东准噶尔兔子泉地区中泥盆统火山湖相风暴岩及沉积构造背景

摘要

During the period of Devonian,Tuziquan area in east Junggar was located in a tectonic background of the Central Asian accretion-type Orogens in Paleozoic.The Middle Devonian Yundukala Formation are mainly composed of volcanic lacustrine sediments.Based on measuring the section in detail,Volcanic lacustrine tempestites have been found in the Middle Devonian Yundukala Formation.The tempestites contain many typical sedimentary structures in this set of strata,such as erosional structures,storm-surge structures,storm eddy structures,tear-pull structures,contemporaneous de-formation structures and quickly deposited structures after storm.According to analysis on the section sequence,we can draw the conclusion that tempestites formed in the wedge-top basin that developed above on the accretionary wedge,and four types of storm sedimentary sequences have been recognized. The discovery of tempestites in Yundukala Formation of Devonian reflects that this region was located in low latitude(5o~20o)zone where storm deposit developed.The re-search on tempestites from Tuziquan area in east Junggar has important significance not only for the restoration of paleo-geography and paleoclimate of this region, but also for the sedimentary tectonic setting of the east Junggar in Devonian.%东准噶尔兔子泉地区泥盆纪时期处于中亚古生代增生造山带大背景下，中泥盆统蕴都喀拉组以火山湖相沉积为主。通过剖面测制于该组中发现一套火山湖相风暴岩沉积，发育许多典型的风暴沉积构造，包括风暴侵蚀构造、风暴浪构造、风暴涡流构造、风暴撕裂构造、同生变形构造及风暴期过后的正常沉积等。结合剖面基本层序分析，认为风暴岩发育于增生楔上的楔顶盆地中，可划分出4种风暴沉积序列。泥盆纪蕴都喀拉组风暴岩的发现表明，东准噶尔兔子泉地区中泥盆世处于低纬度（5°~20°）风暴作用带，本次研究对恢复该区古地理和古气候及探讨沉积构造背景具重要意义。