Shandong Geological Survey Institute

Jinan, China

Shandong Geological Survey Institute

Jinan, China
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Ren P.,Chinese Academy of Geological Sciences | Xie H.,Chinese Academy of Geological Sciences | Wang S.,Shandong Geological Survey Institute | Nutman A.,University of Wollongong | And 8 more authors.
Precambrian Research | Year: 2016

Voluminous Neoarchean plutonic and supracrustal rocks are well developed in the Western Shandong Province of the North China Craton, which has been divided into a late Neoarchean crustally-derived granite belt, a middle to early Neoarchean ancient rock belt and a late Neoarchean juvenile rock belt. Earlier studies provided reconnaissance evidence for ~2.60 Ga metamorphism in some areas. This study presents SHRIMP zircon U-Pb dating and O isotope analysis on nine metamorphosed igneous rock samples (gneissic tonalite, gneissic trondhjemite, gneissic quartz diorite and meta-gabbro) from the ancient rock belt. Magmatic zircons vary in age from 2.74 Ga to 2.60 Ga, whereas metamorphic and anatectic zircons vary in age from 2.63 Ga to 2.59 Ga, with an age peak of 2.61 Ga. In this study, we identified 2.69-2.67 Ga metamorphic zircons for the first time. Most of zircons, whether magmatic or metamorphic, have δ18O values of +4.5‰ to +6.5‰ (V-SMOW). However, the oldest tonalite sample with a protolith age of 2735 Ma has zircons showing low δ18O (V-SMOW) values, particularly in recrystallized domains and overgrowths. This suggests at least in local crustal extension and influx of meteoric water during the evolution of the rocks. Combined with data from earlier studies, we draw the conclusion that the Western Shandong Province experienced a regional tectono-thermal event at ~2.60 Ga, as a result of high heat flow and crustal extension, perhaps caused by a mantle plume or mantle overturn activity. Therefore we conclude that 2.60 Ga can be regarded the break between early and late Neoarchean crustal accretion. The O isotope study indicates that in some cases, trondhjemitic leucosome was not derived from nearby gneissic tonalite, although they show a close relationship in outcrop. © 2016 Elsevier B.V..


Liu S.,Chinese Academy of Geological Sciences | Liu S.,National Taiwan University | Jahn B.-M.,National Taiwan University | Wan Y.,Chinese Academy of Geological Sciences | And 6 more authors.
Gondwana Research | Year: 2015

The North China Craton is an ideal place for studying the transition of the Earth's thermal structure and tectonics at the Archean-Proterozoic boundary due to its good preservation of the ~. 2.5. Ga tectono-thermal events. We report the discovery of a high-pressure mafic granulite from the Jiaodong Terrain in the North China Craton. The mafic granulite occurs as garnet-clinopyroxene-orthopyroxene-hornblende gneiss enclaves within a late-Archean trondhjemite-tonalite-granodiorite (TTG) gneiss. Typical high-pressure mineral assemblage of garnet-clinopyroxene-plagioclase-quartz. ±. rutile has been identified. Plagioclase. +. clinopyroxene. ±. orthopyroxene. ±. hornblende symplectite surrounding garnet ("white eye") is also observed. Using the conventional geothermobarometry and the pseudosection modeling, a clockwise metamorphic P-T path with the peak conditions at ~. 17. kbar and ~. 880. °C was determined. Zircon U-Pb analyses (SHRIMP) on the overgrowth rim of zircon grains of two samples from the same outcrop yielded a metamorphic age of 2473. ±. 6. Ma (MSWD. =. 0.8). The analyses on magmatic core gave a probable magmatic age of 2527. ±. 12. Ma (MSWD. =. 1.9). The high-pressure granulite facies metamorphism corresponds to a collisional event between the ~. 2.5. Ga crust and ~. 2.9. Ga crust at the dawn of Paleoproterozoic in the North China Craton. It also represents a new but rare case of a subduction-collision tectonics at the Archean-Proterozoic transition and provides insight into the change of the Earth's thermal structure. © 2014 International Association for Gondwana Research.


Wang W.,Chinese Academy of Geological Sciences | Zhai M.-G.,CAS Institute of Geology and Geophysics | Tao Y.-B.,Shandong Geological Survey Institute | Santosh M.,Kochi University | And 4 more authors.
Precambrian Research | Year: 2014

Metamorphosed clastic rocks provide important constrains on the composition of upper continental crust. Here we report and characterize a sequence of Neoarchean paragneiss in association with migmatite from the Qixingtai area in Western Shandong Province (WSP) in the North China Craton (NCC), that represent metamorphosed moderate- to fine-grained clayey clastic rocks. The garnet from the paragneiss is characterized by nil or weakly compositional zoning. The biotite shows low TiO2 content (<2wt.%) and high Fe/[Fe+Mg] molar ratios (0.45-0.48). The P-T estimates suggest that the paragneiss sequence was metamorphosed at 5.5-5.7kbar and 678-679°C. The detrital zircons from the sillimanite garnet gneiss yield concordant 207Pb/206Pb ages from 2.78 to 2.53Ga (discordance ≤15%), suggesting that the protolith sediments were deposited after 2.53Ga. The overgrowth rims on the detrital zircons of the paragneiss and those from the leucosome of the migmatite show similar low Th/U values, moderate Th and high U and common lead contents, indicating that the metamorphic and anatectic zircons formed under fluid-rich conditions. The intrusive contact between the massive monzogranite and the banded migmatite suggests that the regional metamorphic/anatectic event occurred before the emplacement of the monzogranite. However, the upper intercept ages, defined by the overgrowth rims of the pre-existing zircons from the leucosome, are broadly similar to those of the crystallization of the magmatic zircons from the monzogranite within errors at 2.50Ga. The paragneiss exhibits SiO2 contents in the range of 58wt.% (garnet gneiss)-70wt.% (sillimanite gneiss), and negative correlations with Al2O3 (23.4-15.4wt.%), TiO2 (0.90-0.35wt.%), MgO (4.5-1.1wt.%), FeOt (8.3-2.6wt.%) and Cr (382-131ppm). The REE patterns also show a systematic change from garnet gneiss to sillimanite gneiss. In trace element discrimination diagrams, the paragneiss plots between the end-members of komatiite/basalt and TTG/granite, suggesting that the sediments sourced from a mixture of ultramafic-mafic and felsic protoliths. Combined with the geochronological data, we suggest that the 2.75-2.71Ga komatiite-tholeiite sequence of the Taishan association and TTGs in the central terrane and the 2.56-2.53Ga TTGs in the southwestern part of the WSP as the potential provenance for the clastics. The protolith of the paragneiss in the Qixingtai area belong to the sedimentary sequence of the Taishan association. Spatially associated coeval arc-like assemblage and other geological evidence suggest that, (1) the metasediments were likely deposited in a back arc basin, (2) the upper amphibolites-facies metamorphism, constrained by the mineral assemblages in the paragneiss, might be related to the closure of the basin, and (3) the generation of large volumes of matured K-rick continental crust occurred not earlier than 2.53. Ga in the WSP granite-greenstone belt. © 2014 Published by Elsevier B.V.


Wang W.,CAS Institute of Geology and Geophysics | Wang W.,Beijing Center | Zhai M.,CAS Institute of Geology and Geophysics | Wang S.,Shandong Geological Survey Institute | And 6 more authors.
Geological Journal | Year: 2013

The western Shandong Province (WSP) is one of the typical Neoarchaean granite-greenstone belts in the Eastern Block of the North China Craton (NCC) and is an important region to investigate the early Precambrian evolutionary history of the NCC. The Taishan association, consisting of a ~2.7Ga komatiite-tholeiite sequence and a ~2.5Ga felsic volcano-sedimentary sequence, is the major lithological assemblage in the WSP. In the Qixingtai area, the felsic volcano-sedimentary sequence, partly subjected to anatexis, is composed of hornblende gneiss, voluminous fine-grained biotite gneiss and biotite plagioclase gneiss. SHRIMP zircon dating shows that the protolith of the biotite plagioclase gneiss formed after ca. 2.53Ga. The tonalite intrusion into the volcanic protoliths of the fine-grained biotite gneiss and biotite plagioclase gneiss occurred at 2.52Ga. Our age data constrain the time of formation of the felsic volcano-sedimentary sequence in the Taishan area as 2.53-2.52Ga. The majority of zircons from the felsic volcano-sedimentary rocks have intermediate εHf(t) values (-1.2 to +2.1). The whole rock Nd isotopes of the Taishan felsic volcano-sedimentary rocks yield the εNd(t=2522Ma) values of +2.6 to -1.8 and TDM2 ages 3.03-2.68Ga. These values indicate the pre-existing crust was reworked at the end of the Neoarchaean (~2.5Ga). The Taishan felsic volcano-sedimentary rocks are rhyodacite-dacite and andesite in composition. These rocks and the tonalite display similar high SiO2 (65-72wt.%) and low MgO (1-2wt.%) content. In contrast, the minor andesites in the area have lower SiO2 (61-62wt.%) and higher MgO (5.3-6.3wt.%), suggesting more mantle contribution during their petrogenesis. However, the Mg-rich andesites have identical rare earth element and multi-element patterns with the rhyodacite-dacites and distinguish them from the Taishan sanukitoids. We suggest that the 2.53-2.52Ga felsic volcanics of the Taishan association are the products of partial melting of a subducted oceanic crust. The andesites were produced by minor modification of the ascending tonalite-trondhjemite-granodiorite-type magma by the mantle wedge. Our study indicates that (1) the tectonic regime of the WSP greenstone belt was dominated by an arc-subduction system at ~2.52Ga and (2) the 2.53-2.52Ga felsic volcano-sedimentary rocks and intrusive tonalite are the products of crustal reworking. The felsic volcano-sedimentary sequence of the Taishan association and other ~2.5Ga arc-like assemblages in the NCC provide important clues to understand the nature of the tectonothermal events at the end of the Neoarchaean. © 2013 John Wiley and Sons, Ltd.


Wan Y.,Chinese Academy of Geological Sciences | Wan Y.,Beijing Center | Liu D.,Chinese Academy of Geological Sciences | Liu D.,Beijing Center | And 10 more authors.
Precambrian Research | Year: 2011

The evolution of the North China Craton (NCC) is well known for a marked 2.55-2.50Ga tectonothermal event. However, supracrustal and intrusive rocks of 2.75-2.70Ga are in fact widely distributed in the western Shandong Province, the most important area of Archaean basement in the eastern part of the NCC. This paper reports SHRIMP U-Pb dating and LA-ICPMS Hf isotopic composition of zircons from 2.75-2.70Ga supracrustal and trondhjemite-tonalite-granodiorite (TTG) rocks in that area. Three fine-grained (hornblende) biotite gneiss samples (known locally as leptynite, with meta-volcanic or volcanosedimentary rock protoliths) and five TTG samples have SHRIMP zircon U-Pb ages varying from 2.75 to 2.70Ga and 2.74 to 2.71Ga, respectively. Zircons from most of the samples have high positive e{open}Hf(t) values (+4.7 to +10.0) and tDM(Hf) ages (2.85-2.60Ga) similar to their zircon U-Pb ages. This indicates that the rocks represent largely juvenile crustal additions derived from depleted mantle only a short time before. However, some granitoids show e{open}Hf(t) zircon values of -13.6 to +5.1 and tDM(Hf) of 3.51-2.80Ga. Therefore, the strong 2.75-2.70Ga tectonothermal event in the western Shandong Province involved not only juvenile addition to the continental crust but also intracrustal recycling of older components. Combined with craton-wide data, it is shown that the NCC is similar to many other cratons around the world where tectonothermal events of ∼2.7Ga are well developed. However, the main difference is that in the NCC, superimposed ∼2.5Ga tectonothermal events were much stronger than in most other cratons. © 2011 Elsevier B.V.


Wang W.,CAS Institute of Geology and Geophysics | Wang W.,Beijing Center | Wang W.,Wuhan University | Yang E.,Shandong Geological Survey Institute | And 8 more authors.
Precambrian Research | Year: 2013

Western Shandong Province (WSP) is one of the typical Neoarchean granite-greenstone belts in the North China Craton (NCC). The Taishan association, consisting of a ∼2.7Ga komatiite-tholeiite sequence and a ∼2.5Ga felsic volcanic-sedimentary sequence, is the major supracrustal assemblage in the WSP. The ∼2.7Ga komatiite-tholeiite sequence can be subdivided into the Yanlingguan and Liuhang units. The 150-800m thick basaltic lava sequence of the Liuhang unit is exposed in the Qixingtai area, with the bottom unit composed of massive and layered basalts. Pillow basalts and tuff dominate the upper parts of the sequence. We report a weighted mean SHRIMP 207Pb/206Pb zircon age of 2706±9Ma (MSWD=0.61) for a trondhjemitic dike that intrudes the base of the pillow basalts, constraining the timing of this sequence to be older than this age. The basaltic lava sequence in the Liuhang unit is characterized by voluminous tholeiites and a minor component of enriched basalts. The tholeiites show relatively high MgO (5.5-9.0wt.%), but low TiO2 (0.8-1.3wt.%) and Nb (2.1-3.3ppm) contents. They display co-variations between Zr and other immobile trace elements and flat REE and trace elements patterns on chondrite- and primary mantle-normalized diagrams, respectively. In contrast, the enriched basalts have low MgO (3.6-5.4wt.%), but high TiO2 (1.6-2.2wt.%) and Nb (8.4-11.6ppm) contents. They display moderately enriched LREE and fractionated HREE patterns on chondrite-normalized diagrams. The basaltic sequence of the Liuhang unit displays a moderate range of initial e{open}Nd (-0.1 to +3.0) values. The element concentration and Nd isotopes of tholeiitic rocks in the Liuhang unit are comparable with the contemporaneous tholeiites in greenstone belts globally. In particular, the geochemical systematics of the tholeiite and enriched basalts show close similarity with those of the Wawa greenstone belt in the Superior Province.The Nb/Th, La/Smcn and Nb/La ratios of these basalts indicate that the basaltic lava sequence of the Liuhang unit has not been significantly affected by crustal contamination compared to the Yanlingguan komatiite-tholeiite sequence. The variation in lithology and geochemistry of basalts between the Liuhang and Yanlingguan units reflects a lateral change in composition of the ∼2.7Ga basaltic eruption. We propose that the komatiite-tholeiite sequence in the Taishan association was derived from an upwelling mantle plume with eruption close to the continental margin within an ocean basin. Our study does not provide any evidence to support that the WSP granite-greenstone belt was subjected to significant arc-plume interaction during the early Neoarchean. Our results contribute to the understanding of early Neoarchean crustal growth globally identified from different regions. © 2012 Elsevier B.V..


Wan Y.,Chinese Academy of Geological Sciences | Dong C.,Chinese Academy of Geological Sciences | Wang S.,Shandong Geological Survey Institute | Kroner A.,Chinese Academy of Geological Sciences | And 5 more authors.
Precambrian Research | Year: 2014

Western Shandong Province is a typical area of the North China Craton (NCC) where Neoarchean plutonic and supracrustal rocks are widely distributed. Early studies documented that ~2.7Ga and ~2.5Ga magmato-tectono-thermal events are well developed in the area. Here we report SHRIMP U-Pb ages and Hf-in-zircon isotopic data from ten samples of different magmatic rock types including hornblendite, gneissic tonalite, gneissic trondhjemite and gneissic granite. Magmatic zircon grains have 207Pb/206Pb ages ranging from 2667 to 2598Ma. Some rocks contain ~2.5Ga metamorphic rims and ~2.7Ga zircon cores. The magmatic zircon grains have e{open}Hf(t) values and Hf crustal model ages of -1.1 to +11.3 and 3.02-2.4Ga, respectively. Combined with an earlier study, our main conclusions are that the middle Neoarchean rocks mainly occur together with early Neoarchean rocks in the northeastern portion of the central belt. Juvenile additions to continental crust and crustal recycling played important roles in the middle Neoarchean of western Shandong Province, and the entire Neoarchean tectonic evolution can be divided into middle to early Neoarchean (2.75-2.6Ga) and late Neoarchean (2.6-2.5Ga) events. © 2014 Elsevier B.V.


Xie S.,Chinese Academy of Geological Sciences | Xie H.,Chinese Academy of Geological Sciences | Wang S.,Shandong Geological Survey Institute | Kroner A.,Chinese Academy of Geological Sciences | And 6 more authors.
Precambrian Research | Year: 2014

Eastern Shandong is one of the important early Precambrian areas in the North China Craton, where extensive 2.5, 2.7 and 2.9Ga magmatic activities have been identified, followed by very strong late Neoarchean and Paleoproterozoic tectono-thermal events. We carried out SHRIMP zircon dating, Hf-in-zircon isotope analysis and a whole-rock geochemical study on ca. 2.9Ga Mesoarchean magmatic rocks. These include gneissic diorite, gneissic quartz diorite, gneissic tonalite and gneissic high-Si trondhjemite and were identified in five new areas. All these rocks contain ca. 2.5Ga metamorphic zircons. The dioritic and tonalitic rocks are enriched in large ion lithosphile (LIL) elements (K, Rb, Ba) and depleted in Nb and P with moderate to highly fractionated REE patterns, similar in chemical compositions to Archean TTG rocks worldwide. The high-Si trondhjemites are characterized by very high SiO2 and very low FeOt+MgO. The magmatic zircon grains from all these rocks are similar in their Hf isotopic compositions and have εHf(t) values ranging from +1.3 to +9.9. Combined with previous work, our main conclusions are: (1) eastern Shandong underwent a major magmatic event at ca. 2.9Ga; (2) diorites and tonalites formed by melting of thickened lower crust or the root of an oceanic plateau, whereas the high-Si trondhjemites were derived from melting of intermediate to felsic rocks; (3) the Mesoarchean (ca. 2.9Ga) was a major period of juvenile crustal addition from the depleted mantle, earlier than the major crustal growth period at 2.7-2.8Ga in the North China Craton; (4) the 2.7-2.9Ga rocks underwent strong metamorphism at ca. 2.5Ga, probably as a result of magmatic underplating. © 2014 Elsevier B.V.


Wan Y.-S.,Chinese Academy of Geological Sciences | Wang S.-J.,Shandong Geological Survey Institute | Ren P.,Chinese Academy of Geological Sciences | Xie H.-Q.,Chinese Academy of Geological Sciences | And 2 more authors.
Acta Geoscientica Sinica | Year: 2015

Culaishan is one of the most important areas with well-exposed Neoarchean rocks in western Shandong. In this paper, the authors carried out SHRIMP U-Pb zircon dating on three samples. Tonalitic gneiss has a weighted mean 207Pb/206Pb age of (2711±11) Ma for magmatic zircon with some recrystallization. It is inferred that a metamorphic event occurred at ~2.6 Ga. Zircons from a meta-quartz diorite sample show banded zoning with strong recrystallization, the age of 2.51 Ga is considered to be closer to the metamorphic time, and the intrusive time of the quartz diorite should be between 2.53 Ga and 2.55 Ga. Magmatic zircons from monzogranite show lead loss to different degrees, but the crystallization age might be ~2.5 Ga, as shown by the distribution of age data on concordia. Combined with geochemical study and previous work, the authors determined the Neoarchean geological evolution in the Culaishan area and redefined the boundary between the early Neoarchean (2.60~2.75 Ga) rock belt and the late Neoarchean (2500~2550 Ma) belt of juvenile rocks in the northwestern portion of western Shandong. ©, 2015, Science Press. All right reserved.


Wan Y.,Chinese Academy of Geological Sciences | Liu D.,Chinese Academy of Geological Sciences | Wang S.,Shandong Geological Survey Institute | Dong C.,Chinese Academy of Geological Sciences | And 8 more authors.
American Journal of Science | Year: 2010

Western Shangdong Province experienced major crustal growth as a result of 2.75 to 2.50 Ga tectonothermal events, different from other Archean areas in the North China Craton. Besides early Neoarchean tonalite-trondhjemite-granodiorite (TTG) and supracrustal assemblages, there are large volumes of late Neoarchean gabbroic, dioritic and granitic rocks in western Shandong. SHRIMP zircon dating of thirty-one samples of different rock types from late Neoarchean rocks yielded a narrow age range from 2560 to 2490 Ma. Based on these data and previously published results, the following conclusions can be drawn: 1) the Archean basement can be divided into three belts: a Late Neoarchean (2525-2490 Ma) crustally-derived granite belt in the northeast, an Early Neoarchean (2.75-2.60 Ga) rock belt in the center, and a Late Neoarchean (2550-2500 Ma) belt of juvenile rocks in the southwest; 2) the tectonic regime in western Shandong Province probably changed from compressional to extensional at around 2525 Ma (between 2530 and 2520 Ma); 3) crustal recycling with addition from the mantle occurred at the end of the Neoarchean; 4) the late Archean magmatic rocks were probably formed in an arc environment.

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