Cross section (geology)

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An example of a geologic cross section
A cross section of the Anadarko Basin. The letters A and B at the top correspond to the line labeled A--B on the smaller map. In this example, the vertical scale is exaggerated compared to the horizontal scale.

In geology, a cross section or cross-section, also known as a geologic(al) section, is a diagram representing the geologic features intersecting a vertical plane.

Description

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A cross section is drawn as a vertical map, as if the ground had been cut open and exposed along a given line. Various lines, colors, patterns, and symbols are used to represent different rock sections and features. Because the length of the studied area is often much greater than the depth, the diagram's scale can be vertically exaggerated to emphasize the depth or height of features and make them more visible. The plane a cross section illustrates is typically labeled as a line on a map of the surrounding region.[citation needed]

An example cross section of an anticline with a dike cutting through, with the map of its surface expression showing strike and dip information

Cross sections are made by interpreting and extrapolating a broad range of information about a region's geological characteristics. This can include data from the surface, subsurface, and existing geological maps. Analyzed data can include rock samples, structure orientation, boreholes, relationships between structures, seismic surveys, etc.[1] Because much of the extrapolated information cannot be directly observed, there is an inherent amount of uncertainty about the accuracy of the final product.[2][3]

Terminology

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The diagram is variously known as a cross section,[4][5][6] geologic(al) section,[7] or simply section.[8]

Uses

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It is used to illustrate an area's structure and stratigraphy that would otherwise be hidden underground. The features described in a cross section can include rock units, faults, topography, and more. They often accompany geological maps, complementing the overhead view with a side-on view, which can help to visualize the three-dimensional structure of the region and clarify the relationships between features.[9][1]

See also

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References

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  1. ^ a b "The geological cross-sections. Institut Cartogràfic i Geològic de Catalunya". www.icgc.cat. Retrieved 14 November 2021.
  2. ^ Randle, Charles H.; Bond, Clare E.; Lark, R. Murray; Monaghan, Alison A. (24 April 2018). "Can uncertainty in geological cross-section interpretations be quantified and predicted?". Geosphere. 14 (3): 1087–1100. Bibcode:2018Geosp..14.1087R. doi:10.1130/GES01510.1. hdl:2164/10441. ISSN 1553-040X.
  3. ^ Lark, R. M.; Thorpe, S.; Kessler, H.; Mathers, S. J. (17 July 2014). "Expert modelling of a geological cross-section from boreholes: sources of uncertainty and their quantification" (PDF). Solid Earth Discussions. 6 (2): 1687. Bibcode:2014SolED...6.1687L. doi:10.5194/sed-6-1687-2014.
  4. ^ "16.1: Introduction to Geological Maps and Cross-sections". Geosciences LibreTexts. 16 June 2021. Retrieved 28 September 2025.
  5. ^ Genge, Matthew J., "Geological cross-sections", Geological Field Sketches and Illustrations: A Practical Guide (Oxford, 2019; online edn, Oxford Academic, 19 Dec. 2019), accessed 28 September 2025.
  6. ^ "The geological cross-sections". icgc. Retrieved 28 September 2025.
  7. ^ "Geological sections, 1817-1819". Geological sections. Retrieved 28 September 2025.
  8. ^ Marjoribanks, Roger W. (1997). "Geological Mapping in Exploration". Geological Methods in Mineral Exploration and Mining. Dordrecht: Springer Netherlands. p. 9–30. doi:10.1007/978-94-011-5822-0_2. ISBN 978-94-010-6459-0. Retrieved 28 September 2025.
  9. ^ Stieglitz, Ronald D. (1988), "Cross-sections", General Geology, Encyclopedia of Earth Science, Dordrecht: Kluwer Academic Publishers, pp. 100–103, doi:10.1007/0-387-30844-x_21, ISBN 978-0-442-22499-8, retrieved 14 November 2021
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