TEKTITE BUBBLES AND THE GENESIS OF SPLASHFORM SHAPES, STARBURSTS AND NAVELS

Splashform tektites display a variety of shapes including oblate spheroids, teardrops, dumbbells and straps which are usually explained as originating from rotational effects during the time the glass was still liquid and in flight. Some of these shapes show surface features called starbursts and navels. The starburst patterns have been attributed to collisions with other tektites during flight. Navel formation is not well understood and may result from multiple situations.

Recently a number of large tektites from China, and other southeast Asian countries have become available for examination and some of these show large bubbles or fragments of same. Some of these new tektites show bubbles in stages of escape from liquid but viscous tektites. Here it is proposed that bubble escape may have a role in forming the shapes of at least some tektites. The starbursts may represent bubble escape points that become visible as radiating fractures after etching of the glass on Earth. Navels, too, may be related to bubble escape where the inside of the cavity is pushed against the opening where the gas escaped.

Photos of these tektites and the relation of temperature and atmospheric pressure in bubble collapse will be examined.