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1.
苏北盆地晚白垩世-古新世海侵湖泊的证据及其地质意义   总被引:5,自引:1,他引:4  
傅强  李益  张国栋  刘玉瑞 《沉积学报》2007,25(3):380-385
通过对苏北盆地钻井岩心分析研究总结得出,在晚白垩世、古新世苏北盆地曾与海相通,并遭受海侵影响。海侵的原因,可能是从晚白垩世晚期起,中国东部的地应力条件以引张力占优势,并在华北—渤海湾、苏北—南黄海和东海陆架区,发育了一系列为早第三纪巨厚沉积物所充填的半地堑箕状盆地,海水由东海向黄海海侵,造成陆架上箕状盆地在短时期内与海水相通。苏北盆地在晚白垩世泰州组—古新世阜宁组沉积形成了以全盆地阜二段、阜四段为主,局部泰二段的富含介形虫的暗色泥岩,成为该盆地的主力烃源岩。古生物以及岩矿、地球化学等方面的证据可以确定苏北盆地晚白垩世—古新世发育的湖盆环境可统称“近海湖泊”或将海侵层段称“海侵湖泊”,而至始新世戴南和三垛组沉积时则可统称内陆湖泊和河流冲积平原环境。通过对苏北盆地晚白垩世—古新世海侵湖泊的确切与充分的认识分析,不仅对苏北盆地晚白垩世—古新世时期的湖盆古地理重建,而且对烃源岩的发育与分布以及生油气潜力评价都具有重要的意义。  相似文献   

2.
全球性的构造运动末期一般伴着海退和干旱的气候环境,而蒸发岩沉积与大地构造条件紧密相关。中亚卡拉库姆盆地、阿富汗_塔吉克盆地、塔里木盆地自晚侏罗世至中新世以来至少发生了3次大规模海侵_海退旋回,每次海侵_海退均受特提斯构造事件控制。卡拉库姆盆地、阿富汗_塔吉克盆地为晚侏罗世—早白垩世蒸发岩沉积、塔里木盆地的莎车次级盆地为晚白垩世—古新世蒸发岩沉积,库车次级盆地为古新世—中新世蒸发岩沉积,形成特提斯构造域自西向东蒸发岩沉积时代逐渐变新的盐湖链。中亚及塔里木盐湖链在海侵_海退旋回的控制下,至少发生5次大规模的蒸发岩沉积,发育2种不同的蒸发岩沉积序列,分别对应3次海退期蒸发岩沉积序列及2次断续海侵期蒸发岩沉积序列,具体为晚侏罗世晚期(海退期)卡拉库姆盆地、阿富汗_塔吉克盆地蒸发岩沉积;早白垩世—晚白垩世早期(断续海侵期)阿富汗_塔吉克盆地蒸发岩沉积;晚白垩世晚期(海退期)莎车次级盆地蒸发岩沉积;古新世—中新世(断续海侵期)莎车次级盆地、库车次级盆地蒸发岩沉积;中新世晚期—上新世早期(海退期)库车次级盆地蒸发岩沉积。塔里木与中亚古盐湖发育受控于特提斯构造事件及海侵_海退旋回,而海侵_海退旋回又控制2种不同的蒸发岩沉积序列。蒸发岩沉积序列、古盐湖演化阶段、蒸发岩物质来源、沉积环境决定了盐类矿物沉积类型(单一化学岩型、陆缘碎屑岩_化学岩型),卡拉库姆盆地、阿富汗_塔吉克盆地盐类矿物与塔里木盆地相比,种类简单,反映了盆地化学岩与陆源碎屑_化学岩沉积的区别及后期构造运动对盐类矿物种类的主控作用。  相似文献   

3.
The Late Permian Dalong Formation in Hubei, Hunan, Guizhou and Guangxi in South China could be subdivided into several sedimentary types according to the lithology, indicative of the great spatial variations of both the lithology and sedimentary facies. The Dalong Formation deposited during the highest transgression of Late Permian, in particular under the anaerobic and suboxic conditions, which shows a strong linkage with the hydrocarbon source rocks. The Dalong Formation has some favorable properties such as hydrocarbon source rocks, including the sediments deposited in highest transgression sea level, the deep slope sedimentary environments and the low sedimentary rate, which raises the importance of the investigations on the sedimentary features, the geochemical properties and their relationship with the oil potential. __________ Translated from Earth Science—Journal of China University of Geosciences, 2007, 32(6): 774–780 [译自: 地球科学—中国地质大学学报]  相似文献   

4.
东特提斯域思茅盆地钾盐成矿研究进展   总被引:1,自引:0,他引:1  
王立成  刘成林  沈立建  伯英 《地质学报》2018,92(8):1707-1723
思茅盆地位于东特提斯域,其内的勐野井钾盐矿是我国唯一的前第四纪固体钾盐矿,长期以来对此钾盐矿与呵叻巨型钾盐盆地的资源量差异和成因存在着有较大争议。特别是如下几个问题:其钾盐成矿时代是晚白垩世和古新世,还是侏罗纪的争议;其物质来源还存在陆源,海源和多源的不同认识;矿床成因机理模式也悬而未决。本文在前人研究基础上,结合项目组的最新进展,对上述这些问题的进行梳理与评述认为:勐野井组地层为晚白垩世Albian-Cenomanian期,同沉积的原生钾盐也是在此时期富集成矿;钾盐成矿后期特别是约14Ma以来,受到多期次的热液流体作用,形成次生脉状钾盐:钾盐成矿物质可能以中特提斯洋侵入的海水为主,辅以陆源水体和深部流体。总结认为,思茅与呵叻等盆地在晚白垩世都是干旱沙漠环境中彼此隔绝的小湖盆,随着中特提斯洋海水自西向东的入侵,海水由思茅流向了呵叻,形成了统一的思茅-呵叻海,这个模型可以解释有关成钾物源及思茅与呵叻盆地的成钾关系。思茅盆地钾盐矿的形成和后期变化始终受到了构造活动的控制,经历了最初断陷阶段,到沉积后期受印度-欧亚大陆碰撞导致的挤压和走滑运动影响。  相似文献   

5.
以东准噶尔双井子地区巴塔玛依内山组和石钱滩组剖面为研究对象,通过岩矿鉴定、地球化学分析、锆石U-Pb定年和牙形刺挑选等方法,对巴塔玛依内山组和石钱滩组的年代学特征进行了研究。结果表明,巴塔玛依内山组火山岩的形成时间始于348. 7±2. 9Ma,318. 7±4. 2Ma之后结束,侵入岩的形成时间为255. 9±3. 5Ma,这些样品中普遍含有捕获锆石,这些锆石具有岩浆锆石的特征,年龄介于早石炭世杜内期和前寒武纪之间(354. 7~971. 2Ma),与盆地周边发育的岛弧火成岩和蛇绿岩年龄相仿,此外在石钱滩组灰岩内得到4颗牙形刺化石,分属于2个属,分别为Idiognathodus和Streptognathodus。以此为基础,通过搜集整理前人数据,得到如下结论:(1)巴塔玛依内山组火山岩地层是穿时的,从早石炭世到晚石炭世连续发育,形成时间介于348. 7±2. 9Ma~300. 4±1. 3Ma之间;(2)巴塔玛依内山组上部的石钱滩组形成于318. 7±4. 2Ma之后的晚石炭世;(3)卡拉麦里蛇绿岩所代表的准噶尔洋盆闭合时间在晚泥盆世法门期和348. 7Ma之间;(4)准噶尔盆地基底可能由岛弧和洋壳组成,且存在前寒武纪基底。本研究旨在确定巴塔玛依内山组和石钱滩组地层时代,并为卡拉麦里洋闭合时限以及盆地基底性质等问题的解决提供依据。  相似文献   

6.
赵志刚  王鹏  祁鹏  郭瑞 《地球科学》2016,41(3):546-554
东海盆地处于西太平洋俯冲带前缘,是发育在华南克拉通基底之上的,以晚白垩世-新生代沉积为主的新生代盆地.东海盆地性质是在活动大陆边缘减薄陆壳之上的,由于洋-陆俯冲消减所引起的张裂、拉伸作用而形成的弧后裂谷型盆地,是西太平洋众多“沟-弧-盆”体系的一部分.东海盆地陆架外缘隆起控制着东海盆地的演化过程,该地质单元形成于晚白垩世,是陆缘隆起和增生楔的复合体,中新世后由于菲律宾海板块的活动而解体为现今的钓鱼岛隆褶带和琉球隆起.结合对陆架外缘隆起的研究后认为,东海盆地晚白垩世以来的演化历程具有3大构造阶段,即:第一阶段,古新世-中始新世西部坳陷形成发展期;第二阶段,中始新世-渐新世东部坳陷形成发展期,其中,中晚始新世太平洋板块的转向是东、西部坳陷构造迁移的分界点;第三阶段,中新世-全新世,东海盆地进入到菲律宾板块影响时期,原先的构造格局开始分解.   相似文献   

7.
东海陆架盆地伸展率和压缩率及构造跃迁   总被引:1,自引:0,他引:1       下载免费PDF全文
东海陆架盆地位于欧亚板块的东南缘和西太平洋活动大陆边缘,本文选取了东海陆架盆地主要凹陷的17条地震剖面,采用平衡剖面技术,计算了主要凹陷新生代不同演化阶段的伸展率和压缩率。分析表明,东海陆架盆地构造演化总体由西向东跃迁。晚白垩世至晚古新世东海陆架盆地裂陷中心在西部坳陷带,始新世东迁至东部坳陷带,上新世东迁至东海陆架盆地东侧的冲绳海槽盆地。古新世中后期东海陆架盆地西部坳陷带北侧昆山凹陷反转;中新世东部坳陷带的西湖凹陷反转。东海陆架盆地西部坳陷带与东部坳陷带构造演化不同,证明了东海陆架盆地的东西分带。西部坳陷带北部的长江坳陷和南部的台北坳陷构造演化不同,东部坳陷带北部的西湖凹陷和南部的钓北凹陷构造演化不同,证明了东海陆架盆地的南北分块。  相似文献   

8.
The Salar de Atacama basin, the largest “pre-Andean” basin in Northern Chile, was formed in the early Late Cretaceous as a consequence of the tectonic closure and inversion of the Jurassic–Early Cretaceous Tarapacá back arc basin. Inversion led to uplift of the Cordillera de Domeyko (CD), a thick-skinned basement range bounded by a system of reverse faults and blind thrusts with alternating vergence along strike. The almost 6000-m-thick, upper Cretaceous to lower Paleocene sequences (Purilactis Group) infilling the Salar de Atacama basin reflects rapid local subsidence to the east of the CD. Its oldest outcropping unit (Tonel Formation) comprises more than 1000 m of continental red sandstones and evaporites, which began to accumulate as syntectonic growth strata during the initial stages of CD uplift. Tonel strata are capped by almost 3000 m of sandstones and conglomerates of western provenance, representing the sedimentary response to renewed pulses of tectonic shortening, which were deposited in alluvial fan, fluvial and eolian settings together with minor lacustrine mudstone (Purilactis Formation). These are covered by 500 m of coarse, proximal alluvial fan conglomerates (Barros Arana Formation). The top of the Purilactis Group consists of Maastrichtian-Danian alkaline lava and minor welded tuffs and red beds (Cerro Totola Formation: 70–64 Ma K/Ar) deposited during an interval of tectonic quiescence when the El Molino–Yacoraite Late Cretaceous sea covered large tracts of the nearby Altiplano-Puna domain. Limestones interbedded with the Totola volcanics indicate that this marine incursion advanced westwards to reach the eastern CD slope. CD shortening in the Late Cretaceous was accompanied by volcanism and continental sedimentation in fault bounded basins associated to strike slip along the north Chilean magmatic arc to the west of the CD domain, indicating that oblique plate convergence prevailed during the Late Cretaceous. Oblique convergence seems to have been resolved into a highly partitioned strain system where margin-parallel displacements along the thermally weakened arc coexisted with margin-orthogonal shortening associated with syntectonic sedimentation in the Salar de Atacama basin. A regionally important Early Paleocene compressional event is echoed, in the Salar de Atacama basin by a, distinctive, angular unconformity which separates Paleocene continental sediments from Purilactis Group strata. The basin also records the Eocene–Early Oligocene Incaic transpressional episode, which produced, renewed uplift in the Cordillera de Domeyko and triggered the accumulation of a thick blanket of syntectonic gravels (Loma Amarilla Formation).  相似文献   

9.
陈颐亨 《沉积学报》1989,7(4):69-76
作者据海区和周边岛屿的地质、地球物理和钻井资料描述了东海的白垩纪-第三纪古地理。并绘制了该时期的系列古地理图,从而有可能归纳出东海在某些时期具有“南海北陆”,古地貌上犹如今日渤海-黄海陆缘海盆及其周边陆地环抱等特点。同时简略地讨论了海水进退和古气候,分析了东海东部活动大陆边缘构造背景出现的时间。  相似文献   

10.
东海盆地长江凹陷美人峰组是古近系重要的地层单元之一,但因其缺少精确的古生物化石记录,时代归属和区域地层对比关系长期悬而未决,尚无定论。本文应用LA- ICP- MS定年方法,对长江凹陷CJ- 2井所揭露的美人峰组顶部两套凝灰岩夹层进行了锆石U- Pb同位素测年。结果表明,来自美人峰组顶部两件凝灰岩样品分别形成于61. 0±0. 87 Ma和62. 25±0. 92 Ma,证明该组沉积时代归属于早古新世,区域上对应于丽水- 椒江凹陷下古新统月桂峰组。烃源岩评价结果显示,美人峰组发育较好的烃源岩,有机质丰度达到中等至好,有机质类型为Ⅲ型。基于地震剖面构造精细解析,长江凹陷的美人峰组可以连续追踪到浙东坳陷,该坳陷大规模发育古新统,残余厚度达800~2000 m,指示古新世,浙东坳陷发生大规模伸展裂陷,形成NNE向展布大型裂陷带,美人峰组将是一套潜在的烃源岩层系。首次在东海盆地长江凹陷美人峰组获得高精度年龄,不仅确定了美人峰组沉积时代归属,也为东海盆地古新世区域地层的划分与对比、盆地古地理重建、构造演化、油气勘探与资源评价等提供了新的地质依据。  相似文献   

11.
基于前人文献,对塔里木盆地新生代海相沉积问题进行梳理,进而探讨该盆地新生代海侵的次数和范围以及海退的时限、原因。研究表明,新生代,塔里木盆地至少经历古近纪的阿尔塔什晚期至齐姆根早期(古新世早期至古新世晚期)、卡拉塔尔期—乌拉根期(始新世中期)、巴什布拉克中期(始新世晚期至早渐新世)等三期海侵;塔里木盆地中新世仍有海相地层这一认识获得广泛认可仍需更多的地质证据来支持。塔里木盆地海侵范围在卡拉塔尔—乌拉根组沉积时期达到最大,向东可达玛扎塔格地区,在盆地北缘和南缘分别可以到达库尔勒以东地区和洛浦县阿其克以东地区。由于受到全球海平面变化和构造运动的共同影响,副特提斯海新生代从塔里木盆地退却的沉积记录包括齐姆根组顶部、乌拉根组顶部、巴什布拉克组第四段和第五段,时间上分别对应于古新世晚期、始新世中晚期和早渐新世。  相似文献   

12.
Sedimentary Characteristics of the Cretaceous in the Songliao Basin   总被引:2,自引:0,他引:2  
The rupture of the lithosphere in Late Jurassic brought about the eruption of basaltic magma in the Songliao Basin. The evolution of the basin in Cretaceous progressed through six stages: pre-rift doming, extensional fracturing, fault subsidence, fault downwarping, downwarping and shringkage, resulting in the deposition of terrstrial facies nearly 10,000 m thick. There are different depositional sequences in these stages: the depositional period of the Early Cretaceous Shahezi and Yincheng Formations is the development stage of the down-faulted basin, forming a volcanic rock-alluvial fan-fan delta-lacustrine (intercalated with episodic turbidites)-swamp facies sequences; the period of the Early Cretaceous Dengluku Formation is the transformation stage of fault subsidence into fault downwarping of the basin, forming a sequence mainly of alluvial plain-lacustrine facies; the depositional period of the Early Cretaceous Quantou Formation-Late Cretaceous Nenjiang Formation is the downwarping stage of the basin, forming an alluvial plain-delta-lacustrine facies sequence; the period of the Late Cretaceous Sifangtai Formation-Mingshui Formation is the shringkage stage of the basin, forming again a sequence mainly of alluvial plain-alluvial fan and small relict lacustrine facies. These vertical depositional sequences fully display the sedimentary characteristics of a failed continental rift basin. Many facts indicate that the two large-scale lake invasions, synchronous with the global rise of sea level, which took place in the downwarping stage of the basin development, led to the connection between the lake and sea.  相似文献   

13.
下古新统月桂峰组是东海陆架盆地丽水-椒江富生烃凹陷的主力烃源岩系.利用钻井、地震及烃源岩有机地球化学、古生物等资料,在烃源岩特征及其发育的构造-沉积与古气候背景分析的基础上,探讨了控制丽水-椒江凹陷下古新统月桂峰组烃源岩发育的主要因素,并建立了相应的形成模式.丽水-椒江凹陷月桂峰组烃源岩分布广、厚度大,存在多个厚度中心;有机质丰度较高,有机质类型以Ⅱ2型为主,处于成熟-高成熟阶段.月桂峰组烃源岩发育于分割性较强、相对封闭的湖泊环境和半湿润-湿润南亚热带型气候条件,以低等水生生物贡献为主.月桂峰组烃源岩的发育主要受沉积-沉降速率、母质来源及有机质保存条件等因素控制,其形成模式可概括为“快速沉降,湿润气候,水生有机质贡献为主,淡水-微咸水,弱氧化-弱还原环境”.   相似文献   

14.
华北陆台晚古生代岩相古地理   总被引:1,自引:0,他引:1  
唐开疆 《沉积学报》1989,7(4):97-104
位于天山-阴山、昆仑山-秦岭两大纬向构造带之间的华北陆台。在稳定地壳基底上逐渐发展形成晚古生代多旋回克拉通大型含煤盆地。加里东运动使陆台缺失O3-C1沉积,晚石炭世至晚二叠世陆台为海陆交互相滨海、湖泊、三角洲沉积,随着古地理环境演变,陆台各沉积古地理环境在时、表现为由老至新、自北向南迁移。  相似文献   

15.
在东昆仑山脉西段祁漫塔格山中东部的尕林格南地区发育一套火山岩,调查显示火山活动爆发相→溢流相相间的韵律周期较明显,见由玄武质含火山角砾凝灰岩→玄武岩、玄武质凝灰岩→安山岩、安山质角砾凝灰岩→安山岩,以及安山质含火山角砾凝灰岩和安山岩质凝灰岩→玄武岩组成的4个韵律。根据研究区安山质火山角砾凝灰岩的LA-ICP-MS锆石U-Pb年龄222.2±2.1Ma,将该火山岩地层由前人划分的顶志留统—下泥盆统契盖苏组火山岩段重新厘定为上三叠统鄂拉山组。岩石地球化学研究结果表明,该套火山岩属于亚碱性钙碱性系列岩石,具有富钾、同源岩浆演化的特点,并具弧火山岩和碰撞火山岩的地球化学特征,为陆内造山作用下的产物,较好地记录了东昆仑祁漫塔格造山带在晚三叠世岩浆演化的地质信息。  相似文献   

16.
Glauconite is widely distributed in space and time.In China glauconite-bearing strata are extensive occurrence ranging from Late Cretaceous to Middle Proterozoic in age.X-ray powder analysis,X-ray diffracition analysis and differential thermal analysis revealed that glauconite has a mica-type structure between dioctahedron and trioctahedron.Its chemical composition is:Al2O310.6%,SiO249.23%,MgO3.24%,Fe2O317.40%,FeO1.8%,and K2O7.92%,Its crystal form and thermal properties are very similar to those of mica-like clay minerls.According to isotopic age determinations of glauconite in modern oceans (including the East China Sea,the South China Sea and the Yellow Sea),we consider that in the extreme case glauconite is an authigenic mineral.It is generally formed in sedimentary rocks.Is has further proved that glauconite can be used to determine the ages of sedimentary rocks.  相似文献   

17.
Combined subsidence and thermal 1D modelling was performed on six well-sections located in the north-western Mid-Polish Trough/Swell in the eastern part of the Central European Basin system. The modelling allowed constraining quantitatively both the Mesozoic subsidence and the magnitude of the Late Cretaceous–Paleocene inversion and erosion. The latter most probably reached 2,400 m in the Mid-Polish Swell area. The modelled Upper Cretaceous thickness did not exceed 500 m, and probably corresponded to 200–300 m in the swell area as compared with more than 2,000 m in the adjacent non-inverted part of the basin. Such Upper Cretaceous thickness pattern implies early onset of inversion processes, probably in the Late Turonian or Coniacian. Our modelling, coupled with previous results of stratigraphic and seismic studies, demonstrates that the relatively low sedimentation rates in the inverted part of the basin during the Late Cretaceous were the net result of several discrete pulses of non-deposition and/or erosion that were progressively more pronounced towards the trough axis. The last phase of inversion started in the Late Maastrichtian and was responsible for the total amount of erosion, which removed also the reduced Upper Cretaceous deposits. According to our modelling results, a Late Cretaceous heat-flow regime which is similar to the present-day conditions (about 50 mW/m2) was responsible for the observed organic maturity of the Permian-Mesozoic rocks. This conclusion does not affect the possibility of Late Carboniferous–Permian and Late Permian–Early Triassic thermal events.  相似文献   

18.
Tertiary sequences in the Elazig and Malatya Basins, eastern part of Taurus Orogenic Belt, are investigated with the aim of defining the benthic foraminiferal biozones. Tertiary geological units from bottom to top are as follows: Basement rocks, Zorban Formation, Yildiztepe Formation, Suludere Formation, Gedik Formation (Malatya Basin); Elazig Magmatics, Keban Metamorphics, Harami Formation, Kuscular Formation, Seske Formation, Kirkgecit Formation (Elazig Basin). Middle-Upper Eocene Yildiztepe, Suludere and Gedik Formations; Upper Paleocene-Lower Eocene Seske Formation and Middle-Upper Eocene Kirkgecit Formation are all characterized by interbedded clastics and carbonate rocks. Six stratigraphic sections are studied in detail for foraminiferal biostratigraphy. Eight benthic foraminiferal biozones are reported. These are; Coskinolina rajkae biozone in the Late Paleocene (Thanetian), Assilina yvettae, Idalina sinjarica biozones in the Late Paleocene; Asterocyclina alticostata gallica biozone in the Early Eocene (Late Cuisian), Nummulites millecaput biozone in the Middle Eocene (Middle Lutetian), Nummulites aturicus biozone in the Middle Eocene (Late Lutetian), Nummulites perforatus biozone in the Middle Eocene (Bartonian), Nummulites fabianii biozone in the Late Eocene (Priabonian). Some key taxa are illustrated.  相似文献   

19.
The western part of the Tarim Basin in Xinjiang is one of the main areas in China where the marineCretaceous is well developed. The Upper Cretaceous Yingjisha Group represented mainly by sediments of lit-toral, near-shore neritic and estuarine facies is divided in ascending order into the Kukebai Formation, theOytak Formation, the Ygezya Formation and the Tuylouk Formation. For about thirty years, the basal beds of the Kukebai Formation had been considered to be the lowermostmarine horizon of the Cretaceous in the western part of the Tarim Basin, which represents the earliest trans-gression of the Cretaceous Sea into this region. Recently. marine trace fossils, Ophiomorpha nodosa, O.tuberosa and Thalassinoides? spp. were found in abundance and fine preservation from the upper subcycle andupper part of the lower subcycle of the Kezlesu Group underlying the Kukebai Formation. The fact indicatesthat the marine transgression there took place earlier than the Kukebaian. Process of transgression and regression and change of environment in the West Tarim Basin during the pe-riod from the late Early Cretaceous to the end of the Cretaceous is also discussed in this paper.  相似文献   

20.
张岳桥 《地质学报》2008,82(9):1229-1257
基于野外和钻孔测井资料分析、火山岩同位素年代学分析 (40Ar-39Ar and SHRIMP U-Pb)、地震剖面的构造解释、断层运动学的野外分析结果,综合研究了胶莱盆地及其邻区白垩纪-古新世沉积构造演化历史。岩性地层分析表明,胶莱断陷盆地由三套地层单元所充填:早白垩世莱阳群和青山群、晚白垩世-古新世王氏群。青山群火山岩的同位素年代学测试结果给出了该火山岩的喷发时代在120~105 Ma。地震剖面的构造解译结果揭示胶莱盆地伸展构造受到深部两个拆离构造系统控制:一个发育于盆地南部地区,拆离断面位于深部8~10 km,向南缓倾于苏鲁造山带之下;另一个拆离系统由一系列北倾的犁式断层组成、分布于宽阔的胶莱盆地北部地区,主拆离面向北倾。这两个拆离系统分别形成于早白垩世莱阳群和晚白垩世-古新世王氏群沉积阶段。通过对不同地层单元断层滑动矢量的野外测量和古构造应力场反演,以及地层时代和同位素年代学测试结果的制约,建立了白垩纪-古新世构造应力场演替的年代序列。结果表明,胶莱盆地在白垩纪-古新世之间经历了伸展-挤压应力体制的交替演化。早白垩世伸展作用经历了两个不同的阶段:早期NW-SE向伸展和晚期近W-E向伸展。在早白垩世末期至晚白垩世初期,盆地遭受NW-SE向挤压,导致了胶莱盆地的缩短变形和郯庐断裂带的左旋走滑活动。晚白垩世-古新世时期,构造应力场转变为N-S向伸展,直到古新世末期,构造应力场转换为NE-SW向挤压。胶莱盆地和沂沭裂谷系白垩纪-古新世沉积构造演化历史对华北地区岩石圈减薄过程的动力学背景提供了重要的构造地质学制约。笔者推断,早白垩世两期引张应力作用是分别对华北地区增厚地壳或岩石圈的重力垮塌和岩石圈拆沉的响应,而早白垩世末期NW-SE向挤压记录了古太平洋板块与亚洲陆缘俯冲碰撞产生的远程效应。晚白垩世-古新世的引张伸展作用完全不同于早白垩世伸展构造,它指示了沿NNE向郯庐断裂带的右旋走滑活动及其拉分作用,在动力学上受到青藏地区块体的陆-陆碰撞产生的远程效应和古太平洋板块向亚洲大陆俯冲作用的联合应力场控制。  相似文献   

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