The Lead Isotope Characteristics and Tracing Significance of Ore Metallogenic Material in the Geza Arc,Yunnan

2014 ◽  
Vol 1073-1076 ◽  
pp. 2054-2057
Author(s):  
Xue Long Liu ◽  
Na Zhang ◽  
Jian Kang
Keyword(s):  
Lower Crust ◽  
Lead Isotope ◽  
Development Stage ◽  
Island Arc ◽  
Geochemical Characteristics ◽  
Pb Isotopes ◽  
Isotopic Data ◽  
Porphyry Deposits ◽  
Intrusive Rocks ◽  
Polymetallic Ore

Geza arc is the important parts of Yidun island arc in southwest of Sanjiang tectonic magmatic belts, it located in the southern tip of the Yidun island arc, which is a newly discovered copper polymetallic ore concentration area in the recently years in China. Based on the development stage of island arc orogenic, the distribution of intrusive rocks, composition, geochemical characteristics, Geza island arc granits belt can be divided into three belts. Geza island arc several typical porphyry deposits Pb isotopic data show that Pb206/Pb204 17.680~19.165, Pb207/Pb204 15.453~15.773,change in scope, Pb208/Pb204 37.730~39.654. Most of samples are normal lead, Pb isotopes focused on the side of orogenic evolution line and the lower crust range,with the characteristics of crust-mantle mixed source.

Petrogenesis and tectonic setting of the Dapingliang Late Neoproterozoic magmatic rocks in the eastern Kuluketage Block: geochronological, geochemical and Sr–Nd–Pb–Hf isotopic implications

2019 ◽  
Vol 157 (2) ◽  
pp. 173-200
Author(s):  
Wei Chen ◽  
Xinbiao Lü ◽  
Xiaofeng Cao ◽  
Wenjia Ai
Keyword(s):  
Rare Earth ◽  
Partial Melting ◽  
Rare Earth Element ◽  
Mantle Plume ◽  
Lower Crust ◽  
Earth Element ◽  
Continental Rift ◽  
Isotopic Data ◽  
Magmatic Rocks ◽  
Intrusive Rocks

AbstractIn the past ten years, a great deal of geological study has been reported on the magmatic rocks exposed in the central and western region of the Kuluketage Block, while similar research in the eastern region has rarely been reported. In this paper, we report zircon U–Pb geochronological, zircon Lu–Hf isotopic, whole-rock elemental and Sr–Nd–Pb isotopic data for the Dapingliang intermediate-acid intrusive rocks in the eastern Kuluketage Block, in order to evaluate its petrogenesis and tectonic significance. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) zircon U–Pb dating provided a weighted mean 206Pb/238U age of 735 ± 3 Ma for the albitophyre (D1), 717 ± 2 Ma for the granite porphyry (D2) and 721 ± 1 Ma for the diorite porphyrite (D3). Geochemical analyses reveal that D1 and D2 belong to Na-rich alkaline A-type granites, and D3 shows the features of high-K calc-alkaline I-type granite. D1 and D2 are characterized by light rare earth element (LREE) enrichment and relative depletion of high field strength element (HFSE), with relatively flat heavy rare earth element (HREE) patterns and obviously negative Eu anomalies. D3 is characterized by the enrichment of LREE and depletion of HFSE, with negative slope HREE patterns and slightly negative Eu anomalies. In tectonic discrimination diagrams, D1 and D2 fall in the within-plate granite (WPG) field, indicating a rift setting. Although D3 falls within the volcanic arc granite (VAG) field, it most likely formed in a rift setting, as inferred from its petrology, Sr–Nd–Hf isotopes and regional tectonic evolution. Based on pronounced εNd(t), εHf(t), Pb isotopic data, TDM2 and high (87Sr/86Sr)i and elemental compositions, D1 was derived from the partial melting of basement amphibolites of the old lower crust. D2 originated from a mixture of the old lower crust and depleted mantle-derived magmas and was dominated by partial melting of the basement amphibolites of the lower crust. D3 could have been formed by partial melting of K-rich hornblende in the lower crust. Combining previous studies, we think that the c. 745–710 Ma magmatic rocks were formed in a continental rift setting. A partial melting scheme, triggered by underplating of mantle plume-derived magmas, is proposed to interpret the formation of c. 745–710 Ma A-type and I-type granitoids, mantle-derived mafic dykes, bimodal intrusive rocks, adakitic granites and volcanic rocks. These magmatic activities were probably a reflection of the break-up of the Rodinia supercontinent.Highlights(1)Circa 720 Ma magmatism in the eastern Kuluketage Block.(2)Na-rich granite was derived from partial melting of basement amphibolites.(3)The c. 745–710 Ma magmatic rocks were formed in a continental rift setting.(4)The underplating of mantle plume-derived magmas is proposed.

Tectonic Environment and Geochemical Characteristics of Geza Arc Magmatic Rocks in Sanjiang Orgenic Belt, SW China

2013 ◽  
Vol 734-737 ◽  
pp. 444-447
Author(s):  
Xue Long Liu ◽  
Wen Chang Li ◽  
Yan Yang ◽  
Guang Hou Yin
Keyword(s):  
Development Stage ◽  
Island Arc ◽  
Geochemical Characteristics ◽  
Late Triassic ◽  
Type I ◽  
Tectonic Environment ◽  
High K ◽  
Type Granite ◽  
The Rich ◽  
Granite Rocks

Geza island arc located in the southwest Sanjiang tectonic igneous rock belts, it was a products of Ganzi-Litang oceanic crust diving to Zhongdian Landmasses in late Triassic and a important of newly discovered copper polymetallic belts in the recent years in China. The regional strong tectonic-magmatic activity throughout the island-arc orogenesis from beginning to the end, the rich mineralization developed in the different times and different circumstances. Based on the development stage of island arc orogenic,the distribution of intrusive rocks, rocks composition, geochemical characteristics, Geza island arc granit belt can be divided into three belts. Lithogeochemical characteristics show that the porphyry (porphyrite) and island-arc granite rocks have the same rock series (high-K calc-alkaline) and the same genetic type (I-type granite); these rocks trace elements very similar to granite of island arc, which enriched in Ba, La, Hf, Au,chalcophile elements Cu,Pb, siderophile elements Mo, Ni, and depleted in Rb, Nb, P, Ti.

Chapter 2.1b Ferrar Large Igneous Province: petrology

2021 ◽  
pp. M55-2018-39 ◽  
Author(s):  
David H. Elliot ◽  
Thomas. H. Fleming
Keyword(s):  
Ross Sea ◽  
Lower Jurassic ◽  
Weddell Sea ◽  
Geochemical Characteristics ◽  
Large Igneous Province ◽  
Geographical Pattern ◽  
Chemical Type ◽  
Igneous Province ◽  
Intrusive Rocks ◽  
Basic Rocks

AbstractThe Lower Jurassic Ferrar Large Igneous Province consists predominantly of intrusive rocks, which crop out over a distance of 3500 km. In comparison, extrusive rocks are more restricted geographically. Geochemically, the province is divided into the Mount Fazio Chemical Type, forming more than 99% of the exposed province, and the Scarab Peak Chemical Type, which in the Ross Sea sector is restricted to the uppermost lava. The former exhibits a range of compositions (SiO2 = 52–59%; MgO = 9.2–2.6%; Zr = 60–175 ppm; Sri = 0.7081–0.7138; εNd = −6.0 to −3.8), whereas the latter has a restricted composition (SiO2 = c. 58%; MgO = c. 2.3%; Zr = c. 230 ppm; Sri = 0.7090–0.7097; εNd = −4.4 to −4.1). Both chemical types are characterized by enriched initial isotope compositions of neodymium and strontium, low abundances of high field strength elements, and crust-like trace element patterns. The most basic rocks, olivine-bearing dolerites, indicate that these geochemical characteristics were inherited from a mantle source modified by subduction processes, possibly the incorporation of sediment. In one model, magmas were derived from a linear source having multiple sites of generation each of which evolved to yield, in sum, the province-wide coherent geochemistry. The preferred interpretation is that the remarkably coherent geochemistry and short duration of emplacement demonstrate derivation from a single source inferred to have been located in the proto-Weddell Sea region. The spatial variation in geochemical characteristics of the lavas suggests distinct magma batches erupted at the surface, whereas no clear geographical pattern is evident for intrusive rocks.

The Duck Pond and Boundary Cu–Zn deposits, Newfoundland: new insights into the ages of host rocks and the timing of VHMS mineralization

2010 ◽  
Vol 47 (12) ◽  
pp. 1481-1506 ◽  
Author(s):  
Vicki McNicoll ◽  
Gerry Squires ◽  
Andrew Kerr ◽  
Paul Moore
Keyword(s):  
Volcanic Rocks ◽  
Sedimentary Rocks ◽  
Isotopic Data ◽  
Sulphide Ores ◽  
Intrusive Rocks ◽  
Felsic Volcanic ◽  
Host Rocks ◽  
Felsic Volcanic Rocks

The Duck Pond Cu–Zn–Pb–Ag–Au deposit in Newfoundland is hosted by volcanic rocks of the Cambrian Tally Pond group in the Victoria Lake supergroup. In conjunction with the nearby Boundary deposit, it contains 4.1 million tonnes of ore at 3.3% Cu, 5.7% Zn, 0.9% Pb, 59 g/t Ag, and 0.9 g/t Au. The deposits are hosted by altered felsic flows, tuffs, and volcaniclastic sedimentary rocks, and the sulphide ores formed in part by pervasive replacement of unconsolidated host rocks. U–Pb geochronological studies confirm a long-suspected correlation between the Duck Pond and Boundary deposits, which appear to be structurally displaced portions of a much larger mineralizing system developed at 509 ± 3 Ma. Altered aphyric flows in the immediate footwall of the Duck Pond deposit contained no zircon for dating, but footwall stringer-style and disseminated mineralization affects rocks as old as 514 ± 3 Ma at greater depths below the ore sequence. Unaltered mafic to felsic volcanic rocks that occur structurally above the orebodies were dated at 514 ± 2 Ma, and hypabyssal intrusive rocks that cut these were dated at 512 ± 2 Ma. Some felsic samples contain inherited (xenocrystic) zircons with ages of ca. 563 Ma. In conjunction with Sm–Nd isotopic data, these results suggest that the Tally Pond group was developed upon older continental or thickened arc crust, rather than in the ensimatic (oceanic) setting suggested by previous studies.

Lead isotope ratios in lead-glazed ceramics determined by laser ablation multi-collector inductively coupled plasma mass spectrometry for discriminating purpose

2018 ◽  
Vol 10 (21) ◽  
pp. 2456-2463 ◽  
Author(s):  
Chunlei Zong ◽  
Zhian Bao ◽  
Wangli Ran ◽  
Xue Ling ◽  
Lu Chen ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Laser Ablation ◽  
Inductively Coupled Plasma ◽  
Lead Isotope ◽  
Pb Isotopes ◽  
Lead Isotope Ratios ◽  
Inductively Coupled ◽  
Icp Ms ◽  
Plasma Mass Spectrometry

Herein, the potential of laser ablation multi-collector inductively coupled plasma mass spectrometry (LA-MC-ICP-MS) for the determination of Pb isotopes of lead-glazed ceramics has been investigated.

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