论川西炉霍裂谷的沉积建造特征
- 1. 中国科学院地球化学研究所, 贵阳 550002;
- 2. 西南冶金矿产勘查开发院,成都 610051
基金项目:
中国科学院矿床地球化学开放研究实验室基金
作者简介:
王小春，男，1965年10月出生，高级工程师，博士，矿床学专业。
- 收稿日期:
1999-01-26
- 修回日期:
1999-04-22
- 刊出日期:
1999-12-10
摘要: 通过地层划分与对比以及建造分析，确定了川西炉霍裂谷存在浊积岩建造，（火山）混杂式建造和深海碳硅泥建造，并探讨了它们与裂谷的发生、发展和消亡之间的关系。
On the Characters of Sedimentary Formations In the Luhuo Rift,Western Sichuan
- 1. Institute of Geochemistry, Chinesc Academy of Sciences,Guiyang 550002;
- 2. Southwest Institute or Metallurgical Mineral Resources Exploratiou and Deveopment, Chengdu 610051
- Received Date:
1999-01-26
- Rev Recd Date:
1999-04-22
- Publish Date:
1999-12-10
Abstract: The Luhuo rift occurs in the internal parts of the Songpan-Ganzi massif,western Sichuan,which was bounded by the deep-seated Jiajilong-Quesuo fault and Seda fault. The boundary faults dipped northeastward and southwestward respectively, which constituted the garben-like type sea basin. Teh Luhuo rift is character- istically different from the neighboring parts in that there are basic volcanic rocks and calcareous breccias.Through the classificaiton and correlation of strata and formation analysIs,it is determined that there are turbidity formation,(volcanic) melange formation and bassyal sea carbon-silicon-mud formation in the Luhuo rift. The turbidite formation is the chief formation in the Triassic system. The Bouma sequence,various bedding structures are existed in the rock series. The granulometric analysis result as well as the lower maturities of composition and texture suggests the origin of turbidity fluid. Compared with the chemical composition of major elements and rare earth elements for graywack and slate in different distinct tectonic environments, it can be revealed that the continental island-arc source for the provenance of the Triassic turbidite in the rift.The melange formation and/or volcanic melange formation was olistostrome formed by short-distance transportation and deposition,which occur as stratified between age-determined marine strata. The bassyal sea carbon-silicon-mud formation consists of purple radiolaria-bearing silicon mudstone,gray,gray-purple and purple sponge-spiculte-bearing micrite, and silty mudstone. There are horizontal bedding and quasi-boxwork in mi-crite,which shows less hydrodynamic condition and starved calm bassyal environment. Combined with other data related to tectonic activity,vilcanoic and magmatic intrusive,the evolution from beginning,development to closing of the Luhuo rift may be divided into four stages as follows. 1)Primary rifting(in late-Permian) in which carbonate rock formation, clastic formation and tholeiite formtation were developed, accompanied with stratified basic-ultrabasic intrusive bodes,2)Deposition depression stage(from early-Triassic to late stage of late-Triassic) during which bassyal sea carbon-silicon-mud formation,melange formation nad turbidite formation were developed,3)Intense rifting stage (in the middle stage of late-Triassic)in which the volcanic melange formation was developed, accompanied with the intrusion of basic-ultrbasic dykes, and 4 ) Withering stage(in the late stage of late-Triassic) in which the turbidite formation was formed.
王小春. 论川西炉霍裂谷的沉积建造特征[J]. 沉积学报, 1999, 17(S1): 798-804.
| 引用本文: |
王小春. 论川西炉霍裂谷的沉积建造特征[J]. 沉积学报, 1999, 17(S1): 798-804.
|
WANG Xiao-chun. On the Characters of Sedimentary Formations In the Luhuo Rift,Western Sichuan[J]. Acta Sedimentologica Sinica, 1999, 17(S1): 798-804.
| Citation: |
WANG Xiao-chun. On the Characters of Sedimentary Formations In the Luhuo Rift,Western Sichuan[J]. Acta Sedimentologica Sinica, 1999, 17(S1): 798-804.
|
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