Geologic Map of the Kechumstuk Fault Zone in the Mount Veta Area,
Fortymile Mining District, East-Central Alaska

By Warren C. Day,1 J. Michael O’Neill,1 Cynthia Dusel-Bacon,1
John N. Aleinikoff,1 and Christopher R. Siron2

1. U.S. Geological Survey
2. Full Metal Minerals, Ltd., Vancouver, B.C., Canada

2014

Scientific Investigations Map 3291

ABSTRACT

This map was developed by the U.S. Geological Survey Mineral
Resources Program to depict the fundamental geologic features
for the western part of the Fortymile mining district of
east-central Alaska, and to delineate the location of known
bedrock mineral prospects and their relationship to rock types
and structural features.  

This geospatial map database presents a 1:63,360-scale geologic
map for the Kechumstuk fault zone and surrounding area, which
lies 55 km northwest of Chicken, Alaska. The Kechumstuk fault
zone is a northeast-trending zone of faults that transects the
crystalline basement rocks of the Yukon-Tanana Upland of the
western part of the Fortymile mining district. The crystalline
basement rocks include Paleozoic metasedimentary and metaigneous
rocks as well as granitoid intrusions of Triassic, Jurassic, and
Cretaceous age. The geologic units represented by polygons in
this dataset are based on new geologic mapping and
geochronological data coupled with an interpretation of regional
and new geophysical data collected by the Alaska Department of
Natural Resources, Division of Geological and Geophysical Surveys.
The geochronological data are reported in the accompanying
geologic map text and represent new U-Pb dates on zircons
collected from the igneous and metaigneous units within the map
area.  

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 SIM3291, 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 any such warranty.  The USGS 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
SIM3291.pdf
SIM3291.met

Datafiles directory
 
       	AK_Eagle A-4_geo.tif
       	AK_Eagle A-5_geo.tif
       
	  	AK_40_mile_Kechumstuk.gdb.zip directory (contains GIS data as
                geodatabase feature classes)
			
		Alteration
		Attitudes
		Fold_Axes
		Geology
		Geology_Lines
		Lineations
		Prospects
		SHRIMP_U_Pb_Zircon_Ages
		Topography
		Xsec_Trace			

       SIM3291_shapefiles.zip directory:
		Alteration.shp (dbf/prj/sbn/sbx/shp.xml/shx)
		Attitudes_r2.shp (dbf/prj/sbn/sbx/shp.xml/shx)	
		Fold_Axes.shp (dbf/prj/sbn/sbx/shp.xml/shx)
		Geology_area.shp (dbf/prj/sbn/sbx/shp.xml/shx)
		Geology_Lines_r2.shp (dbf/prj/sbn/sbx/shp.xml/shx
		Lineations.shp (dbf/prj/sbn/sbx/shp.xml/shx)
		Prospects.shp (dbf/prj/sbn/sbx/shp.xml/shx)
		SHRIMP_U_Pb_Zircon_Ages.shp (dbf/prj/sbn/sbx/shp.xml/shx)
		Topography
		Xsec_Trace.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/3291/ or http://dx.doi.org/10.3133/sim3291
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.