provide a test for the hypothesis of faunal change at the Triassic-Jurassic boundary recently proposed by OLSEN and SUES (1986). They are remarkable for the numerical abundance and quality of preservation of the bones, the lithological diversity of fossil-bearing deposits, and the excellent degree of stratigraphic resolution. The vertebrate remains from the McCoy Brook Formation currently repre...

This study combines detailed geologic mapping, tephrochronology, U-Pb zircon dating, and published drill core data to evaluate the time transgressive 3-dimensional (thus 4-dimensional) structure evolution of two volcanoes on Hachijo-jima juvenile Izu-Bonin intra oceanic arc. The regional Ata-Torihama tephra (Ata-Th; 0.24 Ma) Kikai-Tozurahara (K-Tz; 0.095 from Kyushu are intercalated within volu...

The garnet amphibolites, from the Akom II area in Archaean Congo Craton, were examined to determine geochemical affinity and tectonic environment. study uses mineral assemblages whole-rock geochemistry identify setting of amphibolites associated with monzogabbro pyroxenites. studied rocks are amphibolites. Mineralogically, contain hornblende + plagioclase ± quartz epidote apatite opaque, indic...

The study area is located in the western portion of Isfahan, in Shahrekord-Dehsard Terrene. This area is part of the Sanandaj- Sirjan structural Zone. In this area, metamorphosed igneous outcrops contain greenschist and metabasite rocks. These rocks have metamorphed into greenschist facies and belong to the Triassic-Jurassic age. The etabasite is mainly composed of plagioclase, amphibole, epido...

with suggestions that fractionation of tholeiitic basalt in this pressure To model magmatic crystallization processes for mafic to intermediate range yields an alkalic basalt. Both trends may occur for natural compositions at high pressure, liquidus phase relations in the basalts depending on the Na2O content of the parental magma. forsterite–anorthite–diopside–silica (FADS) tetrahedron within ...