Fossiliferous Areas

Recently, I was looking for public databases for a study implying geological data. I finally found that the website infoterre.brgm.fr was providing different kind of maps (in 1/1 000 000 and 1/50 000).

This website is monitored by the BRGM (Bureau de recherches géologiques et minières). Several layers are provided for each French region, with various granularities. The main one (S_FGEOL) is showing the overall structure whereas the most detailed dataset is showing points where specific observations have been made.

In this small blog, I'm using these maps to look for fossiliferous areas. We'll start with a brief overview and then maybe try to interpolate something (Why not?)!

Interactive Map

Let's start by plotting the points where fossiliferous areas have been identified. We are going to use it as a starting point.

Now that we can clearly see the points, let's try some Bayesian Inference. We are using several parameters: average altitude, most present geological type and the fossil observations.

Please keep in mind that for this project, as I'm not an expert, I'll try to lose you the best I can to make you believe that I'm right and robust.

We use grids of 1 km and focus only on Ain department in France (01) to see if it works well.

First, let's look at a heatmap of observed fossils:

Now that we have this in mind, let's look at the mean posterior distribution under a basic formula:

PS: Euler might have never worked on the nautilus shape