Keratophyre from the Neoproterozoic Hatat Formation, Oman
Keratophyre is a volcanic rock of intermediate composition. Although similar to trachyte, keratophyre's plagioclase component is richer in sodium than the plagioclase found in trachyte.[1] Keratophyre forms lava flows and subvolcanic intrusions (dykes and sills). Keratophyre occurs, for example, at Hüttenrode in the Harz Mountains of Germany and in the Berwyn Hills of Wales.[2] Keratophyre tuff of Early Devonian age occurs in Sauerland (Germany).[3]
The term quartz keratophyre has traditionally been used in the Nordic countries to describe a metamorphosed, felsic extrusive rock, corresponding to rhyolite, dacite, or rhyodacite according to IUGS terminology.[4]
^Jevons, H. Stanley (1904). "Note on the Keratophyres of the Breidden and Berwyn Hills". Geological Magazine. 1 (1): 13–16. Bibcode:1904GeoM....1...13J. doi:10.1017/S0016756800119223. S2CID 131021424.
^Wolf, K. H. (editor) (1981). Handbook of Strata-bound and Stratiform Ore Deposits (Part III volume 9): Regional Studies and Specific Deposits. Amsterdam: Elsevier. p. 539. ISBN 0-444-41824-5. {{cite book}}: |author= has generic name (help)
^Slagstad, T. (2003) Geochemistry of trondhjemites and mafic rocks in the Bymarka ophiolite fragment, Trondheim, Norway: Petrogenesis and tectonic implications, Norwegian Journal of Geology, vol. 83, pp. 167-185. Trondheim ISSN 0029-196X
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...
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...
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...
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...
Gerhard W. (December 1, 1985). "Trondhjemite and metamorphosed quartz keratophyre tuff of the Ammonoosuc Volcanics (Ordovician), western New Hampshire...
Cambrian age politic sediments formed together with volcanic rocks such as keratophyre, spilite, and pyroclastic flows, associated with tholeiitic island arc...
Riphean-Cambrian segment of the Vardar Zone, including phyllite, spilite and keratophyre, epidote-chlorite, spilite-mica schist and low-grade metamorphic shales...
common, mainly basalt, andesite and dacite, transformed into spilite, keratophyre and pyroclastic rocks. Older Triassic rocks and the carbonate platform...
the Shaida prospect show layered quartz plagioclase porphyry, quartz keratophyre and aleuropelites (siltstone or mudstone) interbedded with volcanic layers...
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