Abstract Intraplate basaltic volcanism commonly exhibits wide compositional ranges from silica-undersaturated alkaline basalts to silica-saturated tholeiitic basalts. Possible mechanisms for the transition involve variable degrees of partial melting a same source, decompression at different mantle depths (so-called ‘lid effect’), and melt-peridotite interaction. To discriminate between these me...

Kimberlite magmatism occurs as a result of volatile fluxed melting the convecting upper mantle underlying cratonic lithospheric regions. During passage to Earth's surface, proto-kimberlite magma can interact with, and assimilate, variably enriched producing hybrid melts consisting asthenospheric components including contributions from metasomatic domains. The halogen elements (F, Cl, Br, I) chl...

A number of possible hypotheses have been proposed to explain the origin mid-lithospheric discontinuities (MLDs), typically characterized by ?2-6% reductions in seismic shear wave velocity (VS) at depths 60 km ?150 cratonic sub-continental lithospheric mantle (SCLM). One such hypothesis is presence low-shear velocity, hydrous and carbonate mineral phases. Although, silicates carbonates can caus...

In Cameroon, most of the iron formation occurrences reported are found within Nyong and Ntem Complexes. The Anyouzok deposit is located in Complex greenstone belts, which represent NW margin this Congo craton. main lithological units comprise formations (IFs) unit, consisting banded IFs (BIFs) sheared BIFs (SBIFs), associated metavolcanic rocks unit mafic granulite, garnet amphibolite, biotite ...

Abstract The assembly–breakup of the Columbia/Nuna supercontinent is one most important issues in Precambrian geology. reconstruction Indochina Block Columbia poorly constrained by far, due to deficiency available geochronological and geochemical data for exposed rocks. Mesoproterozoic plagioclase amphibolites Kontum Complex have significant implication within supercontinent. This study present...

Previous geochronological data indicate a protracted Devonian magmatic activity developed in the Sierra de San Luis, Sierras Pampeanas of Argentina, with three major crystallization events: 393±3, 384±2, and 377±2 Ma. Previously reported whole-rock Sm-Nd isotopes define two average distinctive εNdt values: -1.37 -3.47, they are consistent new presented here. The first signature is assumed for p...

Abstract The Sao Joao do Sabugi Pluton (SJSP) (∼579 Ma) is one of the most expressive occurrences Ediacaran, syn- to post-collisional shoshonitic rocks in Rio Piranhas-Serido Domain, Borborema Province, NE Brazil. petrography, whole rock and mineral composition this pluton were investigated characterize its open-system magmatic differentiation processes. composed three groups: gabbro-diorite, w...

Pyroxenite and nepheline-pyroxene rocks coexist with dolomite-bearing calcite marbles in Tazheran Massif the area of Lake Baikal, Siberia, Russia. Pyroxenites occur a continuous elongate zone between beerbachites (metamorphosed gabbro dolerites) 5 cm to 20 m fragments among marbles. Pyroxene pyroxenite is rich calcium alumina (5–12 wt% Al2O3) has fassaite composition. The may originate from maf...

The Central Asian Orogenic Belt (CAOB) is the world’s largest accretionary orogenic belt, and its formation related to closure of Paleo-Asian Ocean (PAO). However, time style PAO remain controversial. To address these issues, this paper presents zircon U-Pb dating, whole-rock geochemistry Lu-Hf isotope analyses volcanic rocks in Faku-Kaiyuan area on northern margin North China Craton. results s...

Noble gas isotopic composition of fluid inclusions was analyzed in amphibole, plagioclase and clinopyroxene phenocrysts from the shoshonitic dacitic volcanic products Ciomadul dome field, youngest system within Carpathian-Pannonian Region. The highest Rc/RA ratios (3.0–3.8 RA) were obtained for high-mg Malnaş shoshonite. High-Al amphiboles Bixad pumices have between 1.16 2.11 RA. These values o...