Filters: Tags: Permafrost and Periglacial (X)5 results (84ms)
The Alaska Division of Geological & Geophysical Surveys (DGGS), in partnership with the U.S. National Cooperative Geologic Mapping Program, mapped approximately 450 mi2 of the Talkeetna Mountains region of central Alaska at 1:50,000 scale over the course of six weeks in 2014. This area contains significant exposures of Late Triassic mafic volcanics and gabbro sills that have been the focus of region-wide exploration for the Strategic and Critical platinum-group elements (PGEs). The area also exposes numerous inactive and possibly active faults which project through the area of proposed hydropower development. The resulting geologic map offers an improved understanding of the geology, structural history, and mineral...
This 1:50,000 scale geologic map describes the distribution of unconsolidated deposits, identifies local geologic hazards, and provides information about the depositional environment and basic engineering properties of common surficial-geologic materials in and around Shaktoolik, Alaska. Map units are the result of combined field observations and aerial imagery interpretation. A suite of local ground observations were collected over a two-week period in July 2011 by a helicopter-supported team of DGGS geologists and collaborators. Field investigations included soil test pits, sample collection, soil and rock description, oblique aerial photography, and documentation of landscape morphology.
Surficial-geologic map of parts of the Sagavanirktok and Toolik river drainages, northern Brooks Range foothills, Alaska
This map shows the distribution of unconsolidated deposits and undifferentiated bedrock exposed at the surface in the Sagavanirktok A-3, A-4, B-3, B-4, and portions of the Sagavanirktok A-5 and B-5 quadrangles. Units were mapped by interpretation of stereo pairs of approximately 1:65,000-scale false-color infrared aerial photographs taken in June and August 1978, as well as 2.5 m and 10 m resolution SPOT imagery collected in 2009 and 2010. Fieldwork was completed in 2008.
This map shows the distribution of surficial deposits and undifferentiated bedrock in parts of the Livengood C-3 and C-4 quadrangles, Tolovana mining district.
This report presents the findings of a geologic and geotechnical evaluation of a landslide at the Yukon River bridge (the E.L. Patton Bridge). The Yukon River bridge landslide occurred in fall 2012 between approximately 375 and 575 feet west of the bridge. Although there was no damage to the bridge foundation, the landslide's close proximity to the bridge and concerns over additional failures prompted multiple evaluations, including landslide documentation, drainage assessments, and geotechnical studies. This report was prepared to convey the general characteristics of the rock mass, characteristics of rock discontinuities, and the geomorphic expression of the 2012 landslide in the vicinity of the bridge. We determined...