Lithostratigraphy Quiz



9 Questions

What is a geological formation?

What is the fundamental unit of lithostratigraphy?

What must a formation be in order to be mapped at the surface or traced in the subsurface?

What are the boundaries of a formation chosen for?

What characteristics are included in the lithology of a formation?

What is the purpose of formally designating a formation?

What is a stratotype?

What are geological formations typically named after?

What is the informal use of the term 'formation'?


Fundamental Unit of Lithostratigraphy: Summary

  • A geological formation is a body of rock with a consistent lithology that distinguishes it from adjacent rock bodies and occupies a particular position in the stratigraphic column.
  • Formations are the fundamental unit of lithostratigraphy, the study of strata or rock layers.
  • A formation must be large enough that it can be mapped at the surface or traced in the subsurface.
  • Formations are tabular and may consist of a single lithology or a heterogeneous mixture of lithologies.
  • Geologic maps showing where various formations are exposed at the surface are fundamental to fields such as structural geology.
  • The boundaries of a formation are chosen to give it the greatest practical lithological consistency.
  • The lithology of a formation includes characteristics such as chemical and mineralogical composition, texture, color, primary depositional structures, and fossils regarded as rock-forming particles.
  • The contrast in lithology between formations required to justify their establishment varies with the complexity of the geology of a region.
  • Geologic formations are typically named after a permanent natural or artificial feature of the geographic area in which they were first described.
  • As with other stratigraphic units, the formal designation of a formation includes a stratotype, which is usually a type section.
  • The definition and recognition of formations allow geologists to correlate geologic strata across wide distances between outcrops and exposures of rock strata.
  • "Formation" is also used informally to describe the odd shapes (forms) that rocks acquire through erosional or depositional processes.


Test your knowledge on the fundamental unit of lithostratigraphy with this informative quiz! Learn about the characteristics and boundaries of geological formations and their importance in fields such as structural geology. Challenge yourself to identify the key components of a formation's lithology and the reasons for their establishment and naming conventions. Sharpen your understanding of geologic maps and the correlation of strata across different areas. Don't miss the opportunity to expand your knowledge on this fascinating topic!

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