Introduction: Despite many studies on the Howardite-Eucrite-Diogenite (HED) meteorite suite, the internal structure of asteroid 4-Vesta is still debated. Some studies favor the hypothesis of a global magma ocean, leading to a layered structure and a relatively thin crust [e.g. 1]. Other petrological and geochemical evidences tend to favor a more complex structure, involving intrusions, which al...

Silicic, mafic and alkali intra-seam tonsteins have been known from SW China for a number of years. This paper reports on the geochemical compositions of coals and tonsteins from three seam sections of the Songzao Coalfield, SW China, and evaluates the geological factors responsible for the chemical characteristics of the coal seams, with emphasis on the influence from different types of volcan...

This contribution analyzes water chemical data for the Choapa basin, North Central Chile, for the period 1980-2004. The parameters considered are As, Cu Fe, pH, EC, SO₄⁻², Cl⁻¹, and HCO[Formula: see text], from samples taken in nine monitoring stations throughout the basin. Results show rather moderate contents of As, Cu, and Fe, with the exception of the Cuncumén River and the Aucó creek, expl...

Re cently the Whitesail Lake map area (NTS 093E), im me di ately north and east of Bella Coola, BC has been the fo cus of re gional map ping pro grams, in clud ing the cur rent Geoscience BC funded map ping pro gram of Mahoney et al. (2006) and the map ping con ducted in 2004 un der the Rocks to Riches pro gram (Mahoney et al., 2005). The re gional map ping ex er cise dis cov ered a new oc cur ...

Evidence for a c. 600 Ma rifted passive margin in eastern Australia exists in the form of multiple belts of mafic volcanic rocks preserved along the western margin of the Tasman Fold Belt System, and giving rise to elongate magnetic anomalies. Outcrop, drillhole and geophysical evidence points to piles of lavas, volcaniclastic and intrusive rocks up to 6 km thick, extending for strike lengths o...

The North Tabriz Fault is seismologically an active fault with current right lateral strike-slip movements. Restricted mafic to intermediate Late Cretaceous igneous rocks are exposed along the North Tabriz Fault. Whole rock samples and clinopyroxene phenocrysts geochemistry were studied in order to characterize the petrogenesis of these mafic rocks and their possible relation to an oceanic crus...

New geochemical data including Sm/Nd isotopic data show evidence for an early Paleozoic arc/back-arc complex in the Nashoba terrane of southeastern New England. The Nashoba terrane lies between rocks of Ganderian affinity to the northwest and Avalonian affinity to the southeast. It consists of early Paleozoic mafic to felsic metavolcanic and metasedimentary rocks that were intruded by intermedi...

Charnockitic rocks form extensive orthogneiss plutons in many granulite terranes and are less commonly found in unmetamorphosed plutons, which have formed in various tectonic regimes. Geochemically, clearly igneous charnockites cover nearly the whole range of granite chemistry, from magnesian to ferroan and from calcic to alkalic. Pyroxenes from unmetamorphosed charnockitic rocks have compositi...

U-Pb ages obtained on zircons from the investigated migmatites place new constraints on the evolution of the crustal rocks in the Takab area. SHRIMP U-Pb dating of inherited zircon in the melanosome parts of mafic migmatites from the Takab complex gives a discordant age with an upper intercept of 2961±72 Ma (MSWD=0.5) and a lower intercept of 24.2±5.7 Ma (MSWD=1.7). In the concordia diagram, th...