Formation of carbonatite-related giant rare-earth-element deposits by the recycling of marine sediments
نویسندگان
چکیده
Carbonatite-associated rare-earth-element (REE) deposits are the most significant source of the world's REEs; however, their genesis remains unclear. Here, we present new Sr-Nd-Pb and C-O isotopic data for Cenozoic carbonatite-hosted giant REE deposits in southwest China. These REE deposits are located along the western margin of the Yangtze Craton that experienced Proterozoic lithospheric accretion, and controlled by Cenozoic strike-slip faults related to Indo-Asian continental collision. The Cenozoic carbonatites were emplaced as stocks or dykes with associated syenites, and tend to be extremely enriched in Ba, Sr, and REEs and have high (87)Sr/(86)Sr ratios (>0.7055). These carbonatites were likely formed by melting of the sub-continental lithospheric mantle (SCLM), which had been previously metasomatized by high-flux REE- and CO2-rich fluids derived from subducted marine sediments. The fertility of these carbonatites depends on the release of REEs from recycled marine sediments and on the intensity of metasomatic REE refertilization of the SCLM. We suggest that cratonic edges, particularly along ancient convergent margins, possess the optimal configuration for generating giant REE deposits; therefore, areas of metamorphic basement bounded or cut by translithospheric faults along cratonic edges have a high potential for such deposits.
منابع مشابه
بررسی عناصر کمیاب و خاکی نادر در حوزههای زغالی ایران (در معدن زیر زمینی زغالسنگ کارمزد)
This research presents data on widespread abnormal accumulations of Trace and Rare Earth Elements in many coal deposits worldwide. There have been many studies on the distribution and geochemistry of REEs in coal. ∑REE content in most coals varies from several µg/g to several hundred µg/g, and the REEs are distributed in minerals although some are associated with organic material in coal. In th...
متن کاملEvaluation of the Paleocene-Eocene deposits, Jahrum Formation, base on 2-D seismic data, Central Persian Gulf
The Persian Gulf is part of an asymmetric foreland basin related to the Zagros Orogen. It has been episodically flooded for much of its history which are reflected in sedimentary successions. The evaluation of this succession from depositional trend view, in central Persian Gulf during Paleocene-Eocene, is the aim of this article. The sedimentary rocks physical characteristics effects on seismi...
متن کاملMass Change Calculation of Elements in the Khut Cu Deposit, West of Yazd
Khut Copper deposit, located in west of Yazd, is one of the most important skarn deposits in Taft mining area that situated in the middle part of the Urumieh-Dokhtar magmatic belt. Intrusion of Khut granodioritic stock into carbonate component of the Nayband Formation has led to the formation of Cu skarn deposit and different skarn zones. Mass changes has led to mineralogical changes in the dif...
متن کاملMineralogical Studies in Assisting Beneficiation of Rare Earth Element Minerals from Carbonatite Deposits
Rare earth elements (REE) are either housed in exotic REE minerals that sporadically populate the host rock or they occur as ionic substitutions in the crystal structure of existing rock-forming minerals. The genesis of REEs in carbonatite rocks can result in intricate mineralogical textures between REE minerals, host rock minerals, and minerals formed by later processes. Upfront mineralogical ...
متن کاملOrigin of unusual HREE-Mo-rich carbonatites in the Qinling orogen, China
Carbonatites, usually occurring within intra-continental rift-related settings, have strong light rare earth element (LREE) enrichment; they rarely contain economic heavy REE (HREE). Here, we report the identification of Late Triassic HREE-Mo-rich carbonatites in the northernmost Qinling orogen. The rocks contain abundant primary HREE minerals and molybdenite. Calcite-hosted fluid inclusions, i...
متن کامل