TY - JOUR

T1 - Modeling of the formation of nonisothermal zoning in magnesian skarns in the ore-magmatic fluid systems of intrusive traps of the southern Siberian Platform

AU - Mazurov, M. P.

AU - Bykova, V. G.

PY - 2017/5/1

Y1 - 2017/5/1

N2 - Using the Selector PC application, we studied the process of formation of magnesian skarns at the contact of dolerites with carbonate-salt deposits. The physicochemical parameters of metasomatic processes were estimated by studying the localization of skarn ore shoots and mineral assemblages in the deposits of the Angara-Ilim type. The action of magmatic fluids on the system dolerite-magnesian salt deposits and dolerite-carbonate-salt deposits resulted in zonal columns of infiltration magnesian skarns. The computation was carried out using a dynamic multireservoir model of a flow reactor with a constant temperature gradient and a uniform pressure. We have established that changes in the C/H ratio and Cl content in the fluid source affect the composition of the produced mineral assemblages. Depending on the temperature during the formation of skarns, different mineral assemblages are produced: diopside, enstatite, anorthite, quartz, ilmenite, hercynite, and pyrrhotite at 1040-1010 °C; monticellite, forsterite, magnetite, geikielite, periclase, spinel, calcite, and graphite at 980-740 °C; and calcite, dolomite, phlogopite, halite, and graphite at 710-380 °C. Wollastonite is observed in the rear zone of magnesian skarns. We examined the temperature-dependent sequence of formation of different types of silicates, spinels, and Ti-containing minerals in the metasomatic column. The computation results show that during crystallization, the tholeiitic magma releases a fluid phase with C/H = 0.1-1.0, amounting to 1.5-2.0 wt.%.

AB - Using the Selector PC application, we studied the process of formation of magnesian skarns at the contact of dolerites with carbonate-salt deposits. The physicochemical parameters of metasomatic processes were estimated by studying the localization of skarn ore shoots and mineral assemblages in the deposits of the Angara-Ilim type. The action of magmatic fluids on the system dolerite-magnesian salt deposits and dolerite-carbonate-salt deposits resulted in zonal columns of infiltration magnesian skarns. The computation was carried out using a dynamic multireservoir model of a flow reactor with a constant temperature gradient and a uniform pressure. We have established that changes in the C/H ratio and Cl content in the fluid source affect the composition of the produced mineral assemblages. Depending on the temperature during the formation of skarns, different mineral assemblages are produced: diopside, enstatite, anorthite, quartz, ilmenite, hercynite, and pyrrhotite at 1040-1010 °C; monticellite, forsterite, magnetite, geikielite, periclase, spinel, calcite, and graphite at 980-740 °C; and calcite, dolomite, phlogopite, halite, and graphite at 710-380 °C. Wollastonite is observed in the rear zone of magnesian skarns. We examined the temperature-dependent sequence of formation of different types of silicates, spinels, and Ti-containing minerals in the metasomatic column. The computation results show that during crystallization, the tholeiitic magma releases a fluid phase with C/H = 0.1-1.0, amounting to 1.5-2.0 wt.%.

KW - dolerites

KW - magnesian skarns

KW - metasomatism

KW - numerical modeling

KW - CONTACTS

KW - SEDIMENTARY COVER

KW - DOLERITE

KW - ROCK-SALT

UR - http://www.scopus.com/inward/record.url?scp=85019193377&partnerID=8YFLogxK

U2 - 10.1016/j.rgg.2016.10.012

DO - 10.1016/j.rgg.2016.10.012

M3 - Article

AN - SCOPUS:85019193377

VL - 58

SP - 541

EP - 550

JO - Russian Geology and Geophysics

JF - Russian Geology and Geophysics

SN - 1068-7971

IS - 5

ER -