Other Projects at
GEO-HAZ
(Updated Jan. 16,
2008)
The following projects are mostly local, rather than national
or international, and involve the application of engineering geology principles
to rather small construction or development projects. However, we apply the
same quality standards to these small projects as to our larger projects, as
our small clients can attest.
GeoHazards Division: GEOLOGIC MAPS (most recent at
top)
Geologic Map of the Climax 7.5’
Quadrangle, Lake County, Colorado
GEO-HAZ completed field mapping the
Quaternary deposits of the Climax 7.5’ quadrangle, Colorado, under contract with the Colorado
Geological Survey (STATEMAP Program). The map should be available in summer
2008 at http://dnr.state.co.us/geostore/
Geologic Map of the Maysville 7.5’
Quadrangle, Chaffee County,
Colorado
GEO-HAZ completed field mapping the
Quaternary deposits of the Maysville 7.5’ quadrangle, Colorado, under contract with the Colorado
Geological Survey (STATEMAP Program). The map should be available in early 2008
at http://dnr.state.co.us/geostore/
Geologic Map of the Buena Vista West 7.5’
Quadrangle, Chaffee County,
Colorado
GEO-HAZ completed field mapping the
Quaternary deposits of the Buena Vista West 7.5’ quadrangle, Colorado, under contract
with the Colorado Geological Survey (STATEMAP Program). The map is available at
http://dnr.state.co.us/geostore/ProductInfo.aspx?productid=OF05-08
Geologic Map of the Buena Vista East 7.5’
Quadrangle, Chaffee County,
Colorado
GEO-HAZ completed field mapping the
Quaternary deposits of the Buena Vista East 7.5’ quadrangle, Colorado, under contract
with the Colorado Geological Survey (STATEMAP Program). The map is available at
http://dnr.state.co.us/geostore/ProductInfo.aspx?productid=OF04-04
.
Geologic Map of the Copper
Mountain 7.5’ Quadrangle, Summit County, Colorado
GEO-HAZ completed field mapping the
Quaternary deposits of the Copper Mountain 7.5’ quadrangle, Colorado, under contract
with the Colorado Geological Survey (STATEMAP Program). The map is available at
http://dnr.state.co.us/geostore/ProductInfo.aspx?productid=OF03-20
Geologic Map of the Breckenridge 7.5’
Quadrangle, Summit County, Colorado
GEO-HAZ completed field mapping the
Quaternary deposits of the Breckenridge Mountain 7.5’ quadrangle, Colorado, under contract
with the Colorado Geological Survey (STATEMAP Program). The map is available at http://dnr.state.co.us/geostore/ProductInfo.aspx?productid=OF02-07
Geologic Map of the Richmond
7.5’ Quadrangle, Cache County,
Utah
Go to: http://ugspub.nr.utah.gov/publications/misc_pubs/MP-95-3Richmond.pdf
Geologic Map of the Logan
7.5’ Quadrangle, Cache County,
Utah
Go to: http://ugspub.nr.utah.gov/publications/misc_pubs/MP-96-1Logan.pdf
Surficial Geologic Map of the East Cache Fault Zone, Cache County, Utah
http://ugspub.nr.utah.gov/publications/united_states_geological_survey/geologic_maps/mf/MF-2107.pdf
Quaternary Geologic Mapping
of Seven 7.5’ Quadrangles in the San Gabriel
Valley, L.A. Basin, California
This 1970s-vintage, unpublished mapping for USGS was updated
and digitized by GEO-HAZ in 2000, and subsequently formed the basis for the
California Geological Survey’s Seismic Hazard Maps of these 7
quadrangles.
latest
Semi-Annual Technical Report (PDF file)
accompanying
map (PDF file)
GeoHazards Division: MINEABLE RESOURCE
ASSESSMENTS/ PHASE 1 ESAs
Mineable Resource Assessment, Allen Easement, Saguache County, Colorado
GEO-HAZ performed a Mineable Resource Assessment for the 100-acre
easement, 5 miles west of Crestone,
Colorado. The study was requested
by the conservation agency that will be holding the new Conservation Easement
on the easement.
Mineable Resource Assessment, Malville Property,
Saguache County, Colorado
GEO-HAZ performed a Mineable Resource Assessment for several small
lots in the Baca Grande subdivision, Saguache
County, Colorado,
adjacent to a greenbelt. The study was requested by the conservation agency
that will be holding the new Conservation Easement on the lots.
Mineable Resource Assessment, Kerr Property, Saguache County, Colorado
GEO-HAZ performed a Mineable Resource Assessment for the 160-acre
easement, 2 miles west of Hooper, Colorado.
The study was requested by the conservation agency that will be holding the new
Conservation Easement on the property.
Phase 1 Environmental Site Assessment, Pocket
Park, Town of Crestone, Colorado
GEO-HAZ performed a Phase 1 ESA for the Town of Crestone,
Colorado. The
study was requested by the State funding agency that underwrote the park land
acquisition.
Mineable Resource Assessment, Spanish Meadow, Saguache County, Colorado
GEO-HAZ performed a Mineable Resource Assessment for a multi-lot
area within the Baca Grande subdivision, adjacent to a greenbelt south of Crestone, Colorado.
The study was requested by the conservation agency that will be holding the new
Conservation Easement on the property.
Mineable Resource Assessment, Owsley Ranch, Gunnison County, Colorado
GEO-HAZ performed a Mineable Resource Assessment for the 680-acre
Owsley Ranch, 20 miles east of Gunnison,
Colorado. The study were
requested by the conservation agency that will be holding the new Conservation
Easement on the Ranch.
Transaction Screen Report and Mineable Resource
Assessment, Wright’s Upper Ranch, Mineral County, Colorado
GEO-HAZ performed a Transaction Screen Report
and Mineable Resource Assessment for the 780-acre Wright’s Upper Ranch,
20 miles west of Creede, Colorado. These studies were requested by
the conservation agency that will be holding the new Conservation Easement on
the Ranch.
GeoHazards Division: GEOLOGIC HAZARDS
Rockfall Potential Associated With Proposed Quarrying, Crescent Park,
Jefferson County, Colorado: precarious
rocks are abundant on the steep hillslope above the Crescent Park Subdivision,
and a large quarry has been proposed on the backside of the hill. We used a
raster GIS to calculate the maximum ground motion velocities at all points on
the hillslope, given the limitations on quarry blast size stipulated by
Jefferson County. We then compared these velocities with those observed to have
toppled precarious rocks in small to moderate earthquakes. The analysis
suggested that blast vibrations would be sufficient to topple the most
precarious rocks. Based on this issue, groundwater concerns, and a lack of
mitigation by the quarry operator, the County Commissioners
denied the quarry application.
Slope Stability of the Dekker-Dallman Property, Estes Park, Colorado:
the owners of this parcel planned to excavate into the base
of the granite hillslope to enlarge the building pad, but upslope property
owners were concerned about undermining the hill. We mapped rock types, joint
orientations and spacing, and concluded that discontinuities in the granite
were not favorably oriented for sliding or wedge failure. In addition we
performed a rockfall hazard analysis using CRSP to suggest mitigation during
blasting and after a building was constructed on the pad.
Flooding and Debris Flow Hazards at River
Valley Ranch, Carbondale,
Colorado: this upscale
residential subdivision and golf course development occupies the Holocene
alluvial fans of 3 small tributaries to the Crystal River.
We dug backhoe pits on all 3 fans to characterize the type of flooding, typical
deposit thickness, and recurrence times for flood events. Based on this data,
flood mitigation measures were tailored to each drainage, ranging from
pass-through channels to debris basins.
Foundation Geology and Stability of Peterson Dam, Larimer County, Colorado:
the old earthfill Peterson Dam is slated for replacement by a slightly larger
roller-compacted concrete dam. We mapped the foundation at a scale of 1 inch=
10 feet and analyzed old faults and joints for sliding and overturning. An
additional concern was that the reservoir basin behind the dam had been created
by large-scale landsliding of the valley wall. However, detailed foundation
mapping showed that no landslide failure planes occurred beneath the dam
footprint.
Geology, Seismicity, and Stability of the Bisri Dam Area, Lebanon: we performed
photogeologic mapping and review services for the proposed Bisri Dam in Lebanon, and
analyzed possible peak ground motions from nearby earthquakes. However, due to
a Department of State ban on travel to Lebanon, we could not do field
checking.
Quaternary Faults As Possible Mining Targets, Battle Mountain, Nevada:
we mapped Quaternary fault scarps in the Basin-and-Range terrain northeast of Battle Mountain, Nevada,
for a mining exploration company. This company had previously documented that
gold deposits were associated with Quaternary normal faults nearby, and wished
to know whether a large lease block contained any Quaternary normal faults. Of
course it did. But they haven’t sent us any gold yet.
Geology and Geologic Hazards Along the Proposed Realignment
of US Highway
50 in Provo Canyon, Utah: straightening
of US Highway 50 involved cuts into historic and prehistoric landslides, so
cutslope stability was a design issue. We mapped all the historic and
prehistoric landslides, and predicted peak ground motions from possible
earthquakes for use in pseudo-static or Newmark stability analyses.
GIS Division
Historic Road Use and RS 2477 Rights of Way to
the Robacker Parcel, Jefferson County,
Colorado
GEO-HAZ reviewed historic maps and aerial photographs to
reconstruct the age of construction and abandonment of wagon roads, trails, and
automobile roads near the Robacker parcel, in the foothills of the Front Range. The analysis was performed in support of
litigation to condemn a road right of way across land adjacent to the Robacker
parcel.
Digitize Historic Geologic Maps, Aspen
Mountain, Colorado:
the Aspen Mountain Ski Area, as well as the Town of Aspen, is underlain by extensive silver mines
developed in the 1870s-1920s. We digitized the oversize, 1:10,000 geologic maps
contained in the 1890 U.S. Geological Survey Folio describing the Aspen Mining
District. We then rubber-sheeted these old maps to the modern Colorado State
Plane Coordinate System, so that the Aspen Ski Company can use the information
on mine shaft location and landslide location in its GIS system.
Digitize Seismic Hazard Maps, U.S.
Virgin Islands:
our GIS Division digitized hard-copy seismic hazard maps at 1:24,000 scale for
the U.S. Virgin Islands. Unfortunately, there was no field checking included in
this data conversion project.