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合肥市滨湖新区全新世沉积物粒度特征及其古环境意义
管后春 李运怀 刘正茹
摘 要:对合肥市滨湖新区大量第四纪钻孔作了地层描述、粒度分析,对代表性钻孔ZK1303采集的样品平均粒径、分选系数、偏度及峰度进行了统计分析,并绘制出样品的频率曲线和概率累积曲线,以及据地层描述绘制出岩性基本层序图,据此探讨了该沉积区全新世以来的沉积环境.结果表明,此钻孔全新世地层自下而上至少存在3个大的沉积旋回,各沉积旋回底层基本以含砾砂土为主,向上变为细砂、粉砂、砂质粉土、粉质粘土、粘土;3个大的沉积旋回中又至少发育了11个次级正向粒序沉积旋回.综合各统计参数在垂向上的分布特征、频率曲线、概率累积曲线特征和研究区地理位置特征,初步判定5、10及21号样品对应的地层为河床滞留沉积;初步判定该区全新世以来至少经历11次湖泊进退更替,其中有3次巨大的湖退;对应于每个沉积旋回,沉积环境有各沉积旋回底层河流相向上过渡到河湖相沉积.
关键词:全新世;粒度分析;沉积环境;滨湖新区;合肥
分类号:P534.63532 文献标识码:A
文章编号:1005-6157(2009)02-091-5
GRAIN SIZE FEATURES OF THE HOLOCENE SEDIMENTS IN THE BINHU NEW DISTRICT OF HEFEI CITY AND THEIR PALEO-ENVIRONMENTAL IMPLICATIONS
GUAN Hou-chun LI Yun-huai LIU Zheng-ru
基金项目:安徽省地质勘查专项(2005-56),中国地质调查局国土资源大调查项目(1212010610608)资助
作者简介:管后春(1979-),男,安徽六安人,硕士,主要从事第四纪地质调查与研究工作用.E-mail:guanhouchun@163.com
作者单位:管后春(安徽省地质调查院,安徽合肥,230001)
李运怀(安徽省地质调查院,安徽合肥,230001)
刘正茹(合肥市国土资源局,安徽合肥,230001)
参考文献:
[1]Udden J A.Mechanical composition of clastic sediment.Geo Soc Am Bull,1914,25:655~744
[2]Passega R.Textures as characteristics of clastic depositon.American Association of Petroleum Geologists Bulletin,1957,41:1952~1984
[3]Sahu B K.Depositional mechanisms from the size analysis of elastic sediments.Journal of Sedimentary Petrology,1964.34:73~83
[4]Visher.Grain size distribution and depositional processes.Journal of Sedimentary Petrology,1969,39(3):1074~1106
[5]张晓帆,冯英进,胡亚平.沉积岩粒度分析专家系统.沉积学报,1995,13(1):126~132[Zhang Xiaofan,Feng Yingjin,Hu Yaping.Grain-size analysis expert system for sedimentary rock.Acta Sedimentologica Sinica,1995,13(1):126~132
[6]曲政.沉积物粒度数据表征方法的研究.中国粉体技术,2001,7(4):24~31
[7]Finney B P,Johnson T C.Sedimentation in Lake Malawi(East Africa)during the past 1 0,000 years:A continuous paleoclimatic record from the southern tropics.Palaeogeograpgy,Palaeoclimatology,Palaeocology,1991.85:351~366
[8]Sondag F,Soubies F,Ledru M P.Geochemical markers of Palaeoenvironments:Relations between climatic changes,vegetation and geochemistry of lake sediments,southern Brazil.Applied Geochemistry,1993.2:165~170
[9]丁仲礼,余志伟.第四纪时期东亚季风变化的动力机制.第四纪研究,1997,42(1):66~69
[10]Lamoureux X S.Five centuries of interannual sediment yield and rainfall-induced erosion in the Canadian High Arctic recorded in lacustrine varies.Water Resources Research,2000,36(1):309~318
[11]Royall D.Lake-sediment-based evaluation of recent sediment yield from a small Appalachian watershed,Thompson Lake,Virginia.Physical Geography,2000,21(1):68~88
[12]张璞,陈建强,田明中,等.福建省漳州市第四纪沉积物粒度特征及其沉积环境.沉积学报,2005,23(2):275~283
[13]于学峰,周卫健,刘晓清,等.青藏高原东部全新世泥炭灰分的粒度特征及其古气候意义.沉积学报,2006,24(6):864~869 |
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