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从近年来对甘肃敦煌党河和敦煌阿克塞河进行的详细的工作中发现了在现代边滩砂级颗粒中也会发育叠瓦构造,且远比砾石中的叠瓦构造复杂。首先,研究发现砂级叠瓦构造的倾角比砾石叠瓦构造的倾角变化要大,介于12°~88°之间,倾角均值在51°~63°,明显大于同河段砾石叠瓦构造的倾角34°,倾角如此之大可能与颗粒的紧密堆积有关;其次,倾向无砾石叠瓦构造那么稳定,有时可在小范围内呈现出双倾向。叠瓦构造倾角的统计分析数据也表明其稳定性不好;三是砂级叠瓦构造可以受薄层的控制,也可以呈层块状;四是根据砂级颗粒的接触关系又可以将其分为两种:颗粒支撑的叠瓦构造和含杂基的颗粒支撑叠瓦构造。颗粒支撑的叠瓦构造发育在“清水”环境,一般是在洪水的稳定期形成的;而含杂基的颗粒支撑砂级叠瓦构造则是发育在浊水环境,可能是在洪水的高峰时期形成的。砂级叠瓦构造的研究对于沉积环境的研究、古流分析和储层的研究具有重要的意义。颗粒支撑的砂级叠瓦构造还可以形成特殊的屏蔽孔隙,成为很好的储集空间,是砂岩储层出现各向异性的根本。
From the detailed work carried out in recent years on the Dunhuang Danghe and Dunhuang Aksai rivers in Gansu province, it has been found that the shoal structure developed in the modern beach sand grade granite is much more complex than the shingles in the gravel. First of all, it is found that the dip angle of the sand-graded tile structure is larger than that of the gravel shingle structure, ranging from 12 ° to 88 ° and the mean value of dip angle is from 51 ° to 63 °, which is obviously larger than that of the gravel shingle structure The inclination of 34 ° may be related to the close accumulation of particles. Second, the tendency to non-gravel shingle structure is so stable that it sometimes shows a double dip within a small area. The statistical analysis of the dip angle of the shingled tile also shows that its stability is not good. The third is that the sand-graded tile structure can be controlled by thin layers and can also be layered. Fourthly, according to the contact relationship of sand-grained particles, Divided into two types: granular support shingle structure and heterogeneous particle support shingle structure. Particle-supported shingles are developed in a “clear water” environment and are generally formed during the flood’s stabilization period; while the heterogeneous particle-bearing sand-graded tile structures are developed in a turbid water environment, probably in flood Formed during the peak Research on sand-graded tile structure is of great significance to the study of sedimentary environment, paleo-current analysis and reservoir research. Sand-graded tile structure with particle support can also form special shielding pores and become a good reservoir space, and is the fundamental anisotropy of sandstone reservoirs.