摘要
在野外剖面和岩心观察基础上,介绍了柴达木盆地西部古近系湖相风暴岩沉积特征,建立了湖泊风暴沉积模式,探讨风暴岩发育条件及意义.研究区风暴沉积是由风暴浪作用于浅湖泥坪上,使沉积物搅起、形成泥岩砾屑,并通过风暴流搬运到三角洲或滨浅湖滩坝中,与未固结砂质沉积物一起沉积形成.其典型沉积构造特征丰富,单层风暴沉积发育不完整,常见多次风暴作用形成若干不完整风暴岩叠置层.风暴岩的发现有利于加深对该区沉积相的认识,风暴岩频繁发育,表明研究区在古近系沉积时,易受到古气候影响,湖盆水动力较强,部分原始沉积砂体会受到湖泊水体的改造,形成新的滨浅湖滩坝砂体,形成良好的岩性油气藏.
Based on the field section and cores obserw/tion, this paper presents the characteristics of lacustrine elastic tempestites in Paleogene of Tsaidam Basin, sets up the storm deposition model in this area, including the conditions and significance of the tempestite formation. The tempestites are composed of unconsolidated arenaceous sediment and boulder clay, which were from the sediments of mere mudflat churned up by storm wave, and transported to delta and beach bar of shore shallow lake. A plenty of the sedimentary structures of typical tempestite appears with less of monolayer storm sediment, and the superposed half-baked tempestites formed by polygenic storm wave are often observed. The existence of tempestites is helpful to in-depth understanding of sedimentary facies in this area, indicating that the Tsaidam was subjected to influence of the paleoclimate in this area, and the hydrodynamic force of lacustrine basin was correspondingly intensified. Parts of original sandy sediments were vulnerable to be reconstructed, shaping new beach bar of shore shallow lake. It is suggested that the tempesite sand body can be as a favorable reservoir rock and could form prospective lithologic hydrocarbon reservoir.
出处
《新疆地质》
CAS
CSCD
北大核心
2011年第2期125-129,共5页
Xinjiang Geology
关键词
柴达木盆地
古近系
风暴岩
沉积模式
Tempestite
Sedimentary model
Tsaidam basin
Paleogene
