Exceptional dunes, Miocene fluvial rocks, central Spain
Ahh yes, does this remind you of Reservoir Dogs? If you are lost, google it and see the similarities…
These are some beautiful exposures in the Loranca basin of central Spain. This beautiful area is home to the Tortola Formation, a Miocene fluvial succession displaying ‘labyrrinthine’ facies architecture (whatever that means).
Overall this succession is a low net-to-gross system, meaning that there is a lot of mudstone and not a lot of sandstone. This is most likely due to a low ratio of sedimentation rate to accomodation, a predominance of mud in the source area, climate (hot and humid), high accomodation (i.e. a subsiding basin), or a combination of these factors (or a few I havent thought of right now). See the below photo for a look at the stratigraphy, where isolated channels ‘float’ in mudstone. That hill is about 100 m high.
The Tortola Formation has great large-scale cross straification, as seen above, and also in the image below. This photo shows the progressive migration of a barform from right to left (indicating paleoflow into or out of the page). Note the sigmoidal architecture, classic for these fluvial bars.
This is a great area to look at fluvial rocks, and the food, wine, and lodging in the nearby towns is also fantastic. I recommend the Casa del Canonigo in Huete, a charming place.