Comparison of the trace element composition of Tagish Lake with other primitive carbonaceous chondrites

Abstract

A meteorite fall on 2000 January 18 was detected by U.S. Defense Department satellites which established its pre-impact orbit. Fresh samples were collected from frozen Tagish Lake in British Columbia a week later and some properties of these samples reveal it to be a unique meteorite. We characterized Tagish Lake and 8 other samples using inductively-coupled plasma mass spectrometry and radiochemical neutron activation analysis: data for 47 elements reveal that each of 9 carbonaceous chondrites of different type exhibit the Orgueil-normalized plateaus expected for members of such types. Trends evident in Tagish Lake differ from all other carbonaceous chondrites, including CI and CM. Samples of Tagish Lake collected later show similar patterns affected by weathering.