CONDITIONS OF HIGH-GRADE METAMORPHISM IN THE DALRADIAN OF CONNEMARA, IRELAND

被引:27
作者
BARBER, JP
YARDLEY, BWD
机构
[1] School of Environmental Sciences, University of East Anglia, Norwich NR4 7TJ, United Kingdom
关键词
Erosion - Silicate minerals;
D O I
10.1144/gsjgs.142.1.0087
中图分类号
P [天文学、地球科学];
学科分类号
07 ;
摘要
In E Connemara, Ireland, Dalradian metasediments were initially metamorphosed to kyanite-staurolite grade at pressures above 7 kbar. The subsequent emplacement of basic to intermediate magmas, accompanied by uplift and erosion, produce a steepening of the geothermal gradient and led to the formation of migmatitic garnet-cordierite-sillimanitegneisses in the highest grade regions in the S. Cation exchange equilibria between coexisting mineral pairs suggest that partial melting took place under high temperatures (=750°C) and moderate pressures (4.5-6 kbar). Fluid inclusion studies and andalusite occurrences from migmatite leucosomes suggest that crystallization of the melts occurred at lower pressures (
引用
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页码:87 / 96
页数:10
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共 40 条
[21]  
Leggo P. J., 1966, Q J GEOL SOC LOND, V122, P91, DOI DOI 10.1144/GSJGS.122.1.0091
[22]   THE P-T-X RELATIONS OF THE CORDIERITE-GARNET-SILLIMANITE-QUARTZ EQUILIBRIUM [J].
LONKER, SW .
AMERICAN JOURNAL OF SCIENCE, 1981, 281 (08) :1056-1090
[23]   CORDIERITE-GARNET-H2O EQUILIBRIUM - A GEOLOGICAL THERMOMETER, BAROMETER AND WATER FUGACITY INDICATOR [J].
MARTIGNOLE, J ;
SISI, JC .
CONTRIBUTIONS TO MINERALOGY AND PETROLOGY, 1981, 77 (01) :38-46
[24]   MELTING REACTIONS IN SYSTEM NAALSI3O8-KALSI3O8-SIO2-H2O TO 20 KILOBARS COMPARED WITH RESULTS FOR OTHER FELDSPAR-QUARTZ-H2O AND ROCK-H2O SYSTEMS [J].
MERRILL, RB ;
ROBERTSON, JK ;
WYLLIE, PJ .
JOURNAL OF GEOLOGY, 1970, 78 (05) :558-+
[25]  
Newton R., 1981, THERMODYNAMICS MINER, P131, DOI DOI 10.1007/978-1-4612-5871-1_7
[26]  
PIDGEON RT, 1969, SCOTTISH J GEOLOGY, V5, P375
[27]   EXPERIMENTAL DETERMINATION OF KYANITE-ANDALUSITE AND ANDALUSITE-SILLIMANITE EQUILIBRIA - ALUMINUM SILICATE TRIPLE POINT [J].
RICHARDS.SW ;
GILBERT, MC ;
BELL, PM .
AMERICAN JOURNAL OF SCIENCE, 1969, 267 (03) :259-&
[28]   AN EXPERIMENTAL-STUDY OF HORNBLENDE STABILITY AND COMPOSITIONAL VARIABILITY IN AMPHIBOLITE [J].
SPEAR, FS .
AMERICAN JOURNAL OF SCIENCE, 1981, 281 (06) :697-734
[29]  
TANNER PWG, 1979, GEOL SOC LOND SPEC P, V8, P243, DOI DOI 10.1144/GSL.SP.1979.008.01.25
[30]   MINERAL REACTIONS IN PELITIC ROCKS .1. PREDICTION OF P-T-X(FE-MG) PHASE RELATIONS [J].
THOMPSON, AB .
AMERICAN JOURNAL OF SCIENCE, 1976, 276 (04) :401-424