title: High cristobalite and high tridymite in a middle eocene deep-sea chert.
abstract: The high-temperature forms of cristobalite and tridymite have been found occurring in a Middle Eocene, radiolarian-rich claystone. Evidence indicates that these crystals formed at low temperature and were chemical precipitates. Scanning electron microscopy, energy-dispersive x-ray analysis (microprobe), and x-ray diffraction provided the data upon which the determinative mineralogy was based.
authors.forename: J A
authors.initials: JA
authors.lastname: Klasik