作　　者： ; ; ; (李永安）; (翟永建）; (张正坤）; (沙普斯）; (麦克威廉斯）; (考克斯）;

机构地区： 新疆地质矿产局地质矿产研究所

出　　处： 《新疆地质》 1989年第3期78-88,共11页

摘　　要： 新疆阿克苏—柯坪地区震旦纪包括二套冰成岩,其同位素年龄为7.4—7.7×10~2Ma.古地磁样品采自乌什县尤尔美那克到苏盖特布拉克一带,中心座标:经度79.5°E,纬度40.9°N震旦纪系中至少可能发生了6次地磁极性倒转,极性变化频繁,与世界其他地区震旦系的极性是一致的.震旦纪各时期内的古地磁方向变化较小,震旦纪-尼盆纪之间存在较大的虚极移.震旦纪冰成岩形成于低纬度区,这与柴达木、华南北美、南非和澳大利亚古冰川形成的古纬度是一致的,这为冰成岩形成是全球等时性提供了古地磁依据. From top to bottom, Sinian strata of Aksu-Keping region can be divided into two parts. They are :Qigebulake fm. and Sugaitebulake fm. of upper Sinian; and lower Sinian's Youermeinake fm. and Qiaoenbulake fm.. Their main lithological characters are limestones, dolomites, sandstones, glacigene rocks and basalts. Basalt samples' viscid magnetic remanence are moved by lower temperature thermal demagnetization, and high temperature thermal demagnetization reveal a stable magnetic remanence direction that declination is about 180? and inclination is more shallow. The difference of each sandmentary rocks sample is more clear, especially declinations. This time we obtain a general average direction: Da=195?, Ia.=-16?, K=9.6?, a=9.0?;and paleolatitude is 8?N or 8?S. That means Sinian glacier formed at low latitude ergjon.

关 键 词： 阿克苏 柯坪 震旦纪 古地磁 极性倒转 冰川 低纬度

领　　域： [天文地球]