During the COUIX of I :50 000 scale regional mapping in the Northern Selkirk Mountains (NTS 082M) various granitic rocks were sampled for U-Pb geochronology. This report presents new U-Pb data, interpreted ages, and the implications of these results for hvo such samples from the Selkirk Allochthon: the Downie Creek otihogneiss, and the Goldstream Pluto”. The Downie Creek orthogneiss consists of...

The Tafassasset meteorite which was found the Tenere dessert, Niger, in 2000 and 2001 consists of 26 pieces with a total weight of ~110 kg. The well-preserved meteorite has been studied by several groups [1-4], but until today no consensus on the meteorite's classification was obtained. Reasons for this difficulty are:-texture and mineral abundances vary considerably,-different individual stone...

Introduction: Beta decay of Re is characterized by the lowest known decay energy, which makes direct counting determination of the decay constant very difficult. The best direct estimate for λRe (1.64·10 y ±3.1%) was obtained by the radiochemical in-growth method [1]. This result was generally accepted for geochronology, although its uncertainty precludes precise comparison of Re-Os ages with o...

In situ laser ablation inductively coupled mass spectrometry (LA ICP-MS) is used to determine the U-Th-Pb age of phosphates ferromerrillite and apatite in Los Angeles shergottitic meteorite. The initial 207Pb/206Pb was refined by analyzing K-rich diaplectic glass. LA ICP-MS mapping document zones elevated U Th content establish textural controls on isotope ages. By critically assessing dispersi...

The B and Pb isotope systems are widely applied tracers of recycling processes occurring during subduction. Studies examining these complementary systems as a pair enjoy considerable success, where B primarily records the thermal and fluid evolution of the subducting slab, whereas the tripartite Pb system constrains the source of subducted material returned to volcanic arcs. However, interpreta...