世界地质
世界地質
세계지질
WORLD GEOLOGY
2009年
4期
476-484
,共9页
牛洪燕%金秉福%刘春暖%宫立新
牛洪燕%金秉福%劉春暖%宮立新
우홍연%금병복%류춘난%궁립신
芝罘岛%黄土状黄土%碎屑矿物%黏土矿物%物质来源%古气候变化
芝罘島%黃土狀黃土%碎屑礦物%黏土礦物%物質來源%古氣候變化
지부도%황토상황토%쇄설광물%점토광물%물질래원%고기후변화
Zhifu Island%loess-like loess%detrital minerals%clay minerals%material source%paleoclimatic change
沉积矿物是记录物源信息和古气候变迁的良好载体.通过显微镜碎屑矿物鉴定和黏土矿物X射线衍射峰能谱分析对芝罘岛黄土状黄土2个剖面13个样品进行处理,并对数据进行数学统计分析.结果表明,芝罘岛黄土状黄土矿物种类、矿物形态特征、磁铁矿和岩屑的高含量等都揭示了黄土来源的多源性和近源性,末次冰期时的海底平原沉积物以及洪积、残积物是芝罘岛黄土状黄土的重要物源,而西北内陆沙漠吹来的细颗粒物质相对较少.普通角闪石、绿帘石含量较高的黄土堆积后期是以远源沉积为主,且以风力搬运为主;磁铁矿、岩屑含量较高的早、中期是以近源沉积为主,搬运动力较复杂.根据黄土状黄土的剖面层序特征,碎屑矿物以及黏土矿物垂相变化特征,说明黄土堆积的早期,气候是相对温暖湿润的,之后变得寒冷干燥,后来又逐渐回暖,然后再转冷,呈现出末次冰期该地冷暖交替的气候旋回.
沉積礦物是記錄物源信息和古氣候變遷的良好載體.通過顯微鏡碎屑礦物鑒定和黏土礦物X射線衍射峰能譜分析對芝罘島黃土狀黃土2箇剖麵13箇樣品進行處理,併對數據進行數學統計分析.結果錶明,芝罘島黃土狀黃土礦物種類、礦物形態特徵、磁鐵礦和巖屑的高含量等都揭示瞭黃土來源的多源性和近源性,末次冰期時的海底平原沉積物以及洪積、殘積物是芝罘島黃土狀黃土的重要物源,而西北內陸沙漠吹來的細顆粒物質相對較少.普通角閃石、綠簾石含量較高的黃土堆積後期是以遠源沉積為主,且以風力搬運為主;磁鐵礦、巖屑含量較高的早、中期是以近源沉積為主,搬運動力較複雜.根據黃土狀黃土的剖麵層序特徵,碎屑礦物以及黏土礦物垂相變化特徵,說明黃土堆積的早期,氣候是相對溫暖濕潤的,之後變得寒冷榦燥,後來又逐漸迴暖,然後再轉冷,呈現齣末次冰期該地冷暖交替的氣候鏇迴.
침적광물시기록물원신식화고기후변천적량호재체.통과현미경쇄설광물감정화점토광물X사선연사봉능보분석대지부도황토상황토2개부면13개양품진행처리,병대수거진행수학통계분석.결과표명,지부도황토상황토광물충류、광물형태특정、자철광화암설적고함량등도게시료황토래원적다원성화근원성,말차빙기시적해저평원침적물이급홍적、잔적물시지부도황토상황토적중요물원,이서북내륙사막취래적세과립물질상대교소.보통각섬석、록렴석함량교고적황토퇴적후기시이원원침적위주,차이풍력반운위주;자철광、암설함량교고적조、중기시이근원침적위주,반운동력교복잡.근거황토상황토적부면층서특정,쇄설광물이급점토광물수상변화특정,설명황토퇴적적조기,기후시상대온난습윤적,지후변득한랭간조,후래우축점회난,연후재전랭,정현출말차빙기해지랭난교체적기후선회.
Sedimentary are minerals good carrier to record material source and paleoclimatic change. Using microscope identification of detrital minerals and X-ray diffraction (XRD), the authors analyse the clay minerals of 13 samples from 2 profiles of loess-like loess in Zhifu Island, and the data by mathematical statistics. The results show the mineral taxa, morphological characteristics and the high contents of magnetite and deris revealed the multi-sources and near-derived features of the loess-like loess in Zhifu Island, and the main sources of loess are seabed plain, diluvium and residual sediments in the last glacial period, while thin sediments from Northwest inland desert are rare. The late period of loess accumulation with high contents of hornblende and epidote is mainly far-source sedimentary with wind transport, and the early and middle periods of loess accumulation with high contents of magnetite and deris are mainly near-source sedimentary with complex transport. Profile sequence characteristics of loess and vertical variational characteristics of detrital and clay minerals indicate the climate in Zhifu Island was warm and wet in early period of loess accumulation, then changed to cold and dry, after that turned to warm, and to cold again. The fact shows the climate cycle of cold-warm alternate in the last glacial period.
