Zircon ion probe data set of Yanshanian intermediate acid rocks in the northern margin of North China and its adjacent areas

This data is zircon U-Pb age data of Yanshanian intermediate acid rocks in the northern margin of North China and its adjacent areas. Zircon U-Pb dating was completed using cameca ims-1280hr in the ion probe Laboratory of Institute of Geology and Geophysics, Chinese Academy of Sciences. The U-Th-Pb isotope ratio was obtained by the calibration of standard zircon Pl e sovice. Simultaneous interpreting of the standard deviations obtained from the long-term monitoring of standard samples and the accuracy of the single point test were used to obtain the sample single point error, taking the standard sample Qinghu as the accuracy of the unknown sample monitoring data. The measured 204Pb value is used for ordinary Pb correction. The isotopic ratio and age error are all 1 σ。 Harmonic age and mean age were calculated using isoplot software. Through the obtained data, we can find out the temporal and spatial distribution of magmatism in the study area, establish the chronological framework of the northern margin of North China and its adjacent areas, and provide chronological basis for further study of geodynamic mechanism in this area.

0 2021-09-22

Zircon Hf isotopic data set of Yanshanian intermediate-acid rocks in the northern margin of North China and its adjacent areas

This data is the Hf isotopic geochemical data of zircon microregions of Yanshanian intermediate acid rocks in the northern margin of the North China Craton and its adjacent areas. The experimental instrument is multi receiver inductively coupled plasma mass spectrometer (MC - ICP - MS), and the testing unit is Tianjin geological survey center of China Geological Survey. Some data have been published in high-level SCI journals, and the data are true and reliable. Through the obtained data, the variation law of zircon Hf isotopic composition in the study area can be found out, which can provide deterministic evidence for identifying the magmatic source area and specific magmatic process in the study area, and then provide new constraints on the Yanshanian tectonomagmatic evolution in the area.

0 2021-09-22

Whole rock Mg isotope data set of Yanshanian intermediate acid rocks in the northern margin of North China and its adjacent areas

The data are the whole rock mg isotopic geochemical data of Yanshanian intermediate acid rocks in the northern margin of North China and its adjacent areas. The whole rock mg isotope data were obtained by MC-ICP-MS analysis. During the whole test period, the indoor standard samples were analyzed and tested, and the results were consistent with the previous reported data of the same standard sample within the error range, which showed that the Mg chemical composition process of the sample did not produce fractionation caused by improper manual operation. In addition, the test results of international standard samples mag-1 (mudstone standard sample), bhvo (basalt standard sample), andesite standard sample and rhyolite standard sample are also consistent with the previously published data, which further ensures that the artificially introduced fractionation is generated in the whole set of chemical treatment process including dissolved samples. Finally, the repeated analysis of the same sample has obtained consistent results, which proves the good reproducibility of Mg isotope test. Through the obtained data, the variation law of isotopic composition in the study area can be found out, the properties of rock source area, melting conditions and magmatic evolution process can be analyzed in detail, and the dynamic process of tectonic magmatic process can be traced.

0 2021-09-06

Sulfide S isotope data set of Yanshanian intermediate acid rocks in the northern margin of North China and its adjacent areas

This data is sulfide sulfur isotope data of Yanshanian intermediate acid rocks in the northern margin of North China and its adjacent areas. Sulfide S isotope data were obtained by la-mc-icp-ms analysis. The S isotope data of sulfide has not been published, and the data are true and reliable. The s isotopes of sphalerite and pyrite can define the variation law of S isotopic composition in the study area. A detailed analysis of the properties of rock source area, melting conditions and magmatic evolution process is of limited significance for tracing the dynamic process of tectonic magmatic process

0 2021-09-03

Data set of activation, migration and enrichment mechanism of rare earth elements during weathering and eluviation (2017-2021)

The data of this project after sampling and testing are as follows: (1) In 2017, bedrock core samples from 2 and 3 boreholes were collected from renju rare earth mining area in Guangdong Province. After mechanical crushing, slicing and single mineral selection, they passed the Key Laboratory of minerals and mineralization, Guangzhou Institute of geochemistry, Chinese Academy of Sciences, and Australian analytical testing (Guangzhou) testing company used X-ray powder diffractometer, X-ray fluorescence spectrometer and X-ray fluorescence spectrometer The mineral composition, iron oxide composition, whole rock chemical composition, mineral chemical composition, rare earth occurrence state and other data of 2 # and 3 # boreholes in renju rare earth deposit in Guangdong Province were measured by ICP-AES, visible short wave infrared reflectance spectroscopy and electron microscope; (2) In 2018, goethite samples were synthesized in the Key Laboratory of minerals and mineralization, Guangzhou Institute of geochemistry, Chinese Academy of Sciences. The phase, morphology and surface physicochemical properties of the synthesized samples were tested by X-ray fluorescence spectrometer, electron microscope, zeta potential analyzer and other instruments; The synthetic goethite was used to simulate the adsorption of rare earth ions. The concentration of rare earth ions was measured by inductively coupled plasma emission spectrometer to characterize the adsorption capacity and adsorption behavior of rare earth ions on the surface of goethite; The surface complexation model software visual MINTEQ was used to fit the adsorption data and determine the intrinsic adsorption constants of rare earth ions. (3) In 2018, kaolinite and halloysite samples were obtained in Maoming, Guangdong Province and Linfen, Shanxi Province, respectively. The phase, morphology and surface physicochemical properties of the samples were tested by X-ray powder diffraction, scanning electron microscopy, zeta potentiometry and other instruments; The adsorption capacity and behavior of rare earth ions on kaolinite and halloysite were characterized by ICP-AES. (4) In November 2018, 32 weathering profile samples of metamorphic rocks were collected in the ion adsorption rare earth mining area of metamorphic weathering crust in Ningdu County, Ganzhou City, Jiangxi Province. After mechanical crushing, slicing, chemical sequential extraction and whole rock acid dissolution experiments, the samples were passed through the Key Laboratory of minerals and mineralization, Guangzhou Institute of geochemistry, Chinese Academy of Sciences, Aoshi analytical testing (Guangzhou) Co., Ltd. uses X-ray powder diffraction, X-ray fluorescence spectrometer, inductively coupled plasma mass spectrometry, METTLER TOLEDO five easy plus ™ The mineral composition, chemical composition, pH value of soil erosion, thin section identification and SEM image data of ion adsorption type rare earth ore profile of metamorphic rock weathering crust were produced by testing with pH meter, optical microscope and electron microscope; (5) In 2021, the survey of rare earth ore was carried out in Dongyuan County, Guangdong Province, and the sampling work of 17 sections was completed. 62 samples were collected and the ion phase extraction and chemical analysis of 62 samples were carried out; The test and analysis can provide a theoretical basis for the enrichment, migration and mineralization of rare earth elements in weathering eluvial rare earth deposits.

0 2021-07-20

Paleomagnetic data set of the Hoh Xil and Sichuan Basins in the Qinghai-Tibet Plateau (2019-2020)

This set of data is used to reconstruct the magnetostratigraphy of the Hoh Xil basin in the interior of the Qinghai-Tibet Plateau and the Sichuan Basinaround the eastern margin of the plateau, and then combined with other chronological methods to establish high-precision chronological scales of the two basins. All the data are thermal demagnetization data, including two parts: one is the paleomagnetic data of the strata about 1000 meters in the top of the Hoh Xil basin; The second is the paleomagnetic data of the bottom strata in Sichuan Basin. The data were measured or obtained in the State Key Laboratory of continental dynamics, Northwestern University and the laboratory of paleomagnetism and geochronology, Institute of Geology and Geophysics, Chinese Academy of Sciences. The preliminary processing results show that the data quality is high.

0 2021-07-12

Mineral composition data set of Zhijin and Weng'an phosphorites in Guizhou

1) The data set includes the whole rock XRD data of Zhijin and Weng'an phosphorites, SEM data and TEM data of Zhijin phosphorites in Guizhou Province. The purpose of this data set is to provide the macro and micro mineral composition information of Guizhou phosphorites from micro scale to nano scale and sub nano scale; 2) The three data were obtained by XRD, SEM and TEM, respectively. The whole rock XRD data is obtained by grinding the sample into powder, the SEM image is obtained by making the block sample into thin section, and the TEM image is obtained by powder method, ion thinning method, ultra-thin section method and FIB method. 3) The data set can well show the mineral composition of Zhijin phosphate rock and Weng'an phosphate rock in Guizhou; 4) This data is of great significance for a detailed understanding of the mineral composition, morphology, distribution state between minerals of Zhijin and Weng'an phosphate deposits in Guizhou, and for understanding the sedimentary environment and formation process of phosphate deposits in this area.

0 2021-07-07

Mineralogical and geochemical data of deep sea sediments in the Central Indian Ocean Basin

The data are the mineralogical and geochemical data of deep-sea REE rich sediments in the central Indian Ocean basin, including core profile photos, smear photos and identification, XRD patterns, SEM photos, major and trace elements of whole sediment, EPMA and La ICP-MS data of single mineral (apatite, micro nodules and calyptosite), organic carbon and nitrogen analysis of whole sediment, and the data of trace elements of whole sediment SR Nd isotopic compositions of whole sediments, REE phase analysis of sediments, REE data of seawater pore water and paleomagnetic data. The analytical samples were collected from the 34th and 42nd voyages of the Chinese ocean, including 6 stations of columnar sediments and 4 stations of seawater. Through the data obtained, we can explore the occurrence minerals and enrichment mechanism of rare earth elements, so as to evaluate and explore the deep-sea rare earth resources in the Indian Ocean.

0 2021-07-06

Molybdenum isotope tracing petrogenesis of adakitic rocks and associated mineralization

Molybdenum (Mo) isotopes could be fractionated during redox-related hydrothermal and Earth-surface processes. Distinct Mo isotope features of different reservoirs, thus, make Mo isotopes as a potential tracer for the recycling of crustal materials, as well as chalcophile element enrichment and mineralization. Here, we report the Mo isotope compositions of 61 early Cretaceous high-K calc-alkaline rocks (defined as adakitic rocks) with distinct source affinities from central-eastern China, including low-Mg adakitic rocks from the Dabie orogen, ore-barren high-Mg adakitic rocks from along the South Tan-Lu Fault and high-Mg ore-bearing adakitic rocks from the Lower Yangtze River Belt. Low-Mg adakitic rocks have the lightest δ98MoNIST3134 of –0.48‰ to –0.03‰, and both ore-barren and ore-bearing high-Mg adakitic rocks display heavier isotope compositions and larger variations: for example, –0.38‰ to 0.41‰ and –0.58‰ to 1.39‰, respectively. Magma evolutions (e.g., hornblende crystallizations) appear to dominate the Mo isotope variation in low-Mg adakitic rocks but could not account for those in ore-barren and ore-bearing high-Mg adakitic rocks. Instead, the mixing trends of Ce/Mo versus δ98Mo and εNd(t) indicate that ore-barren and ore-bearing high-Mg adakitic rocks were derived from interactions of a common enriched mantle (low Ce/Mo ratio, low εNd(t) and δ98Mo) with two different end-members having similarly high Ce/Mo ratios but distinct δ98Mo features. The high Ce/Mo component end-member for ore-barren adakitic rocks characterized by low δ98Mo, as well as moderately to extremely enriched εNd(t) and unradiogenic Pb isotope, represents the lower continental crust similar to the source of low-Mg adakitic rocks. By contrast, the high Ce/Mo end-member for ore-bearing high-Mg adakitic rocks has extremely high δ98Mo (>1.5‰), implying the involvement of subduction reduced sediments. On the other hand, the common enriched mantle end-member was proposed to be a result of mantle metasomatism by chalcophile metal–enriched fluids derived from subduction oxidized sediments. This work demonstrates that Mo isotopes can be useful for understanding adakitic source affinities and associated Cu-Au-Mo mineralization, which emphasizes generation of initial metal enrichment by subduction oxidized sediments in the mantle.

0 2021-07-02

Subducted Mg-rich carbonates into the deep mantle wedge

Recent studies have concluded that subducted calcium (Ca-) rich carbonates could be dissolved in slab-derived aqueous fluids and transported upwards into the shallow mantle wedge (75-120 km), while magnesium (Mg-) rich carbonates could be delivered to a greater depth (i.e., the mantle transition zone, ~410 km), melted, and recycled into the convective upper mantle. However, it remains unknown whether or not Mg-rich carbonates can be transferred to the deep mantle wedge (> ~120 km) by subduction-zone fluids, which, if true, is important for tracing deep carbon. In this paper, we report a comprehensive mineralogical, geochemical, stable (Mg and O) and radiogenic isotopic (zircon U-Pb) study of garnet clinopyroxenites from the Maowu ultra-mafic massif (a slice of the mantle wedge) in the Dabie orogeny, Central China. Whole-rock and mineral trace elemental features and zircon U-Pb ages reveal evidence of mantle wedge metasomatism by a slab-derived melt or supercritical fluid from the subducted rutile-bearing eclogitic Paleo-Tethys oceanic crust, in addition to subsequent metamorphism occurring during the Triassic collision between the South and North China blocks. Combined with the results of previous works, the high Th/U ratios of both whole rocks and metasomatized zircons with no oscillatory zoning lead us to infer that a supercritical liquid rather than a melt was the metasomatic agent during oceanic subduction at peak conditions (5.3-6.3 GPa and ~800°C, 160~190 km). Abundant carbonate mineral inclusions (including calcite, dolomite and magnesite) and the high δ18OVSMOW values of the metasomatized zircons (up to 12.2‰) indicate that sedimentary carbonates were leached by the supercritical fluid. Furthermore, whole-rock δ26Mg values (-0.99‰ to -0.65‰) that are lower than normal mantle values (-0.25±0.07‰) imply that the incorporated carbonates contain not only calcites but also a certain amount of dolomites (approximately 1 - 10 wt.% of the metasomatic supercritical liquid). The dissolved Mg-rich carbonates in the slab-derived supercritical liquid could effectively modify the Mg isotope composition of the deep mantle wedge. Our study represents a critical step towards achieving a broad understanding of the behaviours of recycled carbonate during slab subduction.

0 2021-07-02