2009 Portland GSA Annual Meeting (18-21 October 2009)
Paper No. 26-9
Presentation Time: 9:00 AM-6:00 PM


STORM, Lauren1, FRIEHAUF, Kurt1, YUAN, Zhenlei2, XIAO, Ping3, and MOOREHEAD, Anthony1, (1) Dept. Physical Sciences, Kutztown University, Kutztown, PA 19530, lstor989@live.kutztown.edu, (2) Henan Scientific Academy of Land & Resources, 41 Huanghe Road, Zhengzhou, Henan province, 450053, China, (3) China University of Mining and Technology, Beijing, 100083, China

Mesoproterozoic Xiong’er Group andesite hosts Cretaceous molybdenum ores in the Dong Gou molybdenum deposit in the eastern Qinling Mountains of Henan, China. Current mining activity is done by hand mucking and hauling high grade ores from shallow underground workings. Thin, discontinuous K-feldspar veins characterize earliest mineralization styles, which are cut by quartz-molybdenum veins associated with hydrothermal biotite alteration of andesite. Where hairline quartz-molybdenite veins cut feldspar phenocrysts in the andesite, K-feldspar overgrowths fill the vein. Quartz-molybdenite veins became thicker, more continuous, and planar as the system evolved, reflecting cooling and transition to a more brittle strain environment. Molybdenite-barren, blue apatite-K-feldspar veins crosscut early quartz-molybdenite and evolved through time from apatite-dominant to K-feldspar-dominant modes with minor molybdenum on vein margins. Thick quartz-molybdenite-pyrite veins that crosscut barren apatite-rich veins record a second stage of molybdenite mineralization. K-feldspar-chlorite-quartz-pyrite veins postdate both molybdenite stages.

Early fluorine-rich phases such as fluorite and topaz reported at Dong Gou by Wei et al. (2009) were not exposed at mine levels examined in this study, suggesting fluorine in this part of the deposit may be locked up in apatite veins.

The Dong Gou deposit represents an important variation on the extension-related, high-fluorine-type molybdenite deposits in the eastern Qinling metallogenic belt.

2009 Portland GSA Annual Meeting (18-21 October 2009)
General Information for this Meeting
Session No. 26--Booth# 25
Economic Geology (Posters): All subjects, including IOCG and Porphyry Copper Deposits; Epithermal-Hot Springs; Non-Sulfide Ores; Gold; Magmas and Volatiles; and Copper in Asia
Oregon Convention Center: Hall A
9:00 AM-6:00 PM, Sunday, 18 October 2009

Geological Society of America Abstracts with Programs, Vol. 41, No. 7, p. 84

© Copyright 2009 The Geological Society of America (GSA), all rights reserved. Permission is hereby granted to the author(s) of this abstract to reproduce and distribute it freely, for noncommercial purposes. Permission is hereby granted to any individual scientist to download a single copy of this electronic file and reproduce up to 20 paper copies for noncommercial purposes advancing science and education, including classroom use, providing all reproductions include the complete content shown here, including the author information. All other forms of reproduction and/or transmittal are prohibited without written permission from GSA Copyright Permissions.