北部湾沉积物粘土矿物分布特征及其环境意义  

Distribution Features of Clay Mineral of Sediments in the Beibu Gulf and Their Environmental Significance

作　　者：何海军[1] 甘华阳[1] 石要红[1] 刘文涛[1] 

机构地区：[1]国土资源部海底矿产资源重点实验室,广州海洋地质调查局,广东广州510075

出　　处：《地质与勘探》2016年第3期584-593,共10页Geology and Exploration

基　　金：中国地质调查局项目“南海北部湾全新世环境演变及人类活动影响研究”(编号:1212010914027)资助

摘　　要：本文以南海北部湾SO-31沉积柱为研究对象，研究了14C年代学和粘土矿物学特征，并对部分全王拉气候事件进行了对比，为古环境、古气候的恢复提供基础资料，也为全球重大气候事件在该区域的响应提供信息。结果显示全新世以来地层沉积正常，平均沉积速率为0．57mm／a。粘土成分主要由蒙脱石、伊利石、高岭石和绿泥石组成，组合类型为蒙脱石一伊利石一高岭石一绿泥石型。全新世以来环境气候演变可划分为五个阶段：低温期阶段、干湿交替的寒冷气候阶段、逐渐升温阶段、干旱温暖气候阶段、湿热阶段。气候在每个阶段背号下还存在一些次级波动，总体趋势为干湿交替，温度逐渐上升。由于海域环境及矿物指标的影响，北部湾SO-31沉积柱粘土矿物记录的降温事件时间比其他指标记录的新仙女木降温事件发生时间滞后500～800a。This study focuses on 14C chronology and clay mineralogy of SO -31 sedimentary cores in the Beibu Gulf of the South China Sea. It also compares part of global climate events. The purpose is o provide basic information for paleoenvironmental and paleoclimatic recovery, as well as global cli- mate event response in this region. The results show that the sedimentary strata was normal with an average deposition rate of 0.57mm/a in Holocene. The main clay minerals are smectite, illite, kaolinite and chlorite. Clay minerals comprise the combination of smectite-illite- kaolinite-chlorite. The palaeocli- mate of Beibu Gulf has experienced five stages since Holocene： relatively cold period, alternating wet and dry cold period, gradually heating period, arid warm period,and wet-hot period. In addition, the clay mineral indexes also recorded several sub cold-warm changes under the background of five main pe- riods. The trend of climate change was alternating wet and dry, and the temperature rose gradually. Due to the marine environment and mineral indica- tors, the time of cooling events recorded by clay minerals in SO -31 Beibu Gulf were 500 -800 years later than the time of YD cooling events which were recorded by other indicators.

关 键 词：粘土矿物 分布特征 环境意义 沉积速率 北部湾 

分 类 号：P66[天文地球—地质学]