Role of Crustal Contamination in Formation of the Jinchuan Intrusion and Its World-Class Ni-Cu-(PGE) Sulfide Deposit, Northwest China

The Wuxing Pt–Pd-rich Cu–Ni sulfide deposit in Heilongjiang Province, Northeast China, is located to the northeast of the Dunhua–Mishan fracture of the eastern Central Asian Orogenic Belt. The mafic–ultramafic complex consist of early-period hornblende–olivine pyroxenite, diopsidite, and hornblende pyroxenite and late-period gabbro and diabase units. An early-period hornblende pyroxenite yielded a zircon U–Pb age of 208.2 ± 2.6 Ma and a late-period diabase yielded a U–Pb age of 205.6 ± 1.1 Ma, with zircon εHf(t) values of +1.24 to +8.13. The early- and late-period lithofacies are relatively enriched in LILE (Rb, Ba, and Sr) and LREE, and variably depleted in HFSE (Nb, Ta). The whole-rock and single-mineral analyses of the early-period lithofacies yield (87Sr/86Sr)i ratios of 0.7055–0.7083 and εNd(t) ratios of −7.98–+3.10. These geochemical data suggest that the parental magmas of the Wuxing complex are high-Mg subalkaline basaltic in nature and were derived from an enriched mantle source. The magmas chamber formed after the injection of magma into the crust along with crustal contamination, producing early crystalline minerals and ore-bearing magmas. The rupturing of the magma chamber released evolved magmas, which then ascended and generated Pt–Pd-bearing lithofacies and Cu–Ni sulfide orebodies by fractional crystallization, accumulation, and liquation. During the late period, the residual magma invaded the early lithofacies and Cu–Ni orebodies. The fluids exsolved from the gabbroic magmas concentrated the mineralized metal elements and enhanced the precipitation of Pt–Pd-bearing veinlet-disseminated orebodies and Pt–Pd–Cu–Ni orebodies.

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ANECDOTES AND CONTOURS OF HIGHER EDUCATION IN INDIA

International Journal of Research -GRANTHAALAYAH ◽

10.29121/granthaalayah.v3.i11.2015.2914 ◽

2015 ◽

Vol 3 (11) ◽

pp. 35-42

Author(s):

Gopal Krishna Thakur

Keyword(s):

Higher Education ◽

Education System ◽

The Sustainable Development ◽

Higher Education System ◽

The Core ◽

Education In India ◽

World Class ◽

Historical Trajectory ◽

World Class Universities

Higher education is considered as an invaluable instrument for the sustainable development of human being and society through a dynamic process of creation, advancement, and dissemination of knowledge. In a fast developing country like India the role of higher education assume utmost importance. Universities have a pivotal role in realizing this goal. Our higher education system has had a glorious past in the form of world-class universities like Nalanda, Vikramsila, and Taxila, which attracted students and intellectuals from all over the world those days. However, in the present time we are lagging far behind in terms of qualitative education and research. This necessitates a serious concern and introspection to look into the nuances and flaws of our system that make our higher education system stand at where it is now. This paper, based on the analysis of various reports and Govt. documents, discusses some of the issues, which are at the core of the main concerns pertaining to higher education in India. Taking a snapshot of the historical trajectory of higher education system in India to the present time, this paper presents an overview of the higher education system in India and points out some most relevant concerns troubling the issue at the core.

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The Metallogeny of the Lubei Ni–Cu–Co Sulfide Deposit in Eastern Tianshan, NW China: Insights From Petrology and Sr–Nd–Hf Isotopes

Frontiers in Earth Science ◽

10.3389/feart.2021.648122 ◽

2021 ◽

Vol 9 ◽

Author(s):

Ping Li ◽

Ting Liang ◽

Yonggang Feng ◽

Tongyang Zhao ◽

Jiangtao Tian ◽

...

Keyword(s):

Lithospheric Mantle ◽

Crustal Contamination ◽

Primary Magma ◽

Phase Iii ◽

Hf Isotopes ◽

Cobalt Sulfide ◽

Geodynamic Setting ◽

Sulfide Deposit ◽

Eastern Tianshan ◽

Clastic Rocks

The Lubei Ni–Cu–Co deposit situated in western segment of the Huangshan-Jing’erquan mafic–ultramafic rock belt in eastern Tianshan of the Central Asian Orogenic Belt (CAOB). The estimated reserve is approximately 9.11 million tons of ore resources with average grades of 0.82 wt% Ni, 0.52 wt% Cu, and 0.03 wt% Co. The Lubei intrusion is mainly composed of gabbro (phase I), peridotite (phase II), pyroxene peridotite (phase III), olivine pyroxenite (phase IV), and diorite (phase V), which intruded into the early Carboniferous tuffaceous clastic rocks. Zircon Laser Ablation–Inductively Coupled Plasma–Mass Spectrometry (LA–ICP–MS) U–Pb age of the diorite (phase V) from the edge of the intrusion is interpreted as the top-limit metallogenic age, which is consistent with the formation ages of the Huangshan and Xiangshan Ni–Cu deposits in eastern Tianshan. The roughly parallel rare earth element (REE) curves of the Lubei intrusion indicate the magma originated from a homologous source. The slightly enriched large ion lithophile elements (LILE) are compared to high field strength elements (HFSE) with negative Nb and Ta anomalies show that the Lubei intrusion has arc-affiliate geochemical characteristics. The Sr–Nd–Hf isotopes show that the magma was derived from depleted lithospheric mantle, while suffering 4–10% lower crustal contamination with slight contamination of the upper crust. Based on a comprehensive conservation of regional geological, geochemical, and geochronological evidence, the primary magma of the Lubei intrusion was identified that it was derived from the partial melting of metasomatized lithospheric mantle previously modified by subduction events. The Lubei nickel–copper–cobalt sulfide deposit was formed after the primary magma experienced fractional crystallization, crustal contamination, and sulfide segregation in a post-collisional extensional geodynamic setting after the closure of the Kanggur ocean basin in the early Permian.

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Evergreen Library Penetrating into Classroom Teaching: Applying and Expanding – Take Tianzhu No.1 High School in Northwest China as a Sample

IASL Annual Conference Proceedings ◽

10.29173/iasl7961 ◽

2021 ◽

Author(s):

Zhou Wenjie

Keyword(s):

High School ◽

Information Quality ◽

School Library ◽

Northwest China ◽

School Libraries ◽

Vital Role ◽

Literacy Skills ◽

Classroom Teaching ◽

The World

This paper provides a study of the school library programs sponsored by the Evergreen Education Foundation (EEF) and identifies the vital role of school libraries in improving students’ information quality. Based on analyzes Strategies for building literacy skills in the library of Tianzhu No.1 High School, the study confirmed the program developed reading and literacy skills among students. As EEF programs continue to expand into other locations in China, it is the authors’ hope that this study may provide useful information and analysis based upon which decisions about future programs can be made. It is also their hope that this study provides impetus for more studies on the rural library programs in other areas of China or programs in other underdeveloped regions of the world.

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Petrology, mineral chemistry, and geochemistry of Late Triassic Ni–Cu ore-bearing mafic–ultramafic intrusions, Hongqiling, northeastern China: petrogenesis and tectonic implications

Canadian Journal of Earth Sciences ◽

10.1139/cjes-2018-0014 ◽

2019 ◽

Vol 56 (2) ◽

pp. 111-128

Author(s):

Ai Li ◽

Jian Wang ◽

Yue Song

Keyword(s):

Crustal Contamination ◽

Parental Magma ◽

Mineral Chemistry ◽

Late Triassic ◽

Sulfide Deposit ◽

Chemical Compositions ◽

Tholeiitic Magma ◽

Average Value ◽

Central Asian ◽

History Of

The Hongqiling magmatic Ni–Cu sulfide deposit, situated on the southern margin of the eastern Central Asian Orogenic Belt (CAOB), is composed of over 30 mafic–ultramafic intrusions. These ore-bearing intrusions are composed mainly of harzburgite, lherzolite, websterite, orthopyroxenite, and norite (gabbro). The constituent minerals are olivine, diopside, bronzite, calcic-hornblende, plagioclase, and spinel with orthopyroxene as a dominant mineral in these intrusions. These ore-bearing intrusions are not Alaskan-type complexes. Spinel and clinopyroxene both exhibit different chemical compositions from those in the Alaskan-type complexes. The rocks that make up the intrusions have high contents of MgO (average value = 25.20 wt.%) and low TiO2 (average value = 0.58 wt.%). The high MgO contents of the minerals and the high Mg# (71) of the calculated melt in equilibrium with olivine demonstrate that the parental magma of the Hongqiling mafic–ultramafic intrusions was a high-Mg tholeiitic magma. The Hongqiling ore-bearing mafic–ultramafic intrusions and the calculated “trapped liquids” for the olivine-orthopyroxene cumulate rocks are all enriched in large-ion lithophile elements and depleted in high field strength elements. The Ce/Pb, Ta/La, Th/Yb, and (La/Sm)PM values and the depletion of Nb and Ta suggest that the magma experienced crustal contamination. The Hongqiling ore-bearing intrusions display many similarities with mafic–ultramafic intrusions that formed in a post-collisional extensional environment in the western CAOB (e.g., Huangshanxi). Common features include their whole-rock compositions and mineral chemistry. Combined with the evolutionary history of the eastern segment of the CAOB, we believe that the Late Triassic Hongqiling mafic–ultramafic intrusions formed in a post-collisional extensional environment.

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