Abstract
Grains consisting of intergrowths of chlorite and mica (biotite and/or phengite) are common in very low-grade metamorphosed shales, siltstones and sandstones of the Brottum formation (Upper Palaeozoic; the Sparagmite region of S Norway). Mineralogical and chemical evidence indicate that these chlorite-phengite intergrowths result from differential alteration of detrital biotite during late diagenesis-early metamorphism. Microprobe analyses show that of 20 chlorites analysed, 17 fall in the brunsvigite field (with 2 ripidolites and 1 diabantite).-R.A.H.
| Original language | British English |
|---|---|
| Pages (from-to) | 271-287 |
| Number of pages | 17 |
| Journal | Neues Jahrbuch fur Mineralogie, Abhandlungen |
| Volume | 154 |
| Issue number | 3 |
| State | Published - 1986 |