中文摘要：

通过对三塘湖盆地马朗凹陷二叠系条湖组凝灰岩样品主量与微量元素分析、薄片观察、阴极发光和扫描电镜观测,结合马朗凹陷古地形的恢复,研究了条湖组凝灰岩致密储集层的形成及分布特征。条湖组凝灰岩样品分析显示为中酸性,是火山喷发旋回末期的产物。凝灰岩储集岩共有玻屑凝灰岩、晶屑玻屑凝灰岩和泥质凝灰岩3种岩石类型,玻屑凝灰岩储集物性最好,晶屑玻屑凝灰岩其次,泥质凝灰岩最差。玻屑凝灰岩平面上主要分布在中远火山口带,垂向上主要分布在凝灰岩段的中—下部;晶屑玻屑凝灰岩平面上主要分布在近火山口带,垂向上也主要分布在凝灰岩段的中—下部,且多与玻屑凝灰岩呈互层;泥质凝灰岩平面上主要分布在远火山口带,垂向上主要分布在凝灰岩段的上部。凝灰岩的岩石类型受距离火山活动带的远近控制,其厚度分布受火山活动带和沉积古地形共同控制,火山活动带两侧的沉积洼地是凝灰岩分布的主要部位。预测马朗凹陷条湖组凝灰岩发育5个厚度中心,最厚可达40余米。

英文摘要：

Based on analysis of major and trace elements,observation of thin sections,cathodoluminescence and scanning electron microscope of tuff samples,in combination with the restoration of paleotopography in the Malang sag,the formation and distribution characteristics of the Permian Tiaohu Formation tuff tight reservoirs in the Santanghu Basin are examined.The analysis shows that the tuff samples of the Tiaohu Formation are acid-intermediate,and they are the product of the end of the volcanic eruption cycle.The tuff reservoir rock includes vitric tuff,crystal-vitric tuff,and pelitic tuff,among which,vitric tuff has the best physical properties,followed by crystal-vitric tuff,and pelitic tuff is the poorest.Vitric tuff is usually distributed further away from the crater zone laterally and vertically in the central-lower part of the tuff.Crystal-vitric tuff,mostly interbedded with vitric tuff,is usually distributed near the crater zone laterally and also vertically in the central-lower part of the tuff.Pelitic tuff is generally distributed far away from the volcanic crater on the plane,and in the upper part of the tuff vertically.Types of tuffs are affected by the distance from the volcanic activity belt,and the thickness of tuff is controlled by both volcanic activity belt and sedimentary paleotopography.Thus,depositional depressions on both sides of volcanic activity belt are the favorable locations for the development of tuff.It is predicted that there are five thickness centers of tuff in the Tiaohu Formation of Malang sag（Wellarea M1,L1,M56,M7 and southwest of M7）,of which the biggest thickness of tuff is up to approximately 40 m.