四川省石棉县孟获城新近系-第四系昔格达组孢粉组合特征  

Sporopollen Assemblage of the Neogene-Quaternary Xigeda Formation in Menghuocheng,Shimian County,Sichuan Province

作　　者：白宪洲[1,3] 王玉婷 文龙[1,3] 尹建华 BAI Xian-zhou;WANG Yu-Ting;WEN Long;YIN Jian-hua(Sichuan Institute of Geological Survey,Chengdu610081;The108th Geological Team,BGEEMRSP,Chengdu611230;Valuation and Utilization of Startegic Rare Metals and Rare Earth Resource Key Laboratory of Sichuan Province,Chengdu610081)

机构地区：[1]四川省地质调查院,成都610081 [2]四川省地质矿产勘查开发局一〇八地质队,成都610081 [3]稀有稀土战略资源评价与利用四川重点实验室,成都610081

出　　处：《四川地质学报》2021年第4期536-543,共8页Acta Geologica Sichuan

基　　金：甘孜州1∶25万活动断层普查项目;中国地质调查局龙门山-滇中成矿带通安和宁蒗地区地质矿产调查项目四川1∶5万孟获城等6幅区域地质矿产调查子项目(编号:121201010000150016-04)共同资助

摘　　要：通过对四川石棉县孟获城新近系-第四系昔格达组的岩性组合、沉积构造及孢粉组合特征研究,得出其下部为含中细砾粗砂岩与粉砂质泥岩互层,中部为细砾岩夹煤线,上部为粘土岩夹煤线,沉积环境为河流-滨至浅湖。所有样品中都含有大量的蕨类植物,蕨类孢粉中含量最多的是水龙骨科(Polypodiaceae)。木本针叶植物中含量最多的属种为松属(Pinus)、铁杉(Tsuga)。阔叶木本植物总体相对较少,含量最多的属种为榆(Ulmus)。草本植物含量较多的属种为蒿属(Artemisia)、禾本科(Gramineae)等。可划分为六个孢粉组合,其植被面貌及其植被反映的古气候变化存在周期性变化,由温暖湿润的针阔叶混交林(第一孢粉组合)-寒冷湿润的针叶林(第二、三孢粉组合)-温暖湿润的针阔叶混交林(第四孢粉组合)-寒冷湿润的针叶林(第五、六孢粉组合)。为该区新近纪-第四纪环境演化研究提供基础资料。The Neogene-Quaternary Xigeda Formation in Menghuocheng,Shimian County,Sichuan Province consists of interbeds of medium-fine gravelly coarse sandstones and silty mudstones in the lower,fine conglomerate intercalated with coal seam in the middle and clayrock intercalated with coal seam in the upper.The sedimentary environment is river-shore to shallow lake.All of the samples contain large amounts of fern with the largest amount of Polypodiaceae.Woody conifers are predominated by Pinus and Tsuga.Main broad-leaved woody plant is Ulmus.The major herbaceous plants are Artemisia,Gramineae and so on.There are 6 sporopollen assemblages which reflect a warm and humid climate(assemblage 1),cold and wet climate(assemblages 2 and 3),warm and humid climate(assemblage 4)and cold and wet climate(assemblages 5 and 6),respectively.

关 键 词：孟获城 昔格达组 孢粉组合 古环境 

分 类 号：P534.63[天文地球—第四纪地质学] P52[天文地球—古生物学与地层学]