GIS Coverages of the Castle Mountain Fault, South Central Alaska

Frequently anticipated questions:

• What does this data set describe?
  1. How might this data set be cited?
  2. What geographic area does the data set cover?
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
  5. What is the general form of this data set?
  6. How does the data set represent geographic features?
  7. How does the data set describe geographic features?
• Who produced the data set?
  1. Who are the originators of the data set?
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
• Why was the data set created?
• How was the data set created?
  1. From what previous works were the data drawn?
  2. How were the data generated, processed, and modified?
  3. What similar or related data should the user be aware of?
• How reliable are the data; what problems remain in the data set?
  1. How well have the observations been checked?
  2. How accurate are the geographic locations?
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
  5. How consistent are the relationships among the data, including topology?
• How can someone get a copy of the data set?
  1. Are there legal restrictions on access or use of the data?
  2. Who distributes the data?
  3. What's the catalog number I need to order this data set?
  4. What legal disclaimers am I supposed to read?
  5. How can I download or order the data?
• Who wrote the metadata?

What does this data set describe?

1. How might this data set be cited?
   Labay, K.A., and Haeussler, P.J., 2001, GIS Coverages of the Castle Mountain Fault, South Central Alaska: U.S. Geological Survey Open-File Report 01-504.

   Online Links:

   • http://pubs.usgs.gov/of/2001/of01-504/

2. What geographic area does the data set cover?

   West_Bounding_Coordinate: -150.75
   East_Bounding_Coordinate: -147.75
   North_Bounding_Coordinate: 62.00
   South_Bounding_Coordinate: 61.25
   

3. What does it look like?

   http://pubs.usgs.gov/of/2001/of01-504/images/map.jpg (JPEG)

   Index map showing the extent of the geologic map within south central Alaska, 700x391 pixels, 32-bit RGB true color, 96 kbytes.

4. Does the data set describe conditions during a particular time period?

   Calendar_Date: 2001

   Currentness_Reference:

   publication date

5. What is the general form of this data set?

   Geospatial_Data_Presentation_Form: vector digital data
   

6. How does the data set represent geographic features?
   1. How are geographic features stored in the data set?
      This is a Vector data set.
   2. What coordinate system is used to represent geographic features?
      The map projection used is Albers Conical Equal Area.
      

      Projection parameters:

      Standard_Parallel: 55
      Standard_Parallel: 65
      Longitude_of_Central_Meridian: -154
      Latitude_of_Projection_Origin: 50
      False_Easting: 0
      False_Northing: 0
      

      Planar coordinates are encoded using coordinate pair
      Abscissae (x-coordinates) are specified to the nearest 6.35
      Ordinates (y-coordinates) are specified to the nearest 6.35
      Planar coordinates are specified in meters
      
7. How does the data set describe geographic features?

   arcs

   Characteristics of the arc features in this data set are coded in the .aat, the arc attribute table. The .aat consists of the following items: CODE, CODE-PARA, and SOURCE. (Source: this data set)

   code

   Code is a positive integer value (3 3 I) item in the arc attribute table. Values range from 1 to 8. Code describes the fault types. (Source: this data set)

   Value	Definition
   1	Fault; certain location
   2	Fault; possible location
   3	Fault; approximate location
   4	Fault; concealed
   5	Fault; probable location
   7	Lineation
   8	Anticline

   code-para

   Code-para is a positive integer value (3 3 I) item in the arc attribute table. Values range from 1 to 2. Code-para distinguishes fault types that were lumped on the Detterman and others (1974) and (1976) maps. (Source: this data set)

   Range of values
   Minimum:	1
   Maximum:	2

   code-para2

   Code-para2 is a positive integer value (3 3 I) item in the arc attribute table. Values range from 0 to 1. Code-para2 distinguishes faults that show visible evidence of movement on the Detterman and others (1974) and Haeussler (1998) maps by giving them a value of 1. (Source: this data set)

   Range of values
   Minimum:	0
   Maximum:	1

   source

   Source is a character field (6 8 C) item in the arc attribute table. Source indicates which map the data originated from. (Source: this data set)

   Value	Definition
   CM001	Haeussler, 1998
   CM002	Detterman and others, 1974
   CM003	Detterman and others, 1976
   CM004	Saltus et al., 2001

   points

   Characteristics of the point features in this data set are coded in the .pat, the point attribute table. The .pat includes the following items: LOWELEVATION, HIGHELEVATION and SOURCE. (Source: this data set)

   lowelevation

   Lowelevation is a positive numeric value (3 3 N) item in the point attribute table. It contains the low elevation values given on the Detterman and others (1974) map in meters. (Source: this data set)

   Range of values
   Minimum:	0.0
   Maximum:	7.6

   highelevation

   Highelevation is a positive numeric value (3 3 N) item in the point attribute table. It contains the high elevation values given on the Detterman and others (1974) map in meters. (Source: this data set)

   Range of values
   Minimum:	0.3
   Maximum:	9.1

Who produced the data set?

1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
   • Labay, K.A.
   • Haeussler, P.J.
2. Who also contributed to the data set?

   GIS support by Keith A. Labay Raytheon ITSS contractor.

3. To whom should users address questions about the data?
   U.S. Geological Survey

   Attn: Peter J. Haeussler

   Geologist

   4200 University Drive

   Anchorage, AK
   

   USA

   907-786-7447 (voice)

   pheuslr@usgs.gov

Why was the data set created?

Provide land managers with an authoritative source for the location of the fault in the Talkeetna Mountains and Susitna Lowland. Digital maps may be displayed at any scale or projection, however the geologic data in this coverage is not intended for use at a scale larger than 1:63,360.

How was the data set created?

1. From what previous works were the data drawn?

   Detterman and others, 1974 (source 1 of 4)

   Detterman, R.L., Plafker, G., Hudson, T., Tysdal, R.G., and Pavoni, N., 1974, Surface geology and Holocene breaks along the Susitna segment of the Castle Mountain fault Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-618.

   Type_of_Source_Media: paper
   Source_Scale_Denominator: 24000
   Source_Contribution:

   Western portion of the line work and all points are based on Detterman and others, 1974

   Detterman and others, 1976 (source 2 of 4)

   Detterman, R.L., Plafker, G., Russell, G.T., and Hudson, T., 1976, Features along part of the Talkeetna segment of the Castle Mountain-Caribou fault system, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-738.

   Type_of_Source_Media: paper
   Source_Scale_Denominator: 63360
   Source_Contribution:

   Eastern portion of the line work is based on Detterman and others, 1976. Geologic line work on this map other than faults was not captured.

   Haeussler, 1998 (source 3 of 4)

   Haeussler, P.J., 1998, Surficial geologic map along the Castle Mountain fault between Houston and Hatcher Pass Road, Alaska: U.S. Geological Survey Open File Report 98-480.

   Type_of_Source_Media: ARC/INFO vector coverage
   Source_Scale_Denominator: 63360
   Source_Contribution:

   The central portion of the line work is based on Haeussler, 1998.

   Saltus et al., 2001 (source 4 of 4)

   Saltus, R.W., Haeussler, P.J., Bracken, R.E., Doucette, J.P., and Jachens, R.c., 2001, Anchorage Urban Region Aeromagnetics (AURA) project - preliminary geopysical results: U.S. Geological Survey Open File Report 01-0085.

   Type_of_Source_Media: ARC/INFO vector coverage
   Source_Scale_Denominator: 63360
   Source_Contribution: Two anticlines are based on Saltus et al., 2001.
   

2. How were the data generated, processed, and modified?

   Date: 2001 (process 1 of 2)

   The Haeussler (1998) map was the easiest to include in this compilation since it was already available digitally. Because of this the attributes from the Haeussler (1998) map were used as the basis for assigning attributes to the arcs from the other coverages. The data from the other two sources was captured by hand digitizing from folded paper maps on a GTCO digizizer into ARC/INFO coverages.
   The Detterman and others (1974) map was comprised of three unregistered aerial photographs with the fault and point locations drawn over them. In order to georeference the data it was digitized in straight table coordinates, and then registration points were established between the photographs and georeferenced images of USGS topographic maps. Due to the lack of prominent features on the photographs the registration points could not be located with as much precision as desired. To compensate for this the faults and points were rubber sheeted to the images of the topographic maps after registration. However, the locations of these faults should still be considered less accurate then those from the other sources.
   The Detterman and others (1976) map drawn over a topographic base, so it could be registered without accuracy problems. All faults on the map were digitized.
   Where there was overlap in between the three sources the Haeussler (1998) map had priority. In two cases fault positions were adjusted to connect with faults from the Haeussler (1998) map.
   One anticline was included from the Saltus et al. (2001) map.
   Together the modified fault coverages and the data from Saltus et al. (2001) comprise the coverage cmfault.
   The unmodified versions of Haeussler (1998), Detterman and others (1974), and Detterman and others (1976) can be found in cmfault_c, cmfault_w, cmfaultw_pnt, and cmfault_e respectively. The data from Saltus et al. (2001) was not modified, so it does not appear in a seperate coverage.
   The arcs and points were then attributed in ARC/INFO. For the purpose of distribution, the coverages have been converted to an interchange format file using the ARC/INFO export command. Person who carried out this activity:
   

   U.S. Geological Survey

   Attn: Keith A. Labay

   4200 University Drive

   Anchorage, AK
   

   USA

   907-786-7410 (voice)

   klabay@usgs.gov

   Date: 03-Jan-2002 (process 2 of 2)

   Creation of original metadata record Person who carried out this activity:
   

   U.S. Geological Survey

   Attn: Keith A. Labay

   4200 University Drive

   Anchorage, AK
   

   USA

   907-786-7410 (voice)

   klabay@usgs.gov

3. What similar or related data should the user be aware of?

How reliable are the data; what problems remain in the data set?

1. How well have the observations been checked?
   Data attribute accuracy is tested by manual comparison of the source with hard copy plots and/or symbolized display of the map data on an interactive computer graphic system. Selected attributes that cannot be visually verified on plots or on screen are interactively queried and verified on screen.
2. How accurate are the geographic locations?
   The data from the Detterman and others (1974) map should be considered less accurate than the data from the other maps.
   Users of this digital geologic map should respect the intentions of the original mappers and the limitations of the map. This geologic map compilation is intended to be used at a scale of 1:63,000; it is not intended to be used at a more detailed scale.
3. How accurate are the heights or depths?
   
4. Where are the gaps in the data? What is missing?
   This data set is comprised of only the faults or elevation points from each source. Other information about the geology such as contacts between units or points without elevation values was not included.
5. How consistent are the relationships among the observations, including topology?
   This data set contains line coverages with arcs that represent faults, linements, or anticlines. Each arc has been assigned a code that indicates what type of feature it represents.
   This data set also contains point coverages that represent high and low elevations along the fault.

How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?

Access_Constraints: None
Use_Constraints:

Acknowledgement of the U.S. Geological Survey would be appreciated in products derived from this data.

1. Who distributes the data set? (Distributor 1 of 1)
   
   USGS Information Services

   Box 25286

   Denver Federal Center

   Denver, CO
   

   USA

   303-202-4200 or 1-888-ASK-USGS (voice)
2. What's the catalog number I need to order this data set? USGS Open-File Report 01-504
3. What legal disclaimers am I supposed to read?

   Although this data has been used by the USGS, no warranty, expressed or implied, is made by the USGS as to the accuracy of the data and related materials. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the USGS in the use of these data, software, or related materials.

4. How can I download or order the data?
   • Availability in digital form:

     Data format:	Geologic units, faults, and other structural features in format ARCE (version 7.2.1) Size: 0.5
     Network links:	http://pubs.usgs.gov/of/2001/of01-504/cmfault.e00 http://pubs.usgs.gov/of/2001/of01-504/cmfault_pnt.e00 http://pubs.usgs.gov/of/2001/of01-504/cmfault_e.e00 http://pubs.usgs.gov/of/2001/of01-504/cmfault_c.e00 http://pubs.usgs.gov/of/2001/of01-504/cmfault_w.e00 http://pubs.usgs.gov/of/2001/of01-504/cmfaultw_pnt.e00

   • Cost to order the data: none

Who wrote the metadata?

Dates:

Last modified: 05-Feb-2016
Last Reviewed: 25-Jan-2002

Metadata author:

Peter N Schweitzer

USGS Midwest Area

Collection manager, USGS Geoscience Data Clearinghouse, http://geo-nsdi.er.usgs.gov/

Mail Stop 954

12201 Sunrise Valley Dr

Reston, VA

USA

703-648-6533 (voice)

703-648-6252 (FAX)

pschweitzer@usgs.gov

Metadata standard:

Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)