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Henry Rowland Cornwall

Publications and source records attributed to Henry Rowland Cornwall.

14 recordsLinked to original sources
USGS1968

Hypogene veins of gibbsite, pyrolusite, and lithiophorite in Nye County, Nevada

Gibbsite, lithiophorite, pyrolusite, and goethite, plus discrete mixtures of gibbsite and lithiophorite and of gibbsite and iron oxide, occur as replacement veins in limestone. Minor accessories are barite, alunite, opal. Minerals of wall-rock alteration are garnet, idocrase, K-feldspar, prehnite, sericite, and quartz. These silicates formed at higher temperature than the vein minerals, but the whole sequence is considered to be a product of the same solutions, of deep-seated origin, deposited over a long period of time.

Nevada↗
USGS1951

Ilmenite, magnetite, hematite, and copper in lavas of the Keweenawan series

The opaque minerals in ten lava flows of the Keweenawan series of Michigan were studied microscopically by the writer. The basaltic lavas , which range in thickness from 100 to 1,400 feet, contain ilmenite , magnetite , hematite , intergrowths of magnetite - ilmenite and ilmenite - hematite , copper sulfides, native copper , and pyrite. Variations of opaque iron minerals with thickness of flow are slight, but native copper predominates in the thinner flows and copper sulfides in the thickest. Pyrite occurs only in the thickest flow. Two groups of opaque minerals and their alteration products are distinguished. The earlier group includes magnetite , ilmenite , magnetite - ilmenite and ilmenite - hematite intergrowths, copper sulfides, and native copper . The later group includes hematite , native copper , chalcocite, pyrite, chlorite, and sphene. The second-generation minerals formed by the action of volatiles escaping from the lavas . The ratio of Ti to total Fe correlates with the degree of differentiation of the lavas , but the ratio of ferric to ferrous iron does not. The latter ratio was controlled primarily by the action of escaping volatiles.

Economic Geology↗
USGS1943

The Arlington copper mine: North Arlington, New Jersey

The Arlington copper mine is located in North Arlington, Bergen Co., N. J. The ore deposit occurs in a 10- to 30-foot thick arkosic sandstone layer, interbedded in red shale. Copper mineralization is associated with thin diabase sills and dikes. It would probably not be feasible to develop the underground workings since they are overlain by the residential section of North Arlington. One area, containing approximately 11,000 tons of indicated ore could possibly be quarried.

New Jersey↗