earth science

Marnes Rouges Inférieures Formation

Marnes Rouges Inférieures Formation is a earth science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Marnes Rouges Inférieures Formation rather than just read about it. In short: The Marnes rouges inférieures Formation (lower red marls Formation) is a geological formation located in the south of France and dating from the upper Cretaceous (upper Campanian to lower Maastrichtian) between 72.5 and 70 million years ago approximately. This formation consists of marls, sandstones, conglomerates, and siltstones, corresponding to fluvial deposits (river channels and floodplains) deposited in what w…

Key takeaways

Marnes Rouges Inférieures Formation belongs to earth science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Marnes Rouges Inférieures Formation to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Marnes Rouges Inférieures Formation from memory before moving on to harder problems.

Reference excerpt

The Marnes rouges inférieures Formation (lower red marls Formation) is a geological formation located in the south of France and dating from the upper Cretaceous (upper Campanian to lower Maastrichtian) between 72.5 and 70 million years ago approximately. This formation consists of marls, sandstones, conglomerates, and siltstones, corresponding to fluvial deposits (river channels and floodplains) deposited in what was then the Ibero-Armorican island, a landmass made up of large part of France and Iberian Peninsula. The Marnes rouges inférieures Formation contains abundant remains of terrestrial vertebrates, mainly titanosaurians sauropod dinosaurs.

Location The Marnes rouges inférieures Formation is located in the department of Aude and Ariège in Occitania region. The formation crops out mainly in the Rennes-les-Bains syncline, located in the Upper Aude Valley, whose rocks can be seen particularly near the villages of Campagne-sur-Aude, Espéraza, Fa, Granès, Rennes-le-Château, Brenac, Saint-Ferriol. The Marnes rouges inférieures Formation conformably overlies the Grès d'Alet Formation (Alet Sandtones Formation) and conformably underlies the Calcaires de Vignevieille Formation (Vignevieille limestones Formation). The Marnes rouges inférieures Formation is also present in Ariège department in the Benaix, Dreuilhe, Péreille, and Le Mas d'Azil anticlines, where it lies unconformably on several Upper Cretaceous formations Coniacian to late Campanian in age.

Lithostratigraphy and depositional environment The Marnes rouges inférieures Formation reaches about 130 metres (430 ft) in thickness and is subdivided into four members including from bottom to top:

The Marnes rouges de Campagne Member (Red Marls of Campagne) : this member is composed of marmorized, ochre to red sandy mudstones, with a few conglomerates and sandstones levels. These rocks correspond to floodplain silts. These layers reach about 20 metres (66 ft) in thickness according Fondevilla et al. or 25 to 30 m (82.0 to 98.4 ft) according to Bilotte. The Grès des Estous Member (Estous Sandtone) : about 10 metres (33 ft) in thickness (a little less according to Fondevilla et al.), this member is almost exclusively composed of sandstones layers sometimes separated by thin red mudstone levels. These sandstones correspond to braided river channels. The Marnes rouges de la Maurine Member (Red Marls of Maurine) : this member is predominantly composed of red mustones, with minor ochre brown, orange, and purple mudstones, and some conglomeratic and silty levels. The mudstones correspond to floodplains silts, while the conglomeratic intercalations represent ancient river channels.. The presence of numerous calcareous pedogenetic concretions and the intense marmorization of the mudstones indicate the existence of paleosols.. Bilotte attributes to this member a thickness of 20 to 30 m (65.6 to 98.4 ft). Fondevilla et al. assign it a much greater thickness, around 100 m (328.1 ft). The Poudingue Fleuri Member (Fleuri Conglomerate) : this member, 5 to 15 m (16.4 to 49.2 ft) thick, consists of a conglomerate with a sandstone-carbonate matrix and calcareous cement. This conglomerate is of fluvial origin and corresponds to former gravel banks with large pebbles. In places, the Poudingue Fleuri forms the top of the Marnes rouges inférieures Formation, directly supporting the Vignevieille Limestones Formation. In other sections, the Poudingue Fleuri is intercalated in the upper part of the Marnes rouges de la Maurine Member.

Dating In 1985, Bilotte reported in the marnes rouges de Campagne Member the presence of a palynological association suggesting a late Campanian age, and consequently attributed a Maastrichtian age to the three overlying members.. In 2016, a magnetostratigraphic study revealed that the upper part of the Marnes rouges de Campagne, the Grès des Estous, and the first twenty meters of the Marnes rouges de la Maurine belong to the normal chron C32n corresponding to the beginning of the lower Maastrichtian. More specifically, the vertebrate localities in the basal part of the Marnes rouges de la Maurine are located at the top of subchron C32n.1n, corresponding to an age of 71.5 million years. The rest of the Marnes de la Maurine, as well as the Poudingue Fleuri, are located in the reverse chron C31r, corresponding to the upper part of the lower Maastrichtian. Thus, the age of the Poudingue Fleuri, at the top of the Marnes rouges inférieures Formation, is estimated to be between 70 and 69.5 million years old. Above, the upper Maastrichtian could be limited to a few meters in the Vignevieille limestones or is totally absent. Regarding the lower part of the Marnes rouges inférieures Formation, the Campanian-Maastrichtian boundary (set at 72.2 million years) would be located below the section sampled by Fondevila et al., probably in the middle or lower part of the Marnes rouges de Campagne Member, or even lower in the Grès d'Alet Formation. These results indicate that in the Upper Aude Valley, the Marnes rouges inférieures Formation dates almost exclusively from the lower Maastrichtian, with only the lower half of the Marnes rouges de Campagne Member possibly dating from the top of the Campanian. In the Plantaurel massif in Ariège, the Marnes rouges inférieures Formation becomes younger due to the progressive and diachronic migration of continental facies towards the west in a context of marine regression. In this region, the Marnes rouges inférieures Formation grade laterally into the Marnes d'Auzas Formation, which has a lagoonal and continental origin and dates back to the late Maastrichtian.

The Bellevue quarry

… excerpt ends here. Continue reading the full article.

Illustrations

Worked examples

Example 1 — a first encounter with Marnes Rouges Inférieures Formation

Start with the simplest possible case. Write down what Marnes Rouges Inférieures Formation claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In earth science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Marnes Rouges Inférieures Formation before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Marnes Rouges Inférieures Formation ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Marnes Rouges Inférieures Formation

In research: Marnes Rouges Inférieures Formation appears in earth science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Marnes Rouges Inférieures Formation in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Marnes Rouges Inférieures Formation is common in secondary-school and first-year university syllabi. It links to neighbouring topics Conglomerate formations, Cretaceous France, Fluvial deposits, so understanding it makes those chapters shorter.
In everyday life: Look for Marnes Rouges Inférieures Formation outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study Marnes Rouges Inférieures Formation in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Marnes Rouges Inférieures Formation means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Marnes Rouges Inférieures Formation out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Marnes Rouges Inférieures Formation in simple terms?

Why does Marnes Rouges Inférieures Formation matter?

Because it connects several earth science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Marnes Rouges Inférieures Formation?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Marnes Rouges Inférieures Formation.