-
Keratophyre is a
volcanic rock of
intermediate composition.
Although similar to trachyte,
keratophyre's plagioclase component is
richer in
sodium than...
- 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...
-
rifting at that time.
Closely allied to
trachyte is the rock type
called keratophyre,
which is the sodium-rich-plagioclase
equivalent of trachyte. Geology...
-
diorite and plagiogranite. The
sedimentary sequence consists of
volcanic keratophyre and
spilite interbedded with
greywacke and argillite.
Fossil radiolaria...
-
presumably the name was
transferred from the hill,
which is made of
keratophyre (green
volcanic rock), to the
castle and
adjacent settlement.
Other explanations...
-
around 440
million years ago. A
series of basalts, rhyolites, felsites,
keratophyres,
mugearite and ****ociated
sedimentary rocks (quartzites, etc.) are grouped...
-
metamorphosed fine-grained clastics, with conglomerate,
limestone and
keratophyre lenses.
Continental clastics,
limestone and
volcanic rocks following...
-
Cambrian age
politic sediments formed together with
volcanic rocks such as
keratophyre, spilite, and
pyroclastic flows, ****ociated with
tholeiitic island arc...
-
Cretaceous with the
eruption of the
Water Island Formation,
consisting of
keratophyres and
pillow basalts.
Igneous activity then
changed to that of an island...
- the
Shaida prospect show
layered quartz plagioclase porphyry,
quartz keratophyre and
aleuropelites (siltstone or mudstone)
interbedded with
volcanic layers...
