TY - JOUR
T1 - Fractionation modelling of segregations in the Toomba Basalt, north Queensland
AU - Stephenson, P. J.
AU - Zhang, M.
AU - Spry, M.
PY - 2000/4
Y1 - 2000/4
N2 - Segregations that are darker than their host basalt are locally common in the Late Pleistocene Toomba Basalt flow northwest of Charters Towers. At Basalt Corner this flow has been inflated to a thickness of 17 m and segregations are displayed in pipes, sheets, veins and vesicles. Their chemical compositions are distinct from the host hawaiite and least-square mixing solutions provide close models involving crystallisation of olivine, plagioclase, augite and magnetite in the cooling host basalt and gas-pressure extraction of residual melt to form the segregations. Trace-element concentrations are consistent with this mechanism and can, in general, be modelled using mineral partition coefficients from the literature. Segregations may concentrate near the edges of the inflation structures.
AB - Segregations that are darker than their host basalt are locally common in the Late Pleistocene Toomba Basalt flow northwest of Charters Towers. At Basalt Corner this flow has been inflated to a thickness of 17 m and segregations are displayed in pipes, sheets, veins and vesicles. Their chemical compositions are distinct from the host hawaiite and least-square mixing solutions provide close models involving crystallisation of olivine, plagioclase, augite and magnetite in the cooling host basalt and gas-pressure extraction of residual melt to form the segregations. Trace-element concentrations are consistent with this mechanism and can, in general, be modelled using mineral partition coefficients from the literature. Segregations may concentrate near the edges of the inflation structures.
UR - http://www.scopus.com/inward/record.url?scp=0034082865&partnerID=8YFLogxK
U2 - 10.1046/j.1440-0952.2000.00780.x
DO - 10.1046/j.1440-0952.2000.00780.x
M3 - Article
AN - SCOPUS:0034082865
SN - 0812-0099
VL - 47
SP - 291
EP - 300
JO - Australian Journal of Earth Sciences
JF - Australian Journal of Earth Sciences
IS - 2
ER -