Dataset Identification:
Resource Abstract:
- description: New 1:24,000-scale geologic mapping along the Interstate-70 urban corridor in western Colorado, in support of
the USGS Central Region State/USGS Cooperative Geologic Mapping Project, is contributing to a more complete understanding
of the stratigraphy, structure, tectonic evolution, and hazard potential of this rapidly developing region. The 1:24,000-scale
Frisco quadrangle is near the headwaters of the Blue River and straddles features of the Blue River graben (Kellogg, K.S.,
1999, Neogene basins of the northern Rio Grande rift —partitioning and asymmetry inherited from Laramide and older uplifts:
Tectonophysics, v. 305, p. 141-152.), part of the northernmost reaches of the Rio Grande rift, a major late Oligocene to recent
zone of extension that extends from Colorado to Mexico. The Williams Range thrust fault, the western structural margin of
the Colorado Front Range, cuts the northeastern corner of the quadrangle. The oldest rocks in the quadrangle underlie the
Tenmile Range and include biotite-sillimanite schist and gneiss, amphibolite, and migmatite that are intruded by granite inferred
to be part of the 1,667-1,750 Ma Routt Plutonic Suite (Tweto, Ogden, 1987, Rock units of the Precambrian- basement in Colorado:
U.S. Geological Survey Professional Paper 1321-A, 54 p.). The oldest sedimentary unit is the Pennsylvanian Maroon Formation,
a sequence of red sandstone, conglomerate, and interbedded shale. The thickest sequence of sedimentary rocks is Cretaceous
in age and includes at least 500 m of the Upper Cretaceous Pierre Shale. The sedimentary rocks are intruded by sills and dikes
of dacite porphyry sills of Swan Mountain, dated at 44 Ma (Marvin, R.F., Mehnert, H.H., Naeser, C.W., and Zartman, R.E., 1989,
U.S. Geological Survey radiometric ages, compilation “C ” —Part five —Colorado, Montana, Utah, and Wyoming:
Isochron/West, no. 53, p. 14-19. Simmons, E.C., and Hedge, C.E., 1978, Minor-element and Sr-isotope geochemistry of Tertiary
stocks, Colorado mineral belt: Contributions to Mineralogy and Petrology, v. 67, p. 379-396.). Surficial deposits include
(1) an old, deeply dissected landslide deposit, possibly as old as Tertiary, on the south flank of Tenderfoot Mountain, (2)
deeply weathered, very coarse gravel deposits, mostly along Gold Run and underlying Mesa Cortina; the gravels are gold bearing
and were mined by hydraulic methods in the 1800's, (3) glacial deposits of both Bull Lake (middle Pleistocene) and Pinedale
(late Pleistocene) that were derived from large valley glaciers that flowed down Tenmile and North Tenmile Creeks; the town
of Frisco is underlain mostly by Pinedale-age glacial outwash, (4) recent landslide deposits, including one large (about 1
square kilometer) area just downslope from Lilly Pad Lake, west of I-70, and (5)extensive colluvial and alluvial deposits.
The latest seismic events appear to be middle Pliestocene in age and are associated with small scarps that cut Bull Lake till
but do not cut Pinedale till.; abstract: New 1:24,000-scale geologic mapping along the Interstate-70 urban corridor in western
Colorado, in support of the USGS Central Region State/USGS Cooperative Geologic Mapping Project, is contributing to a more
complete understanding of the stratigraphy, structure, tectonic evolution, and hazard potential of this rapidly developing
region. The 1:24,000-scale Frisco quadrangle is near the headwaters of the Blue River and straddles features of the Blue River
graben (Kellogg, K.S., 1999, Neogene basins of the northern Rio Grande rift —partitioning and asymmetry inherited from
Laramide and older uplifts: Tectonophysics, v. 305, p. 141-152.), part of the northernmost reaches of the Rio Grande rift,
a major late Oligocene to recent zone of extension that extends from Colorado to Mexico. The Williams Range thrust fault,
the western structural margin of the Colorado Front Range, cuts the northeastern corner of the quadrangle. The oldest rocks
in the quadrangle underlie the Tenmile Range and include biotite-sillimanite schist and gneiss, amphibolite, and migmatite
that are intruded by granite inferred to be part of the 1,667-1,750 Ma Routt Plutonic Suite (Tweto, Ogden, 1987, Rock units
of the Precambrian- basement in Colorado: U.S. Geological Survey Professional Paper 1321-A, 54 p.). The oldest sedimentary
unit is the Pennsylvanian Maroon Formation, a sequence of red sandstone, conglomerate, and interbedded shale. The thickest
sequence of sedimentary rocks is Cretaceous in age and includes at least 500 m of the Upper Cretaceous Pierre Shale. The sedimentary
rocks are intruded by sills and dikes of dacite porphyry sills of Swan Mountain, dated at 44 Ma (Marvin, R.F., Mehnert, H.H.,
Naeser, C.W., and Zartman, R.E., 1989, U.S. Geological Survey radiometric ages, compilation “C ” —Part five
—Colorado, Montana, Utah, and Wyoming: Isochron/West, no. 53, p. 14-19. Simmons, E.C., and Hedge, C.E., 1978, Minor-element
and Sr-isotope geochemistry of Tertiary stocks, Colorado mineral belt: Contributions to Mineralogy and Petrology, v. 67, p.
379-396.). Surficial deposits include (1) an old, deeply dissected landslide deposit, possibly as old as Tertiary, on the
south flank of Tenderfoot Mountain, (2) deeply weathered, very coarse gravel deposits, mostly along Gold Run and underlying
Mesa Cortina; the gravels are gold bearing and were mined by hydraulic methods in the 1800's, (3) glacial deposits of
both Bull Lake (middle Pleistocene) and Pinedale (late Pleistocene) that were derived from large valley glaciers that flowed
down Tenmile and North Tenmile Creeks; the town of Frisco is underlain mostly by Pinedale-age glacial outwash, (4) recent
landslide deposits, including one large (about 1 square kilometer) area just downslope from Lilly Pad Lake, west of I-70,
and (5)extensive colluvial and alluvial deposits. The latest seismic events appear to be middle Pliestocene in age and are
associated with small scarps that cut Bull Lake till but do not cut Pinedale till.
Citation
- Title Geologic map of the Frisco quadrangle, Summit County, Colorado.
-
- creation Date
2018-05-21T12:42:52.300721
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Metadata data stamp:
2018-08-06T23:26:59Z
Resource Maintenance Information
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- notes: This metadata record was generated by an xslt transformation from a dc metadata record; Transform by Stephen M. Richard, based
on a transform by Damian Ulbricht. Run on 2018-08-06T23:26:59Z
Metadata contact
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pointOfContact
- organisation Name
CINERGI Metadata catalog
-
- Contact information
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- Address
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- electronic Mail Address cinergi@sdsc.edu
Metadata language
eng
Metadata character set encoding:
utf8
Metadata standard for this record:
ISO 19139 Geographic Information - Metadata - Implementation Specification
standard version:
2007
Metadata record identifier:
urn:dciso:metadataabout:096e0fd1-49c0-496c-ac22-11eccff5a7cb
Metadata record format is ISO19139 XML (MD_Metadata)