Chemical composition and fission-track age of some Muong Nong-type tektites

Fission-track age has been determined for six Muong Nong-type tektites and one indochinite through petrological study. Major elements were then obtained by means of SEM, showing as wide an SiO2 content in the Muong Nong tektites as in tektites generally (71-82 percent). Water content was derived by measuring the hydrogen volume after high frequency induction furnace melting of a finely powdered sample, and the isotope composition of the hydrogen was determined by mass spectrometry. H2O content ranges from 0.08 to 0.10 percent, and delta-deuterium from -56.4 to -79.2 percent; these values preclude the possibility that the water was derived from lunar rocks, and may support a hypothesis of terrestrial origin.