Decay constants in geochronology  

作　　者：IgorM.Villa PaulR.Renne 

机构地区：[1]InstitutfuerGeologie,UniversitaeitBern,Erlachstrasse9a,CH3012Bern,Switzerland／／DipartimentodiScienzeGeologiche,UniversitàdiMilanoBicocca,Milano,Italy [2]BerkeleyGeochronologyCenter,2455RidgeRoad,BerkeleyCA94709,USA／／DepartmentofEarthandPlanetaryScience,UniversityofCalifornia,BerkeleyCA94720,USA

出　　处：《Episodes》2005年第1期50-51,共2页地质幕（英文版）

摘　　要：Geologic time is fundamental to the Earth Sciences, and progress in many disciplines depends critically on our ability to measure time with increasing accuracy and precision. Isotopic geochronology makes use of the decay of radioactive nuclides as a help to quantify the histories of rock, minerals, and other materials. Both accuracy and precision of radioisotopic ages are, at present, limited by those of radioactive decay constants. Modem mass spectrometers can measure isotope ratios with a precision of 10-4 or better. On the other hand, the uncertainties associated with direct half-life determinations are, in most cases, still at the percent level. The present short note briefly summarizes progress and problems that have been encountered during the Working Group's activity.

关 键 词：地球年代学 衰变常数 地球化学 同位素 铀 

分 类 号：P597.3[天文地球—地球化学]