Geologic Map of the Sunshine 7.5' Quadrangle, Taos County, New Mexico

By Ren A. Thompson, Kenzie J. Turner, Ralph R. Shroba,
Michael A. Cosca, Chester A. Ruleman, John P. Lee, and
Theodore R. Brandt

2014

Scientific Investigations Map 3283

ABSTRACT

The Sunshine 7.5' quadrangle is located in the south-central part of
the San Luis Basin of northern New Mexico, in the Rio Grande del Norte
National Monument, and contains deposits that record volcanic,
tectonic, and associated alluvial and colluvial processes over the past
four million years. Sunshine Valley, named for the small locale of
Sunshine, is incised by a series of northeast-trending
drainages cut into Tertiary and Quaternary alluvial deposits forming
an extensive alluvial apron between the east flank of the
Sangre de Cristo Mountains and the Rio Grande. These deposits
predominantly overlie gently eastward-dipping lava flows of Pliocene
Servilleta Basalt erupted from centers west of the map area. Servilleta
Basalt lava flows terminate to the south against the elevated topography
of three volcanic centers of the Taos Plateau volcanic field.
From west to east these are Cerro de la Olla, Cerro Chiflo, and Guadalupe
Mountain that are exposed in the southern part of the map area.
Remnants of Miocene volcanic rocks are exposed near the southwestern edge
of the map area and record evidence of an eroded volcanic terrain
underlying deposits of the Taos Plateau volcanic field. These deposits
are likely fault bounded to the east, roughly coincident with north to
northwest trending, down-to-east faults in the southwestern quarter of
he map area. The down-to-east normal faults reflect the basinward migration
of the western margin of the Sunshine Valley sub-basin of the southern
San Luis Basin.

Pliocene and younger basin deposition was accommodated along predominantly
north-trending fault-bounded grabens and is preserved as poorly exposed
fault scarps that cut lava flows of Ute Mountain volcano, north of the
map area. The Servilleta Basalt and younger surficial deposits record
largely down-to-east basinward displacement. Faults are identified with
varying confidence levels in the map area. Recognizing and mapping
faults developed near the surface in relatively young, brittle volcanic
rocks is difficult because: (1) they tend to form fractured zones tens
of meters wide rather than discrete fault planes, (2) the relative youth
of the deposits has resulted in only modest displacements on most faults,
and (3) some of the faults may have significant strike-slip components
that do not result in large vertical offsets that are readily apparent
in offset of sub-horizontal contacts. Those faults characterized as
“certain” either have distinct offset of map units or had slip planes
that were directly observed in the field. Lineaments defined from magnetic
anomalies form an additional constraint on potential fault locations. 

DISCLAIMERS

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

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.

This database, identified as SIM 3283, has been approved for release
and publication by the U.S. Geological Survey (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 U.S. 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 (USGS), 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 USGS or the U.S
Government shall not be held liable for improper or incorrect use of
the data described and/or contained herein.

DATA FILES

List of files:
00ReadMe.txt
SIM3283.pdf
SIM3283.met

Datafiles directory
 
       sunshine_base.tif/tfw
       sunshine_hillshade.tif/tfw
       
	Sunshine_geology.gdb.zip directory
		sun_geol
			sun_geolines
			sun_labels
			sun_polygons
			sun_sample
			
       SIM3283_shapefiles.zip directory:
		sun_geolines.shp (dbf/prj/sbn/sbx/shp.xml/shx)	
		sun_labels.shp (dbf/prj/sbn/sbx/shp.xml/shx)
		sun_polygons.shp (dbf/prj/sbn/sbx/shp.xml/shx)
		sun_sample.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/3283/ or http://dx.doi.org/10.3133/sim3283
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.

ArcReader may be downloaded free of charge from
http://www.esri.com/software/arcgis/arcreader/download.htm for viewing
additional files included in this report.