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Metamorphic Characteristics of Granulite Facies Rocks in the Laixi‐Pingdu Area in Eastern Shandong Province
Author(s) -
Shiqin Jin,
Danchao Li,
Xianzhou Li,
Fulai Liu
Publication year - 1988
Publication title -
acta geologica sinica ‐ english edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.444
H-Index - 61
eISSN - 1755-6724
pISSN - 1000-9515
DOI - 10.1111/j.1755-6724.1988.mp1001005.x
Subject(s) - granulite , facies , geochemistry , geology , hornblende , metamorphic rock , mineral , metamorphic facies , petrology , geomorphology , chemistry , biotite , quartz , paleontology , organic chemistry , structural basin
Granulite in eastern Shandong is mainly exposed in Laixi, Pingdu, Changyi and Anqiu, and the diagnostic mineral assemblage is Opx+Cpx+Hb+Pl ± Q ± Sea. The appearance of orthopyroxene and its coexistence with hornblende indicate that the reaction Hb+Q = Opx+Cpx+Pl+H 2 O did not proceed completely and therefore these rocks belong to the amphibolite‐ granulite transition facies, i.e., belonging to hornblende‐granulite subfacies. According to the data obtained from such geothermometers and geobarometers as Opx‐ Cpx, Opx‐ Hb, Cpx‐ Hb, Hb‐ PI, Sca‐ Pl and Fe‐ Ti oxides, it has been determined that the temperature of the main metamorphic stage was 720° – 810°C, the pressure 0.5 GPa and fo 2 10 −15.5 , showing a geothermal gradient of 41–46°C / km, and thus the rocks belong to “low‐temperature” and low‐pressure granulite facies.