Scientific article

High-Precision Geochronology of the Xiaojiayingzi Mo Skarn Deposit: Implications for Prolonged and Episodic Hydrothermal Pulses

Publication date2022-11-17
First online date2022-11-17

The timescales and duration of ore-forming processes in skarn systems are not well constrained. To better understand this, we present high-precision chemical abrasion-isotope dilution-thermal ionization mass spectrometry (CA-ID-TIMS) U-Pb zircon and isotope dilution-negative-thermal ionization mass spectrometry (ID-N-TIMS) Re-Os molybdenite geochronology of the Xiaojiayingzi Mo skarn deposit (0.13 Mt Mo at 0.22 wt %), northeastern China. The Xiaojiayingzi deposit is related to an intrusive complex composed of gabbroic diorite, monzodiorite, and granite porphyry. Molybdenite mineralization occurred in two ore blocks, Xiaojiayingzi (0.11 Mt Mo) and Kangzhangzi (0.02 Mt Mo). In the Kangzhangzi ore block, Mo mineralization is concentrated in skarn adjacent to a deep-seated granite porphyry, with minor disseminated and quartz veinlet mineralization within the granite porphyry. In contrast, economic Mo mineralization in the Xiaojiayingzi ore block is concentrated in skarns located between the contact of steeply dipping monzodiorite and the Mesoproterozoic Wumishan Formation, with minor Mo mineralization found in quartz and endoskarn veins hosted in the monzodiorite. Skarn mineralization in both ore blocks converges downward into the mineralized granite porphyry. In the Kangzhangzi ore block, skarn is zoned from deep proximal dark red-brown garnet to shallow distal dark-green pyroxene. In the Xiaojiayingzi ore block, proximal skarn is garnet rich, whereas pyroxene increases away from the monzodiorite-Wumishan Formation contact. In addition, pyroxene becomes more Fe and Mn rich with distance from the intrusions; Pb, Zn, and Ag increase toward the top of the system; and Mo and Fe increase with depth.

Citation (ISO format)
OUYANG, Hegen et al. High-Precision Geochronology of the Xiaojiayingzi Mo Skarn Deposit: Implications for Prolonged and Episodic Hydrothermal Pulses. In: Economic geology and the bulletin of the Society of Economic Geologists, 2022. doi: 10.5382/econgeo.4984
Main files (1)
Article (Published version)
ISSN of the journal0361-0128

Technical informations

Creation11/18/2022 1:23:00 AM
First validation11/18/2022 1:23:00 AM
Update time03/16/2023 9:03:03 AM
Status update03/16/2023 9:03:02 AM
Last indexation05/06/2024 2:37:23 PM
All rights reserved by Archive ouverte UNIGE and the University of GenevaunigeBlack