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F.M. Byers

Publications and source records attributed to F.M. Byers.

At least 19 recordsLinked to original sources
USGS2014

Volcanic activity on Umnak and Great Sitkin Islands, 1946–1948

As part of the United States Geological Survey's volcano program in the Aleutian volcanic arc during 1946–1948, the volcanoes and thermal areas on Umnak and Great Sitkin Islands were studied. In addition to observation of the volcanoes, temperatures of fumaroles were measured and some products of the volcanic activity were collected and analyzed. After an eruption in 1945, Cone A in Okmok Caldera on northeastern Umnak Island remained relatively quiet during the period 1946–1948. The fumarole gases contained water vapor, carbon dioxide, and sulfur dioxide. The incrustations associated with the sulfur dioxide fumaroles are the sulfate minerals halotrichite, gypsum, and soda alum. Temperatures of lava fumaroles at the source of the December, 1945 lava flow from Cone A dropped from an average of 320°C on July 19, 1946, to 90°C on September 5, 1946. With exception of the large central fumarole which reached red heat in 1947, the extra crater fumaroles of Cone A ranged from 96° to 98° C in temperature Cone C, another cone in Okmok Caldera was in the solfataric stage and emitted water vapor, hydrogen sulfide, and probably carbon dioxide. Incrustations associated with fumaroles on this cone consisted of sulfur, pyrite, and aragonite. The temperatures of the fumaroles ranged from 95° to 96°C and were probably kept within this narrow range partly by the heat supplied during condensation of steam. Sixteen large thermal springs emerging from the base of Cone D in Okmok Caldera had an aggregate discharge of approximately 115 cfs and gave off approximately 21,000 kcal of heat per second on September 7, 1946. Water samples of thermal springs on Umnak Island contained as high as 159 ppm of boron expressed as B 2 0 3 and a few parts per million of arsenic and antimony. Several of the thermal springs in southwestern Umnak Island were slightly superheated with respect to the boiling point of water and behaved as small geysers. As has been found elsewhere, the discharge, temperature, and composition of the emanations from a spring is modified by surface conditions of topography and drainage. Thermal springs and fumaroles on Great Sitkin Island occurred at an altitude of about 2000 ft near the head of the west fork of Big Fox Creek. All the fumaroles were at or near a temperature of 100°C. The large crater fumarole in the center of the 1945 crater dome was unapproachable. No change in the activity of Great Sitkin volcano was observed between 1946 and August 1948.

Alaska↗
USGS1999

Active evaporite tectonics and collapse in the Eagle River valley and the southwestern flank of the White River uplift, Colorado

This field trip presents field evidence for Neogene evaporite tectonism, dissolution of evaporates, and related collapse in Eagle River valley and along the southwestern flank of the White River uplift. In the Eagle collapse center, Pennsylvanian evaporite flowed to form anticlinal diapirs, dissolved, and disrupted a lower Miocene basaltic plateau originally at elevations as high as 3.35 km by tilting, faulting, and sagging to elevations as low as about 2.1 km. Also in the Eagle collapse center, the 30 x 10-km, homoclinal Hardscrabble Mountain sank into evaporite during Triassic and Permian collapse followed by Neogene(?) tilting and collapse, based on seismic reflection data. Along the southwestern flank of the White River uplift in the northwestern part of the Carbondale collapse center, parts of the Grand Hogback monocline have collapsed northeastward toward a series of strike-elongate extrusive diapirs. The volume of evaporite removed from the Eagle and Carbondale collapse centers during the Neogene (about 2,250 km 3 from an area of roughly 4,500 km 2 ) was calculated by measuring the departure of collapsed basalts from an assumed original basalt plateau. Regional Neogene uplift and incision of the Rocky Mountains, which locally began about 8-10 Ma, probably triggered dissolution and collapse. Presently the Colorado River removes a dissolved-solids load of about 1.4 x 10 9 kg per year from the two collapse centers.

Colorado↗
USGS1984

Stratigraphic and volcano-tectonic relations of Crater Flat Tuff and some older volcanic units, Nye County, Nevada

The Crater Flat Tuff is herein revised to include a newly recognized lowest unit, the Tram Member, exposed at scattered localities in the southwest Nevada Test Site region, and in several drill holes in the Yucca Mountain area. The overlying Bullfrog and Prow Pass Members are well exposed at the type locality of the formation near the southeast edge of Crater Flat, just north of U.S. Highway 95. In previous work, the Tram Member was thought to be the Bullfrog Member, and therefore was shown as Bullfrog or as undifferentiated Crater Flat Tuff on published maps. The revised Crater Flat Tuff is stratigraphically below the Topopah Spring Member of the Paintbrush Tuff and above the Grouse Canyon Member of the Belted Range Tuff, and is approximately 13.6 m.y. old. Drill holes on Yucca Mountain and near Fortymile Wash penetrate all three members of the Crater Flat as well as an underlying quartz-poor unit, which is herein defined as the Lithic Ridge Tuff from exposures on Lithic Ridge near the head of Topopah Wash. In outcrops between Calico Hills and Yucca Flat, the Lithic Ridge Tuff overlies a Bullfrog-like unit of reverse magnetic polarity that probably correlates with a widespread unit around and under Yucca Flat, referred to previously as Crater Flat Tuff. This unit is here informally designated as the tuff of Yucca Flat. Although older, it may be genetically related to the Crater Flat Tuff. Although the rocks are poorly exposed, geophysical and geologic evidence to date suggests that (1) the source of the Crater Flat Tuff is a caldera complex in the Crater Flat area between Yucca Mountain and Bare Mountain, and (2) there are at least two cauldrons within this complex--one probably associated with eruption of the Tram, the other with the Bullfrog and Prow Pass Members. The complex is named the Crater Flat-Prospector Pass caldera complex. The northern part of the Yucca Mountain area is suggested as the general location of the source of pre-Crater Flat tuffs, but a caldera related to the Lithic Ridge Tuff has not been specifically identified.

Nevada↗
USGS1970

Radiometric ages and stratigraphic sequence of volcanic and plutonic rocks, southern Nye and western Lincoln Counties, Nevada

The geochronology of Tertiary igneous events at the Nevada Test Site and adjacent area is outlined by 36 recently determined K-Ar ages, together with other published K-Ar ages. The first evidence of Tertiary igneous activity is the ash-fall bedded tuffs in the Horse Spring Formation. One such tuff has been dated as 29 m.y. old (late Oligocene). Other ash-flow tuffs and lavas formed during the Miocene and Pliocene, according to radiometric age determinations. The youngest ash-flow tuff in this area is about 6 m.y. old. Great volumes of ash and lava were spewed forth 13 to 11 m.y. ago to form the Paintbrush and Timber Mountain Tuffs. Sixteen replicate age determinations on minerals from four densely welded ash-flow tuffs from these formations gave a pooled standard deviation of about ± 2 percent error, provided anomalous ages were rejected on the basis of rock alteration or analytical difficulties. In the Air Force Gunnery Range, just north of the test site, K-Ar ages suggest that the oldest ash flows, the Monotony Tuff, were emplaced 27.6 m.y. ago (late Oligocene) and were followed by outpourings of lava and ash throughout most of the Miocene. Youngest dated lava is about 13 m.y. old. In the southern Egan and northern Seaman Ranges of central Nevada, the Needles Range (?) Formation has an averaged K-Ar age of about 30 m.y., which compares closely with 29.2 m.y., the average of four earlier K-Ar ages determined by other investigators on known Needles Range Formation in eastern Nevada and western Utah. K-Ar ages given by micas from two exposed plutons in the Nevada Test Site suggest emplacement of these plutons at about 93 m.y. ago (early Late Cretaceous), although earlier emplacement in the Mesozoic would be more consistent with Pb-α ages

Nevada↗