元素的地球化学性质与关键金属成矿:前言   总被引：1，自引：0，他引：1  

孙卫东  李聪颖 《岩石学报》2020,36(1):1-4

正本专辑重点从元素地球化学性质入手,结合地质过程和区域地质及一些具体矿床实例的研究,探讨关键金属的成矿规律。包括22篇文章,内容涵盖钨、锡、铌、钽、钛、锑、铀、铼、硼、钼、铜等多种关键金属的成矿规律。矿床是元素异常富集的地质体,因此,元素在不同地质  相似文献   

Evolution of the lithosphere in the area of the Rhine Rift System     

P. A. Ziegler  P. Dèzes 《International Journal of Earth Sciences》2005,94(4):594-614

The Rhine Rift System (RRS) forms part of the European Cenozoic Rift System (ECRIS) and transects the Variscan Orogen, Permo-Carboniferous troughs and Late Permian to Mesozoic thermal sag basins. Crustal and lithospheric thicknesses range in the RRS area between 24–36 km and 50–120 km, respectively. We discuss processes controlling the transformation of the orogenically destabilised Variscan lithosphere into an end-Mesozoic stabilised cratonic lithosphere, as well as its renewed destabilisation during the Cenozoic development of ECRIS. By end-Westphalian times, the major sutures of the Variscan Orogen were associated with 45–60 km deep crustal roots. During the Stephanian-Early Permian, regional exhumation of the Variscides was controlled by their wrench deformation, detachment of subducted lithospheric slabs, asthenospheric upwelling and thermal thinning of the mantle-lithosphere. By late Early Permian times, when asthenospheric temperatures returned to ambient levels, lithospheric thicknesses ranged between 40 km and 80 km, whilst the thickness of the crust was reduced to 28–35 km in response to its regional erosional and local tectonic unroofing and the interaction of mantle-derived melts with its basal parts. Re-equilibration of the lithosphere-asthenosphere system governed the subsidence of Late Permian-Mesozoic thermal sag basins that covered much of the RRS area. By end-Cretaceous times, lithospheric thicknesses had increased to 100–120 km. Paleocene mantle plumes caused renewed thermal weakening of the lithosphere. Starting in the late Eocene, ECRIS evolved in the Pyrenean and Alpine foreland by passive rifting under a collision-related north-directed compressional stress field. Following end-Oligocene consolidation of the Pyrenees, west- and northwest-directed stresses originating in the Alps controlled further development of ECRIS. The RRS remained active until the Present, whilst the southern branch of ECRIS aborted in the early Miocene. Extensional strain across ECRIS amounts to some 7 km. Plume-related thermal thinning of the lithosphere underlies uplift of the Rhenish Massif and Massif Central. Lithospheric folding controlled uplift of the Vosges-Black Forest Arch.  相似文献   

2: Hydrothermal ore deposits related to post-orogenic extensional magmatism and core complex formation: The Rhodope Massif of Bulgaria and Greece     

Peter Marchev  Majka Kaiser-Rohrmeier  Christoph Heinrich  Maria Ovtcharova  Albrecht von Quadt  Raya Raicheva 《Ore Geology Reviews》2005,27(1-4):53

The Rhodope Massif in southern Bulgaria and northern Greece hosts a range of Pb–Zn–Ag, Cu–Mo and Au–Ag deposits in high-grade metamorphic, continental sedimentary and igneous rocks. Following a protracted thrusting history as part of the Alpine–Himalayan collision, major late orogenic extension led to the formation of metamorphic core complexes, block faulting, sedimentary basin formation, acid to basic magmatism and hydrothermal activity within a relatively short period of time during the Early Tertiary. Large vein and carbonate replacement Pb–Zn deposits hosted by high-grade metamorphic rocks in the Central Rhodopean Dome (e.g., the Madan ore field) are spatially associated with low-angle detachment faults as well as local silicic dyke swarms and/or ignimbrites. Ore formation is essentially synchronous with post-extensional dome uplift and magmatism, which has a dominant crustal magma component according to Pb and Sr isotope data. Intermediate- and high-sulphidation Pb–Zn–Ag–Au deposits and minor porphyry Cu–Mo mineralization in the Eastern Rhodopes are predominantly hosted by veins in shoshonitic to high-K calc-alkaline volcanic rocks of closely similar age. Base-metal-poor, high-grade gold deposits of low sulphidation character occurring in continental sedimentary rocks of synextensional basins (e.g., Ada Tepe) show a close spatial and temporal relation to detachment faulting prior and during metamorphic core complex formation. Their formation predates local magmatism but may involve fluids from deep mantle magmas.The change in geochemical signatures of Palaeogene magmatic rocks, from predominantly silicic types in the Central Rhodopes to strongly fractionated shoshonitic (Bulgaria) to calc-alkaline and high-K calc-alkaline (Greece) magmas in the Eastern Rhodopes, coincides with the enrichment in Cu and Au relative to Pb and Zn of the associated ore deposits. This trend also correlates with a decrease in the radiogenic Pb and Sr isotope components of the magmatic rocks from west to east, reflecting a reduced crustal contamination of mantle magmas, which in turn correlates with a decreasing crustal thickness that can be observed today. Hydrogen and oxygen isotopic compositions of the related hydrothermal systems show a concomitant increase of magmatic relative to meteoric fluids, from the Pb–Zn–Ag deposits of the Central Rhodopes to the magmatic rock-hosted polymetallic gold deposits of the Eastern Rhodopes.  相似文献   

Geodynamic setting of gold deposits in Eastern and Central Trans-Baikal (Chita Region, Russia)   总被引：1，自引：0，他引：1  

Yu. A. Zorin  Lidia D. Zorina  A. M. Spiridonov  I. G. Rutshtein 《Ore Geology Reviews》2001,17(4):1102

It is proposed that there are three types of gold deposits in Eastern and Central Transbaikalia (Trans-Baikal province), namely: (i) high-sulphide intrusion-related deposits with some signs of porphyry deposits, (ii) low-sulphide intrusion-related deposits, and (iii) low-sulphide epithermal Au–Ag deposits. Most of the gold deposits belong to the first two types, and their ages are Middle–Late Jurassic. Deposits of the third type are not numerous, and their age is Early Cretaceous.The majority of the gold mineralization is spatially related to the two branches of the Mongolia–Okhotsk suture, along which Siberia collided, at the Early/Middle Jurassic boundary, with the Mongolia–North China continent and the Onon island-arc terrane located between the two continents. Collision-related thrusting, folding and magmatism lasted until the latest Jurassic, when they gave way to post-collisional rifting that continued until the end of Early Cretaceous.According to their age, relation to magmatism and tectonic framework, the intrusion-related deposits (high- and low-sulphide) were formed in a regional collisional setting. Extensional environments at that time existed only in local areas in the roofs of great magmatic chambers. Low-sulphide epithermal deposits were formed during Early Cretaceous post-collisional rifting.  相似文献   

Regional compilation and analysis of aeromagnetic anomalies for the Transantarctic Mountains–Ross Sea sector of the Antarctic     

M. Chiappini  F. Ferraccioli  E. Bozzo  D. Damaske 《Tectonophysics》2002,347(1-3)

Magnetic observations over the area of the Transantarctic Mountains (TAM) and the Ross Sea have been compiled into a digital database that furnishes a new regional scale view of the magnetic anomaly crustal field in this key sector of the Antarctic continent. This compilation is a component of the ongoing IAGA/SCAR Antarctic Digital Magnetic Anomaly Project (ADMAP). The aeromagnetic surveys total 115 000 line km, and are distributed across the Victoria Land sector of the TAM, the Ross Sea, and Marie Byrd Land. The magnetic campaigns were performed within the framework of the national and international Italian–German–US Antarctic research programs and conducted with differing specifications during nine field seasons from 1971 until 1997. Generally flight line spacing was less than 5 km while survey altitude varied from about 610 to 4000 m above sea level for barometric surveys and was equal to 305 m above topography for the single draped survey. Reprocessing included digitizing the old contour data, improved levelling by means of microlevelling in the frequency domain, and re-reduction to a common reference field based on the DGRF90 model. A multi-frequency grid procedure was then applied to obtain a coherent and merged total intensity magnetic anomaly map. The shaded relief map covers an area of approximately 380 000 km². This new compilation provides a regional image of the location and spatial extent of the Cenozoic alkaline magmatism related to the TAM–Ross Sea rift, Jurassic tholeiites, and crustal segments of the Early Palaeozoic magmatic arc. A linear, approximately 100-km wide and 600-km long Jurassic rift-like structure is newly identified. Magnetic fabric in the Ross Sea rift often matches seismically imaged Cenozoic fault arrays. Major buried onshore pre-rift fault zones, likely inherited from the Ross Orogen, are also delineated. These faults may have been reactivated as strike-slip belts that segmented the TAM into various crustal blocks.  相似文献   

Early Cambrian oceanic plagiogranite in the Silvretta Nappe,eastern Alps: geochemical,zircon U-Pb and Rb-Sr data from garnet-hornblende-plagioclase gneisses     

Bernhard Müller  Urs Schaltegger  Urs Klötzli  Markus Flisch 《International Journal of Earth Sciences》1996,85(4):822-831

 Garnet–hornblende–plagioclase gneisses rich in incompatible elements occur in the crystalline basement of the Austro-Alpine Silvretta nappe and are associated with clinopyroxene norites and harzburgite cumulates. It is proposed here that the gneisses were formerly oceanic plagiogranites. An ε_{Nd( 530 )} value of +5.6 for the gneisses as well as initial ⁸⁷Sr/⁸⁶Sr values of 0.7036–0.7037 for the gabbroic rocks and 0.7026–0.7027 for the ultramafic rocks suggest a mantle source for this rock association. The geochemical characteristics of the garnet–hornblende–plagioclase gneisses indicate that their precursors were derived by fractional crystallization from a basaltic parent magma, by the same process which produced the adjacent clinopyroxene norites and ultramafic cumulates as well. The combined U–Pb upper intercept ages of zircons from two gneiss samples yield an igneous crystallization age of 532±30 Ma, similar to previously dated (mostly calc-alkaline) orthogneisses in the same area. High-quality transparent zircons showed the least degree of discordance, but contain extremely low U and Pb levels. The rock suite, including this plagiogranite, was emplaced within oceanic crust which formed in the latest Precambrian–early Palaeozoic off the northern continental margin of Gondwana. Received: 26 April 1996 / Accepted: 2 August 1996  相似文献   

Reconnaissance geology in Upper Chitral,Baroghil and Karambar districts (northern Karakorum,Pakistan)     

Maurizio Gaetani  Lucia Angiolini  Alda Nicora  Dario Sciunnach  Patrick Le Fort  Seifnullah Tanoli  Asif Khan 《International Journal of Earth Sciences》1996,85(4):683-704

During the summer of 1992 a geological expedition crossed the northern Karakorum range in northern Pakistan, from the Chitral to Karambar valleys, from the villages of Mastuj to Imit. Some of the areas visited were geologically unknown. A number of structural units were crossed, belonging to the Karakorum block or to other crustal blocks north of it. They are: (a) the axial batholith, in which three plutonic bodies have been identified, and (b) the northern sedimentary belt (NSB), in which three major tectonostratigraphic units form thrust stacks dipping to the north. Their internal stratigraphy and structural style are partly different. The most complete contains a crystalline basement, transgressed by a marine succession during the Early Ordovician. The youngest strata are represented by the Reshun conglomerate, of inferred Cretaceous age. The northernmost unit of the NSB is tightly folded, whereas the central one forms a monocline. Vertical faults, mainly strike-slip, dissect the thrusted slabs. Metamorphic deformation is absent or reaches only the anchizone in the studied sector of the Karakorum NSB. To the north of the Karakorum proper there are several other tectonic units, separated by vertical faults. They are, from south to north: (a) the Taš Kupruk zone, with metavolcanics of basaltic to latibasaltic composition; (b) the Atark unit, mostly consisting of massive carbonate rocks of Mesozoic age; and (c) the Wakhan slates which consist of a thick widespread succession of dark slates, metasiltites and sandstones. The fine-grained elastic rocks are supposed to be Palaeozoic to Early Triassic in age. The Wakhan slates are intruded by plutons belonging to the East Hindu Kush batholith, from which a single K/Ar age on muscovite gave a Jurassic age.  相似文献   

北秦岭褶皱带岩浆活动时代特征及地质意义   总被引：2，自引：2，他引：2  

黄萱  孙宝山 《岩石学报》1995,11(3):312-319

本文通过展示截止１９９４年北秦岭地区岩浆岩的Ｋ－Ａｒ、（４０）Ａｒ－（３９）Ａｒ、Ｒｂ－Ｓｒ、Ｓｉｎ－Ｎｄ、Ｕ－Ｐｂ谐和图、单颗粒锆石逐级蒸发（２０７）Ｐｂ－（２０６）Ｐｂ等方法同位素年龄结果，进行综合对比讨论，从而确定这一地区岩浆活动，在早元古末期以后多次发生，直至中生代。它们包括大约２０００Ｍａ、１２１０～９２０Ｍａ、８２２～７９４Ｍａ、４６４～３６０Ｍａ（奥陶纪－早石炭世）、１９５～１０５Ｍａ（早侏罗世－白垩纪）等五个地质时期。另外，根据北秦岭地区岩浆活动对确定变质岩层分层时限的制约的观点，提出该地区变质岩层划分的五个岩群的时序，首先是秦岭群（大于１７００Ｍａ）、然后是宽坪群（１１００Ｍａ前后）、二郎坪群（８００Ｍａ前后）、草滩沟群或丹凤群（４５０Ｍａ前后）、中生代岩群（２００Ｍａ前后）等等。它们是在不同时期，伴随着某一构造运动旋回形成的变质岩层。所展示的年龄资料同时为读者了解各种同位素年代测定方法的适应性，以及了解在复杂地质构造区域，如何有效开展同位素年代学研究，提供有益经验。  相似文献   

Miocene magmatism and tectonics within the Peri-Alboran orogen (western Mediterranean)     

《Journal of Geodynamics》2014

The aim of this paper concerns Miocene igneous activity in the Alboran Sea and Peri-Alboran area (northern Morocco, western Algeria and Betic Cordilleras in Spain), considering its age and its location with regard to major tectonics structures.We have compiled previous K-Ar isotopic ages of lavas and plutonic boulders and intrusives with an error of ±1σ and completed this set by a new K-Ar isotopic age for andesitic tuffites from Alboran Island. Geochemistry of most of these samples has been considered after previous analyses completed with new data for Spain magmatism. These two sets of data allow us to place the magmatic activity within the regional stratigraphy and tectonics and their chronological framework of the three major tectonic phases of the Maghrebian orogen, at 17 Ma (Burdigalian), 15 Ma (Langhian) and 9 Ma (Tortonian). Petro-geochemical characteristics are compared through time and geographical locations. A major goal of this coupled approach is to help the elaboration of possible geodynamical processes.As an application, we present the case study of the Dellys, Djinet and Thenia region (east of Algiers) where the successive magmatic events between 19.4 ± 1 and 11.6 ± 0.5 Ma are closely related to the local tectonics and sedimentation.The Peri-Alboran igneous activity is placed in a multidisciplinary framework. Timing of activity is defined according to the ages of the neighbouring sedimentary units and the K-Ar ages of igneous rocks.In Spain, the Cabo de Gata-Carboneras magmatic province displays late Oligocene and early Miocene leucogranitic dikes, dated from 24.8 ± 1.3 to 18.1 ± 1.2 Ma; three following andesitic to rhyolitic events took place around 15.1 ± 0.8 to 14.0 ± 0.7 Ma, 11.8 ± 0.6 to 9.4 ± 0.4 Ma, 8.8 ± 0.4 to 7.9 ± 0.4 Ma; this last event displays also granitic rocks. Lamproitic magmas dated between 8.4 ± 0.4 and 6.76 ± 0.04 Ma were emplaced after the Tortonian phase.In Morocco, after the complex building of the Ras Tarf volcanic edifice, major calc-alkaline to shoshonitic volcanoes were built between 9.0 ± 0.5 and 4.8 ± 0.5 Ma, in particular the large Gourougou volcanic complex. Near Oujda, volcanic activity of alkaline affinity leads to multiple emissions of basalts throughout Pliocene times until the beginning of Pleistocene, between 6.2 ± 0.3 and 1.5 ± 0.1 Ma.In the Alboran domain, an age of 19.7 ± 0.8 Ma is reported (this study) for the andesitic tuffites that form the emergent part of the Alboran Island. This age is comparable to that of the Algerian tuffites and cherts “silexites” and the Malaga ones in Spain. Younger activity, completely separated from the previous one, forms the low-K basaltic andesitic dikes from Alboran Island, dated between 9.1 ± 0.5 and 7.5 ± 0.3 Ma. Along the Alboran Ridge both low-K and high-K andesites to dacites were emitted in the estimated range of 10.7–8.7 Ma. Low-K and high-K andesites to dacites sampled at ODP sites 977 and 978 into the East Alboran Basin, are dated between 12.1 ± 0.2 and 9.3 ± 0.1 Ma.We propose to relate with the Trans-Alboran lineament only the post-Tortonian igneous activity younger than 9 Ma.  相似文献   

Neogene magmatism and its possible causal relationship with hydrocarbon generation in SW Colombia     

Mónica Vásquez  Uwe Altenberger  Rolf L. Romer 《International Journal of Earth Sciences》2009,98(5):1053-1062

The Cretaceous oil-bearing source and reservoir sedimentary succession in the Putumayo Basin, SW Colombia, was intruded by gabbroic dykes and sills. The petrological and geochemical character of the magmatic rocks shows calc-alkaline tendency, pointing to a subduction-related magmatic event. K/Ar dating of amphibole indicates a Late Miocene to Pliocene age (6.1 ± 0.7 Ma) for the igneous episode in the basin. Therefore, we assume the intrusions to be part of the Andean magmatism of the Northern Volcanic Zone (NVZ). The age of the intrusions has significant tectonic and economic implications because it coincides with two regional events: (1) the late Miocene/Pliocene Andean orogenic uplift of most of the sub-Andean regions in Peru, Ecuador and Colombia and (2) a pulse of hydrocarbon generation and expulsion that has reached the gas window. High La/Yb, K/Nb and La/Nb ratios, and the obtained Sr–Nd–Pb isotopic compositions suggest the involvement of subducted sediments and/or the assimilation of oceanic crust of the subducting slab. We discuss the possibility that magma chamber(s) west of the basin, below the Cordillera, did increase the heat flow in the basin causing generation and expulsion of hydrocarbons and CO₂.  相似文献