Telescoped Tektite Teardrops.

One of the more graphic Lei Gong Mo morphologies is the splatted or telescoped teardrop. The image above presents a developmental sequence (in side view) that nicely illustrates the concept without much need for verbiage. Years ago I proposed the term “splatform” for splashform tektites that show plastic impact (or flight) deformation and these telescoped teardrops were a primary inspiration for the term.

Splatted teardrops come in many variations both in degree of deformation and in angle of attack. Some show sideways flattening, others show all shades of oblique collapse, while those illustrated in this article involved telescoping parallel to the long axis of a teardrop. During the deformation, the tail is first to harden due to heat loss related to surface area vs. mass effects. As the bulbous nose flattened, the already brittle tail telescoped into the frontal “puddle”.

At early stages of development, a flattened base with an elongate tail gives rise to a Hershey’s Kiss form (second from left in the first image). At the most extreme stage, the tail may be completely engulfed, leaving only a pattern of concentric rings on the flattened upper surface to record the place where the tail disappeared into the puddle. This one would be tough to understand without the developmental sequence. (Any serious tektite study collection requires every variation on a theme that one can assemble. In such a context, the story they tell often become obvious.)

Another interesting variation involves a twisting of the tail relative to the frontal puddle. In this case, it appears that the entire body was spinning. As the thick and plastic frontal surface was retarded (or abruptly anchored by contact with the ground), the brittle tail continued its inertial spin for a twist or two. This image is a top view of such a “twister”. In the examples we have inventoried, there is an approximately equal population of specimens with clockwise and counter-clockwise senses of spin. While fine specimens of this sort are to be treasured, they are not rare.

There is some debate regarding the nature of the surface that the splatforms impacted. I have always assumed that it was the ground. The basal surface of strongly splatted examples is typically coarsely pocketed in a manner that reminds me of the texture that forms when molten metal is poured onto moist ground. However, it is noteworthy that in the many hundreds of thousands of tektites (likely well over a million—) that we have handled one by one, there is not a single unequivocal example of an adhering pebble or substrate imprint that one might reasonably expect when a plastic blob of glass splats onto the ground (as does happen with Trinitite and Dakhleh glass). Others have proposed that this sort of deformation may result from interaction with a cushion of compressed air during flight, which would explain a lack of ground-impact evidence. However, I do find it hard to imagine sufficient spin retardation to produce a strong differential with the inertial spin of the tail segment.

In this final image, we see a selection of telescoped tektite teardrops from a Hershey’s Kiss on the left to a flat specimen with a fully engulfed tail on the right. Numbers 7 and 8 have a depressed concave “moat” around the tail remnant. In numbers 9 and 10, the tail remnant is reduced to a simple bump.

While I very much enjoy the imagined sounds of big blobs of black glass thudding onto the ground all around me, the vision of incandescent glass teardrops progressively turning inside out as they struggle to push through air at high velocities is also quite pleasing. The latter option is winning me over. Extreme splatform morphologies are found in China, Vietnam, and Thailand (that I know of for sure—). To expect sufficient heat retention for plastic behavior on ground impact in a body rarely weighing over 100 grams after hundreds of miles of flight is a matter of compounded improbabilities. Combine this with the utter and complete lack of any direct evidence of substrate interaction, and one is left with little alternative but to envision glowing squadrons vigorously buffeted in headwinds. At sufficiently high speeds the atmosphere assumes the character of a very dense material. As I struggle to personalize this phenomenon, my thoughts always turn to a high-speed fall while water-skiing. One can tumble a very long ways across the stony surface of the water before finding anything at all soft!

Splatforms may well have splatted against the hard face of air.

About the Author

Norm Lehrman
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.
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