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1.
弧后盆地火山-沉积特征 总被引：3，自引：0，他引：3
多数被描述的现代弧后盆地的经典例子,诞生于最引入注目的环西太平洋大陆边缘的弧盆体系,而古代的弧后盆示则多幸存于碰撞造山带中,如东特斯构造域内的义敦弧后盆地。目前普遍认为大多数的弧后盆地是与俯冲作用有关的弧后扩张作用形成的。弧后盆地火山－沉积特征主要为：物源具双向性,一是大陆物源区,二是岛弧或扩张中心火山活动处。沉积类型复杂多样,靠近大陆一侧多发半发育浅水碎屑岩和碳酸盐岩沉积;岛弧侧发育大量的火山碎 相似文献
2.
多数被描述的现代弧后盆地的经典例子,诞生于最引人注目的环西太平洋大陆边缘的弧盆体系。而古代的弧后盆地则多幸存于碰撞造山带中,如东特斯构造域内的义敦弧后盆地。目前普遍认为大多数的弧后盆地是与俯冲作用有关的弧后扩张作用形成的。弧后盆地火山沉积特征主要为：物源具双向性,一是大陆物源区;二是岛弧或扩张中心火山活动处。沉积类型复杂多样,靠近大陆一侧多半发育浅水碎屑岩和碳酸盐岩沉积;岛弧侧发育大量的火山碎屑岩与火山熔岩,并与碎屑流、浊积沉积和深水相沉积共生,沉积作用方式多,沉积速率较高等。沉积序列上具有下粗上细的双层结构特征 相似文献
3.
贾进华 《华东地质学院学报》1995,18(1):9-15
热水塘下二叠统位于滇西南澜沧江带西区，为一套弧前深水斜坡盆地环境的碎屑浊流、等深流沉积组合，其物源主要来自东侧的大陆火山岛弧。它们和更东的龙洞河组，形成澜沧江带海西期“弧前－火山弧－弧后”的构造古地理格局，表明思茅地块西侧在晚石炭世－早二叠世为活动大陆边缘，标志着滇西南古特提斯洋板块自西向东的俯冲作用。 相似文献
4.
在吉林中部地区,从伊通放牛沟岛弧与华北大陆板块之间,发育一套早古生代火山－沉积岩系,为同一沉积盆地内不同沉积环境下的岩石组合。通过岩石建造分析、岩石化学及区域构造等方面分析。表明该沉积盆地的构造环境为一未完全封闭的弧后盆地,在早古生代华北板块北缘东端构成非标准的弧一盆构造体系,形成特有的活动大陆边缘。通过沉积岩系形成时代对比,认为该弧后盆地属残留,并提出盆地的构造演化模式。 相似文献
5.
智利铁氧化物铜金型矿床成矿规律、控制因素与成矿演化 总被引：2，自引：0，他引：2
智利中生代铁氧化物铜金型(IOCG)矿床成矿带位于海岸科迪勒拉山带,与斑岩铜金和浅成低温热液型金银矿床共同组成了南美安第斯型活动大陆边缘上成矿系统组合。在成矿时代上,IOCG矿床成矿时代集中在175.6～141,140～100和99～66 Ma BP。IOCG矿床位于弧前盆地、主岛弧带和弧后盆地等五级构造单元中;而斑岩铜金和浅成低温热液型金银矿床位于主岛弧带和弧后盆地中,与IOCG矿床成矿带成对出现。综述了智利超大型IOCG矿床研究和勘查进展,认为智利IOCG矿床主要为富铁质岩浆的火山喷溢作用、岩浆热液—盆地流体混合成矿和岩浆热液成矿作用等3种端元类型。侏罗—白垩纪弧前盆地、主火山岛弧带和弧后盆地等五级构造单元是IOCG矿床定位构造,在晚白垩世发生构造反转后,在安第斯大陆边缘从伸展构造体制转变为走滑挤压收缩构造体制,同时形成了平行于岛弧带的阿卡塔玛(AFZ)断裂系统,AFZ断裂系统导致弧前盆地—主岛弧带—弧后盆地发生构造变形并伴有同构造期岩浆侵入,主岛弧带岩浆活动停滞,晚白垩世深成岩浆弧向东迁移,在岛弧带和弧后盆地反转过程中因岩浆—构造叠加程度不同,形成了IOCG矿床叠加成矿序列,同期,白垩纪斑岩型铜金矿床和浅成低温热液型金银矿床相伴形成。提出富铁基性—超基性岩、IOCG矿床和斑岩型铜金矿床等与弧后盆地构造变形的动力学机制是今后的研究方向。 相似文献
6.
松潘-甘孜造山带义敦岛弧中段三叠纪
火山-沉积盆地的演化 总被引：1，自引：0，他引：1
通过对三叠纪义敦岛弧中段83条剖面和沉积等厚线的综合分析研究,将其划分为义敦弧后前陆盆地、义敦火山弧、昌台-禾尼弧间盆地群、沙鲁里火山岩浆弧、雄龙西-金厂沟弧前盆地群5个次级的构造古地理单元.其中弧后盆地主要有上麻绒和义敦2个沉积中心,义敦火山弧可进一步细分出果德、根隆、郎格、哈逮4个次级火山穹隆,弧间盆地群有拿它盆地、曲登盆地、夏塞盆地、哈日盆地,沙鲁里火山岩浆弧可进一步细分为木合沟和口娘公玛2个次级火山穹隆,弧前盆地有雄龙西盆地、莫坝盆地、金厂沟盆地等8个次级火山-沉积盆地.认为义敦岛弧的演化主要受理塘缝合带演化的控制,也受金沙江缝合带演化的影响,总体上在三叠纪经历了夭折裂陷槽→不成熟岛弧→成熟岛弧→残余盆地的演化历程. 相似文献
7.
通过对三叠纪义敦岛弧中段83条剖面和沉积等厚线的综合分析研究,将其划分为义敦弧后前陆盆地、义敦火山弧、昌台-禾尼弧间盆地群、沙鲁里火山岩浆弧、雄龙西-金厂沟弧前盆地群5个次级的构造古地理单元。其中弧后盆地主要有上麻绒和义敦2个沉积中心,义敦火山弧可进一步细分出果德、根隆、郎格、哈逮4个次级火山穹隆,弧间盆地群有拿它盆地、曲登盆地、夏塞盆地、哈日盆地,沙鲁里火山岩浆弧可进一步细分为木合沟和口娘公玛2个次级火山穹隆,弧前盆地有雄龙西盆地、莫坝盆地、金厂沟盆地等8个次级火山-沉积盆地。认为义敦岛弧的演化主要受理塘缝合带演化的控制,也受金沙江缝合带演化的影响,总体上在三叠纪经历了夭折裂陷槽→不成熟岛弧→成熟岛弧→残余盆地的演化历程。 相似文献
8.
江南中、新元古代岛弧的运动学和动力学 总被引：43，自引：1，他引：43
自经７０年代作者等发表江南中－新元古代岛弧构造观点以来，这一地区已经在８０年代后期和９０年代成为我国大地构造研究热点之一。大量新资料支持以下的古板块构造演化模式，即古华南洋壳中元古代１３（１７）～９．８亿年时向北（西北）俯冲于扬子板块东南边缘之下，形成江南火山岛弧和弧后盆地，在东北段是皖－浙－赣火山岛弧和樟树墩－伏川弧后盆地；新元古代９．８～７．７亿年时发生了陈蔡弧（浙东地体）与皖－浙－赣弧的弧－弧碰撞造山作用，并导致樟树墩－伏川边缘海的崩塌和陆－弧弧后碰撞造山过程。江南古岛弧带经历了多次的后期构造变形。 相似文献
9.
弧－盆体系中岛弧与弧后盆地相间并存是一大特色。本文以昌都地区叠纪弧一盆格局为例,阐明了岛弧、弧后盆地与夹于其间的微陆块等地质特征;划分出２个构造演化阶段,一是早中三叠世江达－阿中岛弧与弧后盆地的发育,二是晚三叠世滞后型岛弧与生达残留弧后盆地的形成,并揭示了其演化的动力学。 相似文献
10.
江南中,新元古代岛弧的运动学和动力学 总被引：2，自引：0，他引：2
自经７０年代作者等发表江南中一新元古代岛弧构造观点以来，这一地区已经在８０年代后期和９０年代成为我国大地构造研究热点之一，大量新资料支持以下的古板块构造演化模式，即古代南洋壳中元古代１３（１７）－９．８亿年时向北（西北）俯地扬子板块东南边缘之下，形成江南火山同岛弧和弧后盆地，在东北段是皖－浙－赣火山岛弧和樟树数－伏川弧后盆地；新元古代９．８－７．７亿年时发生了陈蔡弧与皖－浙－赣弧的弧－弧碰撞造山作 相似文献
11.
Yu.A. Zorin E.V. Sklyarov V.G. Belichenko A.M. Mazukabzov 《Russian Geology and Geophysics》2009,50(3):149-161
We suggest a more rigorous approach to paleogeodynamic reconstructions of the Sayan-Baikal folded area proceeding from update views of the origin and evolution of island arcs and back-arc basins. Modern island arcs and attendant back-arc basins form mainly by trench rollback caused by progressive subduction of negatively buoyant thick and cold oceanic slabs. Slab stagnation upsets the dynamic equilibrium in the subduction system, which accelerates the rollback. As a result, a continental volcanic arc transforms into an island arc, with oceanic crust production in the back-arc basin behind it. As subduction progresses, the island arc and the back-arc basin may deform, and fold-thrust structures, with the involved back-arc basin and island arc complexes, may accrete to the continent (accretion and collision) without participation of large colliding blocks. When applied to the Sayan–Baikal area, the model predicts that the Riphean and Vendian–Early Paleozoic back-arc basins were more active agents in the regional geologic history than it was thought before. They were deposition areas of sedimentary and volcanosedimentary complexes and then became the scene of collision and accretion events, including folding, metamorphism, and plutonism. 相似文献
12.
冲绳海槽是一个处于弧后扩张作用早期的年轻的弧后盆地,是研究弧后扩张作用早期盆地演化和壳幔过程的天然实验室.随着调查研究工作的逐步展开和深入,也发现了一些新的、重要的、亟待解决的科学问题,而火山岩岩石系列归属的厘定又是其他研究工作的基础.在系统收集和整理迄今已有冲绳海槽火山岩资料的基础上,结合近期分析测试数据, 对冲绳海槽火山岩的岩石系列归属进行了重新厘定,探讨了火山岩的构造环境指示意义和浮岩与玄武岩之间的成因联系.研究结果表明:冲绳海槽火山岩分布具有以基性玄武岩和酸性(流纹)英安岩为主的双峰式特征,中性火山岩稀少,基性的玄武岩属于亚碱性系列的橄榄拉斑玄武岩,酸性浮岩可归属为亚碱性岩系的流纹英安岩或流纹岩;在构造环境判别上,冲绳海槽玄武岩表现出大洋中脊和岛弧构造环境的特点,既有别于大洋中脊扩张中心,也有别于成熟型弧后盆地,呈现出弧后早期扩张阶段盆地独特的构造环境特征;广泛分布于冲绳海槽的酸性浮岩表现出一定的岛弧环境的特点;酸性浮岩与玄武岩具有同源性,酸性岩是基性的玄武质岩浆经不同程度结晶分异和同化混染作用的产物. 相似文献
13.
Island arc elements and arc-related ophiolites 总被引：1，自引：0，他引：1
Evan C. Leitch 《Tectonophysics》1984,106(3-4)
All major structural elements in island arc systems, fore-arc, magmatic arc, back-arc basins and remnant arcs, are potential ophiolite sources, and those features that allegedly characterise ophiolites of ocean-ridge origin, sheeted dyke complexes, mantling pelagic rocks, hydrothermal metamorphism and associated mineralization, can also arise within arc settings. Age relations are critical in the interpretation of arc-related ophiolites. Remnants of oceanic lithosphere, identified by a pre-arc initiation age, are restricted to fore-arc, magmatic arc and remnant arc elements, as are ophiolite masses generated at the inception of underthrusting. The latter, apparently common in ancient fore-arc terrains, form in nascent arc systems in which the rate of role back of the subduction hinge exceeds the rate of convergence. Spreading occurs above a foundering slab resulting in some arc-like compositional features. In simple arc systems later ophiolitic rocks have formed either in the active back-arc basin or the magmatic arc. Only those ophiolites that have resided within or very close behind magmatic arcs should show calcalkaline or arc tholeiite magmatic affinities, or be intruded or overlain by these rocks. Volcanic-derived sediment or pelagic material may mantle ophiolites from all arc settings, but pelagic rocks will generally dominate in stratigraphic sequences above remnant arcs and on back-arc basin floors except adjacent to the magmatic arc. Ophiolites generated at major ocean ridges are unlikely to be immediately overlain by sediment with a significant volcanic component whereas such detritus may lie directly on arc-inception, arc and back-arc ophiolites. Some arc-derived ophiolites are preserved in their original tectonic position, others can be identified from their internal features, their relationship to other tectonic elements, and the nature of associated rocks. 相似文献
14.
V. M. Grannik 《Doklady Earth Sciences》2012,445(2):934-938
It has been established that volcanic rocks of the Schmidt, Rymnik, and Terpeniya terranes are fragments of the compound Early to Late Cretaceous-Paleogene East Sakhalin island arc system of the Sea of Okhotsk region. This island arc paleosystem was composed of back-arc volcano-plutonic belt, frontal volcanic island arc, fore-arc, inter-arc, and back-arc basins, and the Sakhalin marginal paleobasin. The continental volcanic rocks dominate in the back-arc volcano-plutonic belt and frontal volcanic island arc. The petrochemical composition of basalts, basaltic andesites, andesites, and trachytes from the frontal island arc formed in submarine conditions are typical of oceanic island arc or marginal sea rocks (IAB). The petrochemical composition of volcanic rocks from the island arc structures indicates its formation on the heterogeneous basement including the continental and oceanic blocks. 相似文献
15.
《Russian Geology and Geophysics》2007,48(1):107-119
Based on a comparative study of geochemistry of metavolcanics and metasediments of two large terranes, Baikal-Muya and Khamar-Daban-Ol’khon, as well as of the Baikal-Patom passive margin and Olokit accretionary wedge, we have recognized volcanosedimentary series accumulated in the settings of island arcs of different maturities and fragments of volcanosedimentary complexes of back-arc and fore-arc basins. Metabasalts of the Medvezhy and Tyya Formations in the basement of passive-margin sequence and the Olokit Group are similar in geochemistry to plateau basalts and mark the beginning of rifting on the platform periphery. The abundance of metavolcanics and turbidites in the Olokit Group permits this structure to be considered an accretionary wedge of the Baikal-Muya island arc. According to the metavolcanics composition, the Baikal-Muya terrane formed in the environment of oceanic ensimatic island arcs and back-arc and inter-arc basins with the minimum amounts of sediments and contains ophiolite slices. The geochemistry of metavolcanics and metasediments of the Ol’khon, Talanchan, and Slyudyanka complexes evidences their formation in the environment of ensialic back-arc sediment-rich basin (Slyudyanka, Ol’khon, and Svyatoi Nos series), mature island arc (Anga-Talanchan paleoarc, Anga and Talanchan Groups), and fore-arc basin (Khangarul’ Group). According to chemistry and evolution history, all these complexes must be assigned to the Khamar-Daban-Ol’khon terrane. 相似文献
16.
KEVIN T. PICKERING 《Geology Today》1989,5(5):160-166
The Cambro-Ordovician Iapetus and Tornquist's Oceans formed a Pacific-type ocean basin rimmed by volcanic island arcs and marginal basins. By the latest Ordovician to earliest Silurian this ocean basin was beginning to close, to become a Mediterranean-type ocean basin. This was caused by the collision between a microcontinent (comprising England, Wales, much of Ireland and parts of north-west Europe), called Eastern Avalonia, and the North American super-continent, Laurentia, which resulted in no oceanic crust remaining in the region of present-day central Newfoundland. Marine basins, however, persisted into the Middle Silurian. Throughout the Silurian and early Devonian, some 40–45 million years, various terranes continued to collide with the North American margin, predominantly under major left-lateral strike-slip until the remaining seaways were eliminated in the early Middle Devonian, to be replaced by terrestrial environments of the Old Red Sandstone. 相似文献
17.
本文重点简述了特提斯构造域内古，中，新三个演化阶段的蛇绿混杂岩与岛弧带的时空展布及其沟－弧－盆体系，所识别出的蛇绿混杂岩，洋中脊拉斑玄武岩，大洋沉积物的岛弧带等地质记录，提供了东特提斯早期大洋岩石圈板块运动的有力证据。同时，与岛弧有关的不同时期不同阶段的各种弧前盆地，弧间盆地和弧后贫地成为造山带板块会聚边缘特征的标志。 相似文献