黑龙江省东部残留盆地群早白垩世沉积相特征及演化   总被引：3，自引：0，他引：3       下载免费PDF全文

和钟铧  刘招君  陈秀艳  何玉平  陈永成 《古地理学报》2008,10(2):151-158

黑龙江省东部残留盆地群早白垩世主要充填滴道组（裴德组）、城子河组（七虎林组和云山组）、穆棱组（珠山组）和东山组。沉积相以冲积扇相、（扇）三角洲相、湖泊相、海相等为主。沉积相研究结果表明,滴道组以冲积扇及（扇）三角洲粗碎屑沉积为主,并伴随有火山岩分布,反映了盆地初始裂陷阶段的沉积环境特点;城子河组和穆棱组沉积时期,三江地区处于整体下沉阶段,现今残留的三江盆地、勃利盆地、鸡西盆地、虎林盆地、宁安盆地、鹤岗盆地和汤原断陷等为统一的近海拗陷盆地,张广才岭-小兴安岭及东三江和完达山地区是盆地主要物源供给区,平面上构成（扇）三角洲-滨浅湖-半深湖-湖底扇的沉积格局,并且伴随有多次海侵事件,海侵方向主要来自虎林盆地东部及绥滨坳陷北部;东山组沉积时期,盆地已明显萎缩,发育局限的（扇）三角洲-滨浅湖相沉积。  相似文献   

Neoproterozoic tectonic synthesis of Uruguay     

《International Geology Review》2012,54(1):51-78

Neoproterozoic–lower Palaeozoic successions in the Brasiliano fold belts are described and a brief synthesis of these terranes is presented in order to erect a tectonic framework for this region. Tectonic events that occurred around the Río de La Plata craton were diachronous and reflected successive stages of the Brasiliano orogenic cycle. They took place in mobile belts that constituted part of the Gondwana supercontinent. The most thoroughly investigated Neoproterozoic sections are located in the eastern and southeastern regions of Uruguay. The Dom Feliciano Belt shows a tectonic evolution from back-arc to foreland basin characterized by fold-and-thrust, thick-skinned belts developed during the Brasiliano/Pan-African orogenic cycle. The most conspicuous features were late-tectonic high-K calc-alkaline granitoids, HT-LP metamorphism, significant displacements along shear zones, and post-tectonic granitoids. The final stage was characterized by post-collisional basins (molassic sequences) and extensional magmatism related to a phase of crustal stretching. Several lithotectonic units are present as basement inliers in the Dom Feliciano Belt: these include a low-to-medium metamorphic grade sequence (the Zanja del Tigre Formation), granitoids and gneisses (the Campanero Unit), high-grade basement of the Cerro Olivo Complex (Palaeoproterozoic or Neoproterozoic), and a low-metamorphic grade orogenic belt (the Rocha Formation). This paper provides a simplified tectonic map of eastern Uruguay, which we use to describe tectonic evolution from Precambrian to early Palaeozoic time.  相似文献   

Sedimentology and depositional architecture of a submarine delta-fan complex in the Durban Basin,South Africa     

《Marine and Petroleum Geology》2016

The seismic stratigraphy, evolution and depositional framework of a sheared-passive margin, the Durban Basin, of South East Africa are described. Based on single-channel 2D seismic reflection data, six seismic units (A-F) are revealed, separated by major sequence boundaries. These are compared to well logs associated with the seismic data set. Internal seismic reflector geometries and sedimentology suggest a range of depositional regimes from syn-rift to upper slope and outer shelf. Nearshore and continental facies are not preserved, with episodic shelf and slope sedimentation related to periods of tectonic-induced base level fall. The sedimentary architecture shows a change from a structurally defined shelf (shearing phase), to shallow ramp and then terminal passive margin sedimentary shelf settings. Sedimentation occurred predominantly during normal regressive conditions with the basin dominated by the progradation of a constructional submarine delta (Tugela Cone) during sea-level lowstands (LST). The earlier phases of sedimentation are tectonic-controlled, however later stages appear to be linked to global eustatic changes.  相似文献   

朝鲜半岛与华北地质之对比研究:进展与问题   总被引：7，自引：5，他引：2  

翟明国 《岩石学报》2016,32(10):2915-2932

华北与朝鲜半岛山水相连,传统上称为中朝克拉通或中朝地块。但是中朝的地质对比研究并不深入。作者所在的研究组有幸同时与南北朝鲜半岛双方展开了合作研究达十年以上,内容涉及到前寒武纪基底、古生代沉积盆地、造山带演化、以及中生代岩浆活动。本文是对我们最新研究成果的一个简要总结,并提出一些仍未解决的或具争议的相关地质问题,希望以此能推动中朝地质和东北亚地质的研究。研究结果总结如下:(1)朝鲜半岛可划分为三个陆块,从北到南分别为狼林、京畿和岭南陆块,分别被临津江和沃川构造带分割;(2)三个陆块的前寒武纪基底虽有差别,但本文认为它们是相似的,并可与华北克拉通基底对比;(3)狼林地块的平南古生代盆地以及位于京畿陆块和岭南陆块之间的太白山古生代盆地与华北古生代盆地可对比;(4)临津江和沃川构造带的演化还有待深入研究,它们并不具有陆陆碰撞造山带的特征;(5)在京畿陆块西南部发现了含榴辉岩的三叠纪变质杂岩(洪城杂岩),其变质时代和岩石组合都可以和苏鲁造山带对比,不含超高压变质矿物。这表明苏鲁造山带东延到朝鲜半岛,并在半岛的京畿陆块西南缘登陆。但是洪城杂岩出露有限,没有穿越切割半岛的证据,因此可能沿半岛西部断裂局部分布或在半岛西缘尖灭,其空间分布需进一步研究;(6)中生代岩浆岩在朝鲜半岛广泛存在,三叠纪岩浆作用可能与印支期造山作用有关;侏罗纪和白垩纪的岩浆岩分布与华北在时代和空间分布上有所差别,晚白垩世岩浆岩在朝鲜半岛集中出露于庆尚盆地。本文还在最后一部分,提出了朝鲜半岛以及中朝对比研究中有争议的和尚需进一步研究的关键问题。  相似文献   

流体混合对砂岩型铀矿成矿作用的影响   总被引：1，自引：0，他引：1  

金若时  张成江  冯晓曦  汤超  朱强  李光耀 《中国区域地质》2014,(2):354-358

探讨不同类型盆地中不同来源、不同组成、不同性质的流体混合对砂岩型铀矿成矿的影响。流体混合不但改变流体的物理化学条件,更重要的是改变流体的化学组成,导致流体化学平衡的破坏,引起流体卸载成矿。不同构造背景下形成的盆地、流体特征及其对砂岩型铀矿成矿的影响不同。铀一油一煤共存盆地中,浅表层含铀氧化性流体与油气有关的有机还原性流体相互作用对铀成矿起重要的控制作用;挤压构造环境下的盆地,在形成过程中造山带流体与盆地深源流体混合对成矿的影响很大;而伸展背景下的断陷盆地或裂谷盆地,往往伴随有深部岩浆和热流体的活动,应重视热液对砂岩型铀矿的改造、叠加富集的作用。  相似文献   

江西广丰、玉山盆地橄榄玄粗岩的SHRIMP锆石U-Pb定年和Sr-Nd-Pb-O元素同位素特征   总被引：2，自引：0，他引：2  

巫建华  项媛馨  钟志菲 《岩石矿物学杂志》2014,33(4):645-656

华夏古板块与扬子古板块结合带内的广丰、玉山红色碎屑沉积盆地均有橄榄玄粗岩产出,SHRIMP锆石UPb年代学研究表明,橄榄玄粗岩锆石U-Pb年龄为93±1 Ma,属晚白垩世早期的产物。广丰盆地橄榄玄粗岩(~(87)Sr/~(86)Sr)_i值为0.706 191~0.706 352,εNd(t)值为0.27~0.55,(~(206)Pb/~(204)Pb)_i值为18.045~18.080,(~(207)Pb/~(204)Pb)_i值为15.503~15.543,(~(208)Pb/~(204)Pb)_i值为38.240~38.256;玉山盆地橄榄玄粗岩(~(87)Sr/~(86)Sr)_i值为0.705 856~0.706 024,εNd(t)值为1.74~1.93,(~(206)Pb/~(204)Pb)_i值为17.956~18.063,(~(207)Pb/~(204)Pb)_i值为15.456~15.498,(~(208)Pb/~(204)Pb)_i值为38.195~38.232。在(~(87)Sr/~(86)Sr)_i-(~(206)Pb/~(204)Pb)_i、(~(143)Nd/~(144)Nd)_i-(~(206)Pb/~(204)Pb)_i和(~(143)Nd/~(144)Nd)_i-(~(87)Sr/~(86)Sr)i图解中,广丰、玉山盆地橄榄玄粗岩均位于亏损地幔(DMM)和EMⅡ型富集地幔之间,而且(~(87)Sr/~(86)Sr)_i和(~(206)Pb/~(204)Pb)_i呈正相关,(~(143)Nd/~(144)Nd)_i和(~(206)Pb/~(204)Pb)_i呈负相关,指示其源区中可能均有DMM和EMⅡ型地幔的贡献;玉山盆地橄榄玄粗岩更偏向DMM端员,指示其DMM端员所占的比例更高。广丰、玉山盆地橄榄玄粗岩具有EMⅡ型地幔的贡献,说明华夏古板块与扬子古板块结合带的岩石圈地幔与华夏古板块的岩石圈地幔属相同类型,为华夏古板块俯冲于扬子古板块之下提供了新的证据。  相似文献   

Autogenic dynamics of alluvial fans in endorheic basins: Outcrop examples and stratigraphic significance   总被引：1，自引：0，他引：1  

Dario Ventra  Gary J. Nichols 《Sedimentology》2014,61(3):767-791

Alluvial fans are relatively simple depositional systems, due to the direct coupling of sediment sources and adjacent accumulation areas. Nonetheless, general models of alluvial‐fan evolution and stratigraphy remain elusive, due to the great sensitivity of such systems to allogenic controls and their strongly case‐specific responses. Autogenic processes intrinsic to alluvial‐fan dynamics can complicate stratigraphic architectures, with effects not easily distinguishable from those of allogenic forcing. A distinction is made here between lateral autogenic dynamics, tied to spatial sediment distribution over fan surfaces, and vertical autogenic dynamics, related to independent incision‐aggradation cycles. Autogenic mechanisms have been highlighted recently by modelling studies, but remain poorly constrained in field‐based studies. Examples are presented here from the margins of the Cenozoic Teruel and Ebro basins (Spain), where alluvial fans accumulated thick successions during phases of basin topographic closure and endorheic drainage which promoted forced aggradation. Fan successions consist of conformable architectures of stacked clastic sheets, laterally continuous and with no evidence of internal unconformities, inset architectures, fan segmentation or preserved incised channels. Continuous aggradation in these closed basins strongly inhibited ‘vertical’ autogenic dynamics in the form of fan head and through fan incision, due to the forced rise in geomorphic base level and the creation of positive accommodation. Furthermore, the lack of incised channels favoured widespread sediment transport and aggradation over broad fan sectors in relatively short time spans, in contrast to the typical occurrence of active lobes and abandoned fan surfaces caused by ‘lateral’ autogenic dynamics. Stratigraphic records of alluvial fans developed in endorheic basins are essentially complete and largely unaffected by autogenic processes. The latter characteristic implies that they can be more unambiguously interpreted in terms of allogenic forcing, because stratigraphic signatures are not complicated by the effects of complex fan autodynamics.  相似文献   

内蒙古大梁道班地区大石寨组火山岩的地质地球化学特征及其构造环境探讨     

金松 《化工矿产地质》2014,(2):73-84

内蒙古锡林浩特大梁道班地区大石寨组火山岩为一套富铝富硅的中酸性钙碱性系列火山岩,岩性组合为安山岩、英安岩、流纹岩等;稀土总量较高且轻重稀土分异明显;Nb、Ta、Ti、P等高场强元素(HFSE)相对亏损,板内元素相对富集。将上述岩石地球化学特征与构造环境判别图解相结合分析,初步确定该地区大石寨组火山岩形成于活动大陆边缘向弧后盆地演化的构造环境中,因此进一步推断大梁道班地区内在早中二叠世处于板块汇聚阶段,西伯利亚板块与华北板块在贺根山一带缝合,这次板块碰撞也标志着本区内古亚洲洋的闭合。  相似文献   

甘肃河西地区2000-2019年水土资源耦合协调特征     

王凌阁  朱睿  陈泽霞  尹振良  卢睿  方春爽 《中国沙漠》2022,42(2):44-53

以甘肃河西地区为研究区,采用耦合协调度模型和农业水土资源匹配系数法分别对河西五市和河西走廊三大内陆河中游地区水土耦合协调情况进行量化研究,并以此为基础通过灰色关联度法分析水土资源耦合协调度影响因素.结果表明:(1)2000-2019年,河西五市水土资源耦合协调度整体提升了 64.65％,由濒临失调转换为初级协调,呈现不...  相似文献   

北山蛇绿岩特征及构造属性   总被引：20，自引：0，他引：20  

杨合群  李英  赵国斌  李文渊  王小红  姜寒冰  谭文娟  孙南一 《西北地质》2010,43(1):26-36

概述了北山地区4条蛇绿岩带的岩石类型组合及岩石地球化学特征,并结合区域地质情况分析认为:红柳河-牛圈子-洗肠井蛇绿岩带形成于早古生代洋盆环境,特征最接近现代洋壳蛇绿岩,在该带北侧保存有标志活动陆缘的公婆泉-东七一山岛弧火山岩带,南侧保存有标志南北两个板块开裂前伸展拉张的浅海—次深海形成的寒武纪含磷钒铀锰沉积岩系地层,说明该蛇绿岩带指示南北两个板块间裂解与聚合的位置。芨芨台子-小黄山蛇绿岩带分布于公婆泉-东七一山岛弧与星星峡-旱山地块之间,形成于早古生代弧后盆地环境。红石山-百合山-蓬勃山蛇绿岩带和辉铜山-帐房山蛇绿岩带形成于晚古生代裂谷拉张最大化至初始小洋盆出现的阶段,即类似于"红海型"海槽的环境。  相似文献