ridm@nrct.go.th   ระบบคลังข้อมูลงานวิจัยไทย   รายการโปรดที่คุณเลือกไว้

Trace Metals And Organic Matter Diagenesis At The Oman Margin

หน่วยงาน National Institute Of Oceanography (NIO), India

รายละเอียด

ชื่อเรื่อง : Trace Metals And Organic Matter Diagenesis At The Oman Margin
นักวิจัย : Alagarsamy, R.
คำค้น : Deep Sea Sediments , Organic Matter Diagenesis , Diagenetic Processes , Trace Metals
หน่วยงาน : National Institute Of Oceanography (NIO), India
ผู้ร่วมงาน : Chester, R.
ปีพิมพ์ : 2540
อ้างอิง : Ph.D. thesis, University of Liverpool,UK- National Institute of Oceanography, Goa, India; 248pp , http://drs.nio.org/drs/handle/2264/131
ที่มา : -
ความเชี่ยวชาญ : -
ความสัมพันธ์ : -
ขอบเขตของเนื้อหา : -
บทคัดย่อ/คำอธิบาย :

Trace Metals (e.g. Mn and Fe) play an important role as secondary oxidants in the degradation of sedimentary OM under sub-oxic conditions. Hence the remineralisation of organic constituents of sediments in the marine environment may significantly control the diagenetic behaviour of a number of trace metals and their cycling and subsequent release to overlying waters. Although, these reactions have been investigated thoroughly in marine sediments, their relationship with the diagenesis of OM has not been directly established. Hence, a study of the diagenesis of OM and trace metals in sediments from the Oman Margin (Arabian Sea) has been undertaken in order to gain an understanding of the relationship between the biogeochemistry of OM and redox-sensitive trace metals. To the best of the knowledge of this author, few recorded studies of trace metal speciation and its association with organic matter in Arabian Sea sediments exist. This study is the first of its kind of organic-rich sediments and attempts to assess the manner in which the degradation of individual organic components affects the solid state speciation of trace metals in the sediments of the Oman Margin (Arabian Sea). To this purpose, two ‘diagenetically-active’ sediment cores from the Oman Margin (abyssal site) and three replicate sediment cores from the shallow environment i.e. most intense part of the OMZ site have been analysed for trace metals Fe, Mn and Cu along with OM constituents such as TOC, TN, THAA and THCH and other bulk parameters. Data for all these are presented in an appendix. The abyssal sediments chosen for this study were influenced by a sandy turbidite, having 3 units on the basis of their sedimentology and geochemistry. The solid state speciation of the non-detrital fractions revealed that Mn spike is a classic feature in the diagenesis of Mn, and the present study has shown that it is composed of ‘new’ Mn3 oxides. There are no other clearly defined relationships in the solid state speciation of ‘aged’ oxides of Mn4, Fe4 and Cu4 that can be defined as being diagenetically-mediated. There was no relationship between OM parameters and Mn (or Fe) solid state speciation, presumably reflecting the complete removal of ‘new’oxides from the deeper sediments. The shallow environment of the most intense part of OMZ sites contrasted with the abyssal sites. There was no detectable non-detrital Mn in these cores due to the lack of Mn3 ‘new’ oxides precipitation in surficial sediments and the reduction and export of any Mn4 ‘aged’ oxides. There were no other clearly defined relationships in the solid state speciation of ‘aged’ oxides of Fe4, that could be defined as being diagenetically-mediated. Differences in OM parameters were linked to the distinct compositions of the cores and the sources of the OM to the cores were complex. Surprisingly, and in contrast with other productive environments such as the Peru Margin, there was little apparent diagenetic modification of OM with increasing sediment depth. There was no relationship between OM parameters and Mn (or Fe) solid state speciation, presumably reflecting in part the low diagenetic activity.

National Institute of Oceanography, Goa/CSIR, New Delhi

บรรณานุกรม :
Alagarsamy, R. . (2540). Trace Metals And Organic Matter Diagenesis At The Oman Margin.
    : National Institute Of Oceanography (NIO), India.
Alagarsamy, R. . 2540. "Trace Metals And Organic Matter Diagenesis At The Oman Margin".
    : National Institute Of Oceanography (NIO), India.
Alagarsamy, R. . "Trace Metals And Organic Matter Diagenesis At The Oman Margin."
    : National Institute Of Oceanography (NIO), India, 2540. Print.
Alagarsamy, R. . Trace Metals And Organic Matter Diagenesis At The Oman Margin. : National Institute Of Oceanography (NIO), India; 2540.