Theb0value of the potassic white micas as a barometric indicator in low-grade metamorphism of pelitic schists

✍ Scribed by F. P. Sassi; A. Scolari

• Publisher: Springer
• Year: 1974
• Tongue: English
• Weight: 662 KB
• Volume: 45
• Category: Article
• ISSN: 0010-7999
• DOI: 10.1007/bf00371166

✦ Synopsis

The b 0 of the potassic white micas was measured in 410 samples of low-grade pelitic schists from the Central Pyrenees, the Abuknma belt, Northern New Hampshire, the Eastern Alps, Otago, the Sanbagawa belt and the Central Pontic Chain. Temperature and rock bulk composition can be considered substantially constant all over the sample range, so that the differences in the b 0 values depend primarily on differences in pressure. The analytical data demonstrate that the b 0 increases for increasing pressure, and that it is practically identical in the mie~s from very different regions belonging to the s~me baric type of metamorphism. With the help of other analytical data (about 600), a b 0 scale was prepared, which makes the distinction of six different facies series possible. The writers, proposing this very rapid new method of barometric analysis, draw attention to its limitations and point out the main fields of its application.