Biomineralization of organic matter in cobalt-rich crusts from the Marcus-Wake Seamounts of the western Pacific Ocean
Biomineralization of organic matter in cobalt-rich crusts from the Marcus-Wake Seamounts of the western Pacific Ocean
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DOI：
10.1007/s13131-014-0552-0
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发表时间：
2014-12
影响因子：
1.4
通讯作者：
Jun Zhao;Haisheng Zhang;Guanghai Wu;Bing Lu;I. Pulyaeva;Haifeng Zhang;Xuehui Pang
中科院分区：
文献类型：
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作者：
Jun Zhao;Haisheng Zhang;Guanghai Wu;Bing Lu;I. Pulyaeva;Haifeng Zhang;Xuehui Pang
通过对西太平洋马库斯-维克海山富钴结壳样品CM 1D 03中有机质的分析，探讨了富钴结壳中有机质的来源、地球化学特征、成矿作用及成矿环境。利用气相色谱（GC）和气相色谱-质谱（GC-MS）联用技术，在CRC样品的不同层中检测到了生物标志物，包括正构烷烃、类异戊二烯、萜烷和甾醇。有机碳（OC）及其稳定同位素（δ 13 C）的含量和生物标志物的组合特征表明，CM 1D 03 CRC矿化有机质主要来源于微生物和低等浮游生物（如细菌和藻类），从海洋表面水，与一些陆地高等植物成分。CRC中氯仿沥青“A”：OC比值较高，在10.51 ~ 20.66之间，表现出明显的正构烷烃运移特征。根据有机质正构烷烃的GC色谱图，将有机质矿化分为四种类型：（1）原始型（细菌和藻类），其特征是中等成熟的正构烷烃，保留了微生物和低等浮游生物有机质的原始特征;（2）微生物降解型，正构烷烃含量低，色谱基线上升，（3）有机质运移型，以主峰碳为nC 18的低碳数正构烷烃为主，无奇偶优势，类异戊二烯和高碳数烃含量低;（4）有机质热液型，以相对低浓度的小分子量正构烷烃、姥鲛烷和植烷为主，并伴有较高浓度的碳数大于18的正构烷烃。研究表明，生物标志物可以记录成矿控制因素及其变化。
Organic matter in cobalt-rich crust (CRC) from the Marcus-Wake Seamounts of the western Pacific Ocean, Sample CM1D03, has been analyzed to understand the source, geochemistry and mineralization of organic matter, and the mineralization environment. Biomarkers, includingn-alkanes, isoprenoids, terpanes and sterols, have been detected in various layers of the CRC sample, using gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). The content of organic carbon (OC) and its stable isotope (δ13C), and the combined features of the biomarkers show that the mineralized organic matter in CM1D03 CRC was mainly derived from microorganisms and lower plankton (e.g., bacteria and algae, respectively) from marine surface water, with some terrestrial higher plant components. The ratio of chloroform bitumen “A”: OC was high in the CRC, between 10.51 and 20.66, showing significant migration characteristics ofn-alkanes. Four mineralization categories of organic matter were recognized based on GC chromatograms ofn-alkane molecules: (1) primitive type (bacteria and algae), which is characterized by moderately mature ofn-alkanes preserving the original characteristics of the organic matter from microorganisms and lower plankton; (2) microbial degradation type, which is characterized by low contents ofn-alkanes and rising baseline in the chromatogram, with the “bulge” being the products of organic matter by biodegradation; (3) organic matter migration type, which is characterized by low carbon number ofn-alkanes withnC18as the main peak carbon, without odd even predominance, and low concentrations of isoprenoids and hydrocarbons with high carbon number; and (4) organic matter hydrothermal type, which is characterized by relatively low concentration of small molecular weightn-alkanes, pristane, and phytane, accompanied by higher concentration ofn-alkanes with carbon number greater thannC18. This study shows that biomarkers can record controlling factors of mineralization and their variation.