New U-Th-Pb Isotope Reference Material for SIMS

U/pb and Cr Isotope Study of the Tafassasset

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...

(U-Th)/(He-Pb) DOUBLE DATING OF DETRITAL ZIRCONS

Geochronology and thermochronology on detrital material provides unique constraints on sedimentary provenance, depositional ages, and orogenic evolution of source terrains. In this paper we describe a method and case-studies of measurement of both U/Pb and (U-Th)/He ages on single crystals of zircon that improves the robustness of constraints in each of these areas by establishing both formatio...

Impact history of the Apollo 17 landing site revealed by U-Pb SIMS ages

8 Secondary ion mass spectrometry (SIMS) U-Pb ages of Ca-phosphates from four texturally 9 distinct breccia samples (72255, 76055, 76015, 76215) collected at the Apollo 17 landing site 10 were obtained in an attempt to identify whether they represent a single or several impact 11 event(s). The determined ages, combined with inferences from petrologic relationships, may 12 indicate two or possib...

PII S 0016 - 7037 ( 00 ) 00408 - 7 206 Pb – 230 Th – 234 U – 238 U and 207 Pb – 235 U geochronology of Quaternary opal , Yucca Mountain , Nevada

U–Th–Pb isotopic systems have been studied in submillimeter-thick outermost layers of Quaternary opal occurring in calcite–silica fracture and cavity coatings within Tertiary tuffs at Yucca Mountain, Nevada, USA. These coatings preserve a record of paleohydrologic conditions at this site, which is being evaluated as a potential high-level nuclear waste repository. The opal precipitated from gro...

U-Pb Zircon Ages and Pb Isotope Geochemistry of Gold Deposits in the Carolina Slate Belt of South Carolina