256 AisnsnjAij report sovhthsonian institution, 1942 



sidered and shall then present a new hypothesis that has recently 

 been worked out on the basis of Philippine material and that seems to 

 present certain features which will doubtless provoke much interest- 

 ing discussion and may even add a new chapter to tektite history. 



First, although no one has yet ever been able to present acceptable 

 proof of the volcanic or other earthly origin of the tektite glasses, 

 there is still an appreciable number of students of this question who 

 believe that such an earthly origin will some day be demonstrated; 

 therefore, this possibility should not be disregarded, although major- 

 ity opinion is today decidedly against it. 



Second, the view known as "the burning light-metal meteorite 

 theory" (a theory developed in its various stages by Goldschmidt, 

 Michel, Lacroix, and Suess) is still regarded by many capable in- 

 vestigators as the most acceptable explanation of tektite origin yet 

 presented. In brief, this view is based on the generally accepted idea 

 that the great seasonal meteoric showers which so frequently visit the 

 earth's atmosphere, and are mostly wholly consumed in the upper air, 

 consist in the main of the light metallic elements which oxidize at 

 normal or relatively low temperatures. It is generally believed that 

 a considerable amount of finely divided silica or siliceous matter is 

 shed from such showers, probably reaching the earth usually as a fine 

 powder or dust. This tektite theory presupposes that the earth has 

 occasionally passed through abnormally thick clouds of such matter — 

 such as, e. g., those which are commonly believed to form the tails 

 of some comets, etc. — and that at such times the quantity of siliceous 

 matter shed would be sufficient to form sizable globules of liquid 

 glass, falling to the earth in solidified form as a tektite shower. 

 (The principal objection to this view, in the mind of the present 

 writer, is the difficulty of explaining the secondary re-fusing of the 

 Australites and the absence of such secondary forms in the Indo- 

 Malaysianites, since the glass of both types is of practically identical 

 composition, color, and specific gravity. Van der Veen, however, 

 has suggested that this difference was due to the more fluid nature 

 of the Australite glass, while the Indo-Malaysianites were more 

 viscous. The increasing viscosity of the Indo-Malaysianite glass, 

 from Java northwestward to South China, seems to support Van der 

 Veen's view.) 



Third, Spencer's "meteorite explosion-crater" theory, while re- 

 garded as unacceptable by a majority of tektite students, is, in my 

 opinion, still to be considered as a possible clue to the origin of many 

 important varieties of pseudo tektites, etc., such as the silica glasses, 

 Darwin glass, the Americanites, the Philippine pseudo Americanites 

 of Santa Mesa and vicinity, the Claveria pseudo tektites, and pos- 

 sibly even the European Moldavites. The essentials of this view are, 

 briefly: Quantities of silica glass of several types have been found 



