Filters: Tags: Colorado Front Range (X)
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We examined patterns of non-native plant diversity in protected and managed ponderosa pine/Douglas-fir forests of the Colorado Front Range. Cheesman Lake, a protected landscape, and Turkey Creek, a managed landscape, appear to have had similar natural disturbance histories prior to European settlement and fire protection during the last century. However, Turkey Creek has experienced logging, grazing, prescribed burning, and recreation since the late 1800s, while Cheesman Lake has not. Using the modified-Whittaker plot design to sample understory species richness and cover, we collected data for 30 0.1 ha plots in each landscape. Topographic position greatly influenced results, while management history did not. At...
Categories: Publication;
Types: Citation,
Journal Citation;
Tags: Colorado front range,
Douglas-fir,
Forest Ecology and Management,
Land management,
Non-native plant species,
Album caption: Crystalloblastic texture of granitic enclave in Silver Plume Granite. Coin is 19 mm. in diam. Crytalline Rocks of the Strawberry Lake Area, Front Range, Colorado. 1985. Published as Fig. 11, U.S. Geological Survey Bulletin 1937. 1990.
Categories: Image;
Types: Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Colorado Front Range,
Photographers,
Young, E. J. collection,
photo print
The feasibility of reconstructing total spring precipitation for the South Platte River basin from tree-ring chronologies using artificial neural networks is explored. The use of artificial neural networks allows a comparison of reconstructions resulting from both linear and nonlinear models. Both types of models produced reconstructions that explained more than 40% of the variation in spring precipitation and were well verified with independent data. Although the nonlinear models produced higher R2 values than did the linear model for the calibration period, they performed less well in the independent period. This result and other model evaluation statistics suggest that, in this study, the nonlinear models contain...
Categories: Publication;
Types: Citation,
Journal Citation;
Tags: Colorado Front Range,
The Holocene,
USA,
artificial neural networks,
climatic reconstruction,
Album caption: Photomicrographs of biotite lamprophyre, ( minette-vogesite ), microcline shows inhomogeneous brown color under the microscop. View "A" Plane -polarized light. View "B" Crossed nicols. Minerals apat, apatite ; biot. biotite, hb, hornblende, mic, microcline. Crystalline Rocks of the Strawberry Lake Area, Front Range, Colorado 1985. Published as Fig. 13-A, 13-B, U. S. Geological Survey Bulletin 1937. 1990.
Categories: Image;
Types: Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Colorado Front Range,
Photographers,
Young, E. J. collection,
photo print
Album caption:Thin parallel biotite schlieren shown here are probably relics of biotite gneiss in Silver plume Granite. Hammer handle is 3 cm. in diam. Crystalline Rocks of the Strawberry Lake Area, Front Range, Colorado. 1985. Published as Fig. 10, U. S. Geological Survey Bulletin 1937. 1990.
Categories: Image;
Types: Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Colorado Front Range,
Photo print,
Photographers,
Young, E. J. collection
This digital map shows the areal extent of surficial deposits and rock stratigraphic units (formations) as compiled by Trimble and Machette from 1973 to 1977 and published in 1979 under the Front Range Urban Corridor Geology Program. Trimble and Machette compiled their geologic map from published geologic maps and unpublished geologic mapping having varied map unit schemes. A convenient feature of the compiled map is its uniform classification of geologic units that mostly matches those of companion maps to the north (USGS I-855-G) and to the south (USGS I-857-F). Published as a color paper map, the Trimble and Machette map was intended for land-use planning in the Front Range Urban Corridor. This map recently (1997-1999)...
The forest-alpine tundra ecotone in the Front Range of Colorado typically occurs as a gradual transition from the treeless tundra to the closed canopy coniferous subalpine forest. We evaluated the patterns of snow, deposition inputs, and soil properties at three spatial scales: across the entire ecotone, with distance from tree limit in the transitional krummholz zone, and around individual trees. Snow depth was deepest in the krummholz zone and lowest in the alpine tundra and upwind of trees near tree limit, but was not predictive of most soil properties except for surface litter decomposition. Inorganic deposition ranged from 0.7 to 7.7 g m−2 yr−1 across the ecotone and tended to be higher downwind than upwind...
Categories: Publication;
Types: Citation,
Journal Citation;
Tags: American Geophysical Union,
Colorado Front Range,
Journal of Geophysical Research,
Niwot Ridge,
dust deposition,
Album caption: Monazite in plagioclase with typical alteration ring of opaque material. Dark grain to right of monazite is radiation-darkend biotite. Plane-polarized light. Crystalline Rocks of the Strawberry Lake Area, Front Range, Colorado. 1985. Published as Fig. 8, U.S. Geological Survey Bulletin 1937. 1990.
Categories: Image;
Types: Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Colorado Front Range,
Photographers,
Young, E. J. collection,
photo print
Album caption: Small mafic enclave in Boulder Creek Granodiorite. Tooth-pick on right is 6 cm. in length. Crystalline Rocks of the Strawberry Lake Area, Front Range, Colorado.1984. Published as Fig. 3, U.S. Geological Survey Bulletin 1937. 1990.
Categories: Image;
Types: Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Colorado Front Range,
Photographers,
Young, E. J. collection,
photo print
Wood load, channel parameters and valley parameters were surveyed in 50 contiguous stream segments each 25 m in length along 12 streams in the Colorado Front Range. Length and diameter of each piece of wood were measured, and the orientation of each piece was tallied as a ramp, buried, bridge or unattached. These data were then used to evaluate longitudinal patterns of wood distribution in forested headwater streams of the Colorado Front Range, and potential channel-, valley- and watershed-scale controls on these patterns. We hypothesized that (i) wood load decreases downstream, (ii) wood is non-randomly distributed at channel lengths of tens to hundreds of meters as a result of the presence of wood jams and (iii)...
Categories: Publication;
Types: Citation,
Journal Citation;
Tags: Colorado Front Range,
Earth Surface Processes and Landforms,
large woody debris,
mountain streams,
spatial distribution,
Album caption Block of biotite lamprophyre (minette-vogesite) showing irregular veining by aligned pink potassium feldspar ( raised, lighter veinlets near coin ). Coin is 19mm. in diam. Crystalline Rocks of the Strawberry Lake Area, Front Range, Colorado. 1985. Pulished as Fig. 12 in U. S. Geological Survey Bulletin 1937. 1990.
Categories: Image;
Types: Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Colorado Front Range,
Photographers,
Young, E. J. collection,
photo print
Cell maps for each oil and gas assessment unit were created by the USGS as a method for illustrating the degree of exploration, type of production, and distribution of production in an assessment unit or province. Each cell represents a quarter-mile square of the land surface, and the cells are coded to represent whether the wells included within the cell are predominantly oil-producing, gas-producing, both oil and gas-producing, dry, or the type of production of the wells located within the cell is unknown. The well information was initially retrieved from the IHS Energy Group, PI/Dwights PLUS Well Data on CD-ROM, which is a proprietary, commercial database containing information for most oil and gas wells in the...
The Boulder Creek Watershed, within the Front Range region of Colorado, is typical of many western watersheds because it is composed of a high-gradient upper reach mostly fed by snowmelt, a substantial change in gradient at the range front, and an urban corridor within the lower gradient section. A stream ecosystem within an urban landscape not only can provide water for municipal, industrial, and agricultural needs, but also can be utilized for recreation, esthetic enjoyment, and wastewater disposal. The purpose of this 26 km bicycle field trip is to explore the hydrology and geochemistry of Boulder and South Boulder Creeks and to discuss topics including flood frequency and hazards, aqueous geochemistry of the...
Categories: Publication;
Types: Citation;
Tags: Colorado Front Range,
flood hazard,
invasive species
This digital map shows the geographic extent of rock stratigraphic units (formations) as compiled by Colton in 1976 under the Front Range Urban Corridor Geology Program. Colton used his own geologic mapping and previously published geologic maps to compile one map having a single classification of geologic units. The resulting published color paper map (USGS Map I-855-G, Colton, 1978) was intended for land-use planning and to depict the regional geology. In 1997-1999, another USGS project designed to address urban growth issues was undertaken. This project, the USGS Front Range Infrastructure Resources Project, undertook to digitize Colton's map at 1:100,000 scale, making it useable in Geographical Information Systems...
Album caption: Monazite in biotite shows intense, dark radiation-damage halo.Although thin section is from biotite gneiss, similar monazite and halos are common in biotite of the Silver Plume Granite. Note garnet in upper right, quartz in lower right, vermicular quarts in biotite at bottom, and three small radiation-damage halos interpreted to be the result of thin section cutting above or below a monazite grain, thereby slicing through the halo only. Plane-polarized light. Crystalline Rocks of the Strawberry Lake Area, Front Range, Colorado. 1985. Published as Fig. 7, U.S. Geological Survey Bulletin 1937. 1990.
Categories: Image;
Types: Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Colorado Front Range,
Photographers,
Young, E. J. collection,
photo print
The Boulder Creek Watershed, within the Front Range region of Colorado, is typical of many western watersheds because it is composed of a high-gradient upper reach mostly fed by snowmelt, a substantial change in gradient at the range front, and an urban corridor within the lower gradient section. A stream ecosystem within an urban landscape not only can provide water for municipal, industrial, and agricultural needs, but also can be utilized for recreation, esthetic enjoyment, and wastewater disposal. The purpose of this 26 km bicycle field trip is to explore the hydrology and geochemistry of Boulder and South Boulder Creeks and to discuss topics including flood frequency and hazards, aqueous geochemistry of the...
Categories: Publication;
Types: Citation;
Tags: Colorado Front Range,
flood hazard,
invasive species
The Total Petroleum System is used in the National Assessment Project and incorporates the Assessment Unit, which is the fundamental geologic unit used for the assessment of undiscovered oil and gas resources. The Total Petroleum System is shown here as a geographic boundary defined and mapped by the geologist responsible for the province and incorporates not only the set of known or postulated oil and (or) gas accumulations, but also the geologic interpretation of the essential elements and processes within the petroleum system that relate to source, generation, migration, accumulation, and trapping of the discovered and undiscovered petroleum resource(s).
Water resource planning is based primarily on 20th century instrumental records of climate and streamflow. These records are limited in length to approximately 100 years, in the best cases, and can reflect only a portion of the range of natural variability. The instrumental record neither can be used to gage the unusualness of 20th Century extreme low flow events, nor does it allow the detection of low-frequency variability that may underlie short-term variations in flow. In this study, tree rings are used to reconstruct mean annual streamflow for Middle Boulder Creek in the Colorado Front Range, a semi-arid region of rapid growth and development. The reconstruction is based on a stepwise regression equation that...
Categories: Publication;
Types: Citation,
Journal Citation;
Tags: Colorado Front Range,
Journal of the American Water Resources Association,
dendrohydrology,
drought,
streamflow reconstruction,
Album caption: Pink porphyroblasts in Boulder Creek Granodiorite near contact with biotite gneiss. Poptop is 4. 5 cm. long. Crystal-line Rocks of the Strawberry Lake Area, Front Range, Colorado. 1985. Published as fig. 4, U. S. Geological Survey Bulletin 1937. 1990.
Categories: Image;
Types: Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Colorado Front Range,
Photographers,
Young, E. J. collection,
photo print
Land use practices in Colorado during the last two centuries altered the supply of sediment and water to many channels in the upper South Platte Basin. As a result of increased supply of sediment and mobility and reduced peak flows, the characteristics of pools associated with channel constrictions, referred to as forced pools, may have been altered. Increased supply of sediment and reduced transport capacity of high flows could lead to aggradation in forced pools. Channel confined by road corridors could lead to high velocities at normal flows, increased energy dissipation from riprap, or even increased pool frequency resulting from failed riprap. To assess potential alterations, four hypotheses were tested: (1)...
Categories: Publication;
Types: Citation,
Journal Citation;
Tags: Bankfull pool spacing,
Colorado Front Range,
Forced pools,
Geomorphology,
Land use effects,
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