哈萨克斯坦Marsel探区下石炭统碳酸盐岩微相特征与沉积环境

根据薄片和岩心资料，识别出哈萨克斯坦Marsel探区下石炭统43种微相类型(MF)和10种微相组合样式(MA)。其中，MF1—MF3为灰泥灰岩，形成于外缓坡或局限低能环境；MF4—MF13为粒泥灰岩，形成于内缓坡泻湖—潮缘带、中缓坡或外缓坡环境；MF14—MF20为泥粒灰岩，形成于局限及低能的内缓坡环境；MF21—MF34为颗粒灰/云岩，多形成于内缓坡潮下带—中缓坡浅滩环境；MF35—MF37为晶粒白云岩，形成于蒸发潮坪环境；MF38—MF43为细粒碎屑岩，主要形成于内缓坡—中缓坡环境。微相组合样式主要包括中—外缓坡微相组合(MA2)、中—低能浅滩微相组合(MA1、MA8)、中缓坡混积微相组合(MA5)、中—高能浅滩—潮坪微相组合(MA6、MA7、MA9)、内缓坡泻湖—潮坪微相组合(MA3)、内缓坡碎屑潮坪微相组合(MA4)和混积潮坪微相组合(MA10)。通过亚相和微相组合分析，认为研究区早石炭世属于缓坡型台地沉积模式。杜内阶—维三段早期，相对海平面缓慢—快速上升，总体以内—中缓坡低能局限泻湖—潮坪和中—外缓坡沉积为主；维三段中期—谢尔普霍夫阶期，相对海平面缓慢—快速下降，主要发育内缓坡低能局限泻湖—潮坪和蒸发潮坪沉积，局部地区发育浅滩和混积潮坪沉积。

Microfacies and Sedimentary Environment of the Lower Carboniferous Carbonates in the Marsel Exploration Area,Kazakhstan

Based on thin sections and drill core data, 43 microfacies (MF) and 10 microfacies association (MA) patterns are identified in the Marsel exploration area in Kazakhstan. The MA comprises five rock types, representing different sedimentary environments: mudstone (MF1-MF3) deposited in the outer ramp or low energy restricted environment; wackstone (MF4-MF13) deposited in lagoons and peritidal flat of the inner, middle or outer ramp; packstone (MF14-MF20) deposited in the low energy restricted inner ramp; grainstone (MF21-MF34) deposited in subtidal area of the inner ramp and shoals of the middle ramp; crystalline dolostone (MF35-MF37) deposited in evaporate tidal flat; fine grained clastic rocks (MF38-MF43) deposited in the inner middle mixed ramp. Types of MA include deposits of the middle outer ramp (MA2), middle low energy shoal (MA1, MA8), middle ramp mixed (MA5), middle high energy shoal and tidal flat (MA6, MA7, MA9), lagoon and tidal flat of the inner ramp (MA3), clastic tidal flat of the inner ramp (MA4), and mixed tidal flat (MA10). Through subfacies and microfacies association analysis, a ramp sedimentary model is established for the Early Carboniferous depositional environment in the Marsel area: During the deposition of the Tournasian lower Visean 3 member, low energy restricted lagoon and tidal flat of the inner middle and middle outer ramp deposits are developed as the relative sea level rises from slow to rapidly. During the deposition of middle Visean 3 member Serpukhovian, low energy restricted lagoon, tidal flat and evaporate tidal flat of the inner ramp deposits were widely developed with local shoals and mixed tidal flat, as the relative sea level falls from slow to rapidly.