南岭东段早侏罗世沉积岩碎屑锆石U-Pb定年及其地质意义——以东坑盆地为例   总被引：1，自引：0，他引：1  

李武显  赵希林  邢光福  岑涛  陶继华 《大地构造与成矿学》2013,37(1):78-86

印支造山运动是华南早中生代最重要的构造-岩浆事件,它在很大程度上影响了华南现今的地形和地貌特点。本文研究了南岭东段赣南早侏罗世东坑火山岩盆地沉积岩的碎屑锆石U-Pb年代,获得最显著的年龄峰值为196Ma、238Ma、364Ma和427Ma,表明该沉积岩并不是外来的震旦纪-寒武纪变质岩,而是早侏罗世裂谷火山盆地的沉积物。缺乏260～290Ma的锆石年龄,很可能反映物质为近源来源。通过与闽西南晚三叠世和华南内陆中-晚二叠世沉积砂岩中碎屑锆石年龄谱对比,反映华南印支早期(290～260Ma)岩浆活动主体在东南沿海地区,晚期(240～200Ma)主体发育在内陆地区。大量印支期侵入岩锆石的出现也很可能表明华南内陆印支造山带在～190Ma已经经历了相当程度的垮塌。  相似文献   

Deformation history and timing of granite emplacement in the Butchers Hill — Helenvale region,northern Hodgkinson Province,Queensland   总被引：1，自引：1，他引：0  

B. K. Davis  R. A. Henderson  M. Lindsay  R. Wysoczanski 《Australian Journal of Earth Sciences》2013,60(5):775-785

Granite plutons of the Whypalla Supersuite in the Butchers Hill — Helenvale region of north Queensland were intruded into the upper crust of the Hodgkinson Formation during contractional deformation associated with the Permian‐Triassic Hunter‐Bowen Orogeny. A four‐stage structural history has been resolved for the area, with fabric overprinting relationships, porphyroblast‐matrix microstructural geometries and isotopic ages being consistent with granite emplacement during D₄ shortening at ca 274 Ma. Microstructural relationships suggest the possibility of a minor syn‐D₃ phase of granite emplacement. The deformation‐emplacement history of the Butchers Hill — Helenvale area is consistent with that recognised regionally for the Hodgkinson Province, indicating province‐wide synchronous syntectonic granite intrusion during a major phase of contractional deformation. Intense syn‐emplacement deformation partitioning was ongoing in the country rocks during progressive D₄ and was associated with upward translation of country rock from the microscale to the macroscale along D₄ cleavages and shears. Kinematic indicators show that this progressive uplift, at the scale of the area examined, was east‐side‐up.  相似文献   

Palaeozoic synorogenic sedimentation in central and northern Australia: A review of distribution and timing with implications for the evolution of intracontinental orogens   总被引：1，自引：1，他引：0  

P. W. Haines  M. Hand  M. Sandiford 《Australian Journal of Earth Sciences》2013,60(6):911-928

The Palaeozoic Alice Springs Orogeny was a major intraplate tectonic event in central and northern Australia. The sedimentological, structural and isotopic effects of the Alice Springs Orogeny have been well documented in the northern Amadeus Basin and adjacent exhumed Arunta Inlier, although the full regional extent of the event, as well as lateral variations in timing and intensity are less well known. Because of the lack of regional isotopic data, we take a sedimentological approach towards constraining these parameters, compiling the location and age constraints of inferred synorogenic sedimentation across a number of central and northern Australian basins. Such deposits are recorded from the Amadeus, Ngalia, Georgina, Wiso, eastern Officer and, possibly, Warburton Basins. Deposits are commonly located adjacent to areas of significant basement uplift related to north‐south shortening. In addition, similar aged orogenic deposits occur in association with strike‐slip tectonism in the Ord and southern Bonaparte Basins of northwest Australia. From a combination of sedimentological and isotopic evidence it appears that localised convergent deformation started in the Late Ordovician in the eastern Arunta Inlier and adjacent Amadeus Basin. Synorogenic style sedimentation becomes synchronously widespread in the late Early Devonian and in most areas the record terminates abruptly close to the end of the Devonian. A notable exception is the Ngalia Basin in which such sedimentation continued until the mid‐Carboniferous. In the Ord and Bonaparte Basins there is evidence of two discrete pulses of transcurrent activity in the Late Devonian and Carboniferous. The sedimentological story contrasts with the isotopic record from the southern Arunta Inlier, which has generally been interpreted in terms of continuous convergent orogenic activity spanning most of the Devonian and Carboniferous, with a suggestion that rates of deformation increased in the mid‐Carboniferous. Either Carboniferous sediments have been stripped off by subsequent erosion, or sedimentation outpaced accommodation space and detritus was transported elsewhere.  相似文献   

Palaeontological age and correlations of the Tertiary deposits of the NW Iberian Peninsula: the tectonic evolution of a broken foreland basin     

F. Martín‐Gonzlez  M. Freudenthal  N. Heredia  E. Martín‐Surez  R. Rodríguez‐Fernndez 《Geological Journal》2014,49(1):15-27

Ages of Cenozoic sedimentary basins yield information that can be used to infer detailed spatial and temporal evolution in the Alpine foreland. The Tertiary deposits of the NW Iberian Peninsula comprise the remains of a broken foreland basin (the West Duero Basin). This work constrains the timing of tectonic fragmentation and the evolution of the western termination of the Alpine Pyrenean–Cantabrian Orogen (NW Iberian Peninsula). The discovery of Issiodoromys cf. minor 1 and Pseudocricetodon in the lower formation of the Tertiary depression of Sarria (the Toral Formation) constrains its age to the late Early Oligocene (MP23–MP25), similar to its age in the El Bierzo depression (MP24–MP25). Sedimentation initiated in the NE of the study area at Oviedo during the Middle Eocene (Bartonian–Early Priabonian MP16–MP17) and migrated towards the west and south during the Early Oligocene. The Toral Formation was deposited in a foreland basin that connected the present day outcrops of the El Bierzo, Sarria and As Pontes Tertiary depressions. The basin was segmented during the westward migration of structural deformation associated with the Orogen, and the subsequent uplift of the Galaico–Leoneses Mountains. The present‐day height above reference level of the base of the Toral Formation has been used to quantify Alpine segmentation that took place after Early Oligocene times. Minimum tectonic uplift assessed is 960 m in the Cantabrian Mountains and 1050 m in the Galaico–Leoneses Mountains. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

The Afeição augen-gneiss Suite and the record of the Cariris Velhos Orogeny (1000–960 Ma) within the Riacho do Pontal fold belt,NE Brazil     

《Journal of South American Earth Sciences》2014

Early Tonian (∼1000–920 Ma) rocks occur within the Transversal Zone of the Borborema Province in Northeast Brazil comprising the 700 km-long sigmoidal Cariris Velhos belt. The Afeição augen-gneiss Suite crops out in the internal zone of the Riacho do Pontal fold belt, about 100 km southwestward of the closest Cariris Velhos occurrence within the Transversal Zone, and has been proposed to represent a continuation of this belt within the Southern subprovince of the Borborema Province. Several plutons included within this unit intrude or are thrust upon metavolcanosedimentary sequences of three different units (Santa Filomena, Paulistana and Morro Branco complexes). The Afeição Suite is composed mostly of calc-alkaline, high-K, peraluminous, high-silica ferroan and magnesian granites. Chondrite-normalized REE patterns are moderate to highly fractionated, with a pronounced negative Eu anomaly. Incompatible element spidergrams show a negative Nb–Ta anomaly, akin to convergence setting (Cordilleran-type) granites. U–Pb zircon data constrain the age of crystallization between 1000 and 960 Ma, thus confirming chrono-correlation with the Cariris Velhos belt. Values of εNd(t) between −1.0 and +3.1 and T_DM of 1.2–1.5 Ga, similar to other Cariris Velhos occurrences, suggest variable mixing of Tonian juvenile sources with older crustal sources, the latter involving Archean/Paleoproterozoic basement. Although there are currently no reliable geochronological data for the supracrustal sequences of the internal zone, cross-cutting relationships indicate that the Santa Filomena and Morro Branco complexes are older or of similar age to the Afeição Suite, and thus could be related to the Cariris Velhos Orogeny. Based on petrographic, lithogeochemical, geochronological and isotope data, and according to previous models proposed for the Cariris Velhos belt, we interpret the Afeição Suite as the southwestern edge of a continental margin magmatic arc accreted to this portion of West Gondwana during the Early Tonian. Late-Brasiliano dextral displacement through the western branch of the Pernambuco shear zone separated these Cariris Velhos occurrences from its equivalents within the Transversal Zone of the Borborema Province (Recanto-type augen-gneiss of the Alto Pajeú Terrane).  相似文献   

Subsurface imaging,TAIGER experiments and tectonic models of Taiwan     

《Journal of Asian Earth Sciences》2014

The seismicity, deformation rates and associated erosion in the Taiwan region clearly demonstrate that plate tectonic and orogenic activities are at a high level. Major geologic units can be neatly placed in the plate tectonic context, albeit critical mapping in specific areas is still needed, but the key processes involved in the building of the island remain under discussion. Of the two plates in the vicinity of Taiwan, the Philippine Sea Plate (PSP) is oceanic in its origin while the Eurasian Plate (EUP) is comprised partly of the Asian continental lithosphere and partly of the transitional lithosphere of the South China Sea basin. It is unanimously agreed that the collision of PSP and EU is the cause of the Taiwan orogeny, but several models of the underlying geological processes have been proposed, each with its own evolutionary history and implied subsurface tectonics.TAIGER (TAiwan Integrated GEodynamics Research) crustal- and mantle-imaging experiments recently made possible a new round of testing and elucidation. The new seismic tomography resolved structures under and offshore of Taiwan to a depth of about 200 km. In the upper mantle, the steeply east-dipping high velocity anomalies from southern to central Taiwan are clear, but only the extreme southern part is associated with seismicity; toward the north the seismicity disappears. The crustal root under the Central Range is strongly asymmetrical; using 7.5 km/s as a guide, the steep west-dipping face on the east stands in sharp contrast to a gradual east-dipping face on the west. A smaller root exists under the Coastal Range or slightly to the east of it. Between these two roots lies a well delineated high velocity rise spanning the length from Hualien to Taitung. The 3-D variations in crustal and mantle structures parallel to the trend of the island are closely correlated with the plate tectonic framework of Taiwan. The crust is thickest in the central Taiwan collision zone, and although it thins toward the south, the crust is over 30 km thick over the subduction in the south; in northern Taiwan, the northward subducting PSP collides with Taiwan and the crust thins under northern Taiwan where the subducting indenter reaches 50 km in depth. The low Vp/Vs ratio of around 1.6 at a mid-crustal depth of 25 km in the Central Range indicates that current temperatures could exceed 700 °C. The remarkable thickening of the crust under the Central Range, its rapid uplift without significant seismicity, its deep exhumation and its thermal state contribute to make it the core of orogenic activities on Taiwan Island.The expanded network during the TAIGER deployment captured broadband seismic data yielding enhanced S-splitting results with mainly SKS/SKKS data. The polarization directions of the fast S-waves follow very closely the structural trends of the island, supporting the concept of a vertically coherent Taiwan orogeny in the outer few hundred kilometers of the Earth.  相似文献   

Geological and palaeomagnetic significance of the Kulgera Dyke Swarm, Musgrave Block, NT, Australia     

A. Camacho  B. Simons  P. W. Schmidt 《Geophysical Journal International》1991,107(1):37-45

b
The Kulgera Dyke Swarm consists of olivine tholeiites which have intruded late Proterozoic transitional-granulite gneisses and granites of the eastern Musgrave Block, in central Australia. Preliminary Rb/Sr results suggest that the dolerites were emplaced at 1054 ± 14 Ma. In addition, a Rb/Sr age of 1060 ± 10 Ma on a biotite from a pegmatite indicates thermal resetting of the country rock minerals during dyke emplacement. Palaeomagnetic investigations of the dykes yield a primary thermoremanent magnetization direction corresponding to a palaeomagnetic pole at 17S, 266E ( A ₉₅= 12). In addition to this primary magnetization, an overprint component was present in many of the samples, providing a palaeomagnetic pole at 30S, 138E ( A ₉₅= 24), which is similar to previous results from other central Australian rocks affected by the Alice Springs Orogeny. The results extend the area of influence of the Carboniferous Alice Springs Orogeny southward into the Musgrave Block. Further, the results provide no evidence for an earlier, Late Proterozoic, Petermann Orogeny affecting the Musgrave Block in the Kulgera region. However, the possibility that a Petermann Orogeny thermal overprint has been erased by the Alice Springs Orogeny cannot be dismissed.  相似文献   

Delamerian Orogeny and potential foreland sedimentation: A review of age and stratigraphic constraints     

P. W. Haines  T. Flöttmann 《Australian Journal of Earth Sciences》2013,60(4):559-570

A review of available geochronology and biostratigraphy leads to the conclusion that a considerable thickness of Cambrian sedimentary rocks exposed in the Arrowie and Stansbury Basins, South Australia, was probably deposited in a foreland setting during early phases of the Delamerian Orogeny. In contrast to most previous stratigraphic correlation schemes, we consider that the pre‐tectonic Kanmantoo Group was deposited synchronously with the locally thick upper Hawker Group in essentially en echelon basins during a final phase of extensional sedimentation within the Adelaide ‘Geosyncline’. The base of the locally overlying ‘redbed package’ (base of the Billy Creek and Minlaton Formations) is interpreted as the sedimentological signature of the onset of convergent deformation and associated uplift within the Delamerian Orogen at about 522 Ma. This early ('Kangarooian') phase of the Delamerian Orogeny is interpreted as the progressive development of a coherent sigmoidal fold‐thrust belt within the combined Fleurieu‐Nackara Arcs, with locally developed high‐temperature‐low‐pressure metamorphism and granitoid intrusions dating from about 516 Ma. The ‘redbed package’ is absent from the Fleurieu‐Nackara Arc region and displays isopach, palaeocurrent and facies trends consistent with derivation from this uplifted area or from the associated flexural bulge to the west. From seismic evidence we conclude that thick foreland basin deposits are present beneath Gulf St Vincent. Late phases of the Delamerian Orogeny led to local and relatively mild deformation of the early foreland deposits.  相似文献   

Three Palaeoproterozoic basins—Yerrida,Bryah and Padbury—Capricorn Orogen,Western Australia     

F. Pirajno  S. A. Occhipinti 《Australian Journal of Earth Sciences》2013,60(4):675-688

The Palaeoproterozoic Yerrida, Bryah and Padbury Basins record periods of sedimentation and magmatism along the northern margin of the Archaean Yilgarn Craton. Each basin is characterised by distinct stratigraphy, igneous activity, structural and metamorphic history and mineral deposit types. The oldest of these basins, the Yerrida Basin (ca 2200 Ma) is floored by rocks of the Archaean Yilgarn Craton. Important features of this basin are the presence of evaporites and continental flood basalts. The ca 2000 Ma Bryah Basin developed on the northern margin of the Yilgarn Craton during backarc sea‐floor spreading and rifting, the result of which was the emplacement of voluminous mafic and ultramafic volcanic rocks. During the waning stages of the Bryah Basin this mafic to ultramafic volcanism gave way to deposition of clastic and chemical sedimentary rocks. At a later stage, the Padbury Basin developed as a retroarc foreland basin on top of the Bryah Basin in a fold‐and‐thrust belt. This resulted from either the collision of the Pilbara and Yilgarn Cratons (Capricorn Orogeny) or the ca 2000 Ma westward collision of the southern part of the Gascoyne Complex and the Yilgarn Craton (Glenburgh Orogeny). During the Capricorn Orogeny the Bryah Group was thrust to the southeast, over the Yerrida Group. Important mineral deposits are contained in the Yerrida, Bryah and Padbury Basins. In the Yerrida Basin a large Pb–carbonate deposit (Magellan) and black shale‐hosted gossans containing anomalous abundances of Ba, Cu, Zn and Pd are present. The Pb–carbonate deposit is hosted by the upper units of the Juderina Formation, and the lower unit of the unconformably overlying Earaheedy Group. The Bryah and Padbury Basins contain orogenic gold, copper‐gold volcanogenic massive sulfides, manganese and iron ore. The origin of the gold mineralisation is probably related to tectonothermal activity during the Capricorn Orogeny at ca 1800 Ma.  相似文献   

阴山晚中生代板内造山特征及其动力机制——以内蒙古大青山为例     

杜菊民  张庆龙  徐士银  杜松金  解国爱 《地质学报》2009,83(7)

内蒙古大青山属我国典型的板内造山带阴山山脉的南部山系,其西段缺少大型低角度推覆构造及大型深成岩对前期演化历史的干扰,是研究阴山板内造山特点及过程的理想区域。通过对大青山西段的构造进行几何学和运动学的分析表明,古老结晶基底以逆冲推覆及基底褶皱的形式广泛地?入中生代的构造变形,以及先存构造样式的广泛复活并对后期地层沉积和断层发育的控制作用是内蒙古大青山地区中生代板内造山的两个基本特征。这些变形特征反映了阴山带板内造山过程中,是以结晶基底为受力层,并控制上覆盖层进行构造变形的,进而表明板内造山主要是由水平挤压应力造成的。结合研究区构造变形特点及邻区中生代构造地质情况的分析认为,晚侏罗世时期之所以在阴山带形成强烈的板内造山运动,是由其北部西伯利亚板块与蒙古褶皱带碰撞产生的板缘应力的远程传递,以及其南侧坚硬的鄂尔多斯地块的阻挡共同作用而形成的。  相似文献