With the gradual decrease of oil resources in China, non-conventional resources such as oil shale, oil sands and heavy oil have aroused much attention among geologists.There are abundant oil shale resources in northwest China, which have been preliminary studied in this paper.Field geological section survey, standard mining investigation, and laboratory analysis of important samples indicate that the oil shale in northwest China has the following features: 1) Oil shale strata 1- 36m thick exist in this region.2) The color of the oil shale is mostly brown-black, black, whereas the color of some oil shale outcrops is maroon.Oil shale is characterized by slightly greasy luster, flaky layered structure, irregular conchoidal fracture, small hardness and light brown streak.3)In hand specimen, oil shale is mainly composed of clay minerals and silt-sized detrital minerals (feldspar and quartz).4) The main chemical components of oil shale are SiO2 and Al2O3, which possess 65.44％ of the rock,indicating that the shale is of the medium ash type.The organic carbon possess 14％ of the oil shale, total carbon poesses16.28％, and oil yield is generally 1.5％-13.7％, for an overall caloric value of 1.66-20.98 MJ/kg.The density of the shale is 1.55-2.46 g/cc.Younger oil shale strata have progressively higher REE abundances.5) Oil shale deposits can be mainly divided into 3 types: littoral-neritic facies sedimentary deposits in middle and late Carboniferous-early Permian strata, remnant lake bay-lacustrine facies sedimentary deposits in late Permian strata,and inland lacustrine - delta facies sedimentary deposits in Mesozoic strata.Oil shale formed in Mesozoic inland deep water-half deep water lacustrine facies is the major industrial type and its origin is similar to "the Black Sea Model." Oil shale layers are also the main oil source rocks in Ordos basin.Oil shale formed in the deltaic environment in middle and late Carboniferous and Jurassic strata are mostly related to coal beds in genesis.6) In this region, the total amount of predicted resources of oil shale is at least 30000×108 t , which is equivalent to about 2100 ×108 t shale oil; among them, oil shale resources in Ordos basin accounts for 99％ and can be compared with oil shale resources in Green River area of western North American.7) In northwest China,identified oil shale deposits are located in the vicinity of large and medium-sized cities, with good development prospects.As long as the problem of environmental pollution has been solved and the appropriate technologies have been used, immense economic benefits are likely to be obtained.%随着石油资源的可用量不断减少,油页岩、油砂与稠油作为一种非常规资源即新能源而备受人们的重视.中国西北地区存在着丰富的油页岩资源.笔者近年来对其进行了初步研究.通过收集前人相关资料、野外地质剖面测量,典型矿区考察、关键样品化验分析等手段,结果表明中国西北油页岩有以下特点:①矿体多呈层状展布,油页岩单层厚度一般为1～36 m.油页岩多为褐黑色、黑色,有的表面因氧化而呈褐红色,略具油脂光泽.片状、层状构造.参差状、贝壳状断口.硬度小,条痕亮褐色.肉眼观察,岩石主要由粘土矿物及粉砂级碎屑矿物(长石及石英)组成.油页岩化学成分主要为SiO2、Al2O3.二者和为65.44x10-2,表明其属中等灰分的油页岩.油页岩有机碳为14x10-2,全碳16.28x10-2.含油率一般为1.5%～13.7%,发热量一般为1.66～20.98 MJ/kg,视密度1.55～2.46 kg/m3.时代越新,油页岩稀土元素丰度越高.主要有3种矿床类型:中、晚石炭世-早二叠世滨浅海相沉积矿床、晚二叠世残余湖湾-湖相沉积矿床以及中生代内陆大型湖泊相沉积矿床.其中中生代大型内陆深水-半深水湖泊相油页岩是主要工业类型,它也是鄂尔多斯盆地主要的生油岩,其成因类似于"黑海模式".中、晚石炭世和侏罗纪形成的油页岩矿床多与煤层共生,形成于三角洲环境.该区预测的油页岩总资源量至少是30000x108t,折合页岩油约2100×108t.其中鄂尔多斯盆地油页岩资源量几近占99%,可与美国西部绿河油页岩媲美.西北地区已查明的油页岩矿均位于大、中城市附近,只要解决好环境污染问题,采用适当的开发技术,必将获得巨大的经济效益.
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