Geologic Map Database of Iron Mountain East Slope for Chromite Analysis

1955 data digitized in 2001 provides a geologic map GIS of the east slope of Iron Mountain, Sweet Grass County, Montana. The database was prepared from USGS Bulletin 1015-D plate 10 by Helen Z. Kayser and Lorre A. Moyer for the USGS Open-File Report 01-321. It consists of ArcInfo datasets containing geologic contacts, structures, rock units, and structural data points.

Use Cases

• Analyze spatial relationships between chromite deposits and geologic contacts (lines) or rock units (polygons).
• Model mineral resource potential by querying the polygon file (ironmtn) for specific rock unit attributes.
• Conduct structural geology studies using point data (ironmtnp) containing measurements like strike and dip.
• Produce customized derivative geologic maps for publication by selecting specific features from the line and polygon datasets.

Strengths

• Data provides detailed geologic mapping at a scale of 1:3077 for a specific mineral-rich area.
• Database consists of two structured ArcInfo datasets: one for lines/polygons and one for points, enabling complex spatial queries.

Limitations

• Original source data is from 1955, potentially lacking modern geologic interpretations or discoveries.
• Not intended for use at scales larger than 1:3077, limiting high-resolution analysis.
• Sample size and specific row/column counts are unknown, making it difficult to assess completeness.

Provenance

Source

Digitized from plate 10 of USGS Bulletin 1015-D (Howland, 1955).

Collection Method

Digitized by Optronics Specialty Co., Inc. from a paper copy, transformed to Montana State Plane South projection, then edited and attributed.

Time Range

1955

Freshness

Original data from 1955, digitized and edited in 2001. No update frequency specified.

Geography

East slope of Iron Mountain, Sweet Grass County, Montana, USA.