GEOLOGICAL FEATURES AND REE GEOCHEMICAL EVOIUTION OF LATE ARCHEAN“FRAMEWORK INTRUSIVE ROCKS” IN THE MOUNT TAISHAN AREA

Late Archean“framework intrusive rocks”refer to meso and melano cratic intrusive rocks which are small in size but relatively widespread in complex areas where Late Archean TTG granitic gneiss and monzogranitic gneiss are exposed in large amounts and which may play a role of the index bed and framework in the establishment of the hierarchy of regional rock unit terms.Their mineral composition is essentially continuous and may have certain genetic relations or belong to a particular genetic series.Their REE abundance increases progressively and their light and heavy REE fractionations also have a general evolutionary trend of becoming more and more marked.