摘要
通过对晚古生代气候演化趋向的分析,探讨了新疆石炭纪和二叠纪植物地理分区的形成与演变。认为植物地理分区在早石炭世晚期末—晚石炭世早期即已形成,随着温带气候区的逐渐扩大,安加拉区植物在新疆自北向南逐渐推移,至晚二叠世中—晚期到达北塔里木。早二叠世—晚二叠世早期南准噶尔、伊犁等地受欧洲东移的干旱气流的影响,有欧美型松柏类混生。塔里木为特提斯生物大区的一部分,植物主要为欧美-华夏区类型。
The Xinjiang area was characterized by tropical-subtropical climate in the Devonian,and obviously climatic zonation in the Carboniferous due to the global climatic change. The temperate zone migrated to South Junggar at the late stage of Carboniferous. The arid climate from Europe intruded into ILi region and South Junggar during ealy Permian to early stage of late Permian. The Tarim was of tropical -subtropical climate during the late Paleozoic due to its fairly low lattitude and affection of warm current of paleo - Tethys.
The climatic differentiation causes rapid differentiation of flora since the late stage of early Carboniferous. The global flora decreased and the regional flora increased in comparison with Devonian, resulting in the formation of floristic provinces of different characteristics. The temperate zone gradually extented to south,and correspondingly the Agara folra extended to south.
The subdivisions of floristic provinces are, respectively, North Junggar region (Angara flora), South Junggar region (transition type)and Tarim region (Euramerica flora)at the early stage of late Carboniferous; Junggar region (Angara)and Tarim region (Euramerican)at the late stage of late Carboniferous ; Junggar region-North Junggar subregion and South Junggar subregion (Angara, coniferophyte of Euramerical type mixed in the latter), and Tarim region (Euramerican -Cathaysian type); Junggar region-North Junggar subregion, South Junggar subregion-North Tarim subregion (Angara type, Cathaysian type mixed and cycad type developed in the latter)and Tarim region (inferred to be of Euramerican-Cathaysian type,mixed with Angara flora).
The collision between Junggar and Tarim blocks occured at the late Carbonifeous, and the orogenesis at the late stage of early Permia. This idea was supported by the following facts;Ⅰ. Epi-continental sea still existed between the two blocks during late Carboniferous to the middle stage of early Permian Ⅱ. Molasse deposits on both sides of Tianshan mainly appeared in Upper Permian; Ⅲ. The mixture type flora between Junggar region and Tarim region formed in the late Permi-
出处
《新疆地质》
CAS
CSCD
1993年第1期13-22,共10页
Xinjiang Geology
基金
国家自然科学基金资助项目(49060009号)
关键词
新疆
石炭—二叠纪
植物地理区
形成
演变
Xingjiang, Carboniferous-Permian, floristic province, formation, evolution
