摘要：

西北地区是指贺兰山及六盘山以西和昆仑山以北的我国西北部的广大地区。作者在各露头剖面及钻井剖面的地层学和岩石学研究的基础上，采用单因素分析综合作图法，编制出了中国西北地区寒武系各统的各种单因素图和寒武纪各世的岩相古地理图。这些岩相古地理图具有定量、多级别和多类型的特点。定量，即每个古地理单元的划分和确定都有确切的定量的单因素数据和图件为依据。多级别，即已划分出三级古地理单元，如陆和海为一级；在海中又划分出台地、盆地和斜坡，为二级；在台地中，又划分出滩、坪、湖等，为三级。多类型，即每个古地理单元，主要是二级和三级古地理单元，还可根据其岩石特征区分出不同的类型，如台地可区分出碳酸盐岩台地、碎屑岩台地等，盆地可区分出硅质岩盆地、碎屑岩盆地、石灰岩盆地、复理石盆地、火山岩盆地等，滩可区分出亮晶颗粒滩（准滩、雏滩）、灰泥颗粒滩（准滩、雏滩）等。这种古地理图在西北地区还是首次出现。西北地区寒武纪岩相古地理格局可概括为“陆海并存，海中台盆相间分布，台中有滩坪湖，台盆间有坡”。新疆北山地区和西昆仑甘青地区的古地理特征有所不同，但其古地理格局和演化阶段以及海进过程则是相同的。

Abstract:

The Northwest China in this paper refers to the broad region bounded by the Helan Mountains and Liupan Mountains to the east, and by the Kunlun Mountains to the south. Based on the study of stratigraphy and petrology of outcrop and well sections, according to the single factor analysis and comprehensive mapping method, the various single factor maps of the Lower, Middle and Upper Cambrian and lithofacies palaeogeography maps of the Early, Middle and Late Cambrian in Northwest China were compiled. These lithofacies palaeogeography maps possess three characteristics, i.e. quantification, multirank and multitype. Quantification means that the determination of each palaeogeographic unit is based on quantitative single factor data and maps. This makes palaeogeography developed into the quantitative stage. Multirank means that palaeogeographic units are classified into three or more than three ranks. For instance, lands and seas are the first rank. In the seas, the platforms, basins and slopes are defined as the second rank. In platforms, the banks, tidal flats, and lakes are further drawn out as the third rank. Multitype means that palaeogeographic units, especially the second and third rank units, can be further divided into different types on the basis of their rock types. For instance, platforms can be divided into carbonate platforms, clastic platforms, etc.；basins can be divided into siliceous basins, clastic basins, limestone basins, flysch basins, etc.；and banks can be divided into sparry grain banks (penebanks, embryonic banks),etc, limemud grain banks (penebanks, embryonic banks), mixed banks (penebanks, embryonic banks) . The framework of lithofacies palaeogeography of the Cambrian in Northwest China can be summerized as following. There were both lands and seas. In seas there were platforms and basins distributed alternatively. In platforms there were scattered banks, flats and lakes. Between platforms and basins there were slopes. The features of lithofacies palaeogeography of the Xinjiang and Beishan Area and that of the West Kunlun, Gansu and Qinghai Area are different；however the framework and evolution stage of lithofacies palaeogeography and the transgression process of the whole Northwest China are just the same.