Preparations for the Final Report
In March 2000, the Infrastructure Resources Project Implementation Team met to kick off preparations for a project Final Report that will provide our stakeholders with a summary of the methods and techniques for analyzing and evaluating infrastructure resources developed during the project and how to use them, a complete listing of the publications produced during the project and where they can be obtained, a description of the digital products produced by the project and where they can be obtained, and discussions of various aspects of infrastructure resources, including reclamation, land use, and resource availability issues. The Implementation Team has tentatively settled on an E-Bulletin format that can be accessed on the Internet and distributed on a CDROM. The Final Report should be available in the late summer or early fall of 2001 and will be distributed at the final stakeholder's meeting.

The tentative Final Report outline, in Rich Text Format, can be viewed or saved to a file for printing by clicking on the link below.  The Implementation Team welcomes and encourages comments and suggestions from any of our stakeholders and collaborators to help ensure that the Final Report is broadly applicable. Dan Knepper will serve as the Final Report coordinator and editor, but comments can be sent to any of the Implementation Team members (see Implementation Team for email addresses and phone numbers).

Display Outline Text File.
Boulder Creek/St. Vrain/Big Thompson River Gravels

Aggregate producers in the Denver metropolitan area have been required to move farther from the market area to obtain new gravel resources because nearby resources are being depleted through mining or have been covered by competing land uses. The gravel deposits of the Boulder Creek, St. Vrain Creek and Big Thompson River are becoming major sources of aggregate for urban development in the area.

Project scientists from the FRIRP conducted field sampling and collected data from four localities along those stream courses during the fall of 1999. The samples are being processed to determine the physical and chemical properties of the aggregate in those areas. The information is being used to prepare gravel deposit models of the Front Range urban corridor.

 


Nelson Pit

 

Airborne Electromagnetic Survey

    Helicopter electromagnetic (HEM) surveys were flown in Weld and Larimer counties of Colorado as part of the Front Range Infrastructure Project.  Detailed surveys were flown over the South Platte, Big Thompson, and St.Vrain drainages covering a total of 260 sq. kilometers (100 sq.miles). The HEM survey consists of a set of parallel flight lines spaced 200 m (1/8 mile) apart. The HEM measurements are made by a torpedo-shaped instrument pod, called a "bird" (below), which is towed below a helicopter. The bird contains electromagnetic transmitters and receivers. Each transmitter emits an electromagnetic signal that interacts with the ground. This signal is detected by the receiver. The interpreted HEM surveys give information on subsurface electrical properties from which the geologic materials and the ground-water quality can be inferred. This information is used to assess gravel and ground-water resources. Preliminary maps of the Big Thompson River and Ft. Lupton areas are shown below.

hem_takeoff.jpg (91068 bytes)
Helicopter and bird lifting off.

 Click on
thumbnail for
detailed image


greely_hem_copy.tif (502396 bytes)
Survey Area




hem_bird.tif (1180140 bytes)
Close-up of the bird

 

Big Thompson River

 Preliminary maps of apparent resistivity have been produced from helicopter electromagnetic (HEM) surveys that were flown in Weld and Larimer counties of Colorado as part of the Front Range Infrastructure Project The surveys were made using a torpedo-shaped instrument pod, called a "bird," which contains electromagnetic transmitters and sensors. Data from the sensors are used to produce the apparent resistivity maps. These maps will be used to determine the location of subsurface aggregate deposits in portions of the South Platte, Big Thompson (at right), and St. Vrain drainages. Further interpretation of the data through a process called inversion will give 3-D subsurface information that will be used by geologists to estimate the quality and amount of aggregate resources in the area. The inversion result will also provide information on ground-water resources.

 

 

Ft. Lupton Area



Click thumbnail to see a closeup of thebrine pit area. Use backbutton to return.                                           

For more information, contact Bruce Smith:
                  bsmith@usgs.gov		 One block of the airborne geophysical survey was flown just east of Ft. Lupton (see index map) to aid in mapping subsurface ground water quality. A USGS funded research study was made of the impact of surface oil-field-produced brine disposal on shallow ground water aquifers (McCormick, 1999). High subsurface conductivities shown in the map (red, yellow) can be explained by elevated dissolved solids in the ground water or clay/silt bearing sediments. The stratigraphic section for the area is Holocene eolian sands and Pleistocene loess overlaying the Araphoe Formation, which is mostly silty with some sand units. The enlargement of part of the study area shows major features in the area of brine disposal. The closed brine disposal pits were not lined and have allowed brines to leak into the local shallow subsurface aquifer. The high conductivity in the immediate area of the pits is most likely associated with subsurface brine which is on the order of 15,000 milligrams per liter dissolved solids. Ground-based  shallow electromagnetic surveys and local monitoring wells show that there is a subsurface plume of high dissolved solids extending east of the brine disposal pits. The subtle high conductivity area extending to the east of the pits correlates well with the high conductivities determined by ground geophysical surveys and water samples from monitoring wells. The airborne survey shows a somewhat larger area of possible contamination than the limited ground surveys and monitoring wells. A complicating factor in hydrologic modeling of the subsurface plume is the local irrigation canal which leaks large amounts of relatively fresh water into the local shallow aquifers. An additional complicating factor in the local ground water quality is the presence of high concentrations of organic compounds in some shallow ground water wells. The high subsurface conductivities estimated from the airborne EM survey in the area of an abandoned poultry farm suggest a possible source and distribution of high ground water dissolved solids. This source has not been evaluated with either drilling or ground geophysics.

Reference

McCormick, M.J., 1999, An investigation of oil-field produced water migration in ground water using numerical modeling and parameter estimation at Weld County Waste disposal, Fort Lupton CO., Colorado School of Mines MS Thesis, 161p.


    		
    

  




  



 



  

      

    

      
        
Seismic Data on Big Thompson Gravel Deposits

        

        The Front Range
        Infrastructure Resources Project involves, in part, an evaluation of the
        ground water and the aggregate resources within the Front Range Urban
        Corridor of Colorado. Three cities within the Urban Corridor —
        Loveland, Longmont, and Greeley — are close to the Big Thompson River
        valley, which may have significant ground water and aggregate resources.
        Presently, however, little is known about the geology of this valley.
        Therefore, a seismic survey was conducted to determine the thickness and
        the gross stratigraphy of the alluvial sediments because this
        information is needed to estimate the ground water and aggregate
        resources. The survey has been completed, and a report on the findings
        is almost finished.

        

        For more information, contact Karl Ellefsen:

                          
        kellefsen@usgs.gov

      

        Collection of seismic (S-wave)
        refraction data in the Big Thompson River valley.

      		
      

    

  



    



  

  

    

      
        Infrastructure Goes to Bath

        

        After a highly competitive
        selection process, two Infrastructure Project research scientists
        had papers selected for oral presentation at the 36th Forum on the Geology
        of Industrial Minerals and 11th Extractive Industry Geology Conference in Bath, England. Bill Langer and Belinda
        Arbogast, both research scientists with the Central Region Mineral
        Resource Team, were selected to present papers at the May 2000
        conference that will be published in
        the Proceedings of the Forum.  Bill's paper is on Aggregate
        Resources of the United States - An Overview. Belinda will present a
        paper on An Overview of Reclamation Law Dealing with Mineral Resource
        Development in the United States of America. Abstracts of these
        papers, in RTF format, can be accessed below.

        

        Langer abstract - Aggregate Resources
        Overview

        

        Arbogast abstract - Reclamation Law		
      
    

  

  




    

  

    

    

      

        Digital
          Aggregate Maps

          

           In
          1973, The Colorado Legislature passed House Bill 1529 which required
          that natural aggregate resources in the populous counties of the state
          be identified and mapped.  In response to that Bill, the Colorado Geological
          Survey prepared potential natural aggregate maps for each of 271 1:24,000-scale quadrangles in the Front Range urban corridor and
          published those maps in Colorado Geological Survey Special Publication
          5B.  These maps have been digitized by the United States
          Geological Survey, repackaged into County coverages, and jointly
          published as a CD-ROM by the Colorado Geological Survey and the USGS
          as U.S. Geological Survey Open-File Report 00-9.  The read.me
          file shown below lists the contents of the newly-published CD-ROM:

          

          READ.ME
          FILE

          

          This README file is a associated with the aggregate datasets that are a digital representation of the Colorado Geological Survey's
          Special Publication 5A/5B entitled, "Sand, Gravel, and Quarry  Aggregate Resources, Colorado Front Range Counties" by  Schwochow,
          Shroba, and Wicklein, published in 1974.  This CD-ROM contains 50 files outlined below:

          

   Metadata files:

      frir_agg.met  (applies to all aggregate datasets)

      frir_qds.met  (applies to quadrangle grid dataset)

      frir_counties.met (applies to county boundary datasets)

          

   Panelled aggregate datasets:

      frir_agg.e00

      frir_aggx.e00 

          

   Aggregate note/names files:

      agg_notes.txt

      agg_names.txt

          

   Individual county aggregate datasets:

      adaag.e00 - Adams county

      adaagx.e00

      araag.e00 - Arapahoe county

      araagx.e00

      bouag.e00 - Boulder county

      bouagx.e00

      cusag.e00 - Custer county

      cusagx.e00

      denag.e00 - Denver county

      denagx.e00

      douag.e00 - Douglas county

      douagx.e00

      elpag.e00 - El Paso county

      elpagx.e00

      gilag.e00 - Gilpin county

      gilax.e00

      hueag.e00 - Huerfano county

      hueagx.e00

      jefag.e00 - Jefferson county

      jefagx.e00

      larag.e00 - Larimer county

      laragx.e00

      pueag.e00 - Pueblo county

      pueagx.e00

      telag.e00 - Teller county

      telagx.e00

      welag.e00 - Weld county

      welagx.e00

          

   Quadrangle grid dataset:

      frir_qds.e00

          

   County boundary datasets:

      adams.e00

      arapahoe.e00

      boulder.e00

      custer.e00

      denver.e00

      douglas.e00

      elpaso.e00

      gilpin.e00

      huerfano.e00

      jefferson.e00

      larimer.e00

      pueblo.e00

      teller.e00

      weld.e00

          

          The .e00 files were created using Arc/INFO's EXPORT command at version 7.1.1.  To
          import the files as coverages, use version 7.x or higher.  The "x" in the name
          of some of the aggregate datasets indicates a point coverage.  Be sure to BUILD
          these coverages using the point option.  The .met and .txt files are ascii files.

          

        		
      

    

    

  


    

    


    

    

      

        Colorado
          Riparian Vegetation Mapping Project
          
The
          Colorado Division of Wildlife has just unveiled a new web site to
          feature its Colorado Riparian Vegetation Mapping Project. The
          Colorado Riparian Vegetation Mapping Project is spearheaded by the
          Division of Wildlife with funding primarily from Great Outdoors
          Colorado.  Other Federal (including the USGS), State, and Private
          Non-Profit groups have also contributed funding to the project over
          the years as well.  The overall goal of the project is to map
          riparian/wetland vegetation in Colorado for use in natural resource
          planning.  These data will be a valuable asset in the analysis of
          infrastructure resources.

          
 

          
Visit the
          DOW web site at:  http://ndis.nrel.colostate.edu/ndis/riparian/riparian.htm

      

    



 


    

      

        3-D
          Image of Urban Areas and Mountains of the Northern Front Range,
          Colorado

          

          USGS
          Geologic Investigations Series I-2750-A is the digital image basemap
          for a series (USGS Geologic Investigations Series I-2750 ) designed to
          present information about infrastructure resources, or other regional
          spatial information, in a manner that can be understood and
          appreciated by experts and the public alike. The 3-D image basemap
          covers much of the northern Front Range urban corridor, including the
          Denver metropolitan area and the rapidly growing areas in western
          Adams, western Arapahoe, eastern Boulder, southeastern Larimer,
          southwestern Weld, northern Douglas, and Jefferson Counties.
          

            

              
                

              
                

                Click
                Here to learn more about this new tool for portraying
                regional spatial data of the northern Front Range urban corridor
                and how you can obtain the digital image basemap for your
                application.

            

          

          
 
        

      

    

    






  

    U.S. Department of the
    Interior, U.S. Geological Survey

    URL: http://rockyweb.cr.usgs.gov/frontrange/new_news.htm 

    Contact: Dan Knepper  mailto:dknepper@usgs.gov

    Updated:    07/24/2000		
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