贵州梵净山基性-超基性岩地质、岩石特征及类型的初步探讨

GEOLOGICAL AND PETROLOGICAL CHARACTERISTICS AND GENETIC TYPE OF THE FANJINGSHAN BASIC AND ULTRABASIC ROCKS, GUIZHOU PROVINCE

The Fanjingshan group, located in the Mt. Fanjing Region, Guizhou Province, is a flysch formation with a thickness of over 10000 meters. Intrusive basic rocks, varying in thickness, consist mainly of layered gabbrodiabase and diabase. Hornstone, spotted slate and ,albite-quartz-slate are commonly recognized in hanging and foot wall rocks as a result of contact metamorphism. Spilite with pillow structure, averaging about 100 meters in thickness, is also widespread. Ultramafic rocks have relatively limited occurrence, accounting for only 13 percent of the total thickness of the intrusives. Alpine ultrabasic rocks have not been found as separate mass. Ultramafic products resulted from in-situ differentiation are noticed and can be assigned to the iron series of ultrabasie rocks. The intrusive basic rocks are classified as subvolcanics that intruded at shallow depth. They are considered to share a common source, to have emplaced into the same position and to be contemporaneous with the sea floor volcanic-spilite, ,and in accordance with its characters, should be assigned to oohidite suit.

The Fanjingshan group, located in the Mt. Fanjing Region, Guizhou Province, is a flysch formation with a thickness of over 10000 meters.Intrusive basic rocks, varying in thickness, consist mainly of layered gabbro-diabase and diabase. Hornstone, spotted slate and albite-quartz-slate are commonly recognized in hanging and foot wall rocks as a result of contact metamorphism. Spilite with pillow structure, averaging about 100 meters in thickness, is also widespread.Ultramafic rocks have relatively limited occurrence, accounting for only 13 percent of the total thickness of the intrusives. Alpine ultrabasic rocks have not been found as separate mass. Ultramafic products resulted from in-situ differentiation are noticed and can be assigned to the iron series of ultrabasic rocks.The intrusive basic rocks are classified as subvolcanics that intruded at shallow depth. They are considered to share a common source, to have emplaced into the same position and to be contemporaneous with the sea floor volcanic-spilite, and in accordance with its characters, should be assigned to ophidite suit.