Fernando Escartín commentary
Mountain. The heat will accompany the peloton during a “leg-breaker” stage with a final climb up La Pandera (HC). The accumulated exhaustion and high temperatures will hinder a stage that could be favourable for a breakaway win, depending on everyone's interests regarding the general classification
The afro-iberian romance
This stage has a very similar geology to the previous one, albeit if this time we depart from sedimentary materials and climb progressively towards Mesozoic limestone mountain ranges (245-65 million years ago). We find Quaternary materials (1-0 million years ago) of fluvial origins (grey colours) and Miocene materials (23-6 million years ago) formed mainly by conglomerate rocks, sand and clay, followed by loams and limestone (salmon and yellow colours in the 3D diagram) that result in very gentle landscapes. From Cabra onwards, we enter Sub-Baetic mountain ranges, characterised by rocks from the three Mesozoic systems: Triassic (245-200 million years ago – purple and blue in the diagram), Jurassic (200-145 million years ago – blue tones) and Cretaceous (145-65 million years ago – green tones).
This stage is doubly interesting from a geological point of view as, besides the presence of the Sub-Baetic Mountain Range Geopark, a karst relief adjacent to the locality of Cabra, we find evidence of the approximation between the African Plate and the Iberian Plate.
Highlights among the karst formations found in the Geopark are the Sima de Cabra, with a diameter of 13m and a 115m descent; the Hoyones Sinkhole (more or less circular depression with a diameter of 300m), and the La Nava de Cabra polje (depression without a defined shape and with much bigger dimensions than a sinkhole).
When we reach Valdepeñas de Jaén we find the Valdepeñas de Jaén Tectonic Window. But, what is a tectonic window? Firstly, let's imagine a cake with two layers: the sponge below and the chocolate icing on top. Let's imagine, hypothetically, that we push the cake on one side and manage to put some of the sponge on top of the chocolate, leaving us with a sequence of sponge-chocolate-sponge-chocolate. This is the exact same cake, only now it is on top. Although it is a simplification, this is what we call “overthrusting” in geology. A tectonic window would be the result of making a hole in the cake so that we could see this overthrust effect. This overthrust formation is the result of the African Plate moving nearer to the Iberian Plate during what we call the “Alpine Cycle”, which is when many of today's main mountainous systems were created.
All that is left is to climb the Pandera Mountain Range from Villares. Beautiful views of the Quiebrajano River are expected at the end. Nowadays, this river has a reservoir but, in ancient times, it could carve through everything as far as the eye could see.
Stage Term: Polje
Term with Balkan origins that describes a depression in the land, formed by karst processes. What draws attention to it is the fact that it has a flat bottom due to the upwelling of underground water that periodically floods the land, making it very fertile.
Jersey wearers after the stage 4
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