华北板块南缘熊耳群火山岩研究的若干问题

本文基于大量的区域地质学，岩石学和地球化学资料，陈述熊耳群的一些重要资料，阐明作用者对一些争议问题的看法，同时指出今后值得注意的一些研究内容。研究表明，熊耳群火山岩以橄榄玄粗岩，安粗岩和粗面英安岩，流纹岩为主，其次为高钾玄武安山岩，高钾安山岩，高钾英安岩；火山岩系列主要为橄榄玄粗岩系，其次为高钾钙碱性岩系；熊耳群是扩张应力背景的产物，但火山岩的地球化学特征表明，能耳期或熊耳期以前的陆下岩石圈地幔历

SOME PROBLEMS IN THE STUDY OF THE VOLCANIC ROCKS OF THE X1ONGER GROUP ON THE SOUTHERN MARGIN OF THE NORTH CHINA PLATE

Based on a vast mount of data on regional geology, petrology and geochemistry, the authors present a number of major data about the Xionger Group, and expound the authors's views about the points at issue. Meanwhile, they point out some issues which merit a detailed study in the future. The study shows that the Xionger Group volcanics consist dominantly of shoshonites, latites, trachydacites and rhyolites with subordinate high-K basaltic andesites, high-K andesites and high-K dacites. Volcanic rock series include mainly the shoshonite series and subordinately the high-K calc-alkalic series. The Xionger Group possibly reveals the product of the extensional stress setting) however, the geochemical characteristics of the volcanic rocks appear to demonstrate that the subcontinental litho-spheric mantle may have experienced the concentration process of subduction zone components (SZC) during the Xionger Stage or prior to the Xionger Stage, and thus, the Xibnger Group volcanics may be assigned to the backarc rift volcanics behind the continental-margin arc or lag-type arc volcanics.