earth science

Huitrera Formation

Huitrera 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 Huitrera Formation rather than just read about it. In short: The Huitrera Formation is a geological formation in the Neuquén Basin in northern Patagonian Argentina whose strata date back to the Early Eocene of the Paleogene, or Casamayoran in the South American land mammal age classification. The formation is together with the Reyhuau basalts part of the Pilcaniyeu Belt, a volcanic belt active in Paleocene to middle Eocene times.

Key takeaways

Huitrera Formation belongs to earth science; place it in that map before memorising details.
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Reproduce the core statement of Huitrera Formation from memory before moving on to harder problems.

Reference excerpt

The Huitrera Formation is a geological formation in the Neuquén Basin in northern Patagonian Argentina whose strata date back to the Early Eocene of the Paleogene, or Casamayoran in the South American land mammal age classification. The formation is together with the Reyhuau basalts part of the Pilcaniyeu Belt, a volcanic belt active in Paleocene to middle Eocene times.

Description The Huitrera Formation was first defined by Ravazzoli and Sesana in 1977. The name has been used to identify various volcaniclastic sequences, among others in the Ñirihuau fold-and-thrust belt. The up to 1,300 metres (4,300 ft) thick formation comprises mudstones and sandstones deposited in a crater lake environment. Part of the formation comprises andesites, dacitic and rhyolitic ignimbrites, volcanic breccias, tuffs and trachybasalts. The formation was initially described as Late Eocene to Early Oligocene, but was later dated to 54.24 ± 0.45 Ma, meaning the Huitrera Formation is Ypresian, or in the SALMA classification, Casamayoran in age.

Fossil content The following macrofossils were reported from the formation:

Birds Ueekenkcoracias Amphibians Llankibatrachus truebae Patagopipa corsolinii Insects Odonata Inacayalestes aikunhuapi Beetles Thesaurus punctatus (originally Catogenus) Flora Menispermites calderensis Raiguenrayun cura Cupressaceae indet. Podocarpaceae indet. Lauraceae indet. The formation has also provided many pollen, analyzed in 2003 by Melendi et al.

See also South American land mammal ages Laguna del Hunco Formation, contemporaneous fossiliferous formation of the Cañadón Asfalto Basin Itaboraí Formation, fossiliferous formation of the Itaboraí Basin of Brazil Bogotá Formation, contemporaneous fossil flora-bearing formation of central Colombia Green River Formation, contemporaneous fossiliferous formation of the central-western United States Klondike Mountain Formation, contemporaneous fossil flora-bearing formation of Washington State Messel pit, Eocene crater lake Lagerstätte of Germany

References

Bibliography Fernández Paz, Lucía; Iannelli, Sofía B.; Echaurren, Andrés; Ramos, Miguel; Bechis, Florencia; Litvak, Vanesa D.; Encinas, Alfonso; Kasemann, Simone; Lucassen, Friedrich; Folguera, Andrés (2020). "The late Eocene–early Miocene El Maitén Belt evolution: Magmatic response to the changing subduction zone geodynamics" (PDF). Journal of South American Earth Sciences. 103 102713. Bibcode:2020JSAES.10302713F. doi:10.1016/j.jsames.2020.102713. Jin, Mengjie; Zwick, Andreas; Ślipiński, Adam; Marris, John W. M.; Thomas, Michael C.; Pang, Hong (2020), "A comprehensive phylogeny of flat bark beetles (Coleoptera: Cucujidae) with a revised classification and a new South American genus", Systematic Entomology, 45 (2): 248–268, Bibcode:2020SysEn..45..248J, doi:10.1111/syen.12392 Aranciaga Rolando, Alexis M.; Agnolin, Federico L.; Corsolini, Julián (2019), "A new pipoid frog (Anura, Pipimorpha) from the Paleogene of Patagonia. Paleobiogeographical implications", Comptes Rendus Palevol, 18 (7): 725–734, Bibcode:2019CRPal..18..725R, doi:10.1016/j.crpv.2019.04.003 Jud, Nathan A.; Iglesias, Ari; Wilf, Peter; Gandolfo, Maria A. (2018), "Fossil moonseeds from the Paleogene of West Gondwana (Patagonia, Argentina)", American Journal of Botany, 105 (5): 927–942, doi:10.1002/ajb2.1092, hdl:11336/183708, PMID 29882954 Ramírez, Leonardo C.; Corsolini, Juan; Di Iorio, Osvaldo (2016), "First fossil record of parasitic flat-bark beetle (Coleoptera: Passandridae) from the Eocene of Patagonia, Argentina", Ameghiniana, 53 (2): 160–169, doi:10.5710/AMGH.29.11.2015.2920, hdl:11336/13059 Prez, Horacio; Massaferro, Gabriela (2013), "Geología y geomorfología del tramo superior del Arroyo Comallo, Río Negro" (PDF), Contribuciones Científicas GÆA, 26: 221–234, retrieved 2020-06-13 Barreda, V.D.; Palazzesi, L.; Katinas, L.; Criscri, J.V.; Telleria, M.C.; Bremer, K.; Passala, M.G.; Bechis, F.; Corsolini, R. (2012), "An extinct Eocene taxon of the daisy family (Asteraceae): evolutionary, ecological and biogeographical implications", Annals of Botany, 109 (1): 127–134, doi:10.1093/aob/mcr240, PMC 3241571, PMID 22179952 Escosteguy, Leonardo; Franchi, Mario (2010), "Estratigrafía de la región de Chapelco, Provincia del Neuquén" (PDF), Revista de la Asociación Geológica Argentina, 66: 418–429, retrieved 2020-06-13 Báez, Ana M.; Pugener, L. Analia (2003), "Ontogeny of a new Palaeogene pipid frog from southern South America and xenopodinomorph evolution", Zoological Journal of the Linnean Society, 139 (3): 439–476, doi:10.1046/j.1096-3642.2003.00085.x Melendi, D.L.; Scafati, L.H.; Volkheimer, W. (2003), "Palynostratigraphy of the Paleogene Huitrera Formation in N-W Patagonia, Argentina", Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen, 228 (2): 205–273, doi:10.1127/njgpa/228/2003/205

Illustrations

Worked examples

Example 1 — a first encounter with Huitrera Formation

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

In research: Huitrera 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 Huitrera 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: Huitrera Formation is common in secondary-school and first-year university syllabi. It links to neighbouring topics Andesite formations, Casamayoran, Dacite formations, so understanding it makes those chapters shorter.
In everyday life: Look for Huitrera 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 Huitrera Formation in 20 minutes

Read the reference excerpt below once, without taking notes.
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Frequently asked questions

What is Huitrera Formation in simple terms?

Why does Huitrera 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 Huitrera 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 Huitrera Formation.