关于我国东南部不同时代花岗岩的年龄及分期问题的讨论

ON THE GEOLOGICAL AGES OF GRANITIC ROCKS IN SOUTH EASTERN CHINA AND THEIR GEOCHRO- NOLOGICAL DIVISION

Made in the present paper is a further diseussion on the genetic relations between orogenic movements and. the formation of granitic rocks. These two major gcological processes affected one another, thus leading to the formation of the con.tincntal crust and its evolution. It seems undoubted that Hereynian granites are closely related to the Hercynian orogeny, especially in the Qinzhou Region. Based upon the geological evidence and geochronological data, the geological timescale for the granites of different ages is proposed as follows : Donganian granites --approximately from 1450 to 1300m.y.; Hsuehfengian granites--from 1000 to 650m.y. ; early-Caledonian granites--from 570 to 420 m.y. ; late-Caledonian granites from 420 to 340 m.y. ; Hercynian granites-- from 800 to 250 m.y. ; Indosinian granites--from 250 to 185 m.y. ; early-Yenshanian granites-- from 185 to 137 m.y. and late.Yenshanian granites- from 137 to 67 m.y.

Made in the present paper is a further discussion on the genetic relations between erogenic movements and the formation of granitic rocks, These two major geological processes affected one another, thus leading to the formation of the continental crust and its evolution. It seems undoubted that Hercynian granites are closely related to the Hercynian orogeny, especially in the Qinzhou Eegion.Based upon the geological evidence and geochronologieal data, the geological time scale for the granites of different ages is proposed as follows: Donganian granites -approximately from 1450 to 1300 m.y.; Hsuehfengian granites - from 1000 to 650 m.y.; early-Caledonian granites - from 570 to 420 m.y.; late-Caledonian granites-from 420 to 340 m.y.; Hercynian granites-from 300 to 250 m.y.; Indosinian granites -from 250 to 185 m.y.; early-Yenshanian granites - from 185 to 137 m.y. and late-Yenshanian granites - from 137 to 67 m.y.