Quartz monzonite forms many of the cliffs, while the crags are biotite gneiss.
2.
The dam sat on a foundation of silt and stable biotite gneiss ( rock ).
3.
The rock is biotite gneiss, formed by metamorphism of sedimentary and volcanic rocks about 100 million years ago.
4.
Eastwards down the Dee and the Don and northwards across the plain of Buchan towards Rattray Head and Fraserburgh there is a development of biotite gneiss, partly of igneous origin.
5.
A study of sodium-rich quartz-alkali feldspar biotite gneiss granulite facies terrane in the Kerala Khondalite Belt near Manali in south India found that " in situ " leucosomes ( light colored segregations ) within the gneiss showed the development of garnet replacing the dark biotite.
मोबाइल