Picrite xenoliths from the eastern Snake River Plain, Idaho

✍ Scribed by John F. Karlo; Charles V. Clemency

• Book ID: 104745422
• Publisher: Springer
• Year: 1980
• Tongue: English
• Weight: 592 KB
• Volume: 73
• Category: Article
• ISSN: 0010-7999
• DOI: 10.1007/bf00371392

✦ Synopsis

Large numbers of picrite xenoliths have been found within Hell's Half Acre, a Holocene lava field of the eastern Snake River Plain. Mineralogically and chemically, they are in close agreement with expectations for fractionates and partly substantiate the hypothesis that fractionation is the primary cause of diversity among the region's tholeiite basalts. The fractionation mechanism interpreted for the picrites' origin is crystallization at the growing front of a solidification network. Consideration of the general characteristics of the tholeiite basalts suggests this mechanism of fractionation may have been of major importance within the province. However, to be widespread, it would require that magma reservoirs meet the geometric constraint of dike-like shapes.