共查询到13条相似文献,搜索用时 46 毫秒
1.
ZHENG Jianping LU Fengxiang YU Chunmei & TANG HuayunFaculty of Earth Sciences China University of Geosciences Wuhan China 《科学通报(英文版)》2004,49(3):277-285
Backscattered electron images, in situ Hf isotopes, U-Pb ages and trace elements of zircons in a banded granulite xenolith from Hannuoba basalt have been studied. The results show that the banded granulite is a sample derived from the early lower crust of the North China craton. It is difficult to explain the petrogenesis of the xenolith with a single process. Abundant information on several processes, however, is contained in the granulite. These processes in-clude the addition of mantle material, crustal remelting, metamorphic differentiation and the delamination of early lower crust. About 80% of zircons studied yield ages of 1842 ±40 Ma, except few ages of 3097-2824 Ma and 2489-2447 Ma. The zircons with ages older than 2447 Ma have high εHf (up to +18.3) and high Hf model age (2.5-2.6 Ga), indicating that the primitive materials of the granulite were derived mainly from a depleted mantle source in late Archean. Most εhf of the zircons with early Proterozoic U-Pb age vary around zero, but two have 相似文献
2.
Mantle xenoliths from Late Cretaceous basalt in eastern Shandong Province: New constraint on the timing of lithospheric thinning in eastern China 总被引:23,自引:1,他引:23
YAN Jun CHEN Jiangfeng XIE Zhi & ZHOU Taixi School of Earth Space Sciences University of Science Technology of China Hefei China 《科学通报(英文版)》2003,48(19):2139-2144
Studies of mantle xenoliths hosted in both the Cenozoic alkali basalt and the Early Paleozoic kimberlite suggest that part of the subcontinental lithosphere as thick as more than 100 km has been lost from the Early Paleozoic to Cenozoic[1—8]. Neither the scale and mechanism nor the accurate timing of the lithospheric thinning has been precisely constrained[7-12]. One of the reasons for this is that there are only a few Mesozoic basalts cropped out, especially, few containing mantle-derived … 相似文献
3.
Thermodynamic evolution of lithosphere of the North China craton: Records from lower crust and upper mantle xenoliths from Hannuoba 总被引:1,自引:0,他引:1
LIU Yongsheng * GAO Shan LIU Xiaoming CHEN Xiaoming ZHANG Wenlan & WANG Xuance . Faculty of Earth Sciences China University of Geosciences Wuhan China . The State Key Lab for Mineral Deposits Research Department of Earth Sciences Nanjing University Nanjing China . Key Laboratory of Continental Dynamics Department of Geology Northwest University Xi抋n China Correspondence should be addressed to Liu Yongsheng 《科学通报(英文版)》2003,48(21):2371-2377
Lithospheric thinning in East China attracts much attention of geologists. In many cases where a lithospheric thinning is inferred, the trigger for instability is a preced-ing episode of crustal thickening by the continental colli-sion[1]. Lithospheric processes (e.g. lithospheric thinning) could be recorded by the thermal history of the lower crustal and upper mantle xenoliths. Xu et al.[2] suggested that the cooling (from >1200 to 850℃) recorded by spinel harzburgite from Northeast China … 相似文献
4.
SHRIMP U-Pb zircon dating for lamprophyre from Liaodong Peninsula: Constraints on the initial time of Mesozoic lithosphere thinning beneath eastern China 总被引:12,自引:0,他引:12
JIANG Yaohui JIANG Shaoyong ZHAO Kuidong NI Pei LING Hongfei LIU Dunyi 《科学通报(英文版)》2005,50(22):2612-2620
It is undebated fact that the lithospheric mantle beneath eastern China was considerably thinned during the Mesozoic time. However, it has no adequate evidence for the exact timing when the lithosphere thinning started. The Liaodong Peninsula is located in the eastern segment of the North China Craton and is one of the important domains to explore the event of lithosphere thinning. SHRIMP U-Pb zircon dating and geochemical study were carried out for the lamprophyre dike swarm that intruded into the magnesite ore-beds in the Dashiqiao Formation of Paleoproterozoic Liaohe Group at the Huaziyu magnesite ore district, Liaodong Peninsula. The results indicate that these lamprophyre dikes were intruded in late Jurassic (155±4 Ma) and show some geochemical characteristics of potassic magmas. It is now accepted that the lithosphere thinning took place in the late Mesozoic, and the peak thinning stage occurred in early Cretaceous (130-120 Ma). Considering the potassic mafic magmatism marking the onset of the lithospheric thinning, we therefore suggest that the studied late Jurassic potassic lamprophyre dike swarm could imply that the late Jurassic is the time that lithosphere thinning started. 相似文献
5.
Chien-Yuan Tseng Houng-Yi Yang WAN Yusheng LIU Dunyi Da-Jen Wen Tzung-Chi Lin Kuo-An Tung 《科学通报(英文版)》2006,51(8):963-970
The Qilian Mountain is considered a part of the Cen- tral Orogenic Belt of China[1]. The Central Orogenic Belt of China, extending for a distance of about 4000 km long in the E-W direction from the east coast west- ward through the mainland China all the … 相似文献
6.
ZHENG Jianping LUO Zhaohua YU Chunmei YU Xiaolu ZHANG Ruisheng LU Fengxiang & LI Huimin . State Key Laboratory of Geological Processes Mineral Resources Faculty of Earth Sciences China University of Geosciences Wuhan China . Tianjin Institute of Geology Mineral Resources Tianjin China 《科学通报(英文版)》2005,50(12):1242-1251
The continental lithosphere growth mainly includes the horizontal accretion at the plate boundaries and vertical accretion within the plate[1]. Mafic magmatic materials, as the products of crust-mantle interaction[2,3], became more and more important in studying the formation and evolu- tion of the lower crust. The previous geologic researcheson Tianshan, extending nearly 2500 km from east to west, and the neighbor area were mainly focused on the Paleozoic collision structure[4 ― 6], Mesozoi… 相似文献
7.
LIUQisheng WUZhenhan HUDaogong YEPeisheng JIANGWan WANGYanbin ZHANGHancheng 《科学通报(英文版)》2004,49(1):76-82
The Nyainqentanglha granite, a batholith with an area of 1500 km^2 in the central Lhasa block, comprises mainly medium-fine-grained biotite monzonitic granite and medium-coarse-grained biotite monzonitic granite. Their contact relationship suggests that the medlum-fine-grained biotite monzonitic granite was crystallized earlier than the medium-coarse-grained monzonitic granite. A SHRIMP U-Pb dating on zircons from representative samples of the batholith shows that the crystallization age of the medium-fine-grained biotite monzonitic granite is 18.3 Ma and that of the medium-coarse-grained monzonitic granite is 11.01 Ma. The emplacement and crystallization of the Nyainqentanglha granite, the youngest granite batholith ever known inside the Lhasa block, have a close relationship with the collisional orogeny, crustal thickening, plateau uplifting,E-W crustal extension and have a dynamic genetic relationship with the crustal partial melting. 相似文献
8.
LA-ICP-MS zircon U-Pb dating for high-pressure basic granulite from North Qinling and its geological significance 总被引:11,自引:0,他引:11
CHEN Danling LIU Liang SUN Yong ZHANG Anda LIU Xiaoming & LUO Jinhai Key Laboratory of Continental Dynamics of the Ministry of Education Department of Geology Northwest University Xi’an China 《科学通报(英文版)》2004,49(21):2296-2304
Inrecentyears,discoveriesofhightoultrahighpressuremetamorphicrocksatthenorthandsouthsidesoftheQinlingGroupinthenorthernpartoftheQinlingMountains(hereafterNorthQinling)haveattractedfocusattentionofgeologistsworldwide.Thenorthhigh-pressure(HP)metamorphicbelt,distributedintheareafromGuanpotoShuanghuaishunorthwardtoShizipin,LushCountyinHenanProvince,consistsmainlyofeclogiteoutcroppedaslenticularmassesofdifferentsizesinthegneissesoftheQinlingGroupclosetothesouthsideofZhuyangguan-Xiaguanfault… 相似文献
9.
Garnet granulite facies xenoliths from Yingfengling Cenozoic basalt in Leizhou, Guangdong Province 总被引:1,自引:0,他引:1
The granulite xenoliths are first found in Yingfengling pyroclastic rocks of Leizhou region, Guangdong Province. Of them high_pressure garnet granulite xenolith found is very sparse in China. Garnet granulite is different from pyroxene granulite in mineral assemblage and composition. \%P_T\% calculation shows that garnet granulite was formed at 1 130-1 160℃and 1.4-1.7 GPa, and pyriclasite at about 800℃and 0.65-0.80 GPa. High xenolith_derived paleogeotherm indicates Cenozoic rifting in Leizhou area. Granulites with varied mineral assemblages were formed at different depths by the metamorphism of the underplated basaltic melt. 相似文献
10.
Paleoproterozoic reworking of ancient crust in the Cathaysia Block, South China: Evidence from zircon trace elements, U-Pb and Lu-Hf isotopes 总被引:4,自引:0,他引:4
LIU Rui ZHOU HanWen ZHANG Li ZHONG ZengQiu ZENG Wen XIANG Hua JIN Song LU XinQian & LI ChunZhong State Key Laboratory of Geological Processes Mineral Resources Faculty of Earth Sciences China University of Geosciences Wuhan China State Key Laboratory of Continental Dynamics Northwest University Xi’an The th Geological Team of Zhejiang Province Lishui 《科学通报(英文版)》2009,54(9):1543-1554
A combined study of zircon LA-ICP-MS U-Pb dating, trace elements and Hf isotope was carried out for gneissic granite from
the Sanzhishu area in Jingning, SW Zhejiang Province. Nearly all the zircons separated from the granite exhibited oscillatory
zoning and high Th/U ratios (>0.1). The REE profile showed a pronounced positive Ce anomaly, negative Eu anomaly and an enrichment
of HREE, which are typical characteristics of magmatic zircon. Thirteen concordant or nearly concordant analytical data yielded
a weighted mean 207Pb/206Pb age of 1860±13 Ma (MSWD=0.084), representing the formation age of the granite. The magmatic zircons had negative εHf(t)
values of −15.6 to −10.0 and two-stage Hf model ages of 3.1 to 3.4 Ga, indicating that the granites were formed by reworking
of ancient crust. The major- and trace-element data indicate that the gneissic granites are metaluminous high-K calc-alkaline
rocks and exhibit the same geochemical characteristics as aluminous A-type granites, implying the emplacement of the granite
in a post-orogenic extensional tectonic setting. We conclude that the Paleoproterozoic crustal reworking event in the Cathaysia
Block of South China marked the transition from assembly to break-up of the Columbia supercontinent.
Supported by National Natural Science Foundation of China (Grant No. 40873004), Special Funds for National Scientific Research
of Commonweal Industries, the Ministry of Land and Resources of China (Grant No. 2008110015), Opening Foundation of State
Key Laboratory of Continental Dynamics, Northwest University (Grant No. 06LCD12) and the Project of Land and Resources Bureau
of Zhejiang Province (Grant No. 2004005) 相似文献
11.
Caledonian reworking of Paleoproterozoic basement in the Cathaysia Block: Constraints from zircon U-Pb dating,Hf isotopes and trace elements 总被引:2,自引:0,他引:2
Wen Zeng Li Zhang HanWen Zhou ZengQiu Zhong Hua Xiang Rui Liu Song Jin XinQian Lü ChunZhong Li 《科学通报(英文版)》2008,53(6):895-904
A combined study of zircon U-Pb dating, Hf isotopes and trace elements has been carried out for granodioritic neosomes of migmatites from the Tianjingping area in northwestern Fujian Province. Zircons are characterized by zoning, higher Th/U ratios (mostly≥0.1), HREE enrichment, and positive Ce and negative Eu anomalies, and show features similar to magmatic or anatectic zircons. Apparent ^206Pb/^238U ages for the zircons are 447±2 Ma (95 % conf., MSWD=0.88), corresponding to a Caledonian event. εHf(t) values are -13.3 to -9.7, indicating a crustal source. Two-stage Hf model ages are 1.7 to 1.9 Ga, suggesting that protolith of the migmates was probably formed in the Paleoproterozoic. The granodioritic neosomes have the characteristics of peraluminous calc-alkaline granite, and their REE patterns and trace elements spidergrams show features of middle to upper crustal rocks. Together with previous studies, we conclude that the protolith of the Cathaysia basement in the Tianjingping area was likely formed in the middle-late Paleoproterozoic and experienced partial melting during the Caledonian period. The recognition of Caledonian reworking of the Paleoproterozoic basement in the Cathaysia Block provides a new insight into the tectonic evolution of the Cathaysia Block in the Caledonian period and the interaction between the Cathaysia Block and the Yangtze Block. 相似文献
12.
SHRIMP U-Pb zircon geochronology of granulites at Rimana (Southern Tibet) in the central segment of Himalayan Orogen 总被引:2,自引:0,他引:2
LI Dewei LIAO Qunan YUAN Yanming WAN Yusheng LIU Demin ZHANG Xionghua YI Shunhua CAO Shuzhao & XIE Defan . Faculty of Earth Sciences China University of Geosciences Wuhan China . Institute of Geology Chinese Academy of Geosciences Beijing China Correspondence should be addressed to Li Dewei 《科学通报(英文版)》2003,48(23):2647-2650
TheCenozoicHimalayanorogenisimportantinun-derstandingcontinentaldynamicprocesses.Lowercrustal,high-grademetamorphicrockshaverecentlybeendiscov-eredinNamcheBarwaandParmir,i.e.therespectivere-gionsofeasternandwesternsyntaxisoftheorogen[1—4].Eclogitesthatunderwentgranulite-faciesmetamorphismhaverecentlybeenreportedintheCadaareatotheeastofMountEverestinthecentralsegmentoftheHimalayanorogen[5].WiththehelpofthegeologicalsurveyofDing-gyeCountyandChentangSheets(scale1︰250000),high-pressuremafic… 相似文献
13.
U-Pb dating of zircons from quartz diorite and its enclaves at Tongguanshan in Anhui and its petrogenetic implication 总被引:16,自引:0,他引:16
The Tongling area, Anhui Province lies in the centralpart of the Cu-Fe-Au mineralization belt of the Mid-dle-Lower Yangtze River region, and hosts the highestincidence of this mineralization belt. Geotectonically, theTongling area is located at the middle of the Lower Yang-tze fold belt in the Yangtze block. Silurian to Triassicshallow marine carbonatite and a few semi-abyssal sili-ceous rocks, continental-ocean arenites are the dominantoutcropping strata. A series of NE trending fold s… 相似文献