Thesis (M.Sc.)--Chulalongkorn University, 2012

Amphibolites around Ban Yup I Pun and Ban Nong Mai Daeng in Wang Nam Khiao area have sparsely exposed within an area of about 65 km². Over 40 rock samples were collected from various amphibolite exposures, for petrographic investigation, whole-rock geochemical and mineral chemistry analyses. Based on petrographic features, these rock samples can be classified as coarse-grained granular amphibolites, layered amphibolites and migmatitic amphibolites. Geochemically, these amphibolites appear to have mafic igneous origin with a signature of oceanic remnant; moreover, indication of E-MORB-type within arc affinities is also observed for their initial provenance. Chondrite-normalized rare earth element (REE) and other trace element patterns supported that amphibolites should have been derived from island arc-related E-MORB. Regarding to P-T calculations, these amphibolites clearly belong to amphibolites facies with estimated P-T of about 686+32°C and 4.2+ 1 Kbar.