TY - JOUR
T1 - Insights into ore genesis of the Jinding Zn–Pb deposit, Yunnan Province, China
T2 - Evidence from Zn and in-situ S isotopes
AU - Deng, Jun
AU - Wang, Changming
AU - Bagas, Leon
AU - Selvaraja, Vikraman
AU - Jeon, Heejin
AU - Wu, Bin
AU - Yang, Lifei
PY - 2017/11/1
Y1 - 2017/11/1
N2 - The Jinding Zn–Pb deposit located in the Mesozoic-Cenozoic Lanping Basin of southwest China has ore reserves of ∼ 220 Mt with an average grade of 6.1% Zn and 1.3% Pb. The mineralization is hosted by sandstone in the Early Cretaceous Jingxing Formation and limestone breccia in the Paleocene Yunlong Formation. Mineralization in both types of host rocks is characterized by a paragenetic sequence beginning with marcasite–sphalerite (Stage 1) followed by pyrite–marcasite–sphalerite–galena (Stage 2), and then galena–sphalerite–pyrite–sulfate–carbonate (Stage 3). Pyrite from these stages have different δ33S compositions with pyrite from Stage 1 averaging − 9.6‰, Stage 2 averaging − 8.9‰, and Stage 3 averaging + 0.3‰. Sphalerite hosted by the sandstone has similar δ66Zn values ranging from 0.10 to 0.30‰ in all stages of the mineralization, but sphalerite samples from the limestone breccia-hosted ore show variable δ66Zn values between − 0.03 and 0.20‰. Our data on sphalerite precipitated during the earlier stages of mineralization has a constant δ66Zn value and cogenetic pyrite displays a very light sulfur isotope signature, which we believe to reflect a sulfur source that formed during bacterial sulfate reduction (BSR). The Stage 3 sphalerite and pyrite precipitated from a late influx of metal-rich basinal brine, which had a relatively constant variable δ66Zn isotopic composition due to open system isotope fractionation, and a near zero δ33S composition due to the influence of abiotic thermochemical sulfate reduction from observed sulfates in the host rock.
AB - The Jinding Zn–Pb deposit located in the Mesozoic-Cenozoic Lanping Basin of southwest China has ore reserves of ∼ 220 Mt with an average grade of 6.1% Zn and 1.3% Pb. The mineralization is hosted by sandstone in the Early Cretaceous Jingxing Formation and limestone breccia in the Paleocene Yunlong Formation. Mineralization in both types of host rocks is characterized by a paragenetic sequence beginning with marcasite–sphalerite (Stage 1) followed by pyrite–marcasite–sphalerite–galena (Stage 2), and then galena–sphalerite–pyrite–sulfate–carbonate (Stage 3). Pyrite from these stages have different δ33S compositions with pyrite from Stage 1 averaging − 9.6‰, Stage 2 averaging − 8.9‰, and Stage 3 averaging + 0.3‰. Sphalerite hosted by the sandstone has similar δ66Zn values ranging from 0.10 to 0.30‰ in all stages of the mineralization, but sphalerite samples from the limestone breccia-hosted ore show variable δ66Zn values between − 0.03 and 0.20‰. Our data on sphalerite precipitated during the earlier stages of mineralization has a constant δ66Zn value and cogenetic pyrite displays a very light sulfur isotope signature, which we believe to reflect a sulfur source that formed during bacterial sulfate reduction (BSR). The Stage 3 sphalerite and pyrite precipitated from a late influx of metal-rich basinal brine, which had a relatively constant variable δ66Zn isotopic composition due to open system isotope fractionation, and a near zero δ33S composition due to the influence of abiotic thermochemical sulfate reduction from observed sulfates in the host rock.
KW - Jinding Zn–Pb deposit
KW - Ore genesis
KW - Sulfur isotopes
KW - Zinc isotopes
UR - http://www.scopus.com/inward/record.url?scp=85006172861&partnerID=8YFLogxK
U2 - 10.1016/j.oregeorev.2016.10.036
DO - 10.1016/j.oregeorev.2016.10.036
M3 - Article
AN - SCOPUS:85006172861
VL - 90
SP - 943
EP - 957
JO - Ore Geology Reviews
JF - Ore Geology Reviews
SN - 0169-1368
ER -