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The reconstruction of paleo‐elevation serves a dual purpose to enhance our comprehension of geodynamic processes affecting terrestrial landforms and to contribute significantly to the interpretation of atmospheric circulation and biodiversity. The oxygen (δ18Ow) and deuterium (δDw) isotopes in atmospheric precipitation are systematically depleted with the increase of altitude, which are typical and widely applicated paleo‐altimeters. The utilization of hydrogen isotope of hydrous silicate minerals within the shear zone system, volcanic glass, and plant leaf wax alkanes offers valuable insights for addressing evaporation and diagenesis. In this paper, we review the principle, application conditions, and influencing factors of the hydrogen isotope paleo‐altimeter. In addition, we discuss the feasibility of utilizing this technique for quantitatively estimating the paleo‐elevation of the southeastern Tibetan Plateau, where multiple shear zones extend over hundred kilometers parallel to the topographic gradient. [ABSTRACT FROM AUTHOR]

Mafic granulite, garnet peridotite, and garnet pyroxenite occurred as slices or lenses within dominant felsic granulite, and they together constitute a high‐pressure metamorphic terrane in the Bashiwake unit, South Altyn Tagh, Northern Tibet, China. Previous studies focused on the metamorphic evolution, and geothermobarometry results indicated that the mafic granulite has experienced high pressure/(ultra‐)high temperature (HP/(U)HT) metamorphism, followed by a medium pressure (MP) granulite‐facies overprint. However, the nature and petrogenesis of the mafic granulite in the dominant felsic granulite are poorly known. Combining the previous geothermobarometry results with the petrographic observations, mineral chemistry, and pseudosection modelling in this study, at least four stages were suggested for the metamorphic evolution of the mafic granulites in the South Altyn Tagh, including the eclogite‐facies stage (3–4 GPa, 910–1000°C), high pressure–ultrahigh temperature (HP–UHT) metamorphism, an isothermal decompression, and subsequent MP granulite‐facies overprint. The U–Pb dating of zircons yielded two age clusters: one age cluster at ca. 500 Ma, representing the retrograde age of HP–UHT metamorphism after the eclogite‐facies stage, and another age cluster of ca. 900 Ma that represented the age of the protolith for the mafic granulite. This indicated that the protolith of the mafic granulite was formed in the early Neoproterozoic and then was taken to extreme temperatures and pressures during the early Palaeozoic orogenic event. The elemental abundances of the mafic granulites in the Bashiwake area clearly indicated that they were higher in FeO and TiO2, but were significantly lower in MgO, Cr, and Ni than those of associated garnet peridotites/pyroxenites, and they showed LREE‐enriched patterns with slightly positive Eu anomalies. Sr–Nd isotopic data suggested a basaltic magmatic origin with crust contamination for the protolith of the mafic granulite. Integrating these results together with previous studies, we suggest that the mafic granulites were derived from the basaltic magma intrusion in the continental crust during the Neoproterozoic and subsequently suffered a common HP/UHT metamorphism with felsic crust rocks in the early Palaeozoic (ca. 500 Ma) after the eclogite‐facies metamorphism related to the continental collision (>500 Ma). [ABSTRACT FROM AUTHOR]

The correlation between dike density and regional‐scale mineralization indicates a fundamental criterion for ore‐forming process. Here, a novel dike distribution density method is formulated for evaluating this correlation and exploring mine targets quantitatively. Three parameters (dike density, dike orientation scatter degree and dike fractal dimension) are proposed to express the degree of irregularity and complexity of dike distribution patterns. This method is applied to the South Alatao Mountains area (China), where the dike swarms show regionally well‐developed density gradients and the mineral deposits are spatially associated with abundant dike swarms. On the basis of this quantitative dike distribution density method, 60% of the deposit targets are delineated in this area. This result indicates that the method is an effective quantification tool for prospecting mine targets. The dike distribution density method is applicable for areas where abundant regional‐scale dike swarms and mineralization occur. It should be considered as an effective and complimentary technique for the common mine prospectivity analysis. [ABSTRACT FROM AUTHOR]

Plagioclase-rich leucosomes and K-feldspar--rich veins are widely distributed within retrogressed eclogite in the Xitieshan area of the North Qaidam ultrahigh-pressure metamorphic terrane, western China. In this contribution, a combined study of petrology, zircon internal structure, zircon U-Pb age, zircon trace-element composition, whole-rock geochemistry, and Sr-Nd isotopes in plagioclase-rich leucosomes and K-feldspar--rich veins provides insight into the nature and timing of partial melting in these rocks. Petrological evidence for partial melting is provided by elongated, highly cuspate feldspars, quartz along grain boundaries (e.g., muscovite, garnet, and clinopyroxene), and felsic veinlets composed of quartz and feldspar along the boundaries of garnet, clinopyroxene, and clinopyroxene-plagioclase symplectite in the metabasite. Whole-rock geochemistry suggests that the plagioclase-rich leucosomes have lower contents of both rare earth elements (REEs) and high field strength elements (HFSEs) but higher large ion lithophile elements (LILEs; e.g., Rb, Ba, K, Sr, and Pb) than the metabasite hosts. The plagioclase-rich leucosomes may be divided into two subgroups according to their distinct REE patterns: (1) higher total REE content with or without weak negative Eu anomalies, and (2) lower total REE content with conspicuous positive Eu anomalies. The Eu-rich group also shows higher Sr content than those in the Eu-poor group. However, the K-feldspar--rich veins show higher REE, HFSE, and LILE concentrations than the plagioclase-rich leucosomes and metabasites. The inherited cores of K-feldspar--rich veins are of typical magmatic origin (oscillatory zoning with high Th/U ratios, enriched heavy [H] REEs, and negative Eu anomalies), yielding 206Pb/238U ages ranging from 904 ± 8 Ma to 915 ± 28 Ma. The zircon cores of plagioclase-rich leucosomes and mantles of K-feldspar--rich veins exhibit no zoning or weak zoning, with flat HREE patterns and no negative Eu anomalies, and they contain mineral inclusions of garnet and clinopyroxene, implying that these zircon domains were formed during an episode of eclogite-facies metamorphism with 206Pb/238U ages ranging from 444 ± 10 Ma to 452 ± 9 Ma. Internal textures and mineral inclusions (quartz, plagioclase, and K-feldspar) and trace-element systematics (steep HREE patterns with negative Eu anomalies and low Th/U ratios) of the zircon rims from plagioclase-rich leucosomes and K-feldspar--rich veins are similar to anatectic zircon. These anatectic zircon domains yielded 206Pb/238U ages ranging from 430 ± 10 Ma to 440 ± 12 Ma, and 406 ± 12 Ma to 430 ± 13 Ma, respectively. An integrated study of petrology, geochronology, and geochemistry demonstrated that the metabasites of the North Qaidam ultrahigh-pressure terrane likely experienced initial partial melting with plagioclase-rich leucosome formation under eclogite-facies conditions and partial melt crystallization during the granulite-facies stage, triggered by dehydration melting involving zoisite and rare muscovite. The K-feldspar--rich veins within the metabasites may be the result of injected melts that were derived from partial melting of nearby gneisses. [ABSTRACT FROM AUTHOR]