The Tagish Lake Fireball and Meteorite [18-Jan-2000]
Information from The Meteoritical Bulletin
British Columbia, Canada
Fell 2000 January 18, 08:43:42 PST (16:43:42 UT)
Carbonaceous chondrite (C2, ungrouped)
A brilliant fireball followed by loud detonations was widely observed over the Yukon Territory and northern British Columbia.
The fireball was also detected by satellites in Earth orbit. Dust clouds from terminal fragmentation events were widely observed. Mr. Jim Brook recovered several dozen meteorites totaling ~1 kg on the ice of Taku Arm, Tagish Lake, on January 25 and 26 (coordinates of first find given above). Between April 20 and May 8, ~500 additional specimens were located on the ice of Taku Arm and a small, unnamed lake 1.5 km to the east. Only ~200 were retrieved however, as many had melted down into the ice making their collection time consuming; recovery was prioritized based on meteorite mass and degree of disaggregation. The total mass collected was between 5 and 10 kg. The strewn field is at least 16 km by 3 km, oriented ~S30°E. Classification and mineralogy (M. Zolensky, JSC; M. Grady, NMH): possibly CI2 group; a matrix dominated chondrite, with a few small chondrules, CAIs, and isolated grains; matrix mainly phyllosilicates, Fe-Ni sulfides and magnetite, with abundant Ca-Mg-Fe carbonates; olivine, Fa0-29, PMD = 2%, with a peak at Fa1; pyroxene, Fs1-7, PMD = 2%, with a peak at Fs2; bulk C content 5.4 wt%, with d13C = +24.3 ?; shock stage, S1. Oxygen isotopes (R. Clayton, UChi): d18O = +18.0-19.0 ?, d17O = 8.3-9.2 ?. Specimens: majority held by UCalg (contact A. Hildebrand) and UWO (contact P. Brown).