Early diagenesis: impact of organic matter on mass physical properties and processes, California continental margin
Early diagenesis: impact of organic matter on mass physical properties and processes, California continental margin
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DOI：
10.1016/s0025-3227(99)00003-1
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发表时间：
1999-07-01
期刊：
影响因子：
2.9
通讯作者：
Lambert, MW
中科院分区：
文献类型：
--
作者：
Bennett, RH;Ransom, B;Lambert, MW
对加利福尼亚大陆坡沉积物（0-80 厘米）的高分辨率（2.5 毫米至亚微米尺度）跨学科研究揭示了海洋有机物质和矿物学对极早期成岩过程中细粒沉积物质量物理性质的重要性。有机材料（大于或等于 2 wt.%）与蒙脱石（大于或等于 5%）的组合与高沉积孔隙率、低有效应力、低孔隙率降低和脱水以及间质流体流动阻抗相关。通过透射电子显微镜和碳同位素研究揭示了影响物理性质的生物（微生物群）和非生物（粘多糖）有机物。使用雷德菲尔德比率的计算表明，含有高有机碳（大于或等于 5 wt.%）的沉积物在孔隙空间中具有“水合”有机物质，其体积可占沉积物总孔隙度的 20%。孔隙水化学和 X 射线衍射显示了可能显着影响沉积物结构的早期成岩过程的证据。沉积物-水界面附近影响沉积物结构的一个重要地球化学过程是生物蛋白石的快速溶解。 (C) 1999 Elsevier Science B.V. 保留所有权利。
High-resolution (scales of 2.5 mm to submicrometer), interdisciplinary studies of California continental slope sediments (0-80 cm) reveal the importance of marine organic material and mineralogy on mass physical properties in fine-grained sediments during very early diagenesis. The combination of organic material (greater than or equal to 2 wt.%) with smectite (greater than or equal to 5%) is associated with high depositional porosities, low effective stresses, low porosity reduction and dewatering, and the impedance of interstitial fluid flow. Living (microbiota) and nonliving (mucopolysaccharides) organic matter, affecting the physical properties, was revealed by transmission electron microscopy and carbon isotope studies. Calculations using the Redfield ratio show that sediments containing high organic carbon (greater than or equal to 5 wt.%) have 'hydrated' organic material in the pore spaces that can occupy a volume that is up to 20% of the total sediment porosity. Pore-water chemistry and X-ray diffraction show evidence of early diagenetic processes that may significantly influence sediment fabric. An important geochemical process near the sediment-water interface that affects sediment fabric is the rapid dissolution of biogenic opal. (C) 1999 Elsevier Science B.V. All rights reserved.