Structural geology is the science that studies the architecture of the earth, from the scale of the crust, down to the imperfections within deformed minerals. It also attempts to uderstand the history of deformation that led to the existing architecture and then relate that history to the forces that caused deformation. It borrows from geometry, trignometry, continuum mechanics, physical chemistry, material science, and many other disciplines.
The three following questions are often asked in trying to understand the structural geology of a region, and in part this course is organized around these questions. 1) What is the architecture of the rocks in this area? This is the descriptive portion and involves language acquisition and three dimensional geometric models. Maps, cross-sections, drill holes and seismic sections are some of the basic data used for developing these models. 2) What was the history of movements that produced this architecture? This is often referred to as kinematic analysis, and the concept of a deformation path is a important here. 3) What are the forces that shaped that history? Here we are interested in the dynamics and physics, the driving forces involved.
In the above photo are Triassic strata from Svalbard that have been uplifted, tilted and folded as part of a Tertiary age fold-thrust belt. How come some layers are folded and others are not? How much longer were the strata when they were unfolded? Did folding occur after tilting or before? How do these structures related to regional crustal deformation and plate motions at the time? These are the types of questions asked in structural geology.
What are some of these forces that might cause deformation?
If you have questions or comments please contact Harmon D. Maher Jr. (firstname.lastname@example.org.), Department of Geography & Geology, University of Nebraska, Omaha, NE 68182