GEOLOGICAL CHARACTERISTICS AND SIGNIFICANCE OF VOLCANIC ROCKS AT THE BOTTOM OF THE MIDDLE TRIASSIC MANGHUAI FORMATION IN YAKOU REGION, SIMAO CITY, YUNNAN PROVINCE是什么意思 GEOLOGICAL CHARACTERISTICS AND SIGNIFICANCE OF VOLCANIC ROCKS AT THE BOTTOM OF THE MIDDLE TRIASSIC MANGHUAI FORMATION IN YAKOU REGION, SIMAO CITY, YUNNAN PROVINCE怎么读