Petrography and geochemistry of the mesozoic granite at Mashhad, Khorasan province, northeastern part of Iran

A petrographic and geochemical study of the Mashhad granite in the northeastern part of LR. Iran reveals that it is of two main varieties - the major body of S-Type continental collision/syncollision biotite/muscovite granite and pegmatites; the other of I-Type, within plate/post collision uplift - homblende-hedenbergite/green biotite granite with the latter intrusive into the former. The hornblende-hedenbergite- compared to the biotite-granite, shows appreciable enrichment in the high field strength (HFS) and rare earth elements. One peculiar character in these granites is the negative correlation of SiO2 and distinct positive correlation of CaO against the HFS and RE elements, and the latter character is attributed to the presence of large amounts of sphene and apatite in the hornblende-hedenbergite granite.