摘要
末端扇出现在有沉积物负载的河流末端蒸发和流量损失消减的地方,多形成于干旱或半干旱的环境中。Mukerji等于上世纪70年代提出了末端扇的沉积学概念,然而在中国至今仍未见这方面的研究。通过对国外多年来末端扇沉积相模式的发展分析,本次以岩心描述和测井相分析为手段,对濮城油田古近系沙河街组沙二上亚段2+3砂组进行了研究,在国内首次提出了末端扇这一沉积相类型,并将其分为三个亚相:近端亚相、中部亚相和远端亚相。研究区中部亚相可进一步细分为分流河道、泥滩、水道漫溢三个沉积微相,分流河道是本区占主导地位的骨架砂体,反映了河流能量的损失和流量的时空波动。本次研究建立了研究区末端扇的沉积模式,根据岩心微相分析和砂体平面展布分析,对该区沉积微相进行了研究,掌握了沉积微相的时空展布和变化规律。
Terminal fan occur where sediment-laden streams decrease in size and vanish as a result of evaporation and transmission losses. They tend to form in arid or semi-arid region which is characterized by a moisture deficit. Mukerji et al. raised the sedimentological concept in the 1970s, however, in China, there has been no study in this aspect as yet. By the analyzing of well log data and careful core descriptions, terminal fan has been put forward on the 2nd to 3rd layer, Upper 2nd Sub-member,Shahejie Formation in the Pucheng oilfield for the first time in China. The model includes a tripartite zonation of terminal fan into proximal, middle and basinal zones. The main sedimentary microfacies of middle zones include distributary channel, mudflat and overbank. Distributary channel patterns are characteristic of terminal fan, and reflect both loss of stream power and spatially--temporally fluctuating discharge. The sedimentary model of the terminal fan is established; the sedimentary microfacies of the Pucheng oilfield are described in detail on the base of depositional sequence and sandbody geometry.
出处
《地质论评》
CAS
CSCD
北大核心
2007年第2期170-179,共10页
Geological Review
关键词
末端扇
濮城油田
沉积微相
分流河道
沉积模式
Terminal fan
Pucheng oilfield
sedimentary microfacies
distributary channel
sedimentary model
