Fossils in Jacksonville FL and Dakar Senegal?

[Jakuzi]

Trying to see if there are any good fossil hunting locales for my brother(Dakar) and my sister(Jacksonville).  I know of the Peace River in Florida.  But I was wondering if maybe the beaches in these areas or anywhere close(within an hour or so) might be hotspots to check out.

 

Thanks for the help!

[bluequark]

I realize I'm several years late in responding, but I think this will be interesting for later fossil-hunters in Senegal.

 

I know a great fossil hunting location within day-trip range of Dakar. Near Thies, there are limestone hills that are full of fossils. I got some images from Google Earth to show the location. The X shows where I went, but I strongly suspect they will be fossil-hunting opportunities along that entire ridge that runs north to south.

The location I went to was a little north of the main road that runs through the area. There's a series of branching gullies there.

This is the view from the road. You can see the hills to the left (or north) of the road, with the arrow pointing to the valleys I visited. To get there, you need to go a little further along, then turn off the paved road to follow smaller dirt roads. (Well, that's the route as of last time I was there, which was a couple years ago.)

Here's what the hills look like in the rainy season. All of that white is eroding limestone, and that's where the fossil-hunting is. I found that the best location was where the valleys join together and flatten out just before spilling out onto the plains; fossils erode and collect there.

Brother for scale, showing the terrain of the area

Here's the kind of fossils you can find here. Lots of clams and snails, a couple other ocean creatures, including a nautilus or ammonite (not sure which). (I also found a shark tooth, but I lost that one soon after, so it's not in the photo. :/ )

 

[bluequark]

If you're interest in geology in general rather than just fossils, there are a couple of neat places right in Dakar. Dakar has a lot of volcanic rock around - I think all of the islands are volcanic rock, as well as much of the western coast.

 

First, there's Snake Island, or Ile de la Madeleine, a short way off the coast. I don't have photos of it on hand myself, but here's the location on Google Earth. You can hire a pirogue to take you out there. It's got bunch of basalt, including some columnar basalt, as well as being a pretty, quiet island in general.

 

The second location is probably the more geologically interesting one. The hill on which the lighthouse (also called "The Phare") is built is volcanic. You can see a number of interesting features there: volcanoclastic layers, basalt, scoria, green olivine crystals, a rock that I think is tuff - sometimes with veins of other rock in it, and maybe even a lava tube (but it might just look like that because of how it weathered).

To get see these, go to the base of the hill, then follow the path down the ravine on its north side. It'll take you all the way down to the beach, then you can go around the base of the hill, all along the edge of the ocean. You can get most of the way to the other side of the hill, at least when the tide isn't high. (I expect pretty much anyone who knows the area will to able to find the lighthouse itself, so I won't bother putting instructions here on how to get to it.)