کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4697170 1637238 2015 17 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Physico-chemical controls on ore deposition in the Arapucandere Pb–Zn–Cu-precious metal deposit, Biga Peninsula, NW Turkey
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات زمین شناسی اقتصادی
پیش نمایش صفحه اول مقاله
Physico-chemical controls on ore deposition in the Arapucandere Pb–Zn–Cu-precious metal deposit, Biga Peninsula, NW Turkey
چکیده انگلیسی

Arapucandere is one of a number of similar Cu–Zn–Pb ± Au–Ag epithermal deposits in the Biga Peninsula, which are mineralogically and tectonically similar. Fluid inclusions have very low salinities between 1.7 and 0 wt.% NaCl and a wide range of temperatures from ~ 360 to 160 °C. There was extensive boiling and “flashing” of the hydrothermal fluids which initiated mineral deposition. The range of temperatures is consistent with emplacement of the veins at ~ 700 m depth, with the pressure decreasing from near lithostatic to near hydrostatic and a decrease in temperature to ~ 250 °C due to adiabatic expansion of the fluids. There is evidence of a limited amount of boiling, but the temperature and pressure decrease was close to the liquid–vapour curve. Flashing of the fluids was caused by sudden drops to sub-hydrostatic pressures and even lower temperatures. Mineralization was caused by these pressure related temperature decreases as there is no evidence of cooling and dilution of the ore-fluids. δ34S values of sulphides indicate a magmatic source but the more negative than usual values also suggest boiling affected isotopes. δD and δ18O of the fluids indicate a mixing between meteoric waters and magmatic fluids, with the large range of δD due to boiling. LA-ICP-MS analyses of fluid inclusions reveal high Cu–Zn–Pb concentrations in the fluids, despite their low salinity, transported as chloride complexes. Exceptional pressure and temperature decrease causing the fluids to “flash” was likely to have been in response to earthquakes.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Ore Geology Reviews - Volume 66, April 2015, Pages 65–81
نویسندگان
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