摘要: |
干容重是沉积学研究中用于计算物质通量的一个重要参量,对于正确认识沉积物的收支平衡、源汇通量以及地貌演化等问题具有重要意义。然而,干容重的分析流程和计算方法仍然缺乏统一的规范,导致干容重的取值不尽合理,影响了沉积学研究的定量化和精准度,这个问题需要引起足够的重视。本文选取了东海内陆架的表层沉积物和柱状沉积物,运用实验测试和间接公式计算两种方法获得了沉积物的干容重,对比分析了两种方法的精准度。研究发现,东海内陆架的细颗粒沉积物的干容重的数值范围是1.1—1.5g/cm3;影响沉积物干容重的主要因素是沉积物的成分与粒度,前者通过颗粒态物质的密度起作用,后者通过孔隙度来影响。建议:干容重的分析测试工作应在采样后尽快完成;运用干容重进行沉积通量计算时,应根据沉积物的平均粒度和孔隙度的空间变化选择合适的数值,以获得更加合理的结果。 |
关键词: 干容重 平均粒径 孔隙度 沉积通量 |
DOI:10.11693/hyhz20191000200 |
分类号:P67 |
基金项目:国家自然科学基金,41876092号;国家杰出青年科学基金,41625021号;上海市教育委员会科研创新计划项目,2019-01-07-00-05-E00027号 |
附件 |
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DRY BULK DENSITY ANALYSIS FOR INNER SHELF SEDIMENTS OF THE EAST CHINA SEA AND ITS SEDIMENTARY IMPLICATIONS |
XUE Cheng-Feng, SHENG Hui, WEI Dong-Yun, YANG Yang, WANG Ya-Ping, JIA Jian-Jun
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State Key Laboratory of Estuarine and Coastal Research, School of Marine Sciences, East China Normal University, Shanghai 200241, China
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Abstract: |
Dry bulk density is often applied to calculate the flux as an important parameter, which has a great significance to understand sediment budget, source-sink fluxes, and geomorphologic evolutions. However, the test and analysis procedures of the previous studies on dry bulk density were lack of uniform norms and not taken seriously. In this paper, dry bulk density of surface sediments and core sediments from the inner shelf of the East China Sea was obtained by means of experimental test and indirect formula calculation. The accuracy of two methods was compared and analyzed to enhance the quantitation and accuracy in sedimentary research. The general value of dry bulk density was determined to be 1.1—1.5g/cm3 for fine particulate matter sediments in the inner shelf of the East China Sea. The main factors affecting dry bulk density were the mineral composition and grain size of the sediments. The former affected by the density of mineral compositions, while the latter affected the porosity. Therefore, the test of dry bulk density should be completed as soon as possible after sampling. In order to accurately estimate the sediment flux, appropriate dry bulk density should be calculated based on the spatial variation of the main grain size and the porosity of sediments. |
Key words: dry bulk density mean grain size porosity sediment flux |