辽东凸起北段新生代隆升时间的确定:来自裂变径迹的证据     

任健  吴智平  徐长贵  李伟  张晓庆  张婧 《世界地质》2015,34(2):408-418

对取自辽东凸起北段凸起带和陡坡带的6个岩芯样品进行了磷灰石裂变径迹(AFT)测试并分析了裂变径迹特征,选定其中2个样品在约束条件下进行热史模拟。结果表明,辽东凸起北段新生代经历了距今50 Ma±孔店组沉积期末及距今24 Ma±的东营组沉积期末的2次构造隆升。通过对辽东湾坳陷东西部的沉积结构和控凹断裂对比可知,辽东湾坳陷一系列NE向隆起具有相似的发育机制。结合渤海湾盆地区域构造背景,推断辽东湾坳陷辽东凸起的形成是古近纪地幔热活动引起的伸展作用在孔店组沉积期末的构造响应,形式为拆离性质的翘倾断块;而辽东凸起的第二次抬升是受东营组沉积期末发生的区域性构造抬升运动影响的结果。  相似文献   

黔中隆起东部龙里—凯里地区油苗有机地球化学特征及其成因分析   总被引：1，自引：1，他引：0       下载免费PDF全文

林家善 谢 渊 刘建清 赵 瞻冯伟明  朱东君 《中国地质》2015,(2):504-514

黔中隆起东部发现有大量的中—古生界油苗。应用色谱、色谱-质谱及同位素等测试技术,系统地研究了油苗的地球化学特征及油源。结果表明,受黔中多期次构造抬升活动的影响油苗的热演化程度均处于成熟阶段;大冶组(T1d)原油的生物标志物、族组分及单体烃碳同位素组成与古生界油苗存在明显差异,其烃源岩为研究区西南部的T1d油页岩;茅口组(P2m)原油为单源供烃,与栖霞组(P1q)烃源岩具亲缘关系;红花园组(O1h)原油具混源特征,主要来源于下寒武统牛蹄唐组,同时受翁项群组(S2w)泥质岩段的影响。其中,S2w泥质岩段具晚期生烃的特征,预示着研究区下古生界存在一套特殊的含油气组合,这对评价该地区的油气前景具积极意义。  相似文献   

渤东低凸起L3构造东营组含煤地层低渗储层特征及成因     

臧春艳  王清斌 《海洋地质译丛》2014,(1):22-26,62

渤东低凸起东营组储集层以低渗为特征,低渗成为制约该区东营组勘探的重要因素.通过多种分析测试方法,研究了渤东低凸起L3构造东营组低渗储集层特征,探讨了低渗储集层成因.L3构造东营组储集层砂岩溶蚀作用发育,斜长石含量低,碳酸盐胶结物含量低,高岭石含量高,石英加大明显.储集层主要以中孔低—特低渗为主,孔径小,连通差,吼道窄,排驱压力大.微量元素分析表明,研究区东营组沉积时为淡水环境;测井和岩心观察证实,地层中含多层碳质泥岩和煤层.早期腐殖酸的溶蚀作用,造成低温下不稳定的斜长石大量溶蚀,这些溶蚀孔隙在后期深埋过程中受压实和成岩作用影响被复杂化、细小化是储集层低渗的主要原因.早期碳酸盐胶结物少,岩石抗压实能力差也是储层低渗的重要原因.  相似文献   

雪峰弧形构造带中段沅陵—桃江地区金矿成矿规律及找矿方向     

娄元林  曾昊  廖驾  陈澍民  陈坤  汪斯毓  杨桃 《地质论评》2024,70(S1):104-106

  相似文献   

新疆塔中卡塔克隆起加里东构造运动的古地震证据   总被引：4，自引：1，他引：3  

乔秀夫  郭宪璞  叶留生  何碧竹  周玮 《岩石学报》2011,27(1):243-252

从塔中顺2井、中12井、顺8井岩心中识别出奥陶系及志留系古地震记录。其中志留系中地震触发沉积物变形记录最强烈,并且出现的变形层也较密集。志留系的软沉积物变形类型有:负载构造、液化砂岩脉、液化角砾岩、碟状构造、液化底劈及混滑层。卡塔克隆起演化受断裂控制,北缘为塔中1号断裂,中部为塔中10号、2号断裂,塔中2号断裂位于隆起的顶部。顺2井位于塔中1号断裂末端、中12井位于塔中10号断裂旁。断裂活动诱发地震,志留系频繁的古地震记录表明塔中地区是一个加里东期断裂与构造隆起地带。塔里木板块内部加里东运动特点是:断裂活动、强地震、隆起与坳陷。  相似文献   

塔中原油超高二苯并噻吩硫特征及其控制因素   总被引：1，自引：1，他引：0  

李素梅  张宝收  张海祖  盛世忠  赵明 《现代地质》2011,25(6):1108-1120

塔中相当部分原油具有高丰度芳香硫——二苯并噻吩(DBTs)特征,其在原油中的绝对丰度高达26 859μg/g,在芳烃中的相对丰度高达58.2%,主要分布在塔中I号构造带下奥陶统、塔中4(TZ4)和塔中1-6(TZ1-6)井区。采用综合地球化学研究途径,对该区原油的高DBTs特征及其主控因素进行初步探讨。分析表明,研究区母源岩较强地控制DBTs的丰度,纯泥岩、页岩中DBTs丰度不高,灰岩、云岩等烃源岩DBTs丰度偏高或超高;观察到在正常油窗范围内,烃源岩和相关原油随成熟度增加DBTs丰度增加,而塔中型高-过熟原油中DBTs丰度有先增加后减小的趋势,表明热成熟作用对该化合物有较强的控制作用;发现生物降解、水洗可使原油中DBTs丰度降低,但对塔中原油中DBTs影响较小;观测到塔中相当部分原油的DBTs含量与硫酸盐热化学还原作用——TSR的作用产物H2S、硫醇、长链烷基四氢噻烷有一定正相关性。对比研究认为,有多种因素控制塔中原油中DBTs丰度与分布,热成熟作用、TSR是导致塔中下奥陶统部分原油高DBTs特征的重要原因,前者可能是主要因素,特殊母源岩因素相对较少,尽管尚不能排除。TZ4井区等石炭系高DBTs原油主要来自深部地层,与下奥陶统抑或更深层高DBTS原油的混入有关。本研究对于该区深层油气勘探具有重要意义。  相似文献   

Geochemical characteristics and origin of reservoir bitumens from Well Zhong 1 in the Katake Uplift,Tarim Basin     

Youjun Tang  Ling Zan 《中国地球化学学报》2011,30(3):398-404

The source of marine crude oils from Tarim Basin is still disputed.However,research on the reservoir bitumens may provide a piece of new evidence to elucidate oil source.Geochemical characteristics of reservoir bitumens from different strata from Well Zhong 1 in the Katake Uplift were discussed here in detail.Pr/Ph ratios of reservoir bitumen from Well Zhong 1 range from 1.14 to 1.39,CPI ratios from 1.01 to 1.08,which indicates no odd-even predominance of normal alkanes,with OEP ratios ranging from 0.98 to 1.05.The contents of gammacerane and C28 sterane of reservoir bitumen from Well Zhong 1 are low,while dibenzothiophene series are abundant.Ster-ane isomerization maturity parameter and Ts/(Ts+Tm) ratio indicate that the reservoir bitumen from Well Zhong1 is mature to highly mature.Based on the differences in biomarker distribution,it is concluded that reservoir bitumen from Well Zhong 1,of which molecular parameters are contrary to those in Cambrian oil from Well Tadong 2,origi-nated from the Upper Ordovician source rocks.  相似文献   

Evolution of Ataúro Island: Temporal constraints on subduction processes beneath the Wetar zone, Banda Arc     

Kim S. Ely  Mike Sandiford  Margaret L. Hawke  David Phillips  Mark Quigley  Joao Edmundo dos Reis 《Journal of Asian Earth Sciences》2011,41(6):477-493

Ataúro is a key to understanding the late stage volcanic and subduction history of the Banda Arc to the north of Timor. A volcanic history of bi-modal subaqueous volcanism has been established and new whole rock and trace element geochemical data show two compositional groups, basaltic andesite and dacite–rhyolite. ⁴⁰Ar/³⁹Ar geochronology of hornblende from rhyo-dacitic lavas confirms that volcanism continued until 3.3 Ma. Following the cessation of volcanism, coral reef marine terraces have been uplifted to elevations of 700 m above sea level. Continuity of the terraces at constant elevations around the island reflects regional-scale uplift most likely linked to sublithospheric processes such as slab detachment. Local scale landscape features of the eastern parts of Ataúro are strongly controlled by normal faults. The continuation of arc-related volcanism on Ataúro until at least 3.3 Ma suggests that subduction of Australian lithosphere continued until near this time. This data is consistent with findings from the earthquake record where the extent of the Wetar seismic gap to a depth of 350 km suggests slab breakoff, as a result of collision, commenced at ∼4 Ma, leading to subsequent regional uplift recorded in elevated terraces on Ataúro and neighbouring islands.  相似文献   

雪峰造山带新元古代构造演化框架   总被引：9，自引：0，他引：9       下载免费PDF全文

柏道远  贾宝华  钟响  贾朋远  刘耀荣  马铁球 《沉积与特提斯地质》2011,(3):78-87

目前对江南造山带新元古代构造演化存在不同认识。本文在系统收集近年来大量高精度年龄数据及岩石地球化学研究成果基础上,重塑了雪峰造山带（江南造山带西段）及其东南缘新元古代构造演化过程：880～820Ma期间雪峰造山带为岛弧岩浆作用阶段,东南缘城步地区为弧前盆地;820～810Ma期间雪峰造山带为弧-陆（主）碰撞阶段,城步地区处于弧前盆地向岛弧发展的过渡时期;810～800Ma期间雪峰造山带进入后碰撞环境,城步地区形成新的岛弧;800～630Ma整体进入裂谷盆地阶段。上述过程反映出扬子陆块东南缘的岛弧增生过程,同时暗示雪峰造山带南东面的雪峰期和南华纪沉积叠覆于华南残留洋盆之上。  相似文献   

Paleomagnetic constraints on the paleogeography and oroclinal bending of the Devonian volcanic arc in Kazakhstan   总被引：1，自引：0，他引：1  

Alexandra Abrajevitch  Rob Van der Voo  Natalia M. Levashova  Mikhail L. Bazhenov   《Tectonophysics》2007,441(1-4):67-84

Numerical modelling, incorporating coupling between surface processes and induced flow in the lower continental crust, is used to address the Quaternary evolution of the Gulf of Corinth region in central Greece. The post-Early Pleistocene marine depocentre beneath this Gulf overlies the northern margin of an older (Early Pleistocene and earlier) lacustrine basin, the Proto Gulf of Corinth Basin or PGCB. In the late Early Pleistocene, relief in this region was minimal but, subsequently, dramatic relief has developed, involving the creation of  900 m of bathymetry within the Gulf and the uplift by many hundreds of metres of the part of the PGCB, south of the modern Gulf, which forms the Gulf's main sediment supply. It is assumed that, as a result of climate change around 0.9 Ma, erosion of this sediment source region and re-deposition of this material within the Gulf began, both processes occurring at spatial average rates of  0.2 mm a^− 1. Modelling of the resulting isostatic response indicates that the local effective viscosity of the lower crust is  4 × 10¹⁹ Pa s, indicating a Moho temperature of  560 °C. It predicts that the  10 mm a^− 1 of extension across this  70 km wide model region, at an extensional strain rate of  0.15 Ma^− 1, is partitioned with  3 mm a^− 1 across the sediment source,  2 mm a^− 1 across the depocentre, and  5 mm a^− 1 across the ‘hinge zone’ in between, the latter value being an estimate of the extension rate on normal faults forming the major topographic escarpment at the southern margin of the Gulf. This modelling confirms the view, suggested previously, that coupling between this depocentre and sediment source by lower-crustal flow can explain the dramatic development in local relief since the late Early Pleistocene. The effective viscosity of the lower crust in this region is not particularly low; the strong coupling interpreted between the sediment source and depocentre results instead from their close proximity. In detail, the effective viscosity of the lower crust is expected to decrease northward across this model region, due to the northward increase in exposure of the base of the continental lithosphere to the asthenosphere; in the south the two are separated by the subducting Hellenic slab. The isostatic consequences of such a lateral variation in viscosity provide a natural explanation for why, since  0.9 Ma, the modern Gulf has developed asymmetrically over the northern part of the PGCB, leaving the rest of the PGCB to act as its sediment source.  相似文献