earth science

Lisandro Formation

Lisandro 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 Lisandro Formation rather than just read about it. In short: The Lisandro Formation, alternatively known as the Cerro Lisandro Formation, is a Late Cretaceous (Late Cenomanian to Early Turonian) geologic formation with outcrops in the Neuquén, Río Negro and Mendoza Provinces of Argentina. It is the youngest formation within the Río Limay Subgroup, the lowest section of the Neuquén Group.

Key takeaways

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

Reference excerpt

The Lisandro Formation, alternatively known as the Cerro Lisandro Formation, is a Late Cretaceous (Late Cenomanian to Early Turonian) geologic formation with outcrops in the Neuquén, Río Negro and Mendoza Provinces of Argentina. It is the youngest formation within the Río Limay Subgroup, the lowest section of the Neuquén Group. Formerly that subgroup was treated as a formation, and the Lisandro Formation was known as the (Cerro) Lisandro Member. The type locality of the Lisandro Formation is the hill known as Cerro Lisandro in Neuquén Province. This formation conformably overlies the Huincul Formation, and it is in turn overlain by the Portezuelo Formation, which is a part of the Río Neuquén Subgroup. The Lisandro Formation varies between 35 and 75 metres (115 and 246 ft) thick, the thinnest of the three formations in its subgroup. It is composed of siltstones and claystones, red in color, which have been interpreted as a swampy to fluvial environment. Usually, the red Lisando Formation rocks are easy to distinguish from the greenish or yellowish deposits of the Huincul Formation.

Fossil content Not many dinosaurs are represented in the Lisandro Formation; other types of animals are frequently found. Fossils documented from this formation are:

freshwater bivalve molluscs fish (Ceratodus and Chaoceratodus) turtles a carcharodontosaurid theropod crocodilians an abelisauroid theropod "Bayosaurus pubica" at least one bird ornithopods (including Anabisetia) a peirosaurid Bayomesasuchus hernandezi a titanosaur sauropod Quetecsaurus rusconii

See also List of fossil sites Bajo Barreal Formation, contemporaneous formation of the Golfo San Jorge Basin Mata Amarilla Formation, contemporaneous formation of the Austral Basin List of dinosaur bearing rock formations

References

Bibliography Fossa Mancini, E.; Feruglio, E.; Yussen de Campana, J.C. (1938). "Una reunión de geólogos de YPF y el problema de la terminología estratigráfica" [A YPF geologists' reunion and the problem of stratigraphy terminology]. Boletín de Informaciones Petroleras (in Spanish). 15: 1–67. Leanza, H.A.; Apesteguia, S.; Novas, F.E.; De la Fuente, M.S. (2004). "Cretaceous terrestrial beds from the Neuquén Basin (Argentina) and their tetrapod assemblages". Cretaceous Research. 25 (1): 61–87. Bibcode:2004CrRes..25...61L. doi:10.1016/j.cretres.2003.10.005. Retrieved 2019-02-16. Sánchez, María Lidia; Heredia, Susana; Calvo, Jorge O. (2006). "Paleoambientes sedimentarios del Cretácico Superior de la Formación Plottier (Grupo Neuquén), Departamento Confluencia, Neuquén" [Sedimentary paleoenvironments in the Upper Cretaceous Plottier Formation (Neuquen Group), Confluencia, Neuquén]. Revista de la Asociación Geológica Argentina (in Spanish). 61: 3–18. Retrieved 2019-02-16.

Worked examples

Example 1 — a first encounter with Lisandro Formation

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

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

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

Frequently asked questions

What is Lisandro Formation in simple terms?

Why does Lisandro 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 Lisandro 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 Lisandro Formation.