This technique provides age maps that show differences in age domains on the order of 20 Ma with in monazite as young as 100 Ma.The effect of sample damage by irradiation of intense and prolonged probe measurement is also described.
For example, the presence of recycled bricks at an archaeological site indicates the sequence in which the structures were built.
Similarly, in geology, if distinctive granitic pebbles can be found in the sediment beside a similar granitic body, it can be inferred that the granite, after cooling, had been uplifted and eroded and therefore was not injected into the adjacent rock sequence.
Local relationships on a single outcrop or archaeological site can often be interpreted to deduce the sequence in which the materials were assembled.
This then can be used to deduce the sequence of events and processes that took place or the history of that brief period of time as recorded in the rocks or soil.
This paper outlines the CHIME (chemical Th–U-total Pb isochron method) dating method, which is based on precise electron microprobe analyses of Th, U and Pb in Th- and U-bearing accessory minerals such as monazite, xenotime, zircon and polycrase.
The age-mapping technique that is applicable to young monazite and zircon is also described.Kazuhiro Suzuki, Professor at the Center for Chronological Research, Nagoya University, received his BSc (1970) from Aichi University of Education, his MSc (1973) and Ph D (1978) from Nagoya University, Japan.Initially employed as an assistant professor at Tokyo Gakugei University in 1977, he then moved to Nagoya University in 1979 as an assistant professor and became a professor in 1995.This technique can identify two or more homogeneous domains that are separated by age gaps smaller than the error on individual spot age analysis.Many features that are insignificant in major element analysis can have major impact in the acquisition of trace element data.Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. 1979, 1986 © Harper Collins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012 Cite This Source (hāf'līf') The average time needed for half the nuclei in a sample of a radioactive substance to undergo radioactive decay.