earth science

La Irene Formation

La Irene 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 La Irene Formation rather than just read about it. In short: La Irene Formation is a Maastrichtian geologic formation in southern Patagonia, Argentina. The formation is 230 metres (750 ft) thick and underlies the Chorrillo Formation and rests on top of the Cerro Fortaleza Formation.

Key takeaways

La Irene 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 La Irene Formation to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of La Irene Formation from memory before moving on to harder problems.

Reference excerpt

La Irene Formation is a Maastrichtian geologic formation in southern Patagonia, Argentina. The formation is 230 metres (750 ft) thick and underlies the Chorrillo Formation and rests on top of the Cerro Fortaleza Formation.

Description The formation comprises lithified, sandy sandstones and lithified, argillaceous, sandy shales deposited in a fluvial deltaic environment. At the base of Cerro Calafate a column of about 230 metres (750 ft) in thickness was measured along the road. The 110 m below represent a succession of sandy banks clear yellowish brown color to white and dark pelitic packages fining upwards cycles are stacked to form a sequence with a clear trend growing grain and stratum. Sandy banks (coarse to fine sand) show increasing thickness from 2 m at the base to more than 9 m, whereas intercalated mudstones show an opposite trend with thickness ranging from 15 m at the base to 1 m. At the top of lower shaly packets (the thickest) are preserved carbonaceous shale intervals, thinly laminated. 120 m above correspond to a succession of amalgamated conglomeratic sandy banks where preservation is extremely rare shaly intervals.

Fossil content The formation has provided many fossil pollen of:

Podocarpaceae Monocotyledoneae Liliidae Cycadopsida Pteridopsida Polypodiopsida Schizaeaceae Gleicheniaceae Selaginellaceae Lycopodiaceae Magnoliopsida Dinophyceae

References

Bibliography Povilauskas, L.; Barreda, V.; Marenssi, S. (2008), "Polen y esporas de la Formación La Irene (Maastrichtiano), sudoeste de la provincia de Santa Cruz, Argentina: primeros resultados", Geobios, 41 (6): 819–831, Bibcode:2008Geobi..41..819P, doi:10.1016/j.geobios.2008.07.002, hdl:11336/114579 Marenssi, Sergio A.; Casadío, Silvio; Santillana, Sergio N. (2003), "Estratigrafía y sedimentología de las unidades del Cretácico superior-Paleógeno aflorantes en la margen sureste del lago Viedma, provincia de Santa Cruz, Argentina" (PDF), Revista de la Asociación Geológica Argentina, 58: 403–416, retrieved 2018-08-30

Worked examples

Example 1 — a first encounter with La Irene Formation

Start with the simplest possible case. Write down what La Irene 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 La Irene 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 La Irene 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 La Irene Formation

In research: La Irene 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 La Irene 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: La Irene Formation is common in secondary-school and first-year university syllabi. It links to neighbouring topics Austral or Magallanes Basin, Cretaceous Argentina, Deltaic deposits, so understanding it makes those chapters shorter.
In everyday life: Look for La Irene 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.

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How to study La Irene Formation in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what La Irene 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 La Irene Formation out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is La Irene Formation in simple terms?

Why does La Irene 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 La Irene 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 La Irene Formation.