Keratophyre is a volcanic rock of intermediate composition. Although similar to trachyte, keratophyre's plagioclase component is richer in sodium than...

rifting at that time. Closely allied to trachyte is the rock type called keratophyre, which is the sodium-rich-plagioclase equivalent of trachyte. Geology...

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...

around 440 million years ago. A series of basalts, rhyolites, felsites, keratophyres, mugearite and associated sedimentary rocks (quartzites, etc.) are grouped...

Cretaceous with the eruption of the Water Island Formation, consisting of keratophyres and pillow basalts. Igneous activity then changed to that of an island...

lava flows and associated strata including felsite, albite-trachyte, keratophyre etc laid down during the Silurian Period. British Geological Survey 1:50...

diorite and plagiogranite. The sedimentary sequence consists of volcanic keratophyre and spilite interbedded with greywacke and argillite. Fossil radiolaria...

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...

focused on the origins of Saint John. The island began to form with keratophyre and pillow basalt below water, creating the two kilometer thick Water...

presumably the name was transferred from the hill, which is made of keratophyre (green volcanic rock), to the castle and adjacent settlement. Other explanations...