Aeromagnetic expression of buried basaltic volcanoes near Yucca Mountain, Nevada

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?
   O'Leary, Dennis W., Mankinen, Edward A., Blakely, Richard J., Langenheim, Victoria E., and Ponce, David A., 2002, Aeromagnetic expression of buried basaltic volcanoes near Yucca Mountain, Nevada: Open-File Report 02-20, Geological Survey (U.S.), Menlo Park, California.

   Online Links:

   • http://pubs.usgs.gov/of/2002/of02-020/

2. What geographic area does the data set cover?

   West_Bounding_Coordinate: -116.6575
   East_Bounding_Coordinate: -116.403889
   North_Bounding_Coordinate: 36.895278
   South_Bounding_Coordinate: 36.500556
   

3. What does it look like?
4. Does the data set describe conditions during a particular time period?

   Calendar_Date: 2002

   Currentness_Reference:

   publication date

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

6. How does the data set represent geographic features?
   1. How are geographic features stored in the data set?
      This is a Point data set. It contains the following vector data types (SDTS terminology):
      • Entity point (19)
   2. What coordinate system is used to represent geographic features?
      Horizontal positions are specified in geographic coordinates, that is, latitude and longitude. Latitude and longitude values are specified in decimal degrees. The horizontal datum used is World Geodetic System 1984.
      The ellipsoid used is WGS 84.
      The semi-major axis of the ellipsoid used is 6378137.
      The flattening of the ellipsoid used is 1/298.257.
      
7. How does the data set describe geographic features?

   2002-020.dbf

   Tabulated labels and features of the magnetic anomalies thought to represent buried volcanic centers in Crater Flat and Amargosa Desert area, Nevada. Table 1 of the report.

   RANK

   Value	Definition
   confirmed
   equivocal
   high confidence
   low confidence
   probable

   ANOMALY_1

   Anomaly label in this report

   Range of values
   Minimum:	A
   Maximum:	S

   ANOMALY_2

   Anomaly label in PVHA report

   Range of values
   Minimum:	A
   Maximum:	G

   ANOMALY_3

   Anomaly label in Connor and others, 2000

   Value	Definition
   (no value)
   A
   AAA
   AAB
   AAC
   AAD
   AAE
   C

   ANOMALY_4

   Anomaly label in Langenheim, 1995

   Value	Definition
   (no value)
   B
   C
   D
   E
   F

   LATITUDE

   Geographic latitude

   Range of values
   Minimum:	36.500555560
   Maximum:	36.895277780
   Units:	decimal degrees

   LONGITUDE

   Geographic longitude

   Range of values
   Minimum:	-116.65750000
   Maximum:	-116.40388890
   Units:	decimal degrees

   POLARIZ

   Polarization of the anomaly

   Value	Definition
   negative
   positive

   AMP_NT

   Amplitude of the anomaly, in nanoTeslas at ground level

   Value	Definition
   (no value)
   70-150
   600
   850
   912 and -1247
   approx 1000

   DEPTHTOTOP

   Estimated depth to top of the structure, in meters, with divergent interpretations given with references

   Value	Definition
   (no value)
   approx 50
   approx 150
   approx 150 (Langenheim and others, 1993); 73 (Carr and others, 1995)
   approx 175 (Langenheim, 1995)
   approx 200 (Langenheim, 1995)
   approx 206 (Langenheim, 1995)
   approx 220
   approx 250

   ANOM_CHAR

   Characteristics of the anomaly or body

   Value	Definition
   (no value)
   approx 77m thick (Carr and others, 1995)
   Extends NW, has double peak
   F, G, H form NE alignment
   L, M, N, O form NE alignment

Who produced the data set?

1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
   • O'Leary, Dennis W.
   • Mankinen, Edward A.
   • Blakely, Richard J.
   • Langenheim, Victoria E.
   • Ponce, David A.
2. Who also contributed to the data set?
3. To whom should users address questions about the data?
   Edward A Mankinen

   USGS WR SW GD

   345 Middlefield Road

   Mail Stop 937

   Menlo Park, CA
   

   USA

   650-329-4669 (voice)

   650-329-4664 (FAX)

   emank@usgs.gov

Why was the data set created?

The geologic record of Plio-Pleistocene volcanism near Yucca Mountain (Crowe and others, 1995) implies that basaltic volcanism could recur within the next million years and perhaps pose a hazard to a potential nuclear waste repository at Yucca Mountain. As part of the Yucca Mountain site characterization program, a probabilistic volcano hazards analysis (PVHA) was carried out (Geomatrix Consultants, 1996). Available information on the locations and ages of Plio-Pleistocene volcanic centers was considered by the PVHA experts and used to characterize the locations, rates, and uncertainties associated with future volcanic activity. The analysis used USGS aeromagnetic survey data (Langenheim and others, 1993) in considering buried volcanic centers.

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?

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: none

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

   Box 25286, Denver Federal Center

   Denver, Colorado
   

   USA

   1-888-ASK-USGS (voice)

   1-303-202-4695 (FAX)

   infoservices@usgs.gov
2. What's the catalog number I need to order this data set? USGS Open-File Report 02-020
3. What legal disclaimers am I supposed to read?

   This report is preliminary and has not been reviewed for conformity with U.S. Geological Survey editorial standards (or with the North American Stratigraphic Code). Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.

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

     Data format:	Anomaly locations and interpretive information about them in format Shapefile (version 1.0)
     Network links:	http://pubs.usgs.gov/of/2002/of02-020/data/of02-020.zip

   • Cost to order the data: none

Who wrote the metadata?

Dates:

Last modified: 23-Feb-2015

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)