A COMPARISON OF LIGNIN AND STABLE CARBON ISOTOPE COMPOSITIONS IN QUATERNARY MARINE-SEDIMENTS
A COMPARISON OF LIGNIN AND STABLE CARBON ISOTOPE COMPOSITIONS IN QUATERNARY MARINE-SEDIMENTS
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DOI：
10.1016/0304-4203(82)90047-0
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发表时间：
1982-01-01
期刊：
影响因子：
3
通讯作者：
VANGEEN, A
中科院分区：
文献类型：
--
作者：
HEDGES, JI;VANGEEN, A
对4个墨西哥湾第四纪沉积岩心和1个美国华盛顿州海岸沉积岩心的有机质进行了木质素和稳定碳同位素组成分析。所有5个岩心的全新世层序都含有相对丰度较高的有机质13C(13C=-19.0~-22.5个/磨)。与PDB[Pee Dee Belemnite，13C/12C比值标准])和较低的木质素浓度，这两者都与海洋来源一致。明显较低的13C浓度(增量13C=-24.0至-25.5‰。)在5个岩心中的4个岩心中，包括华盛顿海岸的岩心，这种趋势以前没有报道过，在冰川时代的底层序列中发生了这种变化。尽管这些更新世沉积物的碳同位素组成是典型的陆源有机质，但它们只含有.apprx。在邻近大陆架的现代沉积物中发现的类似于13C的木质素的5%。冰河时代沉积物中的贫木素有机物似乎要么来自海洋，要么是陆源物质，很可能在沉积时在维管植物残留物中被耗尽。
Organic matter in 4 Quaternary sediment cores from the Gulf of Mexico and 1 core from the Washington State (USA) coast were analyzed for lignin and stable C isotope compositions. Holocene sequences of all 5 cores contain organic matter with high relative abundances of 13C (.delta.13C = -19.0 to -22.5.permill. vs. PDB [Pee Dee Belemnite, 13C/12C ratio standard]) and low lignin concentrations, both of which are consistent with a marine origin. Distinctly lower 13C concentrations (.delta.13C = -24.0 to -25.5.permill.) occur in underlying glacial-age sequences from 4 of the 5 cores, including the core from the Washington coast where such trends are previously unreported. Although the C isotopic compositions of these Pleistocene sediments are typical of predominantly land-derived organic matter, they contain only .apprx. 5% of the lignin found in modern sediments of similar .delta.13C from adjacent continental shelves. The lignin-poor organic matter in the glacial-age deposits appears to be either marine-derived or terrigenous material that likely was depleted in vascular plant debris at the time of deposition.