HomeMy WebLinkAbout982311.tiff GEOLOGIC AND MINERAL
EVALUATION FOR THE PROPOSED
INTERMILL MINOR SUBDIVISION
WELD COUNTY, COLORADO
Prepared for
Intermill Land Surveying
1301 North Cleveland Avenue
Loveland, Colorado 80537
January 17,1998
Commission No.: 1119-87-01-01
Prepared By
FOUNDATION & SOILS ENGINEERING, INC.
5110 Granite Street, Suite D
Loveland, Colorado 80538
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TABLE OF CONTENTS
Transmittal Letter I
Scope 1
Site Description 1
Site Investigation 2
Geology 2
Potential Geologic Hazards and Recommendations 3
Potential Mineral Resources 4
Conclusion 4
List of References 7
Geologic & Vicinity Map Figure 1
Sand, Gravel, & Quarry Aggregate Resources Figure 2
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FOUNDATION Engineering,
AND SOILS II Inc.
January 17, 1998
Commission No.: 1116-87-01-01
Intermill Land Surveying
1301 North Cleveland Avenue
Loveland, Colorado 80537
Gentlemen:
The enclosed report presents the results of a geologic and mineral evaluation for Intermill Minor
Subdivision, a proposed subdivision of Weld County, Colorado.
We appreciate the opportunity to be of service to you on this project. If you have any questions,
please feel free to call.
Respectfully,
Thomas W. Finley,
Engineering Geologist
FOUNDATION & SOILS ENGINEERING, INC.
TWF/jle
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5110 Granite Street, Suite D • Loveland,Colorado 80538 • (970)663-0138 • Fax (970) 663-1660
515 Main Street,Suite C • Longmont,Colorado 80501 • (303) 702-0661
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SCOPE
The following report presents the results of our geologic and mineral evaluation for Remington Place
Minor Subdivision,a proposed subdivision situate in the Southwest Quarter of Section 20,Township
6 North, Range 64 West of the 6th Prime Meridian, Weld County, Colorado.
It is our understanding that the 34.99+acre site is to be divided into five (5)residential lots ranging
in size from 6.3 acres to 7.9 acres. The purpose of this investigation is to identify potential geologic
hazards and potential mineral resources which may conflict with the development intended. The
conclusions and recommendations presented in this report are based upon the acquired field data,
review of the available literature, and previous experience with similar geologic conditions in this
area.
SITE DESCRIPTION
The site is located northeast of Greeley, east of County Road No. 51 on the north side of County
Road No. 66. The parcel consists of a fallow and/or grassy field with a general,gradual slope to the
south and southeast. A small irrigation pond is located near the county road on the future Lot 5. An
existing gas well and tank battery are located near the center of the property on the future Lot 4.
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SITE INVESTIGATION
The site was visually inspected on January 16, 1998. The locations of geologic features are
approximate and should be considered only to the degree implied by the methods used to make those
measurements. A preliminary radiation survey was also conducted at this time.
GEOLOGY
The proposed site lies near the eastern edge of the Colorado Piedmont Section of the Great Plains
Physiographic Province. The Colorado Piedmont is an elongated trough in the Great Plains,adjacent
to the Front Range of the Southern Rockies. The Colorado Piedmont was formed when uplift of the
area in Miocene-Eocene times (20 - 50 million years ago) produced an increase of stream erosion
resulting in scouring next to the foothills and outlying areas. The Piedmont is bordered by the
southern Rockies to the west, Great Plains escarpment to the northeast, and Palmer Divide to the
south. The boundary of the eastern edge Colorado Piedmont is not well defined.
Structurally, the site lies in the Denver Basin, which is a thick accumulation of Paleozoic and
Mesozoic Era sediments involved with down warping in the basin area and uplift of the adjacent
highlands. It is our understanding that faulting has not taken place in the recent historic past in this
area. This area is classified as being in Seismic Zone 1 (Uniform Building Code- Chapter 23).
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The site is overlain with surficial residual and eolian sandy soils. These soils consist primarily of
sand, silt, and clay with anticipated thicknesses of four (4) feet or more. The Soil Conservation
Service maps indicate the northeast section of the property is overlain with potentially flooded areas
associated with a natural drainage.
The Upper Cretaceous Laramie Formation underlies the surficial soils. The Laramie Formation
consists of shale, sandstone and minor coal beds and is considered a potential uranium source. The
thickness of Laramie Formation is in the order of several hundred feet in this area. Outcrops of the
bedrock were not observed.
POTENTIAL GEOLOGIC HAZARDS AND
RECOMMENDATIONS
The shales of the Laramie Formation and associated soils may be potentially expansive. The effects
of the potentially swelling and/or collapsible soil and rock can be minimized by careful planning
prior to construction at the site. A geotechnical investigation should be conducted at each site to
identify if these conditions exist. Our preliminary radiation survey detected no radiation levels
higher than background levels. Sandstones of the Laramie Formation have been considered a
potential uranium deposit. We recommend that preliminary radon mitigation measures be
incorporated in the construction of the homes at the site and that homes be tested for radon after a
normal living routine has been established.
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POTENTIAL MINERAL RESOURCES
The Colorado Geological Survey describes part of this site as being in a non-resource area.
Therefore, we believe that there are no economically extractable mineral resources (excluding oil,
gas, and uranium) on the property.
CONCLUSION
Potential geologic hazards such as expansive soils may be located in various areas of the property.
A geotechnical investigation should be conducted for each building site. Pre-mitigation radon
control methods,such as subslab piping,as well as radon tests are recommended. Economic mineral
resources were not found in the property.
In conclusion, we feel that the development intended is compatible with the geologic conditions at
the site provided the recommendations in this report are met.
The data presented herein were collected to help determine the feasibility of this project.
Professional judgments on design alternatives and criteria are presented in this report. These are
based on evaluation of technical information gathered, partly on our understanding of the
characteristics of the development proposed, and partly on our experience with geologic conditions
in the area. We do not guarantee the performance of the project in any respect,only that our geologic
study and judgments rendered meet the standard of care of our profession.
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LIST OF REFERENCES
Schwochow, S.D., Schroba R.R., and Wicklein, P.C., Atlas of Sand, Gravel, and Quarry Aggregate
Resources-Colorado Front Range Counties,Colorado Geological Survey, Special Publication 5-B,
1974.
Rogers,W.P. Ladwig,L.R.,Hornbaker,A.L., Schwochow, S.D.,Hart, S.S., Shelton,D.C., Scroggs,
D.L.,and Soule,J.M.,Guidelines and Criteria for Identification and Land-Use Controls of Geologic
Hazard and Mineral Resource Areas, Colorado Geological Survey, Special Publication 6, 1974.
Shelton, David C. And Rogers,William P. Environmental and Engineering Geology of the Windsor
Study Area. Larimer and Weld Counties, Colorado, Colorado Geological Survey, Environmental
Geology 6, 1987.
Tweto, Ogden, Geologic Map of Colorado, US Geological Survey, 1979
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