摘要
本文通过岩相特征、粘土矿物分布、早期成岩矿物组合、微量元素等特征的综合分析，认为民和盆地上侏罗统下部为一较典型的湿型冲积扇沉积。冲积扇扇中发育河道冲刷充填和漫流沉积，而泥石流不发育。沉积层序与现代湿型冲积扇可对比。扇体中粘土岩及早期成岩矿物组合中富含高岭石，应与扇体发育时的潮湿气候和弱酸性流体的较强的淋滤有关。由粘土岩中微量元素因子分析进一步表明，该地层中富硼。
Based on the characteristics of rock facies,occurrence of clay minerals and trace elements in mudstones,and early diagenetic mineral assemblage in sandstones,it is indicated that a typical humid alluvial fan in the Upper Jurassic in Minhe basin.The fan in characteristic of channel and sheet flow sedimentary processes,but lack of debris flow.The stratigraphic sequence of the fan resembles that of Quaternary in Taizi River.Abundance of authigenic kaolinate in mudstones and early diagenetic mineral assemblage in sandstones in the fan facies,is related to strong leaching process in acid pore water under relatively humid environment during the fan formation.Mode analysis of 10 trace element contents also shows that the formation is characteristic of B,V enrichment and differs from that of adjacent which formed in non fan facies.
出处
《矿物岩石》
CAS
CSCD
北大核心
1997年第2期61-66,共6页
Mineralogy and Petrology
关键词
冲积扇
沉积
盆地
上侏罗统
民和盆地
humid alluvial fan mudstone trace elements factor analysis Minhe basin
