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Russell G. Tysdal

Publications and source records attributed to Russell G. Tysdal.

32 records · Page 2Linked to original sources
USGS1988

Deformation along the northeast side of Blacktail Mountains salient, southwestern Montana

The Blacktail Mountains salient is a convex-eastward area of stacked Laramide-age thrust faults that trend north and dip west at moderate angles. The thrusts occur in Mississippian to Cretaceous strata above a basement of Archean metamorphic rocks. The northern margin of the salient is delimited by the Jake Canyon fault, a northwest-trending, northeast-dipping Laramide reverse fault. During the Laramide orogeny, the fault formed a common boundary of the present-day Blacktail Mountains and a structural high that existed in the area of the present-day valley of Blacktail Deer Creek. The fault juxtaposed Archean metamorphic rocks upon Phanerozoic strata in the northwest-era half of its extent, and against other Archean metamorphic rocks in the southeastern half. General structural relationships and study of small-scale structures in local areas show that movement along the Jake Canyon fault caused deformation of the north-trending thrust faults and associated folds. During Cenozoic extensional faulting, the Blacktail fault developed northeast of the Jake Canyon fault, and generally delimits the southwestern side of the basin of sedimentary rocks that lies beneath the valley of Blacktail Deer Creek.

Idaho, Montana↗
USGS1982

Metalliferous mineral resource potential of the Seward and Blying Sound quadrangles, southern Alaska

This mineral potential map is the final report in a series of publications that makes up a folio on the Seward and Blying Sound quadrangles of southern Alaska. It draws on data largely presented in previous publications of the folio. The studies were undertaken as part of the Alaska Mineral Resource Assessment Program (AMRAP), a program designed to provide information for Federal, State, local, and industry decisions concerning the future uses of Alaskan lands and resources.

Alaska↗
USGS1978

Mines, prospects, and occurrences map of the Seward and Blying Sound quadrangles, Alaska

The Prince William Sound region may be considered as made up of two extensive and distinctive mineral belts defined by the preponderance of either gold or copper deposits (Capps and Johnson, 1915). In the Seward and Blying Sound quadrangles, the division of the two belts is approximately along the Contact fault, which trends northeast across the quadrangles. The gold belt includes the Moose Pass-Hope district and the Port Wells district. The copper belt is exposed mainly on Latouche, Elrington, Bainbridge, Knight, Chenega, and Glacier Islands and the mainland area between Unakwik Inlet and Columbia Bay.

Alaska↗
USGS1978

Map showing placer deposits of the Seward and Blying Sound quadrangles, Alaska

Placer gold was first recovered from stream gravels of the Seward quadrangle about 1850 by P.P. Doroshin, a mining engineer employed by the Russian-American Company. He obtained a few ounces of gold from gravels from two streams that flow into the Kenai River below Kenai Lake (Moffit, 1906, p. 8). Placer gold was found on Palmer Creek near Hope in about 1888, and on several nearby creeks in 1894 and 1895, precipitating a rush of miners to the region in 1896 (Moffit, 1906, p. 8, 9, 33). Prospecting subsequently was carried on through the Seward and Blying Sound quadrangles, but production of placer gold was confined to the western part of the Seward quadrangle; hence, the map shows only the pertinent area of these quadrangles. Most of the gold was recovered from stream and bench gravels in the western part of the Turnagain Arm drainage system, the most productive gravels from Mills, Canyon, Bear, Resurrection, and Crow Creeks. Only a small amount of gold was recovered from gravels of the Kenai River drainage system, chiefly from Copper Creek, and almost no production was recorded from the Resurrection River or its tributaries. (Resurrection River and Resurrection Creek are two different streams.) Recovery of the gold was effected initially with sluice boxes and later by hydraulic mining methods (Martin and others, 1915, p. 186). Dredges were installed on Resurrection and Sixmile Creeks but never were operated successfully because of many large boulders, thin gravel deposits, and low gold tenor (Paige and Knopf, 1907, p. 119-120; Brooks, 1916, p. 55; Tuck, 1933, p. 523-527). Dredging also proved unsuccessful on the Kenai River for the same reasons (Martin and others, 1915, p. 186-187).

Alaska↗
USGS1977

Sheeted dikes, gabbro, and pillow basalt in flysch of coastal southern Alaska

A Paleocene to Eocene(?) mafic sequence of igneous rocks on Knight Island and a Cretaceous mafic and ultramafic sequence of the Resurrection Peninsula in coastal southern Alaska are characterized by pillow basalts, sheeted dikes, and gabbro intrusions. At both localities, pillow basalts are interbedded with flysch, and the gabbros intrude both the sheeted dikes and the immediately overlying sedimentary rocks. At the Resurrection Peninsula, small bodies of serpentinized dunite are present in the gabbro, and overlying low-grade metasedimentary rocks and mafic tuffs are interbedded with sedimentary rocks. At Knight Island the sheeted dikes intrude Paleocene and Eocene(?) sedimentary rocks. These igneous rocks have petrographic features similar to those of oceanic tholeiites and have some of the characteristics of ophiolites. They apparently were formed near the continental margin, because both sequences intrude and are interlayered with flysch. We believe the igneous rocks were intruded along faults (perhaps leaky transform faults) of ocean floor that happened to be near the continental margin; the faults were oriented parallel to the depositional strike and subsequent deformational strike of the Valdez(?) and Orca Groups.

Alaska↗
USGS1976

A preliminary evaluation of selected earthquake-related geologic hazards in the Kenai Lowland, Alaska

Several major faults exist beneath the Kenai Lowland, and others may be inferred. No surface evidence was found to indicate that any of the faults have been active in Holocene time. The sparse shallow seismicity thus far recorded does not correlate with known faults, nor does it define linear trends suggestive of faulting. Tidal flats at the mouths of the Kenai, Kasilof, and Chickaloon Rivers have been uplifted in the Holocene, however, and the uplift may reflect growing anticlines at depth. Some faults associated with folding may be active, but they are probably too limited in size to generate destructive earthquakes. They could, however, constitute a hazard to manmade structures in their immediate vicinity. Vibrational damage and ground failure during the 1964 earthquake were most extensive north of Tustumena Lake in areas of water-saturated unconsolidated deposits with uneven topography. South of Tustumena Lake, damage resulted mainly from landslides formed along unconfined bluffs and riverbanks, and from submarine sliding and subsidence at Homer Spit. A comparable distribution of surficial effects may be anticipated in future large earthquakes on the Kenai Lowland.

Alaska↗
USGS1974

Geology of the Juazohn Quadrangle, Liberia

As part of a program undertaken cooperatively by the Liberian Geological Survey (LGS) and the U. S. Geological Survey (USGS), under the sponsorship of the Government of Liberia and the Agency for International Development, U. S. Department of State, Liberia was mapped by geologic and geophysical methods during the period 1965 to 1972. The resulting geologic and geophysical maps are published in ten folios, each covering one quadrangle (see index map). The Juazohn quadrangle was systematically mapped by the author from December 1970 to June 1972. Field data provided by private companies and other members of the LGS-USGS project were used in map compilation, and are hereby acknowledged.

Juazohn Quadrangle↗
USGS1970

Geology of the north end of the Ruby Range, southwestern Montana

This study consists of two parts: stratigraphy and sedimentation, and structure of rocks in the northern one-third of the Ruby Range of southwestern Montana. Detailed studies of Cambrian marine dolomite rocks in the Red Lion Formation and in the upper part of the Pilgrim Limestone resulted in their division into distinct rock units, termed lithofacies. These lithofacies contain features suggestive of subtidal, intertidal, and supratidal environments similar to those presently forming in the Persian Gulf. Stromatolltic structures occurring in the uppermost part of the Red Lion Formation are similar to those presently forming in Shark Bay, Australia. The Ruby Range within the map area is broken into a series of northwest-plunging basement (Precambrian metamorphic rock) blocks, differentially uplifted during the Cretaceous-Tertiary orogenic period. These blocks are bordered by upthrust faults, which are nearly vertical in their lower segments and are .low-angle in their uppermost parts. Asymmetrical folds in Paleozoic sedimentary rocks formed in response to the differential uplift of the blocks; thus they too plunge to the northwest. Displaced masses of rock border the range on the three sides within the map area and are interpreted as gravity-slide features resulting from uplift of the range. Normal faulting began blocking out the present range margins by Oligocene time.

Open-File Report↗