Geochemical and Nd isotopic investigations of sediments from the South China Sea
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| Format: | Dataset Open Access |
| Sprache: | en |
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PANGAEA
2003
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| author | Li, Xian-hua Wei, Gangjian Shao, Lei Liu, Ying Liang, Xirong Jian, Zhimin Sun, Min Wang, Pinxian |
| author_facet | Li, Xian-hua Wei, Gangjian Shao, Lei Liu, Ying Liang, Xirong Jian, Zhimin Sun, Min Wang, Pinxian |
| collection | Datos científicos de ciencias marinas y ambientales |
| contents | Secular variations in geochemistry and Nd isotopic data have been documented in sediment samples at ODP Site 1148 in the South China Sea. Major and trace elements show significant changes at ca. 29.5 Ma and 26-23 Ma, whereas epsilon-Nd values show a single change at ca. 26-23 Ma. Increases in Al/Ti, Al/K, Rb/Sr, and La/Lu ratios and a decrease in the Th/La ratio of the sediments beginning at 29.5 Ma are consistent with more intense chemical weathering in the source region. The abrupt change in Nd isotopes and geochemistry at ca. 26-23 Ma coincides with a major discontinuity in the sedimentology and physical properties of the sediments, implying a drastic change in sedimentary provenance and environment at the drill site. Comparison of the Nd isotopes of sediments from major rivers flowing into the South China Sea suggests that pre-27 Ma sediments were dominantly derived from a southwestern provenance (Indochina-Sunda Shelf and possibly northwestern Borneo), whereas post-23 Ma sediments were derived from a northern provenance (South China). This change in provenance from southwest to north was largely caused by ridge jumping during seafloor spreading of the South China Sea, associated with a southwestward expansion of the ocean basin crust and a global rise in sea level. Thus, the geochemical and Nd isotopic changes in the sediments at ODP Site 1148 are interpreted as a response to a major plate reorganization in SE Asia at ca. 25 Ma. |
| format | Dataset Open Access |
| id | pangaea_https___doi_org_10_1594_PANGAEA_713166 |
| institution | PANGAEA |
| language | en |
| publishDate | 2003 |
| publisher | PANGAEA |
| record_format | pangaea |
| spellingShingle | Geochemical and Nd isotopic investigations of sediments from the South China Sea Li, Xian-hua Wei, Gangjian Shao, Lei Liu, Ying Liang, Xirong Jian, Zhimin Sun, Min Wang, Pinxian 184-1144A; 184-1148; COMPCORE; Composite Core; DRILL; Drilling/drill rig; Joides Resolution; Leg184; Ocean Drilling Program; ODP; South China Sea Secular variations in geochemistry and Nd isotopic data have been documented in sediment samples at ODP Site 1148 in the South China Sea. Major and trace elements show significant changes at ca. 29.5 Ma and 26-23 Ma, whereas epsilon-Nd values show a single change at ca. 26-23 Ma. Increases in Al/Ti, Al/K, Rb/Sr, and La/Lu ratios and a decrease in the Th/La ratio of the sediments beginning at 29.5 Ma are consistent with more intense chemical weathering in the source region. The abrupt change in Nd isotopes and geochemistry at ca. 26-23 Ma coincides with a major discontinuity in the sedimentology and physical properties of the sediments, implying a drastic change in sedimentary provenance and environment at the drill site. Comparison of the Nd isotopes of sediments from major rivers flowing into the South China Sea suggests that pre-27 Ma sediments were dominantly derived from a southwestern provenance (Indochina-Sunda Shelf and possibly northwestern Borneo), whereas post-23 Ma sediments were derived from a northern provenance (South China). This change in provenance from southwest to north was largely caused by ridge jumping during seafloor spreading of the South China Sea, associated with a southwestward expansion of the ocean basin crust and a global rise in sea level. Thus, the geochemical and Nd isotopic changes in the sediments at ODP Site 1148 are interpreted as a response to a major plate reorganization in SE Asia at ca. 25 Ma. |
| title | Geochemical and Nd isotopic investigations of sediments from the South China Sea |
| topic | 184-1144A; 184-1148; COMPCORE; Composite Core; DRILL; Drilling/drill rig; Joides Resolution; Leg184; Ocean Drilling Program; ODP; South China Sea |
| url | https://doi.org/10.1594/PANGAEA.713166 |