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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...
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The Sawmill Mountain quadrangle is located in the western Transverse Ranges of California, about 10 km west of Frazier Park. It includes Mt. Pinos, Mt. Abel (Cerro Noroeste), a part of the southern San Emigdio Mountains, and straddles an eleven-kilometer reach of the nearly east-west striking "Big Bend" section of the San Andreas Fault.South of the San Andreas Fault, the oldest rocks include undated amphibolite-grade biotite and hornblende-biotite gneiss that is probably early or middle Proterozoic in age. The older gneiss is intruded by strongly deformed and foliated biotite orthogneiss that has an age on biotite of 67.2+0.5 Ma (Late Cretaceous). Several other weakly foliated to massive Late Cretaceous granitic...
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This digital map shows bedding attitude data displayed over the geographic extent of rock stratigraphic units (formations) as compiled by Colton in 1976 (U.S.Geological Survey Map I-855-G) under the Front Range Urban Corridor Geology Program. Colton used his own mapping and published geologic maps having varied map unit schemes to compile one map with a uniform classification of geologic units. The resulting published color paper map was intended for planning for use of land in the Front Range Urban Corridor. In 1997-1999, under the USGS Front Range Infrastructure Resources Project, Colton's map was digitized to provide data at 1:100,000 scale to address urban growth issues(see cross-reference). In general, the...
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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 Dillon quadrangle is near the headwaters of the Blue River and straddles features of the Blue River graben (Kellogg, 1999), 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,...
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The Lockwood Valley quadrangle is located in the western Transverse Ranges of California, about 10 km southwest of Frazier Park. It includes the western flank of Frazier Mountain, southern Lockwood Valley, and a region of the Los Padres National Forest near northern Piru Creek.The oldest rocks are mostly biotite augen gneiss, in the hanging wall of the Frazier Mountain thrust and in a large body south of the thrust. A U-Pb zircon age for the gneiss is 1690+5 Ma (W. Premo, unpublished data). Two Cretaceous intrusive rocks are named the quartz monzonite of Sheep Creek and the coarse-grained granodiorite of Lockwood Peak. A U-Pb zircon age on the latter is 76.05+0.22 Ma (W. Premo, unpublished data).The northeastern...
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This digital map shows bedding attitude symbols display overthe geographic extent of surficial deposits and rockstratigraphic units (formations) as compiled by Trimble andMachette 1973-1977 and published in 1979 (U.S. GeologicalSurvey Map I-856-H) under the Front Range Urban CorridorGeology Program. Trimble and Machette compiled their geologicmap from published geologic maps and unpublished geologicmapping having varied map unit schemes. A convenient feature ofthe compiled map is its uniform classification of geologicunits that mostly matches those of companion maps to thenorth (USGS I-855-G) and to the south (USGS I-857-F).Published as a color paper map, the Trimble and Machette mapwas intended for land-use planning...
Tags: 08001 = Adams, 08005 = Arapahoe, 08031 = Denver, 08035 = Douglas, 08039 = Elbert, All tags...


    map background search result map search result map Geologic map of the Frisco quadrangle, Summit County, Colorado Geologic map of the Dillon quadrangle, Summit and Grand Counties, Colorado Geologic map of the Sawmill Mountain quadrangle, Kern and Ventura Counties, California A spatial database of bedding attitudes to accompany Geologic Map of the Boulder--Fort Collins--Greeley area, Colorado, by Roger B. Colton A spatial database of bedding attitudes to accompany Geologic map of the greater Denver area, Front Range urban corridor, Colorado, by Donald E. Trimble and Michael N. Machette Geologic map of the Lockwood Valley quadrangle, Ventura County, California Geologic map of the Frisco quadrangle, Summit County, Colorado Geologic map of the Dillon quadrangle, Summit and Grand Counties, Colorado Geologic map of the Sawmill Mountain quadrangle, Kern and Ventura Counties, California Geologic map of the Lockwood Valley quadrangle, Ventura County, California A spatial database of bedding attitudes to accompany Geologic Map of the Boulder--Fort Collins--Greeley area, Colorado, by Roger B. Colton A spatial database of bedding attitudes to accompany Geologic map of the greater Denver area, Front Range urban corridor, Colorado, by Donald E. Trimble and Michael N. Machette