DOI: 10.1016/j.palaeo.2013.02.034
论文题名: Variations in deep-sea benthic foraminifera at ODP Hole 756B, southeastern Indian Ocean: Evidence for changes in deep ocean circulation
作者: Verma S. ; Gupta A.K. ; Singh R.K.
刊名: Palaeogeography, Palaeoclimatology, Palaeoecology
ISSN: 0031-0182
出版年: 2013
卷: 376 起始页码: 172
结束页码: 183
语种: 英语
英文关键词: Antarctic Circumpolar Current
; Antarctic Intermediate Water
; Deep-sea benthic foraminifera
; Southeastern Indian Ocean
英文摘要: Seventy three core samples of 10. cc volume were analysed from Ocean Drilling Program (ODP) Site 756, Hole B with an average interval of 236. kyr per sample. Factor and cluster analyses of 37 high ranking species of benthic foraminifera enabled us to identify four clusters representing four biofacies. Biofacies Sl-Om is characterised by Stilostomella lepidula, Orthomorphina modesta, Robulus gibbus, Bulimina miolaevis and Cibicides cf. lucidus. This biofacies dominates the latest Oligocene to early Miocene interval (24-21. Ma and 18.75-16.5. Ma), indicating low to intermediate dissolved oxygen, organic carbon rich environment, warm and sluggish deep waters. During 21-18.75. Ma, the biofacies Gp-Nu (Globocassidulina pacifica, Nuttallides umbonifera, Trifarina angulosa, Quinqueloculina weaveri, Robulus gibbus and Pullenia bulloides) dominates the benthic assemblage at Hole 756B. This biofacies also has a short lived presence at ~. 16.5. Ma. This was an interval of intense circulation of cold and corrosive deep water similar to Antarctic Intermediate Water (AAIW), and intermediate to high flux of organic matter to Hole 756B. The Antarctic Circumpolar Current (ACC) initiated during this time. From 16.5 to 10.6. Ma, the benthic assemblage at Hole 756B is dominated by biofacies Ub-Gs (characteristic species Uvigerina buzasi, Globocassidulina subglobosa, Laticarina pauperata), indicating intermediate to high food supply and cold deep water. This interval coincides with the middle Miocene positive oxygen isotope shift and permanent build up of Antarctic ice sheets. The late Miocene interval (10.6-6.5) is characterised by biofacies Ec-Bs (dominant species Ehrenbergina carinata, Bolivina spathulata, Osangularia culter and Pullenia osloensis) indicating low oxygen condition with high food supply in the study area. This corresponds to an interval of global biogenic bloom.© 2013 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/69766
Appears in Collections: 过去全球变化的重建
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作者单位: Department of Geology and Geophysics, Indian Institute of Technology, Kharagpur, 721302, India; Wadia Institute of Himalayan Geology, 33 GMS Road, Dehradun, 248001, India
Recommended Citation:
Verma S.,Gupta A.K.,Singh R.K.. Variations in deep-sea benthic foraminifera at ODP Hole 756B, southeastern Indian Ocean: Evidence for changes in deep ocean circulation[J]. Palaeogeography, Palaeoclimatology, Palaeoecology,2013-01-01,376