| 三江地区成矿总结取得初步成果 |
| |
| 关键词: |
| 基金项目: |
|
| 摘要点击次数: 2250 |
| 全文下载次数: 2115 |
| 摘要: |
| PLENTIFUL RESULTS IN SUMMING UP RESEARCH WORK ON WETALLOGENY IN SANJIANG AREA |
| The Sanjiang (the Jjnsha, Lancang and Nujiang Rivers) region on theeastern part of the Qinghai--Xizang (Tibet) Plateau, is one of the importantprospects for metallogeny in China, with a character of intense tectonic activity. In order to sum up the geological findings over the past 30 years,the Ministry of Geology constituted an editorial board for monographs concerning the Sanjiang area in 1981. It has also organized more than a hundred people who are engaged in practical work in this area to summarize thegeological work conducted. Preliminary results have been gained so far. The compilation of the "Memoir of Geology" and the "Memoir of MineralResources" for the Sanjiang area has been completed. The geological map onthe scale of 1:1,000,000 has been prepared. Through the sum-up mentioned above and by analysing critical geologic problems in the field, it is noted that in the Duocai-Yushu, Qinghai andthe Garze-Litang-Wachang, Sichuan occur ultramafic rocks as well as maficcomplex, gabbro, diabase and pillow lava, typical of ocean crustal texture.They have formed ophiolite melange belts due to severe compression, cropping out intermittently. Padiolarian siliceous rocks are also noted in the Litang-Wachang area. All these ophiolites are the remains of oceanic crust ofthe Permian-Triassic ages. This understanding has an important significancein guiding the prospecting work in this area. Four major tectono-metallogenic zones have been divided: Ⅰ.Bomi-Tengchong tin mineralization zone: Rare metal mineralization zone of pegmatitetype occurs both on the east and west sides of the zone, while tin mineralization occurs in the middle and tin deposits have been recognized in morethan ten localities. The stanniferous rock bodies of the Himalayan, high inacidity and rich in potassium,have intruded ioto Carboniferous gravel-bearingslates. The slates have a very high abundance of tin,which is similar to thebelts in west Thailand. Ⅱ.Dengqen-Changning-Lancang iron-tin-polymetallic mineralization zone:The Lancang group of Pre-Ordovician age, exposed in the zone,is represented by a flysch facies with intensely metamorphosed volcanics. The associated sedimentary-metamorphic iron ores are quite widespread. Tin occur-rences and lead-zinc-polymetallic occurrences exist in banded structure andare distributed regularly. The former, closely associated with granite. is anorthern extension of the tin belts of central Malaysia, whereas the latter,associated with volcanics, is rich in silver. Ⅲ. Changdu-Lanping-Simao saline-iron-copper polymetallic mineralization zone: In the northern of this zone occurs the Yulong porphyry copperbelt that is famous in China. It covers an extensive area and contains largedeposits. Big lead-zinc deposits such as the Lanping deposit have alreadybeen discovered in the southern part. This mineralization zone is also a northern extension of the sylvine zone of Thailand. Ⅳ.Yushu-Yidun polymetallic and tin mineralization zone:Here, mineralization is associated with volcanic activities of Late Triassic Epoch andmagmatic activities of Himalayan. Large polymetallic deposits have alreadybeen noted. |
| ZHOU Wei-qin.1983.PLENTIFUL RESULTS IN SUMMING UP RESEARCH WORK ON WETALLOGENY IN SANJIANG AREA[J].Acta Geoscientica Sinica,5(2):131-133. |
| 查看全文 查看/发表评论 下载PDF阅读器 |
|
|
|
|
|