In Situ Heating Behavior by Infrared Microspectroscopy of Organic Components in Tagish Lake Meteorite

The Tagish Lake meteorite is a new type of water- and carbon-rich carbonaceous chondrite. Its total carbon content is approx. 5 wt% and the organic carbon content reaches approx.1.3 wt%. We reported from the Tagish Lake sample#TL3B6 the first in situ observation of the hollow organic globules. TL3B6 is generally enriched in the organic globules that consist of aliphatic and oxygenated functionality similar to the material produced by the laboratory simulation of UV photolysis of interstellar ice analogs suggesting that the organic globules in Tagish Lake may be extremely primitive organic material that formed before or during the formation of the solar system. Here we report the micro-sampling FTIR analysis of the TL3B6 and the in situ step heating experiments: which can allow us to place 1) significant constraints on the organic functionality in Tagish Lake; 2) the thermal stability of the organics; and 3) thermal history of the meteorite and its parent body. For comparison, the membranous films formed from hydrothermal reaction of an OH-bearing amino acid (theronine: Thr) and silica mixture were examined.