Title
2011 Rock Properties Database: Density, Magnetic Susceptibility, and Natural Remanent Magnetization of Rocks in Minnesota
Published Date
2015-11-19
Authors
Group
Minnesota Geological Survey
Author Contact
Minnesota Geological Survey (mgs@umn.edu)
Type
Dataset
Spatial Data
Observational Data
Abstract
Geologic interpretation of gravity and magnetic anomaly data in a given area is greatly enhanced if
density, magnetic susceptibility (MS) and natural remanent magnetization (NRM) data are available for
representative rock-types (Chandler and others, 2008). Along with geologic information from outcrop
and drill-holes, rock property data help relate geophysical anomaly signatures to probable rock types,
and provide constraints on the use of anomaly data as a tool for mapping and for modeling geology at
depth. Rock property data are particularly important to Minnesota where Precambrian rocks, which
comprise the bulk of the bedrock surface, are associated with a wide range of density, MS and NRM
values and are mostly under a thick cover of unconsolidated glacial sediments.
Description
The current database consists of location 9,032 entries. The surface-based, point data include
5,272, 6,939, and 903 density, magnetic susceptibility, and NRM measurements, respectively. Downhole
data from 146 drillcore have also been incorporated, yielding an additional 1,145 and 9,622
measurements of density and magnetic susceptibility, respectively. Finally, the location of new and
some pre-existing rock property sites was improved by using outcrop polygons and improved base-map
overlays to adjust point locations to most-likely positions as necessary. Thus, the revised database
represents a significant improvement in size, types of material, and quality, and should serve the needs
of the MGS and the broader geologic community for many years to come. The thumbnail was taken from a figure in the report that shows the point locations in the 2011 rock property database superimposed on the 2011 bedrock geology map of Minnesota.
Referenced by
Chandler, V.W; Lively, R.S. (2011). Density, Magnetic Susceptibility, and Natural Remanent Magnetization of Rocks in Minnesota: An MGS Rock Properties Database. Minnesota Geological Survey. Retrieved from the University of Minnesota Digital Conservancy, http://hdl.handle.net/11299/175580
Replaces
2003 MGS Rock Properties Database
License
Depositor did not specify a license. Material may be reused with appropriate attribution.
Suggested Citation
Chandler, V.W; Lively, R.S.
(2015). 2011 Rock Properties Database: Density, Magnetic Susceptibility, and Natural Remanent Magnetization of Rocks in Minnesota.
Retrieved from the Data Repository for the University of Minnesota,
http://dx.doi.org/10.13020/D63S3D.
