TEKTITES AND THE LOST PLANET — STAIR 219 



semble in composition neither any igneous rock structure (Barnes, 

 1940) of the earth (they differ radically from obsidian) nor that of 

 any glass produced since the beginning of glass manufacture. Al- 

 though certain sedimentary rocks within the earth's crust approxi- 

 mate their composition it is generally agreed that no natural heat 

 source has existed upon this earth within recent geologic time capable 

 of producing temperatures sufficiently high to fuse this type of glass, 

 since its melting point is nearly 200° C. above that of presently manu- 

 factured Pyrex glasses. 



These facts, together with the many special shapes encountered, 

 definitely indicate but do not prove a flight through the earth's atmos- 

 phere at a velocity sufficient to ablate their surfaces. Although it 

 has been noted that "The meteoric theory of the origin of tektites is 

 certainly one that appeals to the imagination, but in reality there 

 is not a single item of fact that can be adduced in its favor" (Spencer, 

 1933), the winged types, in particular, present an unchallengeable 

 proof that the glass surface has been heated to the liquid phase and 

 simply blown off the rear of the specimen to form a circular apron 

 at its base. Plate 1, figure 1, shows a fragment of such a tektite picked 

 up in Australia. Many stony meteorites also show a glasslike flow 

 over their surfaces. Hence, tektites must also be travelers from out 

 of space. The big questions are : where did they come from ? and how 

 and when and where were they formed ? 



Ordinary meteorites arrive at the earth's surface in all manner of 

 sizes and shapes. They arrive at various speeds not exceeding about 

 50 miles per second, and hence must be following elliptical paths 

 (McKinley, 1951) and are a part of our solar system. Their com- 

 positions vary in unbroken sequence from that of nickel-iron to stone 

 that is similar to certain types of terrestrial rocks. (No meteorite, 

 however, is anything like a granite or the acidic volcanic rocks.) 

 These and other observations made during the past century support 

 the suggestion made by Roisse in 1850 (see reference) that a study 

 of meteorites should result in an understanding of the earth's structure 

 and composition (Brown and Patterson, 1948), since they possibly 

 came from a former planet having physical and chemical character- 

 istics similar to that of the earth. Today few scientists doubt the hy- 

 pothesis that meteorites were once a part of a parent planet (or 

 planets) which circulated around the sun in a fashion similar to the 

 observed motions of the remaining planets of our solar system, 



Tektites differ from other meteorites in two important ways. First, 

 they are of glass — a very special glass — having a high melting point, 

 a low coefficient of expansion, and a high durability, therefore they 

 differ markedly in composition from other meteoric material. Sec- 

 ond, they are found only in small pieces and usually in special shapes. 



