Eighteen fluid inclusion volatile peaks have been detected and identified from 1-2 g samples (quartz) by gas chromatography using heated (approximately 105-degrees-C) on-line crushing, helium carrier gas, a single porous polymer column (HayeSep R;10' x 1/8"; 100/120#; Ni alloy tubing), two temperature programme conditions for separate sample aliquots, micro-thermal conductivity (TCD) and photoionization detectors (PID; 11.7 cV lamp), and off-line digital peak processing. In order of retention time these volatile peaks are: N2, Ar, CO, CH4, CO2, C2H4, C2H6, C2H2, COS, C3H6, C3H8, C3H4 (propyne), H2O (22.7 min at 80-degrees-C), SO2, +/- iso-C4H10 +/- C4H8 (1-butene) +/- CH3SH, C4H8 (iso-butylene), (?) C4H6 (1,3 butadiene), and +/- n-C4H10 +/- C4H8 (trans-2-butene) (80 and - 70-degrees-C temperature programme conditions combined). H2O is analysed directly. O2 can be analysed cryogenically between N2 and Ar, but has not been detected in natural samples to date in this study. H2S, SO2, NH3, HCl, HCN, and H2 cannot be analysed at present. Blanks determined by crushing heat-treated Brazilian quartz (800-900-degrees-C/4 h) are zero for 80-degrees-C temperature programme conditions, except for a large, unidentified peak at approximately 64 min, but contain H2O, CO2, and some low molecular weight hydrocarbons at - 70-degrees-C temperature conditions due to cryogenic accumulation from the carrier gas and subsequent elution. TCD detection limits are approximately 30 ppm molar in inclusions; PID detection limits are approximately 1 ppm molar in inclusions and lower for unsaturated hydrocarbons (e.g., approximately 0.2 ppm for C2H4; approximately 1 ppb for C2H2; approximately 0.3 ppb for C3H6). Precisions (1-sigma) are approximately +/- 1-2% and approximately +/- 13% for H2O in terms of total moles detected; the latter value is equivalent to +/- 0.6 mol% at the 95 mol% H2O level. Major fluid inclusion volatile species have been successfully analysed on a approximately 50 mg fluid inclusion section chip (approximately 7 mm x approximately 10 mm x approximately 100-mu-m). Initial inclusion volatile analyses of fluids of interpreted magmatic origin from the Cretaccous Boss Mtn. monzogranite stock-related MoS2 deposit, central British Columbia of approximately 97 mol% H2O, approximately 3% CO2, approximately 140-150 ppm N2, and approximately 16-39 ppm CH4 (approximately 300-350-degrees-C) are reasonable in comparison with high temperature (approximately 400-900-degrees-C) volcanic gas analyses from four, active calc-alkaline volcanoes; e.g., the H2O contents of volcanic gases from the White Island (New Zealand), Mount St. Helens (Washington, USA), Merapi (Bali, Indonesia), and Momotombo (Nicaragua) volcanoes are 88-95%, > 90% (often > 95%), 88-95% and approximately 93%, respectively; CO2 contents are approximately 3-10%, 1-10%, 3-8%, and approximately 3.5%. CO2/N2 ratios for the Boss Mtn. MoS2 fluids of approximately 190-220 are in the range for known volcanic gas ratios (e.g., approximately 150-240; White Island). The SIGMA-S content of the Boss Mtn. MoS2 fluid prior to S loss by sulphide precipitation may have been approximately 2 mol% since CO2/SIGMA-S molar ratios of analysed high-temperature volcanic gases are approximately 1.5. This estimate is supported by SIGMA-S contents for White Island, Merapi and Momotombo volcanic gases of approximately 2%, approximately 0.5-2.5%, and approximately 2%. COS has been determined in H2O-CO2 fluid inclusions of interpreted magmatic origin from the Boss Mtn. MoS2 deposit and the Tanco zoned granitic pegmatitic, S.E. Manitoba at approximately 50-100 ppm molar levels, which are consistent with levels in volcanic gases. It appears that low, but significant, concentrations of C2-C4 alkanes (approximately 1-20 ppm), C2-C4 alkenes (approximately 1-480 ppb) and alkynes (e.g., C3H4) have been detected in magmatically derived fluids (Boss Mtn. MoS2 deposit; Tanco granitic pegmatitic). Significantly higher, low molecular weight hydrocarbon concentrations have been determined in a CH4-rich (approximately 2%), externally derived fluid of possible metamorphic or deep crustal origin trapped as inclusions in metasomatic wall-rock tourmaline adjacent to the Tanco pegmatite (e.g., 300/470 ppm C2H6; 50/90 ppm C3H8; 3-60 ppm C2H4/C3H6/n-C4H10).
