Geologic map of the Cochiti Dam quadrangle, Sandoval County, New Mexico

By David P. Dethier, Ren A. Thompson, Mark R. Hudson, Scott A. Minor, and David A. Sawyer 

2011

Scientific Investigations Map 3194

ABSTRACT
The Cochiti Dam quadrangle is located in the southern part of the Espaņola Basin and contains sedimentary and volcanic deposits that record alluvial, colluvial, eolian, tectonic and volcanic processes over the past seventeen million years. The geology was mapped from 1997 to 1999 and modified in 2004 to 2008. The primary mapping responsibilities were as follows: Dethier mapped the surficial deposits, basin-fill sedimentary deposits, Miocene to Quaternary volcanic deposits of the Jemez volcanic field, and a preliminary version of fault distribution. Thompson and Hudson mapped the Pliocene and Quaternary volcanic deposits of the Cerros del Rio volcanic field. Thompson, Minor and Hudson mapped surface exposures of faults and Hudson conducted paleomagnetic studies for stratigraphic correlations. Thompson prepared the digital compilation of the geologic map.

The mapped distribution of units is based primarily on interpretation of 1:16,000-scale, color aerial photographs taken in 1992, and 1:40,000-scale, black-and-white, aerial photographs taken in 1996. Most of the contacts on the map were transferred from the aerial photographs using a photogrammetric stereo-plotter and subsequently field checked for accuracy and revised based on field determination of allostratigraphic and lithostratigraphic units. Determination of lithostratigraphic units in volcanic deposits was aided by geochemical data, 40Ar/39Ar geochronology, aeromagnetic and paleomagnetic data. Supplemental revision of mapped contacts was based on interpretation of USGS 1-meter orthoimagery. 


DISCLAIMERS
This database, identified as SIM3194, has been approved for release and publication by the Director of the USGS.  Although this database has been subjected to rigorous review and is substantially complete, the USGS reserves the right to revise the data pursuant to further analysis and review.Furthermore, it is released on condition that neither the USGS nor the United States Government may be held liable for any damages resulting from its authorized or unauthorized use.

Although these data have been processed successfully on a computer system at the U.S. Geological Survey, no warranty, expressed or implied is made regarding the display or utility of the data on any other system, or for general or scientific purposes, nor shall the act of distribution constitute such warranty.  The U.S.Geological Survey shall not be held liable for improper or incorrect use of the data described and/or contained herein.

Any use of trade, product or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Geological Survey.

Although this information product, for the most part, is in the public domain, it also contains copyrighted material as noted in the text.  Permission to reproduce copyrighted items for other than personal use must be secured from the copyright owner.

DATA FILES

List of files:
00ReadMe.txt
SIM3194_map.pdf
SIM3194.met

Datafiles: 
Cochiti_Dam_base.tif 
Cochiti_Dam_base.tfw 
Cochiti_Dam_hillshade.tif
Cochiti_Dam _hillshade.tfw

Cochiti.gdb directory (contains GIS data as geodatabase feature classes)
	Geology
	    Contacts
	    Flow_Directions
	    Lineament
	    Polygons
	    Sample
	    Strike_Dip
	    Unit_label
	    
Cochiti_shapefiles.zip directory:
     CochitiAMLineament.shp (dbf/prj/sbn/sbx/shp.xml/shx)
	CochitiBoundary.shp (dbf/prj/sbn/sbx/shp.xml/shx)
	CochitiContacts.shp (dbf/prj/sbn/sbx/shp.xml/shx)
	CochitiFlow_Directions.shp (dbf/prj/sbn/sbx/shp.xml/shx)	
	CochitiPolygons.shp (dbf/prj/sbn/sbx/shp.xml/shx)
	CochitiSample.shp (dbf/prj/sbn/sbx/shp.xml/shx)
	CochitiStrikeDip.shp (dbf/prj/sbn/sbx/shp.xml/shx)
	CochitiUnitLabel.shp (dbf/prj/sbn/sbx/shp.xml/shx)
	
HOW TO OBTAIN THE DIGITAL FILES

The digital files constituting the geologic map database of this report can be obtained via the Internet from the U.S.Geological Survey publications website. Go to the web page at
http://pubs.usgs.gov/sim/3194/ and follow the directions 
to download the files.

The main product is a Portable Document Format (.pdf) map,
which requires Adobe Acrobat for viewing, and from which paper copies may be printed.  Acrobat software runs on a variety of systems, and is available for download free of charge from Adobe at http://www.adobe.com.