THE DISCOVERY OF PLAGIOGRANITE IN THE JIAONAN AREA, SHANDONG PROVINCE

Plagiogranite was discovered in the Jiaonan area, Shandong province. It occurs in association with Middle Proterozoic metagabbro. The rock consists of 60% plagioclase and 40% quartz and has high Si, low to moderate Al and low K₂O, being similar in chemical composition to oceanic plagiogranite. Its Pb Pb age of single grain zircon is （1 370.6±14.3） Ma.