古地理学报
古地理學報
고지이학보
JOURNAL OF PALAEOGEOGRAPHY
2010年
1期
69-81
,共13页
吴因业%张天舒%张志杰%崔化娟
吳因業%張天舒%張誌傑%崔化娟
오인업%장천서%장지걸%최화연
层序地层学%储集层%体系域%沉积体系%可容空间
層序地層學%儲集層%體繫域%沉積體繫%可容空間
층서지층학%저집층%체계역%침적체계%가용공간
sequence stratigraphy%reservoir%systems tract%depositional system%accommodation
不同学者对体系域的分类及体系域界面的划分有不同的理解,甚至在体系域的发育和分布上,不同盆地都会得出不同的研究结论.滨线迁移类型决定了特定沉积趋势下地层单元的外形和堆积模式,即体系域类型.文中把体系域划分为常规体系域和非常规体系域两大类,常规体系域指经典层序地层学中定义的常见体系域,即低位体系域、海侵体系域(或湖侵体系域)和高位体系域,这些体系域与基准面(相对海平面或相对湖平面)变化引起的滨线迁移密切相关.非常规体系域泛指常规体系域以外的与特定沉积环境相关的所有体系域类型,包括冲积扇一河流沉积体系中的高可容空间体系域和低可容空间体系域、缓坡背景下滨浅海的强制海退体系域、大陆架背景下浅海一深海体系的下降期体系域、滨浅海(湖)环境的海退体系域(或湖退体系域).体系域和基准面关系的可预测性使得层序地层学成为一种寻找盆地内自然资源的极为有效的工具,通过它可以追踪盆地演化不同体系域阶段沉积相的横向变化,帮助认识有经济价值的沉积矿床以及油气储集层、烃源岩和盖层在时间和空间范围内的发育区.这也导致了油气勘探从构造圈闭向复合圈闭和岩性圈团的转变.
不同學者對體繫域的分類及體繫域界麵的劃分有不同的理解,甚至在體繫域的髮育和分佈上,不同盆地都會得齣不同的研究結論.濱線遷移類型決定瞭特定沉積趨勢下地層單元的外形和堆積模式,即體繫域類型.文中把體繫域劃分為常規體繫域和非常規體繫域兩大類,常規體繫域指經典層序地層學中定義的常見體繫域,即低位體繫域、海侵體繫域(或湖侵體繫域)和高位體繫域,這些體繫域與基準麵(相對海平麵或相對湖平麵)變化引起的濱線遷移密切相關.非常規體繫域汎指常規體繫域以外的與特定沉積環境相關的所有體繫域類型,包括遲積扇一河流沉積體繫中的高可容空間體繫域和低可容空間體繫域、緩坡揹景下濱淺海的彊製海退體繫域、大陸架揹景下淺海一深海體繫的下降期體繫域、濱淺海(湖)環境的海退體繫域(或湖退體繫域).體繫域和基準麵關繫的可預測性使得層序地層學成為一種尋找盆地內自然資源的極為有效的工具,通過它可以追蹤盆地縯化不同體繫域階段沉積相的橫嚮變化,幫助認識有經濟價值的沉積礦床以及油氣儲集層、烴源巖和蓋層在時間和空間範圍內的髮育區.這也導緻瞭油氣勘探從構造圈閉嚮複閤圈閉和巖性圈糰的轉變.
불동학자대체계역적분류급체계역계면적화분유불동적리해,심지재체계역적발육화분포상,불동분지도회득출불동적연구결론.빈선천이류형결정료특정침적추세하지층단원적외형화퇴적모식,즉체계역류형.문중파체계역화분위상규체계역화비상규체계역량대류,상규체계역지경전층서지층학중정의적상견체계역,즉저위체계역、해침체계역(혹호침체계역)화고위체계역,저사체계역여기준면(상대해평면혹상대호평면)변화인기적빈선천이밀절상관.비상규체계역범지상규체계역이외적여특정침적배경상관적소유체계역류형,포괄충적선일하류침적체계중적고가용공간체계역화저가용공간체계역、완파배경하빈천해적강제해퇴체계역、대륙가배경하천해일심해체계적하강기체계역、빈천해(호)배경적해퇴체계역(혹호퇴체계역).체계역화기준면관계적가예측성사득층서지층학성위일충심조분지내자연자원적겁위유효적공구,통과타가이추종분지연화불동체계역계단침적상적횡향변화,방조인식유경제개치적침적광상이급유기저집층、경원암화개층재시간화공간범위내적발육구.저야도치료유기감탐종구조권폐향복합권폐화암성권단적전변.
Different scholars have different understanding about the classification of systems tract and division of systems tract surface. Even with regard to the development and distribution of systems tract, they have different conclusions from different basins. The shapes and accumulative models of strata unit, i.e. the types of systems tracts in a given depositional trend depend on types of shoreline shift. Systems tracts are divided into conventional and unconventional ones in this paper. The conventional systems tract is the common systems tract defined in classical sequence stratigraphy, which includes highstand systems tract (HST), lowstand systems tract (LST) and transgressive systems tract (TST)(lacustrine transgressive systems tract). They are closely related to shoreline shift which is caused by base-level (relative sea level or relative lake level) changes. The unconventional systems tract includes all other systems tracts in given depositional environments except the conventional systems tract, which are low-and high-accommodation systems tracts (LAST, HAST) in alluvial fan-fluvial depositional system, coastal to shallow marine forced regression systems tract (FRST) in gentle slope depositional environment, shallow to deep marine falling stage systems tract (FSST) in continental shelf depositional environment, and coastal to shallow marine (lacustrine) regressive systems tract (RST). The predictability of the connection between systems tracts and base-level changes makes sequence stratigraphy as an effective tool in finding natural resources. By means of sequence stratigraphy, we can trace the lateral changes of sedimentary facies at different systems tracts stages of basin evolution and understand the economically valuable sedimentary facies. They are sedimentary deposits and the development districts of reservoirs, source rocks and cap rocks in space and time. This also leads to a conversion from structural trap to combination and lithologic traps in oil and gas exploration.