现代地质
現代地質
현대지질
GEOSCIENCE-JOURNAL OF GRADUATE SCHOOL CHINA UNIVERSITY OF GEOSCIENCES
2001年
1期
74-82
,共9页
梅冥相%马永生%戴少武%吕廷志%张国常%王甘露%谭代友
梅冥相%馬永生%戴少武%呂廷誌%張國常%王甘露%譚代友
매명상%마영생%대소무%려정지%장국상%왕감로%담대우
盆地充填序列%晚古生代%生储盖组合%南盘江盆地
盆地充填序列%晚古生代%生儲蓋組閤%南盤江盆地
분지충전서렬%만고생대%생저개조합%남반강분지
以米级旋回层序为基本工作单元,米级旋回层序在长周期三级层序中的有序叠加形式为基础,在南盘江盆地晚古生代地层中共识别出25个三级层序(沉积层序);以构造不整合面为准,又可进一步归为4个二级层序(构造层序)。根据地层、沉积特征及构造地质涵义,把层序界面归纳为4种类型:构造不整合面、沉积不整合面、淹没不整合面以及它们的相关面,其中构造不整合面类似于类型Ⅰ界面,沉积不整合面类似于类型Ⅱ界面。晚古生代南盘江盆地存在两个明显的造礁期。于三级海平面上升阶段主要发育礁滩相灰岩构成的储层;而在与三级海平面下降相关的强迫型海退过程中则发育白云岩构成的储层。因此,可把南盘江盆地区域性的潜在生储盖组合拟定为3个:以孤立台地上泥盆系生物礁和加里东运动不整合面为主要勘探对象的下组合;以石炭系大埔组白云岩为主要勘探对象的中组合;以茅口组上部和长兴组生物礁及礁顶相白云岩、东吴运动不整合面为主要勘探对象的上组合。
以米級鏇迴層序為基本工作單元,米級鏇迴層序在長週期三級層序中的有序疊加形式為基礎,在南盤江盆地晚古生代地層中共識彆齣25箇三級層序(沉積層序);以構造不整閤麵為準,又可進一步歸為4箇二級層序(構造層序)。根據地層、沉積特徵及構造地質涵義,把層序界麵歸納為4種類型:構造不整閤麵、沉積不整閤麵、淹沒不整閤麵以及它們的相關麵,其中構造不整閤麵類似于類型Ⅰ界麵,沉積不整閤麵類似于類型Ⅱ界麵。晚古生代南盤江盆地存在兩箇明顯的造礁期。于三級海平麵上升階段主要髮育礁灘相灰巖構成的儲層;而在與三級海平麵下降相關的彊迫型海退過程中則髮育白雲巖構成的儲層。因此,可把南盤江盆地區域性的潛在生儲蓋組閤擬定為3箇:以孤立檯地上泥盆繫生物礁和加裏東運動不整閤麵為主要勘探對象的下組閤;以石炭繫大埔組白雲巖為主要勘探對象的中組閤;以茅口組上部和長興組生物礁及礁頂相白雲巖、東吳運動不整閤麵為主要勘探對象的上組閤。
이미급선회층서위기본공작단원,미급선회층서재장주기삼급층서중적유서첩가형식위기출,재남반강분지만고생대지층중공식별출25개삼급층서(침적층서);이구조불정합면위준,우가진일보귀위4개이급층서(구조층서)。근거지층、침적특정급구조지질함의,파층서계면귀납위4충류형:구조불정합면、침적불정합면、엄몰불정합면이급타문적상관면,기중구조불정합면유사우류형Ⅰ계면,침적불정합면유사우류형Ⅱ계면。만고생대남반강분지존재량개명현적조초기。우삼급해평면상승계단주요발육초탄상회암구성적저층;이재여삼급해평면하강상관적강박형해퇴과정중칙발육백운암구성적저층。인차,가파남반강분지구역성적잠재생저개조합의정위3개:이고립태지상니분계생물초화가리동운동불정합면위주요감탐대상적하조합;이석탄계대포조백운암위주요감탐대상적중조합;이모구조상부화장흥조생물초급초정상백운암、동오운동불정합면위주요감탐대상적상조합。
On the basis of the regulary vertical stacking patterns ofmeter-scale cyclic-sequences in the quest for a fundamental unit of stratigraphy and sedimentology, 25 third-order sedimentary sequences that could be furtherly grouped into 4 second-order tectonic sequences are discerned in Late Paleozoic of the Nanpanjiang Basin. According with the natures of stratigraphy and sedimentology as well as the meanings on tectonics, sequence boundaries might be divided into four types: tectonic unconformity that is similar to type I boundary defined by Vail et al., sedimentary unconformity that is similar to type Ⅱ boundary, drowned unconformity and their relative surfaces. There are two reef-building periods in Late Paleozoic of the Nanpanjiang Basin, which are correspond to developing periods of regional oil-generating strata constituted by basin facies shales, so the well congenital forming condition of oil and natural gas is established. In generally, the reservoir constituted by reef and grain beach limestones is formed in the rising process of third-order sea-level changes, and the dolomitic reservoir is generated in forced-regression process resulted from the falling period of third-order sea-level changes. Based on the study on sequence stratigraphy, three regionally potential association of oil-generating strata, reservoir and capping bed could be discerned in Late Paleozoic of the Nanpanjiang Basin: the lower association which Caladonian unconformity and Devonian reefs developed in isolated platform constitute its main prospecting targets; the middle association which its main prospecting target refers to dolomitic reservoir of Carboniferous Dapu Formation; the upper association which its main prospecting targets include the unconformity of Dongwu revolution as well as reef limestones and reef-top dolomites of Middle Permian Maokou Formation, and reef limestones of Late Permian Changxing Formation in isolated carbonate platform.