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Les Orgues d'Ille-sur-Têt, Occitane, France
Note the different layers of soft sandstone formed in ancient beaches as local sea levels changed
The embarrassing thing for Bible-literalist creationists who believe that all rock strata were laid down in about a year during a mythical genocidal flood, is that there is no way the strata that make up the Orgues could have been deposited in a single inundation because, as can be seen in the accompanying photos, the layers are composed of different sized particles of sand, sometimes mixed with pebbles, sometime not, showing they were once part of different sea levels and river flood plains and the whole was then covered in a shallow sea which produced the limestone cap.
And that means they are very old, pre-dating even the Pyrenees because the erosion into their present formation did not start until plate tectonics caused the Pyrenees to rise up at the boundary between the Iberian plate and the Eurasian plate, the Iberian plate itself being pushed north by the African plate.
The resulting uplift exposed the layers of sandstone which now form the Orgues to be lifted up and exposed to the action of, mostly, water, to give them their present shape - which is still being actively eroded. The evidence for this can be seen along the narrow road that runs between the river Têt and the Orgues, where heavy rain has washed sand across the road in places.
The formation of the Orgues d'Ille-sur-Têt is closely related to the broader geological context of the Pyrenees, which includes both tectonic processes and changes in sea levels over time.It's important to understand that the formation of the Orgues d'Ille-sur-Têt is a local phenomenon that occurred after the broader formation of the Pyrenees Mountain range. The Orgues were shaped by the erosive forces of water and wind acting on the sedimentary rocks exposed during the uplift of the Pyrenees. While changes in sea levels over time did play a role in the deposition of the original sedimentary layers, the specific features of the Orgues are primarily a result of subsequent erosion processes. The geological history of the Pyrenees is incredibly complex and has been shaped by various factors over millions of years. The Orgues d'Ille-sur-Têt stand as a remarkable example of the ongoing forces of nature that continue to shape the landscape in this region.
- Sedimentary Deposition: The Pyrenees region, including the area around Ille-sur-Têt, has a long history of sedimentary deposition. During different geological periods, sedimentary rocks like marl, clay, sandstone, and limestone were deposited in ancient seas, lakes, and river systems that once covered the region.
- Tectonic Uplift: As explained earlier, the Pyrenees were formed through the collision of the Iberian and Eurasian plates, leading to intense compression, folding, and uplift of the Earth's crust. This tectonic uplift resulted in the formation of the mountain range we see today.
- Differential Erosion: The tectonic uplift exposed the previously buried sedimentary rocks to the forces of erosion. The Orgues d'Ille-sur-Têt, as well as other unique geological formations in the Pyrenees, are a result of differential erosion acting on these sedimentary rocks. Different layers of sedimentary rocks have varying degrees of hardness, resistance, and erodibility due to their mineral composition and compaction. As a result, softer layers erode faster than harder layers, leading to the formation of distinct features like the Orgues.
- Changes in Sea Levels: Throughout the geological history of the Pyrenees, there have been fluctuations in sea levels, particularly during the periods of sedimentary deposition. Changes in sea levels can influence the distribution of sedimentary environments, leading to the deposition of different types of sediments and contributing to the diversity of rock formations in the area.
This description of the formation of the deposits are from Wikipedia (translated from French):
Geological historyWhich all leaves the creationist myth of a genocidal flood looking exactly what it is - a childish, counter-factual fairy tale, refuted by just about every strand of available evidence.
Installation of materials
Around -14 Ma, Roussillon is a vast plain of accumulation, a monotonous surface dominated by residual reliefs such as the Piton de Força Réal. The sea level is 100 m higher than the current one, a distinctly tropical climate dominates. The landscapes of Roussillon evoke the Sahel or the savannahs of Kenya 5.From −5.96 to -5.3 Ma , the Strait of Gibraltar closed under the effects of tectonics (continental drift). The Mediterranean Sea is deprived of water inflows from the Atlantic Ocean , and sees its level fall by more than 1,500 m . This episode is called “Messenian crisis”. During this period, the Roussillon is notched deep canyons by rivers which gain in force because of the important difference in altitude which now separates them from the base level.
5.3 Ma ago when the impoundment of the Mediterranean Sea took place under the influence of a new movement of the plates, the Mediterranean Sea invaded well-differentiated reliefs. Roussillon is transformed into a marine gulf. The Têt valley resembles an arm of the sea limited to the south by the Aspres hills and to the north by the granite escarpment of the Montalba plateau. The shore reaches the Col de Ternère, which corresponds to a marine intrusion of + 80 m compared to the current level.
With the rising waters, the rivers will deposit materials that today support or arm the cliffs of the Orgues site. The Pliocene filling of the valleys dug in the Messenian presents a characteristic facies of Gilbert deltas which Professor Clauzon has highlighted. 6,7.During the Pliocene the filling continues, it is spread over millions of years. As sedimentary inputs progress, the shore is pushed back towards its current limit and the landscape evolves accordingly: the bay is transformed into a maritime marsh, then into a marshland with fresh and stagnant waters, finally the river takes possession of the space, it spreads its indolent arms in the valley in anastomosed channels forming what are called braided watercourses.
- The argillaceous marine Pliocene was deposited in the deeper zones, following large oblique dips of 10°.
- The sandy marine Pliocene was deposited in shallower depths. It is essentially made up of well-rounded, uncemented fluvial elements, which create by “avalanche system” large oblique slopes which can reach a dip of 35°.
- The continental Pliocene was deposited upstream, in the emerged part. It includes a set of formations that are from upstream to downstream: alluvial fans, with blocks torn by erosion in the hinterland, palustrine facies, alluvial sandy facies with a planar structure and sandy marine facies which correspond to old beach levels.
At that time the landscape resembled the African savannah, expanses of tall grass, yellowed by the sun and battered by the winds spread out to the wooded hills. A few large trees of the acacia family emerge like huge umbrellas. There are monkeys, rodents, elephants (Anancus arvernensis), rhinoceros, hippos, tortoises, gazelles, foxes, lynx, but also species such as the hipparion (ancestor of the current horse) or the machairodus (big cat)8.
It is a pivotal time in the climatic evolution of the planet, the progressive aridification of this tropical climate allows the appearance of the Mediterranean climate and prefigures the quaternary cooling.
In the Quaternary, the Tet stages a set of alluvial terraces. They result from the sinking of the fluvial network in the Pliocene deposits and then from successive fillings linked to eustatic variations in the Mediterranean Sea.
Indeed, during glacial peaks, the enormous quantity of water monopolized in the form of continental ice lowers the sea level. 18,000 years ago, for example, the Mediterranean was 120 m below its current level. During periods of warming, the ice melts, the waters rise and the overloaded rivers are forced to alluvium.
The Orgues site owes its cap, and therefore its existence, to the first cold Quaternaries since, by covering the softer layers of the Pliocene, this sheet of rubble allowed the more fragile underlying land to be protected from erosion and therefore to cross time to reach us.
Evolution of the site
Nowadays the evolution of the site is rapid, the cliffs of sedimentary material are bare. A few islands of vegetation remain on the summits, they are too scattered to effectively preserve the soil from erosion.
The intensity of the Mediterranean rains does not help. These violent precipitations promote runoff: the linear incisions are sharp, the devegetated slopes are notched with gullies, the soils become impoverished and then leave with leaching. On the vertical walls, erosion has become the master of the place, apart from a few mosses and lichens, plants can no longer recolonize the space.
On the contrary, the gentler slopes are still vegetated and therefore protected. They are covered with Mediterranean species capable of withstanding summer aridity. There are holm oaks, pubescent oaks, lentisk pistachio trees, arbutus, stoechas lavender, common immortelle, thyme, rosemary, cottony rockrose, bay leaf rockrose, Montpellier rockrose, tree heather, asparagus, etc.
The site therefore presents a contrasting aspect where the vegetation competes with the bare rock for the space necessary for its survival.
Not only that but the time taken to form them is in the millions of years, not the few thousand that creationists believe Earth has existed for.
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