One of the more interesting aspects of geology is the concept of a dynamic earth. The aspect of geology that most interests me, and has done for many years, is large-scale tectonics and structural geology. What makes it so interesting is not only the scale of the processes that occur but the range of features that can result at smaller scales. These tell-tale signs at the outcrop-scale are what entices a structural geologist, and the ability to observe, identify, record, synthesise, and interpret these features is what make a great structural geologist.
Since July 2013, Dr. Philip Prince of Virginia Tech has been publishing sandbox-style geological models to YouTube on his channel ‘TheGeoModels‘. These models range in complexity and include generic models of structural settings, and real-world analogues such as the Appalachian Mountains which include supporting videos filmed on outcrops to discuss outcrop-scale features such as fabrics, folds, rock types, and mineralogy.
The videos portray interesting structural stories which include ongoing commentary to assist in explaining the ongoing development of the respective geological setting.
Below are two contrasting structural settings:
- The first video shows the development of a rift basin (extension) followed by an inversion (later shortening). The model does a great job of exhibiting the faults that typically form and how faults interact and reactivate in an evolving structural regime. What’s great about this example is that it show how complex real-world geological settings can be; I regularly remind myself of the phrase commonly used by renowned structural geologist Rick Sibson – “Mother Nature is a bitch”.
- The second video, entitled “Mountain building: Uplift, erosion and exhumation” shows the development of thrust sheets and the process of tectonic burial during a continent-continent collision event. This video does a great job of also displaying the process of erosion and providing a look into the structures and orientations you might expect to observe at certain parts of an active or completely eroded orogen (such as an Archean orogen).
So take the time to watch a few of these videos. Many of the concepts are well known by geologist however the details are typically overlooked, yet very important when trying to convey an interpretation of you own…
For many more videos by Dr. Philip Prince go to:
Dr. Philip Prince also maintains a website with articles on the models and geology in the real world: