Structural Measurement Atlas
Atlas / States / Maryland

Maryland strike and dip data

7,038 structural measurements in Maryland, digitized from 14 published geologic maps across 4 sources. Every row carries its azimuth, inclination, measurement type, location confidence and the citation of the map it came from.

Open Maryland on the map

What kinds of measurement

The Atlas separates planar structures, recorded as a strike and dip, from linear ones, recorded as a trend and plunge. This is what Maryland holds:

Measurement typeGeometryMeasurementsShare
Other Planar — strike and dip 2,99243%
Bedding Planar — strike and dip 2,34433%
Cleavage Planar — strike and dip 1,36719%
Foliation Planar — strike and dip 1823%
Lineation (mineral, stretching) Linear — trend and plunge 56<1%
Fold hinge / axis Linear — trend and plunge 54<1%
Joint Planar — strike and dip 37<1%
Vein / dike Planar — strike and dip 6<1%

Where the data comes from

Each source is a survey, agency or program whose published mapping was harvested and reconciled into one schema. Rows are published only where the source's terms permit redistribution.

SourceMeasurementsShare
NGMDB legacy quads 3,18245%
USGS NGMDB GeMS 2,40034%
Maryland Geol. Survey 1,45021%
USGS data releases · MRDS 6<1%

Most-measured published maps

The individual quadrangles and data releases contributing the most measurements in Maryland. The full citation for every map behind a selection ships in the sources.csv of any export.

Published mapYearScaleMeasurements
Geologic map database of the Washington DC area featuring data from three 30 X 60 minute quadrangles: Frederick, Washington West, Fredericksburg2001 1:100,0001,537
Washington & Frederick County 2022 geologic structure 1:24,0001,450
Brezinski, D.K., 2009, Geologic map of Keedysville and parts of Shepherdstown, Harpers Ferry and Charles Town quadrangles, Washington and Frederick Counties, Maryland2009 1:24,0001,124
Geologic Map of the Funkstown Quadrangle, Washington County, Maryland2009 1:24,000903
Bedrock and Surficial Geologic Map of Garrett and Allegany Counties, Maryland2025 1:100,000714
Brezinski, D.K., and J.L. Fauth. 2005, Geologic Map of the Middletown Quadrangle, Frederick and Washington Counties, Maryland, Maryland Geological Survey, Baltimore MD.2005 1:24,000711
Brezinski, D.K., and Fauth, J.L., 2009, Geologic Map of the Myersville Quadrangle and Maryland portion of the Smithsburg Quadrangle, Washington and Frederick Counties, Maryland. Maryland Geological Survey, Baltimore, MD.2009 1:24,000565
Geologic map of the Washington West 30’ × 60’ quadrangle, Maryland, Virginia, and Washington D.C.2017 1:100,00028
Birdseye Mine — https://mrdata.usgs.gov/mrds/show-mrds.php?dep_id=102186031860 1
Mineral Hill Mine — https://mrdata.usgs.gov/mrds/show-mrds.php?dep_id=10242703 1
New London Mine — https://mrdata.usgs.gov/mrds/show-mrds.php?dep_id=101945241945 1
Patapsco Mines — https://mrdata.usgs.gov/mrds/show-mrds.php?dep_id=10145484 1
Springfield Mine — https://mrdata.usgs.gov/mrds/show-mrds.php?dep_id=10267263 1
Unnamed Mine — https://mrdata.usgs.gov/mrds/show-mrds.php?dep_id=10169984 1

Most-measured map units

Where a source recorded the geologic unit a measurement was taken on, the Atlas keeps it. These are the units carrying the most measurements in Maryland.

Map unitAgeLithologyMeasurements
Catoctin Formation - massive metabasalt Zcm Late ProterozoicMeta-mafic rock246
Catoctin Formation - massive metabasalt Zcm Late ProterozoicMetaigneous rock239
Weverton Formation - Buzzard Knob Member Cwb CambrianQuartzite214
Zcm 206
Basement Gneiss Complex - leucocratic gneiss Ygl Middle ProterozoicMedium and high-grade regional metamorphic rock, of unspecified origin196
Conococheague Formation - Elbrook Formation Ce CambrianLimestone172
Chilhowee Group - Harpers Formation Ch CambrianSlate and phyllite, of sedimentary-rock origin144
Tomstown Formation - Dargan Member Ctd CambrianDolomite115
Dh 114
Tomstown Formation - Bolivar Heights Member Ctbh CambrianDolomite111
Df 110
Pc 97

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