Tektite - Occurrence

Occurrence

The majority of known tektites occur only within four geographically extensive strewn fields. These strewn fields are the Australasian, Central European, Ivory Coast, and North American strewn fields. As summarized by Koeberl, the tektites within each strewn field are related to each other with respect to their petrological, physical, and chemical properties as well as their age. In addition, three of the four strewn fields have been clearly linked with impact craters on the basis of petrological and chemical properties as well as their age.

Recognized types of tektites, grouped according to their known strewnfields, their associated craters, and ages are:

• 1. Australasian strewnfield (no associated crater identified, age: 0.77-0.78 million years):
  • Australites (Australia, dark, mostly black)
  • Indochinites (South East Asia, dark, mostly black)
  • Rizalite (Philippines, black)

• 2. Central European strewnfield (Nördlinger Ries impact crater, Germany, age: 15 million years):
  • Moldavites (Czech Republic, green)

• 3. Ivory Coast strewnfield (Lake Bosumtwi impact crater, Ghana, age: 1 million years):
  • Ivorites (Ivory Coast, black)

• 4. North American strewnfield (Chesapeake Bay impact crater, USA, age: 34 million years):
  • Bediasites (USA, Texas, black)
  • Georgiaites (USA, Georgia, green)

Povenmire and others have proposed the existence of an additional tektite strewn field, the Central American strewn field. Evidence for this reported tektite strewn field consists of tektites recovered from western Belize in the area of the villages of Bullet Tree Falls, Santa Familia and Billy White. This area lies about 55 km east-southeast of Tikal where 13 tektites, two of which were dated as being 820,000 years old, of unknown origin were found. A limited amount of evidence is interpreted as indicating that the proposed Central American strewn field likely covers Belize, Honduras, Guatemala, Nicaragua and possibly parts of southern Mexico. It is speculated that the hypothesized Pantasma Impact Crater in northern Nicaragua might be the source of these tektites.