This tutorial stems from an assignment in my structural geology class. We were tasked with creating a cross section for a very complicated geologic and topographic map. The area of interest is the Williamsville Virginia Quadrangle. At first glance, it is a very intimidating map, especially with the contours. Utilizing the basics provided by the TA, I just took it one step at a time. While I am unsure of any mistakes I may have made, the purpose of this is to illustrate the basic steps involved as well as the drafting benefits of tablet use in geology.
First step when doing a cross section is to determine your start and end point on the map. Unless you are given your start and end by your professor or company, it is always best to pick a line where you have ample strike and dip data parallel to your path. If your strike and slip data is not parallel, you have to correct for this data.
Once you have established your start and finish point you then simply line up your blank piece of paper to cover the start and end points. It helps to tape the paper down in the top corners so it doesn't move while you mark your contours and contacts. (More to come as time permits)
- Tutorial Still Under Development -
Here I have added my cross section to a 3D view of the area I took my cross section from. Utilizing the established latitude and longitude marks on the map, I normalized them to find the exact points my cross section started and finished at. I was then able to extract satellite imagery of that very point.
As a note, because my determined topographic profile was made from the contours on the map, I had to warp my cross section slightly in photoshop to fit. Nonetheless, you can see above the non warped version is pretty similar to the established satellite profile. So again, while I will not know my grade for a while on this, I feel for my first real cross section, this was a success.