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对太平洋中部MP2001-01站位柱状样品中可溶有机质(氯仿沥青“A”)、有机碳、生物标志物(正构烷烃、类异戊二烯烃)、化学元素含量和比值[Al、Fe、Ti、Ba、Ba(bio)、Al/Ti和Ba(bio)/Ba]进行了分析和研究,结果显示:(1)柱状样品中可溶有机质含量为(0.074~0.265)×10-3;饱和烃含量为(0.008~0.032)×10-3,占族组成的9.40%~19.20%;芳烃含量为(0.017~0.051)×10-3,占族组成的15.23%~25.54%;非烃含量为(0.037~0.146)×10-3,占族组成的40.67%~56.21%;沥青质含量为(0.011~0.049)×10-3,占族组成的13.51%~23.97%。沉积地层中饱和烃和芳烃含量较低,非烃含量占优势,沉积物的物性呈现出典型的低成熟特征。(2)正构烷烃碳分子数分布范围大多为nC14~nC34,并多呈双峰群分布,主峰碳(MH)大多为nC17~nC19和nC27~nC29,轻、重烃比值(nC2-3/nC2+4)为0.631~0.950;碳优势指数(CPI)为0.983~1.382,显示出沉积物为海洋藻类、浮游生物、细菌和少量陆源高等植物的混合来源;样品中类异戊二烯烃中的姥鲛烷/植烷(Pr/Ph值)在沉积表层(0~1 cm)为最低,随着埋藏深度的增加,该比值有增高的趋势,尤其在8~11 cm和26~29 cm处,该比值达最高,表明此时的氧化程度为最高,指示了所在研究海域经历了还原—弱氧化—氧化—强氧化的大洋沉积环境,显示出该区沉积物在漫长的地质历史时期大多处于氧化环境中。沉积介质的氧化还原强度主要取决于底层水的氧浓度,因此沉积氧化还原条件的演化是推断南极底层流活动的一个重要线索。(3)样品中的有机碳、烷烃总量、nC2-3/nC2+3值、化学元素及其比值[Al、Fe、Ti、Ba、Ba(bio)、Al/Ti和Ba(bio)/Ba]在14 cm层位处均发生突变,暗示着在这一地质时期中曾有过明显的沉积环境变异,这种变化对大洋生物有强烈的影响;气候变化指数Al/Ti显示出,14 cm层位处的上半部比下半部沉积时的气候明显温暖,揭示了沉积环境的变异与古气候的关系。
The contents of soluble organic matter (chloroform bitumen “A ”), organic carbon, biomarkers (n-paraffins, isoprenoids), chemical element contents and ratios in the column of MP2001-01 in the central Pacific Ocean [Al, Fe, Ti, Ba, Ba (bio), Al / Ti and Ba (bio) / Ba] were analyzed and studied. The results showed that the content of soluble organic matter in columnar sample was (0.074-0.265) 3; the content of saturated hydrocarbons is (0.008 ~ 0.032) × 10-3, accounting for 9.40% -19.20% of the total; the content of aromatics is (0.017 ~ 0.051) × 10-3, accounting for 15.23% ~ 25.54% The hydrocarbon content is from 0.037 to 0.146 × 10-3, accounting for 40.67% to 56.21% of the total composition. The asphaltene content is from 0.011 to 0.049 × 10-3, accounting for 13.51% to 23.97% of the total. The content of saturated hydrocarbons and aromatics in the sedimentary strata is lower, and the non-hydrocarbon content is dominant. The physical properties of sediments show typical low-mature characteristics. (2) The n-alkane carbon number distribution ranges mostly from nC14 to nC34, and is mostly bimodal with the main peak carbon (nM) being nC17 ~ nC19 and nC27 ~ nC29. The ratio of light and heavy hydrocarbons (nC2-3 / nC2 +4) was 0.631-0.950, and the carbon dominance index (CPI) was 0.983-1.382, indicating that the sediment was a mixed source of marine algae, plankton, bacteria and a few terrestrial higher plants. The pristane / phytane (Pr / Ph) was the lowest in the sedimentary surface (0-1 cm), and the ratio increased with the burial depth, especially at 8-11 cm and 26-29 cm , Indicating the highest degree of oxidation at this time, indicating that the study area underwent the reduction-weak oxidation-oxidation-strong oxidation of the ocean sedimentary environment, indicating that the sediments in the region during the long geological history mostly in Oxidative environment. The redox strength of the deposition medium depends mainly on the oxygen concentration of the bottom water. Therefore, the evolution of deposition redox conditions is an important clue to infer the laminar flow in the Antarctic. (3) Total organic carbon, total alkanes, nC2-3 / nC2 +3 values, chemical elements and their ratios [Al, Fe, Ti, Ba, Ba (bio), Al / Ti and Ba Ba] all mutated at the 14 cm horizon suggesting that significant sedimentary environmental variation had been observed during this geological period, and this change had a strong effect on marine life. The climate change index Al / Ti showed that 14 The upper half of the cm layer was significantly warmer than the lower half, revealing the relationship between the variation of sedimentary environment and paleoclimate.