- doi:10.1016/0024-4937(73)90076-5. Jevons, H.
Stanley (1904). "Note on the
Keratophyres of the
Breidden and
Berwyn Hills".
Geological Magazine. 1 (1): 13–16...
-
around 440
million years ago. A
series of basalts, rhyolites, felsites,
keratophyres,
mugearite and ****ociated
sedimentary rocks (quartzites, etc.) are grouped...
-
rifting at that time.
Closely allied to
trachyte is the rock type
called keratophyre,
which is the sodium-rich-plagioclase
equivalent of trachyte. Geology...
-
Cretaceous with the
eruption of the
Water Island Formation,
consisting of
keratophyres and
pillow basalts.
Igneous activity then
changed to that of an island...
-
diorite and plagiogranite. The
sedimentary sequence consists of
volcanic keratophyre and
spilite interbedded with
greywacke and argillite.
Fossil radiolaria...
- not
permitted to land. Geologically, the
island is
largely formed from
keratophyre,
though the
northwest coast and the
islet of West Tump are
formed from...
- the
presence of
sheeted ****s.
Geologists have
debated the
origins of
keratophyres,
suggesting a back-arc
basin environment,
although this is challenged...
- lava
flows and ****ociated
strata including felsite, albite-trachyte,
keratophyre etc laid down
during the
Silurian Period.
British Geological Survey 1:50...
- part of a volcano,
formed in the
Devonian sea, can be seen.
Rubble from
keratophyre lava in a white,
potash matrix, has
built a
volcanic breccia here, which...
-
presumably the name was
transferred from the hill,
which is made of
keratophyre (green
volcanic rock), to the
castle and
adjacent settlement.
Other explanations...
