陕北油页岩地质特征、成矿规律及开发条件

陕北油页岩主要分布于鄂尔多斯盆地的三叠系延长组和侏罗系安定组、延安组地层中，其中三叠系延长组的长7、长9、长1是油页岩发育的主要层段。地层总体为一产状平缓的向北西西微倾的单斜构造，地表绝大部分被第四系现代风积沙覆盖。油页岩矿石多呈灰黑色片状，主要成分为硬质粘土类矿物，含少量石英、长石细屑及沥青质点。油页岩分布受基底差异运动形成的构造坳陷盆地控制。成矿受岩相古地理环境控制，深湖一半深湖相沉积环境形成的油页岩分布广泛，品质好，浅湖和三角洲相沉积环境形成的油页岩分布范围小、厚度小、含油率低。鄂尔多斯盆地不仅油页岩资源丰富，而且开发条件优越，具有广阔的开发利用前景，对解决我国油气等常规能源供需矛盾突出的问题非常有利。

ORE FORMATION AND DEVELOPMENT CONDITIONS OF OIL SHALES IN NORTH OF SHAANXI PROVINCE

Oil shales occurring in Northern Shaanxi are mainly distributed in the Triassic Yanchang formation and the Jurassic Anding Formation and the Yan＇ an Formation in Ordos Basin, in which oil shales Chang 7, 9 and 1 are dominant in oil-bearing beds in the Triassic Yanehang Formation. Overlaid most by the Quaternary aeolian sand, the strata have an attitude gently trending toward north-west-west. Oil shales are of mostly schistic grey-black and mainly composed of hard clay minerals with a little quartz, a few feldspar scraps and bituminous flecks. The distribution of oil shales is confined by tectonic depression basin formed by differential movement of basement and the oil formation is related to lithofacies paleogeographic environment. Oil shales formed under the depositional environment of deep-half depth lacustrine are of wide distribution with a good quality and those formed under the depositional environment of shallow lakes and delta facies are of smaller in distribution, thinner in thickness and lower in oil-bearing rate. Ordos Basin is abundant in oil shales resources and with favourable conditions for development, which has a great potential for further exploitation of oil and gas.