Permian and Triassic Sequence Stratigraphy and Sea Level Changes of Eastern Yangtze Platform

The Permian and marine Triassic of eastern Yangtze platform, situated in eastern China, involve 19 orthosequences lasting about 2.7 Ma on average, which can be combined into five orthosequence sets ranging from 8 Ma to 12 Ma. Affected by the regional Dongwu and Indosinian movements, the sequence stratigraphic pattern and sea level changes in the Permian and Triassic of this region are distinctive and obviously different from most other regions in the world, but typical in the broad eastern Tethys and its neighboring areas. In this region not only did the continuous marine Permian and Triassic boundary sequences cause the orthosequence crossing the boundary belonging to type Ⅱ sequence but also the mesosequence including these stratigraphic intervals had its basal boundary in the upper Longlinian (Artinskian) (ca. 278 Ma), that is, the traditional Carboniferous and Permian boundary, and its top boundary moved from the Permian and Triassic boundary upward into the Anisian of Middle Triassic.

Discovery of rhyolitic tuffaceous slate in the southwestern margin of Yangtze Craton:Zircon U-Pb ages(2491 Ma)and tectonic-thermal events

The Mesoproterozoic Dongchuan Group that is widely exposed in Yimen area,central Yunnan Province is a series of sedimentary sort of low-grade metamorphic rocks interbedded with volcanic rocks,which are closely related to the early tectonic evolution of the Earth.However,its formation era,sedimentary filling sequence,and geotectonic characteristics have always been in dispute.In this study,several rhyolitic tuffaceous slate interlayers with a centimeter-level thickness were found in the previously determined Heishan Formation of the Dongchuan Group located to the western part of Yimen-Luoci fault zone.This paper focuses on the study of the rhyolitic tuffaceous slate in Qifulangqing Village,Tongchang Township,Yimen County.LA-ICP-MS zircon dating was conducted,achieving the crystallization age of magma of 2491±15 Ma and the metamorphic ages of about 2.3 Ga,2.0 Ga,and 1.8 Ga for the first time.Meanwhile,according to in-situ Hf isotope analysis,the zirconεHf(t)values were determined to range from−3.0 to 7.6,with an average of 2.7.Furthermore,the first-stage Hf model age(TDM1)was determined to be 2513−2916 Ma,indicating that the provenance of the rhyolitic tuffaceous slate is the depleted mantle or juvenile crust between the Middle Mesoarchean and the Late Neoarchean.Therefore,it is believed that the strata of the slate were deposited in the Late Neoarchean,instead of the Mesoproterozoic as determined by previous researchers.Accordingly,it is not appropriate to group the strata into the Mesoproterozoic Dongchuan Group.Instead,they should be classified as the Maolu Formation of the Neoarchean Puduhe Group given the lithologic association and regional information.Furthermore,the magma ages of 2491±15 Ma are highly consistent with the eras of the large-scale Late Neoarchean orogenic magmatic activities on the northern margin of the Yangtze Craton,and thus reflect the orogenic process consisting of subduction and collision from Late Neoarchean to Early Paleoproterozoic.The magmatic activities during this period were possibly caused by the convergence of the supercontinent Kenorland.Meanwhile,the metamorphic ages of 2.3 Ga,2.0 Ga,and 1.8 Ga are highly consistent with three metamorphic ages of 2.36 Ga,1.95 Ga,and 1.85 Ga of the northern margin of the Yangtze Craton,indicating that the strata experienced Paleoproterozoic tectonic-thermal events.The study area is located on the eastern margin of Qinghai-Tibet Plateau,and thus was possibly re-transformed by magmatism subjected to the subduction of the Meso-Tethys Ocean during the Early Cretaceous.The discoveries made in this study will provide strong petrological and chronological evidence for analyzing the early crustal evolution of the Yangtze block.

Sinian hydrocarbon accumulation conditions and exploration potential at the northwest margin of the Yangtze region, China

Based on outcrop, drilling, logging and seismic data, the reservoir forming conditions, reservoir forming model and exploration potential of the ultra-deep Sinian Dengying Formation at the northwest margin of Yangtze craton region were examined.(1) This area is in craton rifting stage from Sinian to Early Cambrian, characterized by syn-sedimentary faults and rapid subsidence, significant sedimentary differences, and development of Dengying Formation platform margins on both sides of the rift.(2) The Sinian–Cambrian in this area has two sets of high-quality source rocks, Doushantuo Formation and Maidiping-Qiongzhusi Formation;of which, the latter has a thickness of 150–600 m and hydrocarbon generation intensity of(100-200)×10;m;/km;.(3) The mounds and shoals in the platform margin of Sinian Dengying Formation controlled by faults are thick and distributed in rows and zones;they are reformed by contemporaneous–quasi-contemporaneous and supergene karstification jointly, forming pore-type reservoirs with a thickness of 200-400 m.(4) The two sets of source rocks enter oil generation windows from Permian to Early Triassic, and the oil migrates a short distance to the lithologic traps of mounds and shoals to form a huge scale paleo-oil reservoir group;from Late Triassic to Jurassic, the oil in the paleo-oil reservoirs is cracked into gas, laying the foundation of present natural gas reservoirs.(5) The mound-shoal body at the platform margin of Dengying Formation and the two sets of high-quality source rocks combine into several types of favorable source-reservoir combinations, which, with the advantage of near-source and high-efficiency reservoir formation, and can form large lithologic gas reservoirs. The Mianyang-Jiange area is a potential large gas field with trillion cubic meters of reserves. According to seismic prediction, the Laoguanmiao structure in this area has the Deng-2 Member mound-shoal reservoir of about 1300 km^(2), making it a ultra-deep target worthy of exploration in the near future.

Geochronology and geochemistry of lithium-rich tuffs in the Sichuan basin,western Yangtze:Implication for the magmatic origin and final closure of eastern Paleo-Tethys

The felsic volcanogenic tuffs named"green-bean rocks"(GBRs),characterized by a green or yellowish green color,are widely distributed in the western Yangtze platform and have a high lithium content(286-957 ppm).This paper studies the ages,origin and tectonic setting of the GBRs in the Sichuan basin on the western margin of the Yangtze platform through the whole-rock geochemistry and zircon trace elements by using U-Pb dating and Hf-O isotopes.The GBR samples from the Quxian and Beibei sections yielded zircon U-Pb ages of 245.5±1.8 Ma and 244.8±2.2 Ma.These samples can be used as the isochronous stratigraphic marker of the Early-Middle Triassic boundary(EMTB)for regional correlation.The whole-rock and zircon geochemistry,and zircon Hf-O isotopes exhibited S-type geochemical affinities with high positiveδ^(18)0 values(9.28‰-11.98‰),low negativeε_(Hf)(t)values(-13.87 to-6.79),and T_(DM)^(2)ages of 2150-1703 Ma,indicating that the lithium-rich GBRs were generated by the remelting of the pre-existing ancient Paleoproterozoic layer without mantle source contamination in the arcrelated/orogenic tectonic setting.The results of this study demonstrate that the lithium-rich GBRs in the western Yangtze platform were derived from arc volcanic eruptions along the Sanjiang orogen,triggered by the closure of the eastern Paleo-Tethys Ocean and the syn-collision between the continental Indochina and Yangtze blocks at ca.247 Ma.This was marked by a major shift from I-type magmas with intermediateε_(Hf)(t)values to S-type magmas with low negativeε_(Hf)(t)values.Collectively,our results provide new insights into the origin of the GBRs and decodes the closure of the eastern Paleo-Tethys.

宜昌地区灯影组深层丘滩相碳酸盐岩储层特征

宜昌地区灯影组顶部发育微生物碳酸盐岩沉积,由藻叠层石、藻球粒、凝块石等微生物丘建造,以及藻砂屑、滑塌角砾等颗粒云岩组成,属于典型台缘浅滩—台缘斜坡相沉积。顶部高能颗粒滩相带发育大量蜂窝状溶蚀孔洞,深层碳酸盐岩孔隙度平均9.81%,为优质中孔中渗碳酸盐岩储层,是鄂西地区油气勘探开发的重要层系。

四川盆地东缘寒武系盐下油气勘探领域探讨

地球物理资料显示四川盆地东缘齐岳山附近寒武系高台组膏盐岩层下深部存在逆冲构造,其形成过程以及油气地质意义未见深入研究。笔者等综合四川盆地东部石柱地区线束三维和建南地区二维地震反射资料,并结合钻井资料以及区域地质研究成果,从构造继承性的角度探讨四川盆地震旦系灯影组台缘带类型,并分析了川东地区寒武系盐下油气圈闭特征。研究获得如下认识:①川东齐岳山北段构造变形强烈,普遍发育基底卷入构造,构造样式受青白口纪—南华纪裂谷与转换带构造位置的控制。②依据构造继承关系将盆内灯影组台缘带划分为德阳—安岳地区原生型台缘带、万源—达州地区继承型台缘带以及石柱地区继承—改造型台缘带。③依据青白口纪—南华纪裂谷的分布和后期构造作用影响大小,认为沿齐岳山向南至南川一带存在与石柱地区相似的灯影组继承—改造型台缘带,忠县、南川以西存在灯影组继承型台缘带。④研究区新元古界—下寒武统烃源岩、灯影组—龙王庙组滩相白云岩储层与寒武系膏盐岩层系构成完整的生储盖组合。⑤寒武系盐下基底逆冲可形成成排、成带的构造,与灯影组继承—改造型台缘带、龙王庙组滩相白云岩储层配置,形成断层相关的构造—岩性圈闭带,成为川东地区油气规模聚集有利区。研究认为四川盆地东部石柱地区震旦纪—早寒武世早期继承了青白口纪—南华纪裂谷构造特征,燕山期构造反转,高台组盐下形成基底卷入逆冲构造,具备生储盖等基本石油地质条件,具有重要的油气勘探现实意义。

扬子地台西南缘铅锌成矿作用与找矿模型

川滇黔地区作为中国西南地区重要的铅锌工业基地之一,区内成矿条件优越,产有一批不同规模的铅锌矿床,但随着逐年开采,后续接替资源储备不断减少,急需寻找和发现新的矿产地。前人对该区铅锌矿床开展了一系列富有成效的研究工作,取得了诸如后生、碳酸盐岩容矿和构造控矿等一系列的共识。除了以上共识外,当前在成矿流体的通道、容矿空间的形成,成矿物质的来源,成矿时代及成矿背景,找矿模型的建立等方面仍然存在较大争议。本文在总结典型铅锌矿床地质特征的基础上,通过对成矿物质来源、成矿要素、成矿时代及背景等方面的研究成果梳理,总结出区内铅锌矿床成矿物质主要来源于围岩及下伏地层,控矿要素主要有地层、岩性、构造,成矿作用主要形成于印支晚期扬子板块与印支板块碰撞后的伸展环境,建立了扬子地台西南缘区域成矿模式,形成了以找矿要素为核心的综合找矿模型,为该区铅锌矿床找矿勘查提供了依据。

Geophysical evidence for thrusting of crustal materials from orogenic belts over both sides of the Yangtze Block and its geological significance

Based on deep geophysical detections, we have reconstructed the crustal structure from the eastern margin of the Tibetan Plateau to the Jiangnan-Xuefeng orogenic belt. The results suggest that the Yangtze Block was overthrusted by crustal materials in its NW direction from the eastern Tibetan Plateau but in its SE direction from the Jiangnan orogen. These overthrusting effects control the crustal structure from the western Sichuan to the western area of the Jiangnan orogen-Xuefeng orogenic belt. The eastward extruded materials from the eastern Tibetan Plateau were blocked by the rigid basement in the Sichuan Basin, where upper-middle crust was overthrusted whereas the lower crust was underthrusted beneath the Sichuan Basin. The underthrusted unit was absorbed by crustal folding, shortening and thickening in the Yangtze Block, forming the Xiongpo and Longquan Mountains tectonic belts and resulting in the NW-directed thrusting of the Pujiang-Chengdu-Deyang fault, and the western hillsiden fault in the Longquan Mountain. These results provide resolution to the controversy where the eastward extrusion material from the Qinghai-Tibet Plateau had gone. Overall, that Yangtze Block was subjected to thrusting of the crustal materials from the orogenic belts over its both sides. This finding has implications for the study of the intracontinental orogenic mechanism in South China, the reconstruction of tectonic evolutionary history and the kinematics processes during the lateral extrusion of the Tibet Plateau.

扬子地台西南缘康滇断隆带海孜双峰式侵入岩体年代学、地球化学及其地质意义

海孜辉绿岩-花岗斑岩双峰式侵入岩体位于扬子地台西南缘康滇断隆带中的武定-元江裂陷槽内,本文对海孜辉绿岩和花岗斑岩主要进行了LA-ICP-MS锆石U-Pb定年和地球化学研究。花岗斑岩的定年结果为1764±18Ma,辉绿岩的定年结果为1765±5.4Ma。岩相学及地球化学测定数据显示海孜地区辉绿岩具有细粒和粗粒两种结构,与花岗斑岩之间存在明显的组分间断,形成双峰态,其中花岗斑岩为钙碱性（Si O2=70.93%～73.04%,σ=1.28）,辉绿岩属过碱性（Si O2=42.46%～48.26%,σ=15.3）,Hf同位素特征表明两者可能均与幔源母岩浆相关。而海孜双峰式分布特征显示大陆裂谷拉张环境的构造背景,暗示海孜岩体是1.7Ga时昆阳裂谷裂解时期产物,与全球Columbia超大陆的裂解事件相呼应。作为扬子地台西南缘首次发现的1.7Ga双峰式侵入岩,海孜双峰式侵入岩的发现具有重要的地质意义。

中扬子地区海相天然气勘探方向、关键问题与勘探对策

中扬子地区古生界海相层系与上扬子地区具有相似的油气地质基本条件,但经历了长期、曲折的勘探历程,久攻未克。研究分析中扬子地区区域构造、沉积演化,烃源岩、储层沉积相带、成藏组合,认为中扬子地区发育以震旦系、寒武系为勘探主要目的层的下组合和以二叠系、三叠系为主的上组合两个含油气组合,具备发现常规天然气和页岩气的良好石油地质条件,资源潜力大,是寻找规模天然气的重点勘探潜力区。提出上组合有效勘探区域主要为鄂西渝东石柱复向斜、江汉平原区沉湖—土地堂复向斜、当阳复向斜和湘鄂西区的利川复向斜南部地区;下组合勘探以鄂西渝东石柱复向斜及湘鄂西区为有利分布区;湘鄂西区是寒武系牛蹄塘组页岩气勘探有利区,枝江—当阳区块为奥陶系五峰组—志留系龙马溪组页岩气勘探有利区。在勘探思路上,应坚持以构造演化及成藏演化为主线,以储层和保存评价为重点,常规油气与非常规油气并举,强化技术攻关,实现中扬子海相勘探的大突破。

华北地台东缘新元古代地层对比和宏体化石研究的进展和发展趋势

尽管利用多重地层学方法,对华北地台东缘新元古代地层的划分和对比研究取得了很大的进展,但仍然存在很多争议和问题。今后应在以下几方面展开研究:①寻找新元古代Rodinia超大陆热构造事件和冰川事件的地层学标志,厘定这些标志在地层柱中的位置及其与宏体化石演化阶段的对应关系;②结合碳酸盐岩中C、O和Sr同位素地层学研究,寻找和鉴别新元古代地层中的火山岩和火山碎屑岩,测定其中锆石的U-Pb年龄,解决与华南地区新元古代年代地层的对比问题;③划分“辽南生物群”和“淮南生物群”的不同生物组合,明确各组合的演化历程,深入探讨其谱系归属及与华南地区晚新元古代生物群的关系,完善华北地台东缘新元古代生物地层划分和对比的方案。

扬子地台西缘淌塘花岗岩的地球化学特征及锆石U-Pb定年

淌塘花岗岩岩体位于扬子地台西缘,岩石类型为钾长花岗岩。为了揭示其成因意义,本文对淌塘花岗岩体进行了SHRIMP锆石U-Pb定年和地球化学研究。地球化学及岩石学研究的结果显示淌塘花岗岩具有高硅（SiO2=72.70%~77.95%）、高碱（ALK=5.68%~7.32%）、过铝质（ASI=1.41~1.78）的特征,K2O/Na2O平均值为1.18,CaO、MgO含量偏低,其岩石系列为高钾钙碱性系列,属于强过铝质S型花岗岩,其稀土元素含量偏低且轻重稀土元素差异较大（LREE/HREE=2.71~4.09）,部分微量元素的含量显著区别于地壳平均值。锆石SHRIMP U-Pb定年结果获得其成岩年龄为1 063.2±6.9 Ma,属于格林威尔造山期运动产物。地球化学研究表明该花岗岩是由地壳中的泥质岩经过部分熔融形成的,其双峰式的岩浆岩组合模式和Al2O3-SiO2构造环境判别图的投图结果均显示该花岗岩的形成与裂谷环境密切相关,这与1.0 Ga时扬子地台西缘的大地构造背景相呼应,其形成也对应了Rodinia超大陆的汇聚事件。

青藏高原东缘地壳上地幔电性结构研究进展

经过数十年的努力,中国学者针对青藏高原东缘地壳上地幔探测,累积完成超过20000 km的大地电磁测深剖面,取得了一系列重要科学数据和认识,为青藏高原东缘构造格局、地壳上地幔电性结构、地震机制和动力学研究奠定了基础.根据青藏高原东缘的主要构造和断裂分布特征,本文重点对龙门山构造带、川滇构造带和三江构造带三个构造带分区进行研究,主要依据大地电磁探测工作成果和壳幔电性结构特征,系统地对青藏高原东缘地壳上地幔电性结构、与扬子西缘接触关系、汶川地震和芦山地震的电性孕震环境及弱物质流通道等几个方面进行了梳理和分析.一是青藏高原东缘地壳表层岩块和物质沿壳内高导层向龙门山造山带仰冲推覆,表现为逆冲推覆特征的薄皮构造;二是高原东部地壳中下部及上地幔顶部向龙门山造山带和上扬子地块西缘岩石圈深部俯冲,呈现刚性的上扬子地块西缘高阻楔形体向西插入柔性青藏块体的楔形构造;三是将汶川地震和芦山地震的震源投影到大地电磁剖面上,发现震源位于剖面下方的高阻块体与低阻体之间靠近高阻体的一侧,龙门山构造带岩石圈表现出高阻、高密度和高速的"三高"特征,这种非均匀电性结构可能构成地震孕育发生条件;四是川滇和三江地区的多条大地电磁剖面探测结果表明,在青藏高原东缘中下地壳存在下地壳流和局部管道流,大地电磁结果对其空间分布形态、位置及大小进行了较好的刻画.根据研究区壳幔电性结构特征的构造解析和综合实例分析,总结了青藏高原东缘六类壳幔电性结构模型,提出了下一步重点研究领域和目标.总之,青藏高原东缘壳幔电性结构的研究对揭示研究区岩石圈结构和构造格局提供了重要依据,对油气及矿产资源远景评价提供了背景资料,对"Y"型多地震区的构造关系和发震机理研究具有重要指导意义.

扬子克拉通西北缘震旦系油气成藏条件及勘探潜力

基于露头、钻井、测井和地震资料,对扬子克拉通西北缘超深层震旦系灯影组成藏条件、成藏模式与勘探潜力进行系统研究。结果表明:①扬子克拉通西北缘震旦纪—早寒武世早期为克拉通裂陷阶段,表现为同沉积断裂发育与裂陷快速沉降,沉积分异显著,裂陷两侧灯影组发育大型台缘带;②震旦系—寒武系发育陡山沱组与麦地坪组—筇竹寺组两套优质烃源岩,其中后者厚度为150~600 m,生烃强度为(100~200)×10^(8) m^(3)/km^(2);③震旦系灯影组断控台缘带丘滩体厚度大且成排成带分布,受同生期—准同生期和表生期岩溶作用叠加改造,形成厚度为200~400 m的孔洞型储集层;④两套烃源岩主生油期在二叠纪—早三叠世,石油近距离运移至灯影组丘滩体岩性圈闭中聚集形成规模巨大的古油藏群;晚三叠世—侏罗纪古油藏裂解成气,奠定现今天然气藏基础;⑤灯影组台缘带丘滩体与两套优质烃源岩形成多种有利源储配置关系,具备近源高效成藏的条件,可形成大型岩性气藏群。绵阳—剑阁地区是潜在的万亿立方米储量规模大气区,位于该区域的老关庙构造灯影组二段丘滩体面积约1300 km2,是近期超深层勘探值得探索的目标。

海平面变化全球可比性的可靠例证——上扬子地台东南缘奥陶纪层序地层及海平面变化研究

通过对上扬子地台东南缘奥陶纪碳酸盐台地、台缘斜坡和盆地三个不同相区典型剖面的沉积学、生物地层学及岩石地层学等方面的综合研究，在该地区奥陶系中识别出时限为２ ～５ Ｍａ 的１８ 个正层序和相应的１９次海退事件，将其与塔里木、华北及北美、澳洲等大陆对比结果表明，上扬子地台东南缘奥陶纪的绝大部分三级以上海退事件及沉积层序有着良好的全球可比性。

海西—印支期上扬子南缘碳酸盐岩台地边缘沉积特征、演化及其控制因素

海西—印支期上扬子地块发育稳定型的碳酸盐岩大台地,在碳酸盐岩台地南缘台地边缘沉积体系发育,主要包括4种沉积类型:台地边缘滩,台地边缘礁、台地前缘斜坡、滩(礁)间海。据海西—印支期台缘沉积发育及分布特征,可分为4个沉积演化阶段:中泥盆世—晚泥盆世(SS1),台缘沿弥勒—师宗—晴隆—南丹—河池一线呈带状分布,台缘礁滩发育;早石炭世—早二叠世早期(SS2-SS3),台缘沿晴隆—六盘水—安顺呈带状分布,台缘生屑滩发育;早二叠世晚期—晚二叠世(SS4),沿贞丰—紫云—罗店—河池—柳州—娄底呈带状分布,台缘滩、台缘礁交互发育;早三叠世—中三叠世(SS5),沿贞丰—镇宁—贵阳—福泉一线呈带状分布,早三叠世主要发育台缘鲕粒滩,中三叠世台缘礁占优势。这4个阶段的台缘沉积特征表明:台地边缘礁滩沉积体系垂向演化受海平面变化控制,横向迁移主要受同沉积断裂控制,不同类型生物的出现和绝灭控制台缘生物礁滩的类型及特征。

扬子地台北缘寒武纪同沉积断裂控制的斜坡沉积特征

通过对扬子地台北缘寒武系剖面实测以及前人资料的综合分析,研究了同沉积断裂控制的斜坡沉积特征。斜坡区岩石类型丰富,包括砾屑石灰岩、灰泥石灰岩、硅岩和页岩等,沉积构造丰富,沉积厚度远大于台地区以及深海盆地区。断裂带在宏观上控制了扬子地台北缘寒武纪古地理分区,台地区、斜坡—深海盆地区的古地理位置在寒武纪的不同地质时期基本保持不变。寒武纪持续拉伸的构造环境造成斜坡区持续下降拗陷,从而为沉积物的堆积提供了足够大的可容空间,同时来自台地区的沉积物补给充足,导致了斜坡区相对于台地区以及深海盆地区而言具有巨厚的沉积层。

土壤地球化学测量在扬子地台西缘会泽铅锌矿带筇竹寺组中的应用

在详细的地质工作基础上,在扬子地台西缘会泽铅锌矿带新发现含矿层位筇竹寺组中,采用土壤地球化学测量,同时配合物探,进行1∶5 000的大比例尺找矿工作。通过对研究区土壤地球化学异常浓集区进行找矿工程查证,异常浓集中心与新发现矿体吻合较好,表明土壤地球化学测量在该区找矿效果显著,值得在邻区进一步推广。

川东忠县—鱼池地区二叠系—三叠系海槽相、台缘相的发现及勘探意义

川东—鄂西地区晚二叠世—早三叠世发育开江—梁平海槽与城口—鄂西海槽,明确环海槽分布的台地边缘及沉积相带展布对指导二叠系—三叠系礁滩气藏的勘探开发具有重要现实意义。基于川东忠县—鱼池地区窑厂、千野草场、楠木桠和三墱坡剖面长兴组—飞仙关组的现场实测和系统取样分析,结合钻井资料和建南地区前期研究成果,认为大池干—石宝寨—高峰场区块为开阔台地相沉积,而开江—梁平海槽主体未向该区延伸;忠县—鱼池地区发育海槽相深水沉积,开江—梁平海槽与建南地区浅水陆棚直接相连,向东直接连通城口—鄂西海槽主体,其两侧发育台地边缘相礁滩沉积。通过确定台地边缘平面展布规律,进一步扩展了研究区内台地边缘分布范围,为川东地区二叠系—三叠系礁滩气藏的勘探开发揭示了全新的领域。

华北地台东缘早元古代隆-滑构造模式

研究华北地台东部边缘早元古代拉伸构造及与变质核杂岩的比较,提出了隆-滑构造模式。它一般发生在大规模收缩造山作用之前,由于区域拉伸作用,导致下地慢上隆,形成岩浆隆起或基底隆起,使上覆盖层发生重力滑脱。该模式由核部隆起、上部盖层和其间的拆离韧性剪切带组成。核部隆起一般由岩浆隆起(辽吉地区)或基底隆起(胶北地区)构成;上部盖层内发育有顺层滑脱构造系,由底部主滑脱面和内部次级滑脱面及其间的流褶层、片理化带构成。靠近核部隆起的盖层表现为正向滑脱,而滑脱前缘则表现为反向滑脱,具有滑覆特征。