摘要： 青岛灵山岛中生界下白垩统碎屑岩中发育了很好的风暴岩与风暴沉积,其特点是:(1)丘状、洼状构造及丘状、洼状交错层理经常可见;丘状交错层理呈对称或近对称丘状,一般发育在三角洲前缘暗色薄层状砂泥岩互层中,薄层一般厚1~2,cm,有时也可以更厚;砂岩中常有平行层理或低角度交错层理,也可以发育丘状交错层理;细层较厚,多在1~2,cm,甚至3~4,cm;但砂岩多数呈块状;洼状交错层理相对较少,多不完善;洼状构造则相对多见。(2)冲刷侵蚀面非常发育。多波状起伏或凹凸不平,起伏可达20~30,cm,甚至更大;内部的冲刷侵蚀面常不连续,但底部的冲刷侵蚀面连续性很好。(3)中厚层状砂岩内部的冲刷侵蚀面可以分为多个次级层,但常因冲刷面的不连续而上下合并在一起。(4)砂岩中常含有内碎屑,以暗色泥砾为主,小者直径多在1~2,cm,大者可达10,cm以上,形态多变;长轴多顺层分布;有时集中在砂岩的顶部。(5)以中细砂岩为主,没有真正的砾岩;砂岩的分选性可以较好。(6)发育了大量的多尺度、多类型软沉积物的变形构造。(7)有时候含有炭屑。灵山岛风暴岩和风暴沉积的发现,揭示了这套沉积是在一个相对较浅水的湖泊条件下形成的,而非海洋深水;此外,风暴形成的砂岩下移到三角洲前缘相中,使其更加靠近烃源岩,优化了生储关系,有利于油气成藏。

关键词: 风暴岩, 风暴沉积, 丘状洼状层理, 湖泊相, 下白垩统, 灵山岛

Abstract: The typical tempestites and storm deposites developed well in detritus rocks in the Lower Cretaceous of Lingshan Island,Qingdao,Shandong Province. The features are as follows: (1)Hummocky or swaley structures and hummocky or swaley cross-stratification often occur and the hummocky cross-stratification is symmetrical or nearly symmetrical,commonly developed in thin-bedded sand and mud rocks that form in delta foresets. The thin layers are 1-2,cm in thickness and sometimes thicker. The parallel bedding or lower dipping angle cross bedding commonly occurs in the sandstones and sometimes hummocky cross-stratification and hummocky structure can also been observed. The laminea of hummocky cross-stratification is relatively thick,commonly between 1-2,cm,even 3-4,cm. Swaley cross-stratification relatively seldom occurs and commonly not perfect. Nevertheless,the swale structure is relatively common observed. (2)The swashing-eroding surface is considerably developed well and displace wavy ups and downs or is uneven with 20-30,cm height differences or even larger. The inner swashing-eroding surface commonly is not continuous and the bottom swashing-eroding surface is continuous very well. (3)The swashing-eroding surface developing in the medium and thick sandstone can be divided into several sub-layer,and because of discontinuity they combined together. (4)The sandstone contains commonly mudstone intraclast,most of them are dark mudstone with the diameters from 1-2,cm to 10,cm and the shape is polytropic. The long axis of mudstone gravels distributes mostly along the bedding plane. (5)The tempestites and storm deposites are fine to medium sandstones and not true conglomerate. (6)Intergrowth with a lot of multiple-scale and multiple-type soft sidement deformation structures. (7)Sometimes containing a bit of carbonized detritus of mm-scale. The discovery of tempestites and storm deposites reveals that the stratum is formed in relatively shallow water environment,not deep water environment like the sea and ocean. Otherwise,the storm makes the sandstone being sorted better and moves to the lower position of the foresets,resulting in being contacted with hydrocarbon rock and optimize its combination with sandstone reservoir,benefiting to formation of oil and gas trap.

Key words: tempestites, storm deposites, hummocky or swaley cross-stratification, lacustrine face, Lower Cretaceous, Lingshan Island

中图分类号: 

• P512.2