison of extant and extinct Neocallichirus chelipeds:A, major male P1 chela of Neocallichirus karumba (Poore & Griffin,1979) (A1), N. lakhraensis Hyžný & Charbonnier, n. sp., holotype CPAG.RAN.I.64 (A2) and N. khadroensis Hyžný & Charbonnier, n. sp., holotype CPAG.RAN.I.55 (A3); B, major P1 carpus of N. karumba (B1) and N. lakhraensis Hyžný & Charbonnier, n. sp., paratype CPAG.RAN.I.69 (B2); C, major P1 merus of N. karumba (C1), N. khadroensis Hyžný & Charbonnier, n. sp., paratype CPAG.RAN.I.63 (C2) and N. lakhraensis Hyžný & Charbonnier, n. sp., paratype CPAG.RAN.I.69 (C3); D, major female P1 chela of N. karumba (D1), N. lakhraensis Hyžný & Charbonnier, n. sp., paratype CPAG.RAN.I.66 (D2) and N. khadroensis Hyžný & Charbonnier, n. sp., paratype CPAG.RAN.I.59 (D3); E, minor P1 cheliped of N. karumba (E1) and N. lakhraensis Hyžný & Charbonnier,n. sp., paratype CPAG.RAN.I.72 (E2). Specimens of N. karumba are deposited under NHMW 21937 (male) and NHMW 21938 (female). Pho...
FIG. 6. — A-C, Neocallichirus borensis Beschin, De Angeli, Checchi & Mietto, 2006; A, B, holotype... more FIG. 6. — A-C, Neocallichirus borensis Beschin, De Angeli, Checchi & Mietto, 2006; A, B, holotype MCZ 2423; C, MCZ 2427; D-G, Neocallichirus tuberculatus (Lőrenthey in Lőrenthey & Beurlen, 1929) n. comb.; D-F, syntypes MFGI E.9465; H, Neocallichirus lakhraensis Hyžný & Charbonnier, n. sp., holotype CPAG. RAN.I.64; I, Neocallichirus khadroensis Hyžný & Charbonnier, n. sp., holotype CPAG.RAN.I.55; J-L, Neocallichirus maximus (A. Milne-Edwards, 1870). Photographs: M. Hyžný (A-F), and L. Cazes and P. Loubry (H-I). Scale bar: A-I, 10 mm. J-L, not to scale.
Logging data are measurements of physical properties of the formation surrounding a borehole, acq... more Logging data are measurements of physical properties of the formation surrounding a borehole, acquired in situ after completion of coring (wireline logging) or during drilling (Logging-While-Drilling, LWD). The range of data (resistivity, gamma radiation, velocity, density, borehole images,…) in any hole depends on the scientific objectives and operational constraints.
Bioactive metal releases in ocean surface water, such as those by ash falls during volcanic super... more Bioactive metal releases in ocean surface water, such as those by ash falls during volcanic super-eruptions, might have a potentially toxic impact on biocalcifier planktic microorganisms. Nano-XRF imaging with the cutting-edge synchrotron hard X-ray nano-analysis ID16B beamline (ESRF) revealed for the first time a specific Zn- and Mn-rich banding pattern in the test walls of Globorotalia menardii planktic foraminifers extracted from the Young Toba Tuff layer, and thus contemporaneous with Toba’s super-eruption, 74,000 years ago. The intra-test correlation of Zn and Mn patterns at the nanoscale with the layered calcareous microarchitecture, indicates that the incorporation of these metals is syngenetic to the wall growth. The preferential Mn and Zn sequestration within the incipient stages of chamber formation suggests a selective incorporation mechanism providing a resilience strategy to metal pollution in the test building of planktic foraminifers.
The Thuoux and Saint-Pierre d’Argencon sections (Subalpine Basin, southeastern France) are propos... more The Thuoux and Saint-Pierre d’Argencon sections (Subalpine Basin, southeastern France) are proposed as a potential GSSP candidate for the Callovian–Oxfordian boundary. Several aspects of stratigraphy that have recently been applied in the two selected sections are discussed, including ammonite and nannofossil biostratigraphy, palynology, physical stratigraphy, and cyclostratigraphy.
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