The Precambrian rocks in western Ethiopia consist of highand low-grade terranes intruded by granitoids with a wide compositional spectrum. The formation ages of these granitoid rocks are, so far, poorly understood. Single-grain zircon Pb/Pb evaporation and conventional U/Pb dating conducted on four granitoids places time constraints on their emplacement and tectonothermal events. Three granitoi...

Abstract. Zircon U–Pb geochronology is a staple of crustal evolution studies and sedimentary provenance analysis. Constructing (detrital) age spectra straightforward for concordant 206Pb/238U 207Pb/206Pb compositions. But unfortunately, many datasets contain significant proportion discordant analyses. This paper investigates two decisions that must be made when analysing such data. First, the a...

The Pb isotopic compositions of maskelynite and pyroxene grains were measured in ALH84001 and three enriched shergottites (Zagami, Roberts Massif 04262, and Larkman Nunatuk 12011) by secondary ion mass spectrometry. A maskelynite-pyroxene isochron for ALH84001 defines a crystallization age of 4089 ± 73Ma (2σ). The initial Pb isotopic composition of each meteorite was measured in multiple maskel...

Abstract. The age of ore deposits constitutes a decisive element in understanding their formation. Deciphering precise chronology may be challenge the absence mineral phases that can dated by conventional geochronometers. Fluorite is very common either as major or accessory wide variety ores and provide information regarding origin timing mineralizing fluid flows. In this contribution, we explo...

We examine the qualitative features of parton production through materialization in heavy-ion collisions within perturbative QCD, and estimate the magnitude of the resulting parton density created during the early stage of the collisions. The implications for " anomalous " J/ψ suppression observed in Pb+Pb collisions at the CERN SPS are discussed. We argue that the A-dependence of absorption of...