塔城地区晚泥盆世沉积特征及其构造古地理意义

通过对实测剖面层序和沉积特征的详细分析,将塔城北部晚泥盆世塔尔巴哈台组下亚组由下向上分为四个沉积相组合,分别为浊积岩相、浅海陆棚相、滨海相及海陆交互相,构成向上变粗变浅的沉积序列。古流向和沉积演化分析表明,塔城北部地区晚古生代初期位于成吉思-塔尔巴哈台褶皱隆起带以北,其性质为向北开放的大陆边缘,发育晚古生代塔尔巴哈台组深海、浅海、滨海到海陆交互相的沉积体系。准噶尔西北塔城地区晚古生代早期古地理格局可能由南部成吉思-塔尔巴哈台早古生代褶皱带形成的隆起区和其北的向北开放的大陆边缘构成。

Sedimentary characters during the Late Devonian in Tacheng area and their tectono-paleogeography signification

According to the analysis of sequence and sedimentary characters, four sedimentary facies, turbidite, shallow marine, littoral and marine-continental alternating facies have been recognized from the corss-sections in the north of Tacheng area, composing a coarse upward sedimentary association. Study on paleocurrent direction and depositional evolution shows that the north Tacheng area was located to north of the Chengjisi-Taerbahatai fold belts during the early Late Paleozoic and was characterized by a north-opening continental margin that developed a sedimentary system including deep marine, shallow marine, littoral to marine-continental alternating facies. The palaeogeographic pattern in Tacheng area of Northwest Junggar probably consists of a uplift zones of the Early Paleozoic Chengjisi-Taerbahatai fold belts in the south and a north-opening continental margin in the north during the early Late Paleozoic.