Alteration zonation and short wavelength infrared (SWIR) characteristics of the Honghai VMS Cu-Zn deposit, Eastern Tianshan, NW China

Abstract The Honghai VMS Cu-Zn deposit is located in the Dananhu-Tousuquan arc, Eastern Tianshan, northwestern China. Orebodies of the Honghai deposit are buried 300 m underground and hosted by the Middle Ordovician-Upper Silurian Daliugou Formation felsic to intermediate volcanic-sedimentary rocks. At the footwall and hanging wall of the massive sulfide lens, intensive and pervasive phyllic alterations were found. Detailed drill core logging, petrographic study and electron microprobe analyses had delineated six alteration/mineralization zones, namely (from top to bottom) Zone I (chlorite-albite-white mica-carbonate), II (epidote-chlorite-albite-white mica-carbonate), III (quartz-white mica-pyrite), IV (massive sulfide), V (chlorite-pyrite ± white mica) and VI (chlorite-quartz-white mica). Our new data supported the sub-seafloor replacement influence for the Honghai VMS deposit, as evidenced by the presence of (1) sulfide breccias in the immediate host rocks; (2) rapid emplacement of host rocks; (3) strong phyllic alteration in the immediate hanging wall; (4) replacement textures of the massive sulfides; (5) barite as gangue minerals. Moreover, intensive chlorite and epidote alterations and vein mineralization are present in the hanging wall, which are comparable with porphyry-related propylitic alteration. Besides, different mineralogy and mineral chemistry are present between chlorites from the hanging wall and footwall at Honghai, which probably suggested porphyry-style alteration and mineralization overprinting at Honghai. Short wavelength infrared (SWIR) spectral analysis had identified mainly white mica, chlorite and epidote, and minor montmorillonite, calcite, gypsum, kaolinite and prehnite. The wavelengths of the AlOH absorption feature for white mica range from 2194 to 2221 nm, suggesting compositions from paragonite, through muscovite to phengite. The wavelengths of FeOH absorption feature for chlorite range from 2249 to 2261 nm, indicating compositions from Mg-rich to Fe-rich chlorite. According to SWIR measurements and electron microprobe analyses (EMPA), areas proximal to the massive sulfides are characterized by short wavelength of the AlOH absorption feature and high Alvi content of white mica. Petrography and EMPA showed that chlorite in the ore proximal zones are more Mg-rich than that in ore distal zones. These findings indicated high temperature for the white mica formation and more seawater influx during the chlorite formation in areas near the massive sulfides. This study suggested that SWIR analysis, supported by petrographic study and EMPA, can serve as an effective tool in alteration mapping, and mineral geochemical variations are potential deposit-scale exploration vectoring tools.

[1]  J. Huntington,et al.  Infrared spectral reflectance characterization of the hydrothermal alteration at the Tuwu Cu–Au deposit, Xinjiang, China , 2005 .

[2]  A. Şengör,et al.  Evolution of the Altaid tectonic collage and Palaeozoic crustal growth in Eurasia , 1993, Nature.

[3]  J. Walshe,et al.  Giant Porphyry Deposits: Characteristics, Distribution, and Tectonic Controls , 2005 .

[4]  F. Pirajno,et al.  Re–Os dating of chalcopyrite from selected mineral deposits in the Kalatag district in the eastern Tianshan Orogen, China , 2016 .

[5]  J. Gemmell,et al.  Exploration Tools for Linked Porphyry and Epithermal Deposits: Example from the Mankayan Intrusion-Centered Cu-Au District, Luzon, Philippines , 2011 .

[6]  He Zhi-jun.  Ore deposits as a guide to the tectonic evolution in the East Tianshan Mountains,NW China , 2006 .

[7]  W. Herrmann,et al.  The Spectrum of Ore Deposit Types, Volcanic Environments, Alteration Halos, and Related Exploration Vectors in Submarine Volcanic Successions: Some Examples from Australia , 2001 .

[8]  Derek M. Rogge,et al.  Application of Airborne, Laboratory, and Field Hyperspectral Methods to Mineral Exploration in the Canadian Arctic: Recognition and Characterization of Volcanogenic Massive Sulfide-Associated Hydrothermal Alteration in the Izok Lake Deposit Area, Nunavut, Canada , 2015 .

[9]  S. Scott,et al.  A Comparison of Footwall-Rock Alteration and Geothermal Systems Beneath Some Japanese and Canadian Volcanogenic Massive Sulfide Deposits , 1983 .

[10]  M. Hannington,et al.  Mineral-chemical studies of metamorphosed hydrothermal alteration in the Kristineberg volcanogenic massive sulfide district, Sweden , 2003 .

[11]  I. Yusta,et al.  Mineralogical, IR-spectral and geochemical monitoring of hydrothermal alteration in a deformed and metamorphosed Jurassic VMS deposit at Arroyo Rojo, Tierra del Fuego, Argentina , 2012 .

[12]  E. Duke,et al.  Near infrared spectra of muscovite, Tschermak substitution, and metamorphic reaction progress: Implications for remote sensing , 1994 .

[13]  A. Miyashiro,et al.  Tschermak Substitution in Low- and Middle-grade Pelitic Schists , 1985 .

[14]  Deng Xiao-hu.  Geological characteristics of the Hongshi Cu- Au deposit, eastern Tianshan,Xinjiang and discussion of the deposit genesis , 2014 .

[15]  Michelle C. Tappert,et al.  The mineral chemistry, near-infrared, and mid-infrared reflectance spectroscopy of phengite from the Olympic Dam IOCG deposit, South Australia , 2013 .

[16]  W. Herrmann,et al.  A Special Issue on Alteration Associated with Volcanic-Hosted Massive Sulfide Deposits, and Its Exploration Significance , 2001 .

[17]  Sarah Jones,et al.  Short Wavelength Infrared Spectral Characteristics of the HW Horizon:Implications for Exploration in the Myra Falls Volcanic-Hosted Massive Sulfide Camp, Vancouver Island, British Columbia, Canada , 2005 .

[18]  Xia Bin.  Geochemistry and petrogenesis of the Kalatag intrusion in the "Tuha window" , 2006 .

[19]  Zhiming Yang,et al.  EVALUATION OF INTER-INSTRUMENT VARIATIONS AMONG SHORT WAVELENGTH INFRARED (SWIR) DEVICES , 2012 .

[20]  Gao Zhenquan.  The Metallogenic Environment of Kalatage Prophyry Copper (Gold) Deposit and Its Prospecting Perspective,Xinjiang,China , 2006 .

[21]  B. Windley,et al.  Paleozoic multiple accretionary and collisional tectonics of the Chinese Tianshan orogenic collage , 2013 .

[22]  D. Huston,et al.  Zonation of Alteration Facies at Western Tharsis: Implications for the Genesis of Cu-Au Deposits, Mount Lyell Field, Western Tasmania , 2001 .

[23]  M. Santosh,et al.  New 40Ar/39Ar ages from the Kalatag district in the Eastern Tianshan, NW China: Constraints on the timing of Cu mineralization and stratigraphy , 2016, Ore Geology Reviews.

[24]  M. Hey.  A new review of the chlorites , 1954 .

[25]  Y. Chen,et al.  Epithermal deposits in North Xinjiang, NW China , 2012, International Journal of Earth Sciences.

[26]  R. Sillitoe.  Porphyry Copper Systems , 2010 .

[27]  Bin Chen,et al.  Massive granitoid generation in Central Asia: Nd isotope evidence and implication for continental growth in the Phanerozoic , 2000 .

[28]  R. Large,et al.  Stringer system and alteration zones underlying the Hellyer volcanogenic massive sulfide deposit, Tasmania, Australia , 1992 .

[29]  J. Huntington,et al.  Variations in composition and abundance of white mica in the hydrothermal alteration system at Helly , 2011 .

[30]  P. Hauff,et al.  Alteration Mapping in Exploration: Application of Short-Wave Infrared (SWIR) Spectroscopy , 1999, SEG Discovery.

[31]  Thomas Cudahy,et al.  Tracing fluid pathways in fossil hydrothermal systems with near-infrared spectroscopy , 2005 .

[32]  P. Shen,et al.  Petrography, geochemistry and geochronology of the host porphyries and associated alteration at the Tuwu Cu deposit, NW China: a case for increased depositional efficiency by reaction with mafic hostrock? , 2014, Mineralium Deposita.

[33]  D. Huston,et al.  The subsea-floor replacement origin of the Ordovician Highway-Reward volcanic-associated massive sulfide deposit, Mount Windsor Subprovince, Australia , 1999 .

[34]  M. Doyle,et al.  Subsea-floor replacement in volcanic-hosted massive sulfide deposits , 2003 .

[35]  S. Piercey.  A SEMIPERMEABLE INTERFACE MODEL FOR THE GENESIS OF SUBSEAFLOOR REPLACEMENT-TYPE VOLCANOGENIC MASSIVE SULFIDE (VMS) DEPOSITS , 2015 .

[36]  Thomas Cudahy,et al.  Characterization of the hydrothermal systems associated with Archean VMS-mineralization at Panorama, Western Australia, using hyperspectral, geochemical and geothermometric data , 2012 .

[37]  R. Sillitoe.  Are porphyry copper and Kuroko-type massive sulfide deposits incompatible? , 1980 .

[38]  Ross R. Large,et al.  Australian volcanic-hosted massive sulfide deposits; features, styles, and genetic models , 1992 .

[39]  J. R. Lang,et al.  Shortwave Infrared Spectral Analysis of Hydrothermal Alteration Associated with the Pebble Porphyry Copper-Gold-Molybdenum Deposit, Iliamna, Alaska , 2013 .

[40]  Yongfeng Zhu,et al.  The post-collisional Cihai iron skarn deposit, eastern Tianshan, Xinjiang, China , 2015 .

[41]  A. Galley,et al.  Volcanogenic Massive Sulfide Deposits , 2005 .

[42]  Mark G. Doyle,et al.  Short Wavelength Infrared (SWIR) Spectral Analysis of Hydrothermal Alteration Zones Associated with Base Metal Sulfide Deposits at Rosebery and Western Tharsis, Tasmania, and Highway-Reward, Queensland , 2001 .

[43]  Qin Ke.  Geological and fluid inclusion characteristics of Meiling Cu-Au deposit in Kalatage ore belt,eastern Xinjiang,in comparison with typical Zijinshan-style HS-epithermal deposit , 2007 .

[44]  H. White,et al.  Short-Wave Infrared Spectral and Geochemical Characteristics of Hydrothermal Alteration at the Archean Izok Lake Zn-Cu-Pb-Ag Volcanogenic Massive Sulfide Deposit, Nunavut, Canada: Application in Exploration Target Vectoring , 2016 .

[45]  W. Maclean,et al.  Systematics of chlorite alteration at the Phelps Dodge massive sulfide deposit, Matagami, Quebec , 1987 .