西北地区除青海南部有海相侏罗纪、新疆西南部有海相晚白垩世的沉积外,广泛发育着陆■侏罗—白垩纪的盆地沉积,特别是天山—祁连山—秦岭及其以北的广大地区(图1)。盆地面■大者达数十万平方公里,小者不足一平方公里;其地质发展历史长者跨代,短者亦有1—2个纪;仅陆相侏罗—白垩纪的沉积厚度达数千米的盆地也多 In addition to the marine Jurassic in the southern part of Qinghai and the Late Cretaceous sediments in the southwestern Xinjiang, the NW-trending continental Jurassic-Cretaceous sediments, especially the Tianshan-Qilian-Qinling and its north The vast area (Figure 1). Basin surface ■ The largest of hundreds of thousands of square kilometers, the smaller one less than one square kilometer; the geological history of the elderly intergenerational generation, the short are also 1-2 years; only continental Jurassic - Cretaceous sedimentary thickness up to A few kilometers of the basin are also many