What are cracks and fractures? What are hydraulic fractures? For this post, I am in the process of drafting a bunch of figures that explain cracks (fractures) and crack propagation from a Geologist's perspective, specifically about sheeted clastic dikes in Columbia Basin, USA. It will not be an exhaustive treatment of the subject by any means, but it will cover natural fluid-driven tensile fractures in sediments and rocks (i.e., clastic dikes). My goal is to review the pertin