earth science

Mata Amarilla Formation

Mata Amarilla 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 Mata Amarilla Formation rather than just read about it. In short: The Mata Amarilla Formation is a fossiliferous formation of the Austral Basin in southern Patagonia, Argentina. The formation consists of sediments deposited during the Middle Cenomanian, dated to 96.94 to 95.52 Ma.

Key takeaways

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

Reference excerpt

The Mata Amarilla Formation is a fossiliferous formation of the Austral Basin in southern Patagonia, Argentina. The formation consists of sediments deposited during the Middle Cenomanian, dated to 96.94 to 95.52 Ma. The middle section of the formation was previously considered to be the Pari Aike Formation. The Mata Amarilla Formation has provided many fossil vertebrates, among which dinosaurs, fish and turtles, as well as fossil insects, flora and molluscs.

Age

The middle section of the Mata Amarilla Formation has widely been regarded as Maastrichtian in age, but recent dating of a lava tuff layer shows that it dates back to 96.2 ± 0.7 Ma, during the Cenomanian.

Description The Austral (or Magallanes) Basin, is located on the southwestern end of the South American Plate and it is bordered to the south by the Scotia Plate covering an area of approximately 230.000 square kilometres (88.803 sq mi). In the studied area, the Austral Basin underwent three main tectonic stages: (i) a rift stage; (ii) a thermal subsidence stage; and (iii) a foreland stage. The rifting stage is related to the break-up of Gondwana, grabens and half-grabens were formed and filled with volcaniclastic and volcanic rocks intercalated with epiclastic sediments of the El Quemado and Tobífera Formations. Subsequently, the thermal subsidence stage resulted in the deposition of the transgressive quartzose sandstone of the Springhill Formation, and the black mudstone and marl of the Río Mayer Formation. Towards the end of this stage, the Piedra Clavada Formation was deposited, representing a large passive-margin delta system. The foreland stage, in response to the regional change from extensive to compressive regime, resulted in the deposition of the continental Mata Amarilla Formation. This unit is mainly composed of grey and blackish siltstone and claystone, alternating with whitish and yellowish-grey fine to medium grained sandstone. Varela (2014) recognized three informal sections (lower, middle, and upper) on the bases of sedimentological and sequence stratigraphic analysis. The lower section consists of fine-grained intervals with paleosols interbedded with laminated shale and coquina, representing coastal plain and lagoon paleoenvironments. The middle section comprises sandstone and siltstone representing meandering fluvial channels and crevasse splay deposits, intercalated with fine-grained floodplains and subordinate lacustrine deposits. The upper section is dominated by fine-grained deposits, related to distal fluvial channels. Paleosol features and paleosol-derived climatic proxies suggest a subtropical temperate-warm, at 12 ± 2.1 °C (53.6 ± 3.8 °F) and humid, with 1,404 ± 108 millimetres (55.3 ± 4.3 in)/yr, climate with marked rainfall seasonality during the deposition of this unit (Varela et al. 2012b; 2018), in accordance with previous paleobotanical interpretations.

Fossil content

Dinosaurs

References

Bibliography Santamarina, Patricio E.; Barreda, Viviana D.; Iglesias, Ari; Varela, Augusto N. (2018), "Salvinialean megaspores in the Late Cretaceous of southern Patagonia, Argentina", Acta Palaeontologica Polonica, 63: 607–616, doi:10.4202/app.00491.2018, hdl:11336/85086, retrieved 2019-10-13 Material was copied from this source, which is available under a Creative Commons Attribution 4.0 International License. Rauhut, O.W.M (2012), "A reappraisal of a putative record of abelisauroid theropod dinosaur from the Middle Jurassic of England", Proceedings of the Geologists' Association, 123 (5): 779–786, Bibcode:2012PrGA..123..779R, doi:10.1016/j.pgeola.2012.05.008, retrieved 2019-10-13 Varela, A.N.; Poiré, D. G.; Martin, T.; Gerdes, A.; Goin, F. J.; Gelfo, J. N.; Hoffmann, S. (2012), "U-Pb zircon constraints on the age of the Cretaceous Mata Amarilla Formation, Southern Patagonia, Argentina: Its relationship with the evolution of the Austral Basin", Andean Geology, 39 (3): 359–379, doi:10.5027/andgeoV39n3-a01, hdl:11336/260948, retrieved 2019-10-13 available under a Creative Commons Attribution 4.0 International License Ezcurra, M.D.; Agnolin, F.L.; Novas, F.E. (2010), "An abelisauroid dinosaur with a non-atrophied manus from the Late Cretaceous Pari Aike Formation of southern Patagonia" (PDF), Zootaxa, 2450: 1–25, doi:10.11646/zootaxa.2450.1.1, retrieved 2019-10-13

Further reading J. F. Petrulevicius, A. N. Varela, A. Iglesias, A. B. Zamuner, and D. G. Poiré. 2014. First Cenomanian record of insects in the southern Hemisphere, with Perforissidae (Fulgoroidea) and Cupedidae (Coleoptera) from southern Patagonia, Argentina. Cretaceous Research 51:174-185 J. P. O'Gorman and A. N. Varela. 2010. The oldest lower Upper Cretaceous plesiosaurs (Reptilia, Sauropterygia) from Southern Patagonia, Argentina. Ameghiniana 47(4):447-459 A. Iglesias, A. B. Zamuner, D. G. Poiré and F. Larriestra. 2007. Diversity, taphonomy, and palaeoecology of an angiosperm flora from the Cretaceous (Cenomanian-Coniacian) in southern Patagonia, Argentina. Palaeontology 50(2):445-466 F. J. Goin, D. G. Poire, M. S. De Fuente, A. L. Cione, F. E. Novas, E. S. Bellosi, A. Ambrosio, O. Ferrer, N. D. Canessa, A. Carloni, J. Ferigolo, A. M. Ribeiro, M. S. Sales Viana, M. A. Reguero, M. G. Vucetich, S. Marenssi, M. F. Lima Filho and S. Agostinho. 2002. Paleontologia y geologia de los sedimentos del cretacico superior aflorantes al sur del rio shehuen (Mata Amarilla, Provincia de Santa Cruz, Argentina). Actas del XV Congreso Geologico Argentino, El Calafate, 2002 1–6 M. B. Aguirre Urreta. 1989. The Cretaceous decapod Crustacea of Argentina and the Antarctic Peninsula. Palaeontology 32(3):499-552 J. Frenguelli. 1953. La Flora Fósil de la región del Alto Río Chalia en Santa Cruz (Patagonia). Paleontología. Notas del museo XVI(98):239-257 F. Ameghino. 1899. Nota preliminar sobre el Loncasaurus argentinus un representante de la familia de los Megalosauridae en la República Argentina [Preliminary note on Loncasaurus argentinus, a representative of the family Megalosauridae in the Argentine Republic]. Anales de la Sociedad Científica Argentina 47:61-62

Illustrations

Worked examples

Example 1 — a first encounter with Mata Amarilla Formation

Start with the simplest possible case. Write down what Mata Amarilla 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 Mata Amarilla 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 Mata Amarilla 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 Mata Amarilla Formation

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

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Frequently asked questions

What is Mata Amarilla Formation in simple terms?

Why does Mata Amarilla 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 Mata Amarilla 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 Mata Amarilla Formation.