对于点苍山-石鼓变质带区域划分的意见

在以往的研究中,点苍山和哀牢山被认为是同一个变质带。对石鼓带的划分也有很大争议。本文通过岩石学和同位素年代学的研究,认为点苍山和石鼓变质带同为扬子基底的一部分,应属于滇东变质区。它们是在元谋-大红山群之上发育的一套中晚元古变质岩带,具陆内地台型火山-沉积的特点。

THE DIANCANGSHAN-SHIGU METAMORPHIC BELT IN W. YUNNAN, CHINA: THEIR GEOCHEMICAL AND GEOCHRONOLOGICAL CHARACTERISTICS AND DIVISION OF METAMORPHIC DOMAINS

In the past study, the Diancangshan and the Ailaoshan metamorphic belts are believed to belong to a same orogenic metamorphic belt. However, the division and the age of the Diancangshan Group and the Shigu Group are controversal. According to the petrological, metamorpic gological and geochronological study, the authors come to the following conclusions. 1. Both the Diancangshan Group and the Shigu Group are a part of the basement of the Yangtze Plate. 2. The metamorphic rocks of the Diancangshan and the Shigu belts should belong to the eastern Yunnan Province metamorphic domain. They are the volcanic-sedimentary sequences within the Yangtze Plate. 3. The Ailaoshan Group is a early Proterozoic active continental marginal volcanic-sedimentary sequence, which has developed along the southeastern margin of the Yangtze Plate.