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Two Unusual Bow-tie Thailandites

The upper specimen is a 120 gram giant that offers a great story on extensional necking and incipient parting. The odd little 12.4 gram piece, almost an order of magnitude smaller than the one above, remains a mystery to me. Both of these specimens are cylindrical in cross-section.

It has long been accepted tektite dogma that many, or maybe even most, teardrops form when a pin-wheeling dumbbell, still in a semi-molten gooey state, parts in the middle region. This specimen captures the moment of incipient parting better than any other we have seen. The deep grooves on the underside almost certainly represent corrosive forces (of whatever form or vintage) that were taking advantage of brittle fractures that were just forming in the hardening crust of the tektite. Meanwhile, its more molten core stretched like taffy as displayed on the upper left center part.

A view of the opposite side emphasizes the stretchy, ductile nature of the tensional necking. There is a suggestion in the profile that molten interior material was drawn out from beneath an older, deeply pitted crust(right side) , forming an overhung girdling trench.

This returns us to the long argument about the time and place of tektite skin ornamentation. As with so-called “stretch tektites”, the stretched surface has but a few tiny pits, while the apparent crustal highlands are fields of hemispheric pits. I personally believe that the majority of tektite ornamentation is a plasma-erosion effect that occurred within the primary fireball. (Yes, there is terrestrial corrosion, as with Moldavites, but this is about Indochinites!)

And now, the little mystery. Initially I wondered if this one had been culturally modified, perhaps as an ornamental nose- or ear-plug, but there is sufficient pitting around the circumference of the “wheels” to show that this was a primary form.

How does something like this, barely an inch long, form? I used to believe that such flattened ends came from cart-wheeling across the ground while landing hot, but I am now accepting that Indochinites were so solidified by the time of impact that they never show embedded pebbles or vegetation imprints or any other evidence of splatting against anything other than a cushion of compressed air. If anything could make it to the ground with sufficient residual heat to deform in a plastic manner, it would most emphatically not be a tiny one with relative acres of surface area stretched over 12 grams of internal mass. I am open for ideas!

About the Author

Norm Lehrman is a recently retired exploration geologist with over 45 years experience. His career involved fieldwork in over 35 countries on every continent except Antarctica. While stationed in Australia, Norm and his wife, Cookie, became interested in collecting Australites, which ultimately led to a generalized passion for tektites, impactites, meteorites and related materials. In 1999 they founded the Tektite Source business (www.TektiteSource.com) which has evolved into one of the world's premier providers of tektite and impactite specimens. Norm has retired to a ranch near Spokane, Washington, where they continue to serve tektite aficionados worldwide.