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Geology topics

Francis Gerritt Wells

Publications and source records attributed to Francis Gerritt Wells.

8 recordsLinked to original sources
USGS1938

The origin of the iron ore deposits in the Bull Valley and Iron Springs districts, Utah

A summary of the geology of the Bull Valley district, southwestern Utah, and a description of the occurrence of the magnetite and hematite deposits is given, as well as brief descriptions of the ore pits at Iron Mountain and Desert Mound 20 miles to the northeast, in which deposits formed under similar geologic conditions have been developed. Neither the ores nor the country rock show the features characteristic of contact-metamorphic deposits. The following explanation of the origin of the deposits is offered. During the intrusion of monzonite porphyry stocks, the hoods and overlying rock were fractured, causing a sudden release of pressure and liberating FeCl 3 and H 2 O gas from the stocks which were still at high temperature. These gases found ready egress to the surface along tension fissures without appreciably heating the country rock. They deposited magnetite and hematite in the fissures and replaced the contiguous fractured limestone. The period of gas emanation was brief and the hydrothermal stage probably evolved during the later magmatic history never reached this area. The deposits were formed under a cover of less than 5,000 feet.

Utah↗
USGS1937

Recent geologic studies on Long Island with respect to ground-water supplies

Recent studies have shown that relatively impermeable clay beds are widespread on Long Island but that erosion channels cutting through them permit restricted recharge of the underlying beds in some parts of the island. Of the more than 200,000,000 gallons of water a day now pumped from wells, about 65 per cent. comes from the surficial beds of Illinoian or Wisconsin age. Because of the restricted recharge of the lower beds and the desirability of saving these beds for use in localities where the upper beds may more easily be contaminated by salt water, any future large developments of ground water should be drawn from the surficial beds.

New York↗