鄂尔多斯盆地上三叠统延长组浊沸石分布及其成因分析

Genesis and Distribution of Laumontite in Yanchang Formation of Upper Triassic in Ordos Basin

State Key Laboratory of Continental Dynamics, Department of Geology, Northwest University, Xi'an, Shaanxi 710069, China

摘要: 鄂尔多斯盆地上三叠统延长组砂岩中广泛分布着浊沸石胶结物,其形成的次生溶蚀孔隙已成为油气的主要储集空间。通过薄片观察、包裹体测温、扫描电镜及能谱分析、黏土矿物X衍射和电子探针等微观分析和宏观统计研究,初步认为延长组浊沸石主要分布于物源来自盆地东北部老山的三角洲中,其成因与盆地北部阴山造山带火山活动形成的凝灰岩和火山碎屑的成岩变化有关,它们呈孔隙式充填或交代碎屑长石,形成具有多期性。
- 鄂尔多斯盆地 /
- 延长组 /
- 浊沸石
Abstract: Laumontite cement is widely distributed in the sandstone of Yanchang Formation of Upper Triassic of Ordos basin.Secondary pores dissolved from the laumontite aremajor storage space for oil-gas. By thin-section observation, fluid inclusion analysis, SFNI and energy spectrum analysis, X-diffraction and electron microprobe analysis for clay mineral, we hold that the laumontite of the Yanchang formation is distributed in the delta whose sediments come from the ancient hill in the north-easternOrdos basin.The formation of laumontite is related to sediments formed by volcanic activities and volcanic tuff rock from Yinshan Fold belt. Laumontite shows a pore-filling pattern or being replaced feldspar, whose formation has a multi-stage feature.
- laumontite /
- Yahchang Formation /
- Ordos Basin