earth science

Lecho Formation

Lecho 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 Lecho Formation rather than just read about it. In short: The Lecho Formation is a geological formation in the Salta Basin of the provinces Jujuy and Salta of northwestern Argentina. Its strata date back to the Early Maastrichtian, and is a unit of the Salta Group.

Key takeaways

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

Reference excerpt

The Lecho Formation is a geological formation in the Salta Basin of the provinces Jujuy and Salta of northwestern Argentina. Its strata date back to the Early Maastrichtian, and is a unit of the Salta Group. The fine-grained bioturbated sandstones of the formation were deposited in a fluvial to lacustrine coastal plain environment. Dinosaur remains are among the fossils that have been recovered from the formation. According to Frankfurt and Chiappe (1999), the Lecho Formation is composed of reddish sandstones. The Lecho is part of the Upper/Late Cretaceous Balbuena Subgroup (Salta Group), which is a near-border stratigraphic unit of the Andean sedimentary basin. Fossils from this formation include the titanosaur Saltasaurus along with a variety of avian and non-avian theropods.

Fossil content

Dinosaurs

See also List of dinosaur-bearing rock formations Marília Formation

References

Bibliography Walker; Dyke (2009), "Euenantiornithine birds from the Late Cretaceous of El Brete (Argentina)", Irish Journal of Earth Sciences, 27: 15–62, doi:10.3318/IJES.2010.27.15 Agnolin, F.L.; Martinelli, A.G. (2007), "Did oviraptorosaurs (Dinosauria; Theropoda) inhabit Argentina?" (PDF), Cretaceous Research, 28 (5): 785–790, Bibcode:2007CrRes..28..785A, doi:10.1016/j.cretres.2006.10.006 Weishampel, David B.; Dodson, Peter; Osmólska, Halszka (2004), The Dinosauria, 2nd edition, Berkeley: University of California Press, pp. 1–880, ISBN 0-520-24209-2, retrieved 2019-02-21{{citation}}: CS1 maint: publisher location (link) Frankfurt, N.G.; Chiappe, L.M. (1999), "A Possible Oviraptorosaur From The Late Cretaceous of Northwestern Argentina", Journal of Vertebrate Paleontology, 19 (1): 101–105, Bibcode:1999JVPal..19..101F, doi:10.1080/02724634.1999.10011126

Illustrations

Worked examples

Example 1 — a first encounter with Lecho Formation

Start with the simplest possible case. Write down what Lecho 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 Lecho 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 Lecho 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 Lecho Formation

In research: Lecho 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 Lecho 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: Lecho Formation is common in secondary-school and first-year university syllabi. It links to neighbouring topics Cretaceous Argentina, Cretaceous paleontological sites of South America, Fluvial deposits, so understanding it makes those chapters shorter.
In everyday life: Look for Lecho 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 Lecho Formation in 20 minutes

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

Frequently asked questions

What is Lecho Formation in simple terms?

Why does Lecho 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 Lecho 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 Lecho Formation.