Next Article in Journal
Kishonite, VH2, and Oreillyite, Cr2N, Two New Minerals from the Corundum Xenocrysts of Mt Carmel, Northern Israel
Next Article in Special Issue
Tennantite–Tetrahedrite-Series Minerals and Related Pyrite in the Nibao Carlin-Type Gold Deposit, Guizhou, SW China
Previous Article in Journal
Geochemical and Geochronological Constraints on the Genesis of Ion-Adsorption-Type REE Mineralization in the Lincang Pluton, SW China
Previous Article in Special Issue
Rare-Metal Pegmatite Deposits of the Kalba Region, Eastern Kazakhstan: Age, Composition and Petrogenetic Implications
Open AccessArticle

Post-Magmatic Fluids Dominate the Mineralization of Dolomite Carbonatitic Dykes Next to the Giant Bayan Obo REE Deposit, Northern China

1
Institute of Earthquake Forecasting, China Earthquake Administration, Beijing 100036, China
2
Institute of Mineral Resources, Chinese Academy of Geological Sciences, Beijing 100012, China
3
Kunming Natural Resources Comprehensive Investigation Center, China Geological Survey, Kunming 650001, China
*
Author to whom correspondence should be addressed.
Minerals 2020, 10(12), 1117; https://doi.org/10.3390/min10121117
Received: 5 November 2020 / Revised: 7 December 2020 / Accepted: 9 December 2020 / Published: 12 December 2020
(This article belongs to the Special Issue Ore Mineralogy and Geochemistry of Rare Metal Deposits)
The Bayan Obo rare earth element (REE) deposit in Inner Mongolia, northern China, is the largest REE deposit in the world, whose mineralization process remains controversial. There are dozens of carbonatite dykes that are tightly related to the deposit. Here we report the petrological and mineralogical characteristics of a typical dolomite carbonatite dyke near the deposit. The dolomite within the dyke experienced intense post-emplacement fluids metasomatism as evidenced by the widespread hydrothermal REE-bearing minerals occurring along the carbonate mineral grains. REE contents of bulk rocks and constituent dolomite minerals (>90 vol.%) are 1407–4184 ppm and 63–152 ppm, respectively, indicating that dolomite is not the dominant mineral controlling the REE budgets of the dyke. There are three types of apatite in the dyke: Type 1 apatite is the primary apatite and contains REE2O3 at 2.35–4.20 wt.% and SrO at 1.75–2.19 wt.%; Type 2 and Type 3 apatites are the products of replacement of primary apatite. The REE2O3 (6.10–8.21 wt.%) and SrO (2.83–3.63 wt.%) contents of Type 2 apatite are significantly elevated for overprinting of REE and Sr-rich fluids derived from the carbonatite. Conversely, Type 3 apatite has decreased REE2O3 (1.17–2.35 wt.%) and SrO (1.51–1.99 wt.%) contents, resulting from infiltration of fluids with low REE and Na concentrations. Our results on the dyke suggest that post-magmatic fluids expelled from the carbonatitic melts dominated the REE mineralization of the Bayan Obo deposit, and a significant fluid disturbance occurred but probably provided no extra REEs to the deposit. View Full-Text
Keywords: dolomite carbonatite dyke; petrology; mineralogy; metasomatism; REE mineralization; the Bayan Obo deposit dolomite carbonatite dyke; petrology; mineralogy; metasomatism; REE mineralization; the Bayan Obo deposit
Show Figures

Figure 1

MDPI and ACS Style

Hu, L.; Li, Y.; Chuan, M.; Li, R.; Ke, C.; Wu, Z. Post-Magmatic Fluids Dominate the Mineralization of Dolomite Carbonatitic Dykes Next to the Giant Bayan Obo REE Deposit, Northern China. Minerals 2020, 10, 1117. https://doi.org/10.3390/min10121117

AMA Style

Hu L, Li Y, Chuan M, Li R, Ke C, Wu Z. Post-Magmatic Fluids Dominate the Mineralization of Dolomite Carbonatitic Dykes Next to the Giant Bayan Obo REE Deposit, Northern China. Minerals. 2020; 10(12):1117. https://doi.org/10.3390/min10121117

Chicago/Turabian Style

Hu, Le; Li, Yike; Chuan, Maoshan; Li, Ruiping; Ke, Changhui; Wu, Zhongjian. 2020. "Post-Magmatic Fluids Dominate the Mineralization of Dolomite Carbonatitic Dykes Next to the Giant Bayan Obo REE Deposit, Northern China" Minerals 10, no. 12: 1117. https://doi.org/10.3390/min10121117

Find Other Styles
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Search more from Scilit
 
Search
Back to TopTop