Stage 6 of #LaVuelta23 offers a great opportunity to explain the difference between a geographer's and a geologist's perspective on a landscape. From a geographer's point of view, today is a climbing stage, racing from the coast to the top of the Pico del Buitre. But from a geologist's perspective, today is flat stage, just a few minor undulations, riding mostly along the same 'stratigraphic' horizon. Stratigraphy is the sequence of rock layers that was deposited through time. A geologist in eastern Spain is not walking through semi-arid hills, but through shallow seas, just like yesterday (tinyurl.com/sbb3u25n). And all day, the riders will race around the Triassic-Jurassic boundary, maybe a hundred meters up and down. So how come the geology is 'flat' and the geography is not? The Pico del Buitre mountain was formed because of so-called 'thrust' faults, along which the rock layers were pushed up, making spectacular topography. On the map, those faults are indicated with black lines with triangles pointing towards the pushed-up block. The cartoon shows you how such a structure works. And as a result, the Triassic and Jurassic rocks are tilted and we ride along the same horizon from start to finish! So we recommend all sprinters to take a geologist's perspective and go for victory today🤠. @UUEarthSciences @UUGeo @UniUtrecht @Naturalis_Sci @museumnaturalis @lavuelta

All along stage 5 of #LaVuelta23 you'll see white, bedded limestones from the Jurassic and Cretaceous, like in Ares del Maestre. These formed in shallow seas and you see them all over eastern, southern and northern Spain, and they're teeming with (fossil) life! So Spain was below sea level! The dedicated @GeoTdF follower is not surprised: During the Mesozoic, sea level was a few 100 m higher than today because ocean basins were young (see stage 1, tinyurl.com/4rfh3rxv) and Iberia rose a km or so since 30 million years (see stage 4, tinyurl.com/2fj26yy3). But not only all of Spain was flooded, most low-lying continents were, like Arabia, large parts of Africa, and Europe. And high plate tectonic activity means high volcanic CO2 production, so hot climate. The flooded continents became vast, shallow seas. Today they're rare, but they exist in the Arafura Sea between New Guinea and Australia, the Java Sea in Indonesia, or the North Sea between the British Isles and Europe. Those seas were full of life, making calcium carbonate shells and reefs, the so-called 'carbonate factory'. And all those carbonate shells became limestones, like you see along today's route. These limestones captured and stored enormous amounts of CO2. This is part of Earth's thermostat: the flooding of the continents and the high temperatures generate enormous blooming of sea life that, eventually, on millions of year timescales, reduces atmospheric CO2. Now we make concrete by processing limestone, responsible for 4-8% of global CO2 production back into the atmosphere. And in the shallow seas and the islands in between were also larger animals. Today's starting location of Morella is home to a fossil excavation where 5000 fossils of dinosaurs, crocodiles, and turtles have been found. If you're there, check out their dinosaur museum! And if you're standing along the parcours today, have a look in the dust and debris that lies on the softer layers. You may find little brachiopod shells, and other fossils (and if you do, show us!). That's when you're not cheering the riders of course! @UUEarthSciences @UUGeo @UniUtrecht @museumnaturalis @Naturalis_Sci @lavuelta #couchpeloton #Geology