Lunar Mg-suite norite 78238 was dated using the Sm–Nd, Rb–Sr, and U–Pb isotopic systems in order to constrain the age of lunar magma ocean solidification and the beginning of Mg-suite magmatism, as well as to provide a direct comparison between the three isotopic systems. The Sm–Nd isotopic system yields a crystallization age for 78238 of 4334 ± 37 Ma and an initial e Nd value of 0.27 ± 0.74. T...

Parameters indicative of absorption and biological effect in new lead exposure: a prospective study. Determinations have been made of the blood and urinary lead concentrations (Pb-B, Pb-U), haemoglobin concentrations (Hb), packed blood cell volumes (Hcr), urinary 8-aminolevulinic acid (ALA-U) and coproporphyrin concentrations (CP-U), as well as erythrocyte 8-aminolevulinic acid dehydratase acti...

Uranium-lead, Rb-Sr, and Sm-Nd isotopic analyses have been performed on the same whole-rock, mineral, and leachate fractions of the basaltic martian meteorite Zagami to better constrain the U-Pb isotopic systematics of martian materials. Although the Rb-Sr and Sm-Nd systems define concordant crystallization ages of 166 6 Ma and 166 12 Ma, respectively, the U-Pb isotopic system is disturbed. Nev...

Events occurring within the first 10 million years of the Solar System's approximately 4.5 billion-year history, such as formation of the first solids, accretion, and differentiation of protoplanetary bodies, have determined the evolutionary course of our Solar System and the planetary bodies within it. The application of high-resolution chronometers based on short-lived radionuclides is critic...

The redox-sensitive geochemical behavior of uranium permits the use of Th/U ratios as a geochemical proxy for the oxidation state of the atmosphere and oceans during sedimentary processes. Due to the effects of post-depositional uranium mobility on Th/U ratios during events involving oxygenated fluids, direct measurements of Th/U ratios are often misleading, but the whole rock Pb isotope compos...

Introduction: Apatite is one of the minerals that is rarely utilized in U-Pb geochronology, compared to some other U-rich accessory phases. Relatively low U concentration, commonly high proportion of common Pb and low closure temperature of U-Pb system of apatite inhibit its application as geochronological tool when other minerals such as zircon are widely available. However, zircon appear to b...

Introduction: The crystallization age of Zagami has been well established by the Rb-Sr and Sm-Nd isochron techniques. Isotopic analysis on purified mineral fractions yield Rb-Sr ages of 178±3, 174±14, and 163±19 Ma [1-2], and a Sm-Nd age of 163±7 Ma [2]. Whole rock and leachate pairs have also been analyzed for U-Th-Pb isotopes and yield a Th-Pb age of 230±5 Ma and a U-Pb age of 229±8 Ma [3]. C...

Occupational exposure to lead may cause kidney damage. This study was carried out on a cohort of 70 active and 30 retired long term exposed lead smelter workers. Their kidney function was compared with 31 active and 10 retired truck assembly workers who had no occupational exposure to lead. The lead workers had been regularly followed up with measurements of lead concentration in blood since 19...

Introduction: Basaltic shergottite Queen Alexandra Range 94201 originated from an extremely depleted mantle source, and has the highest initial εNd (+ 47.6 ± 1.7) and the lowest initial Sr/Sr (0.701298 ± 14) measured for any martian meteorite to date [1]. Rb-Sr and Sm-Nd isochrons for this sample yield concordant crystallization ages of 327 ± 12 Ma and 327 ± 19 Ma, respectively [1]. Knowledge o...

Has the quark gluon plasma been discovered at the CERN SPS? Experiment NA50 has reported an abrupt decrease in ψ production in Pb+Pb collisions at 158 GeV per nucleon [1]. Specifically, the collaboration presented a striking ‘threshold effect’ in the ψ–to–continuum ratio by plotting it as a function of a calculated quantity, the mean path length of the ψ through the nuclear medium, L, as shown ...