U, Th, Pb and REE abundances and207Pb/206Pb ages of individual minerals in returned lunar material by ion microprobe mass analysis

Pb/Pb geochronology, petrography and chemistry of Zr-rich accessory minerals (zirconolite, tranquillityite and baddeleyite) in mare basalt 10047

“…In addition, instrument sensitivity was too low to measure 204 Pb reliably, preventing corrections to 207 Pb/ 206 Pb for common Pb. Nevertheless, some of the dates obtained by the ARL ion microprobe are consistent with the ages of bulk rocks from other techniques (Andersen and Hinthorne, 1972bHinthorne, , 1973.…”

Thermal history of Apollo 12 granite and KREEP-rich rock: Clues from Pb/Pb ages of zircon in lunar breccia 12013

“…This complicating factor appears to have made it very difficult to unequivocally define the crystallization age of lunar granite in 12013. Although Zr-minerals and merrillite in 12013 have also been dated, their ages vary considerably from <3.9 to 4.3 Ga (e.g., Tatsumoto, 1970;Haines et al, 1971;Andersen and Hinthorne, 1972;Hinthorne and Anderson, 1974), and some results (e.g., Andersen and Hinthorne, 1972) remain controversial due to large uncertainties (c.f., Nyquist and Shih, 1992;Snyder et al, 2000;Nyquist et al, 2001). Meyer et al (1996) observed zircon grains in 12013 during their systematic study on zircons from lunar granites; however, they did not date these zircon grains because the grain sizes (<10 lm) were judged to be too small for analysis by the sensitive high-resolution ion-microprobe (SHRIMP I).…”

Chemical Imaging

“…They include elemental and isotopic characterisation of lunar samples. 20 Nittler et al 23 developed an automated imaging procedure to map the isotopic composition of thousands of micrometer-sized grains and recognised those of circumstellar origin with extreme isotopic anomalies from those formed in the solar system. Such presolar grains in the 50 nm-10 mm size range with exotic isotopic compositions inherited from interstellar chemistry or stellar nucleosynthesis have been extensively studied by SIMS and NanoSIMS using scanning and direct imaging.…”

“…Chemical imaging has been repeatedly used in SIMS since the early days of SIMS instrumentation, in many cases associated with the need of earth and planetary scientists to study tiny and highly heterogeneous samples. [20][21][22][23] In such studies, it is commonly referred to as ''ion imaging'' or ''ion micrography''. Depending on the SIMS method employed (see below) it can also be designated as ''ion microscopy'' or ''isotopography''.…”