Planktic foraminifera from the Paleocene-Eocene Thermal Maximum at Shatsky Rise, Pacific Ocean
Cobertura |
MEDIAN LATITUDE: 32.437730 * MEDIAN LONGITUDE: 158.382645 * SOUTH-BOUND LATITUDE: 32.223660 * WEST-BOUND LONGITUDE: 158.259360 * NORTH-BOUND LATITUDE: 32.651800 * EAST-BOUND LONGITUDE: 158.505930 * DATE/TIME START: 2001-09-19T13:35:00 * DATE/TIME END: 2001-09-27T00:00:00 |
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Data(s) |
18/12/2007
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Resumo |
High-resolution biostratigraphic and quantitative studies of subtropical Pacific planktonic foraminiferal assemblages (Ocean Drilling Program, Leg 198 Shatsky Rise, Sites 1209 and 1210) are performed to analyse the faunal changes associated with the Paleocene-Eocene Thermal Maximum (PETM) at about 55.5 Ma. At Shatsky Rise, the onset of the PETM is marked by the abrupt onset of a negative carbon isotope excursion close to the contact between carbonate-rich ooze and overlying clay-rich ooze and corresponds to a level of poor foraminiferal preservation as a result of carbonate dissolution. Lithology, planktonic foraminiferal distribution and abundances, calcareous plankton and benthic events, and the negative carbon isotope excursion allow precise correlation of the two Shatsky Rise records. Results from quantitative analyses show that Morozovella dominates the assemblages and that its maximum relative abundance is coincident with the lowest delta 13C values, whereas subbotinids are absent in the interval of maximum abundance of Morozovella. The excursion taxa (Acarinina africana, Acarinina sibaiyaensis, and Morozovella allisonensis) first appear at the base of the event. Comparison between the absolute abundances of whole specimens and fragments of genera demonstrate that the increase in absolute abundance of Morozovella and the decrease of Subbotina are not an artifact of selective dissolution. Moreover, the shell fragmentation data reveal Subbotina to be the more dissolution-susceptible taxon. The upward decrease in abundance of Morozovella species and the concomitant increase in test size of Morozovella velascoensis are not controlled by dissolution. These changes could be attributed to the species' response to low nutrient supply in the surface waters and to concomitant changes in the physical and chemical properties of the seawater, including increased surface stratification and salinity. Comparison of the planktonic foraminiferal changes at Shatsky Rise to those from other PETM records (Sites 865 and 690) highlights significant similarities, such as the decline of Subbotina at the onset of the event, and discrepancies, including the difference in abundance of the excursion taxa. The observed planktonic foraminifera species response suggests a warm-oligotrophic scenario with a high degree of complexity in the ocean structure. |
Formato |
application/zip, 4 datasets |
Identificador |
https://doi.pangaea.de/10.1594/PANGAEA.672098 doi:10.1594/PANGAEA.672098 |
Idioma(s) |
en |
Publicador |
PANGAEA |
Direitos |
CC-BY: Creative Commons Attribution 3.0 Unported Access constraints: unrestricted |
Fonte |
Supplement to: Petrizzo, Maria Rose (2007): The onset of the Paleocene-Eocene Thermal Maximum (PETM) at Sites 1209 and 1210 (Shatsky Rise, Pacific Ocean) as recorded by planktonic foraminifera. Marine Micropaleontology, 63(3-4), 187-200, doi:10.1016/j.marmicro.2006.11.007 |
Palavras-Chave | #198-1209B; 198-1210B; A. africana; A. angulosa; A. aquiensis; A. coalingensis; A. decepta; A. esnaensis; A. mckannai; A. nitida; A. primitiva; A. rugosoaculeata; A. sibaiyaensis; A. soldadoensis; A. soldadoensis size; A. subsphaerica; Acarinina africana; Acarinina angulosa; Acarinina aquiensis; Acarinina coalingensis; Acarinina decepta; Acarinina esnaensis; Acarinina mckannai; Acarinina nitida; Acarinina primitiva; Acarinina rugosoaculeata; Acarinina sibaiyaensis; Acarinina soldadoensis; Acarinina soldadoensis, size average; Acarinina sp.; Acarinina subsphaerica; C. trinitatensis; C. wilcoxensis; Chiloguembelina trinitatensis; Chiloguembelina wilcoxensis; Counting >125 µm fraction; Counting >38 µm fraction; Depth; DEPTH, sediment/rock; DRILL; Drilling/drill rig; G. australiformis; G. imitata; G. luxorensis; G. ovalis; G. planoconica; Globanomalina australiformis; Globanomalina imitata; Globanomalina luxorensis; Globanomalina ovalis; Globanomalina planoconica; Globanomanlina australiformis; I. broedermanni; I. convexa; I. tadjikistanensis; Igorina broedermanni; Igorina convexa; Igorina tadjikistanensis; Joides Resolution; Label; Leg198; M. acuta; M. aequa; M. allisonensis; M. apanthesma; M. edgari; M. gracilis; M. occlusa; M. occlusa size; M. pasionensis; M. pasionensis size; M. subbotinae; M. subbotinae size; M. velascoensis; M. velascoensis size; Morozovella acuta; Morozovella aequa; Morozovella allisonensis; Morozovella apanthesma; Morozovella edgari; Morozovella gracilis; Morozovella occlusa; Morozovella occlusa, size average; Morozovella pasionensis; Morozovella pasionensis, size average; Morozovella sp.; Morozovella subbotinae; Morozovella subbotinae, size average; Morozovella velascoensis; Morozovella velascoensis, size average; North Pacific Ocean; Ocean Drilling Program; ODP; ODP sample designation; P. pseudoscitula; P. varianta; P. wilcoxensis; Parasubbotina sp.; Parasubbotina varianta; Planorotalites pseudoscitula; Pseudohastigerina wilcoxensis; S. eocenae; S. eocenica; S. hornibrooki; S. inaequispira; S. inaequispira size; S. triangularis; S. triangularis size; S. velascoensis; S. velascoensis size; Sample code/label; Subbotina eocaena; Subbotina eocenica; Subbotina hornibrooki; Subbotina inaequispira; Subbotina inaequispira, size average; Subbotina sp.; Subbotina triangularis; Subbotina triangularis, size average; Subbotina velascoensis; Subbotina velascoensis, size average; transition M. velascoensis-M. allisonensis; Turborotalia sp. |
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Dataset |