Temperature of crystallization of pyrrhotite and sphalerite from the Highland-Surprise Mine, Coeur d'Alene district, Idaho

Abstract

The ore bodies of the Highland-Surprise Mine are replacements along shear zones in quartzose slate, quartzite, and phyllite of the Prichard formation of the Belt series (Precambrian). Pyrite, arsenopyrite, pyrrhotite, sphalerite, chalcopyrite, and galena are the chief metallic minerals and were probably deposited in that order.Temperatures of formation were estimated for pyrrhotite-pyrite and sphalerite-pyrrhotite assemblages contained in the steeply dipping vein system. Measurements on sixty-two pyrrhotites indicate a range in temperature of crystallization between 370 ø and 492 ø C (no correction required for confining pressures <2,000 bars below 670 ø C), and measurements on fourteen sphalerites indicate crystallization temperatures between 375 ø and 460 ø C (uncorrected for confining pressure). No systematic temperature gradients were recognized.Minor elements in twenty-three pyrrhotite, eight pyrite, thirteen sphalerite, and two galena samples were determined. Partition ratios of nickel and cobalt in pyrrhotite-pyrite and sphalerite-pyrrhotite pairs are erratic. This suggests (a) a dis-equilibrium distribution of these elements between the phases of each mineral pair and/or (b) crystallization of the mineral pairs under different physical conditions.

Exceptional X-Ray contrast: Radiography imaging of a Middle Triassic mixosaurid from Svalbard

“…Complete sphalerite crystals within ribs that are almost completely replaced by baryte, suggests that vertebrate bones could have functioned as fluid ducts where crystals could precipitate. Sphalerite crystallises between 375 degrees and 460 degrees °C [ 55 ], while baryte crystallises down to temperatures of between 120 and 240°C in hydrothermal vents [ 56 ] and between 10 and 70°C at surface pressure [ 57 ]. The high crystallisation temperature of sphalerite is close to the T max calculated for the Botneheia Formation in Edgeøya; between 440 and 447°C at Blanknuten, approximately 20 km north of the Muen mountain [ 58 ].…”

Fluid Chemistry of Mid-Ocean Ridge Hydrothermal Vents: A Comparison between Numerical Modeling and Vent Geochemical Data

“…For S S S S S P S P,S S S S P 200 250 300 350 400°C Mineral formula Mineral 2 50 Figure 1: Temperature stability constraints for minerals occurring in hydrothermally altered mid-ocean ridge basalts. Full black lines: upper and/or lower stability constraints of the phase added in the code according to alteration mineralogy data after 1 Arnold et al [39], 2 Lonsdale et al [40], 3 Henley and Ellis [41], 4 Jenkins et al [42], 5 Reyes [43], 6 Hannington et al [44], 7 White and Hedenquist [45], 8 Jové and Hacker [46], 9 Chipera and Apps [47], 10 Bird and Spieler [48], 11 Monecke et al [49], 12 Hodgkinson et al [50], and 13 Thien et al [51]. Dashed grey lines: nonconstrained mineral phase.…”