地质学报(英文版)
地質學報(英文版)
지질학보(영문판)
ACTA GEOLOGICA SINICA
2002年
1期
126-131
,共6页
吴春明%潘裕生%王凯怡%张健
吳春明%潘裕生%王凱怡%張健
오춘명%반유생%왕개이%장건
biotite-calcic hornblende geothermometer%calibration%random error%application
This paper presents a biotite-calcic hornblende geothermometer which was empirically calibrated based on the garnet-biotite geothermometer and the garnet-plagioclase-hornblende-quartz geobarometer, in the ranges of 560 800°C (T) and 0.26?1.4 Gpa (P) using the data of metadolerite, amphibolite, metagabbro, and metapelite collected from the literature. Biotite was treated as symmetric Fe-Mg-AlVI-Ti quaternary solid solution, and calcic hornblende was simplified as symmetric Fe-Mg binary solid solution. The resulting thermometer may rebuild the input garnet-biotite temperatures well within an uncertainty of 50°C. Errors of 0.2 Gpa for input pressure, along with analytical errors of 5% for the relevant mineral compositions, may lead to a random error of 16°C for this thermometer, so that the thermometer is almost independent of pressure estimates. The thermometer may clearly discriminate different rocks of lower amphibolite, upper amphibolite and granulite facies on a high confidence level. It is assumed that there is a ferric iron content of 11.6% in biotite, and that the iron content in calcic hornblende may be calculated according to the method of Dale et al. (2000). This thermometer can be used for medium- to high-grade metabasites and metapelites.