earth science

Pimenteira Formation

Pimenteira 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 Pimenteira Formation rather than just read about it. In short: The Pimenteira Formation, also known as Pimenteiras Formation, is an Mid to Late Devonian geological formation of the Parnaíba Basin, northeastern Brazil. It mainly outcrops in the states of Piauí and Tocantins.

Key takeaways

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

Reference excerpt

The Pimenteira Formation, also known as Pimenteiras Formation, is an Mid to Late Devonian geological formation of the Parnaíba Basin, northeastern Brazil. It mainly outcrops in the states of Piauí and Tocantins. It is was deposited in a shallow sea, under the influence of currents and storm waves, as well as fluvio-deltaic influences. Being part of the Malvinokaffric Realm, it haboured a diverse fauna of invertebrates such as trilobites, brachiopods, bivalves, gastropods, and tentaculids, as well as elamobranches and plant remains.

History The name 'Pimenteira' was first proposed by Small (1914) to ascribe a shale sequence 20 m in thickness close to the municipality of Pimenteiras, Piauí. Caster (1948), reported on the occurrence of several fossils in the area, like trilobites and shark fin bones, and Kegel (1953) later visited the region between Picos and Pimenteiras, collecting specimens and later describing them. Initially, Kegel (1952) divided the formation into the Itaim and Picos members. Blankennagel (1952) later considered that only the Picos Member is part of the formation, with the Itaim Member being the upper part of the Serra Grande Formation.

Description

Geology The Pimenteiro Formation is made up of dense dark-grey shale sections interlayered with thick to thin sandstone, commonly found are also hummocky cross-stratification. The formation is interpreted as a transgressive system, deposited under a shallow marine environment with the influence of storm waves. It possesses two sub-units, the lower Picos Member and the upper Passagem Member. The Picos Member is composed by sandstone and intercalated siltstone and shale, with common hummocky cross-stratification, representing the first great Devonian transgression into the Parnaíba Basin. The sandstone is well defined in the old strata, of Middle Devonian origin, but it gradually fizzles out as it approaches the upper layers, of Late Devonian origin. The Passagem Member is composed by thin and micaceous sandstone, with asymptotic and hummocky stratification. This unit represents a system of fluvio-deltaic floods, in which turbulent, episodic flows went beyond the coastal limit.

The formation has outcrops on the states of Piauí and Tocantins. Sediments on the eastern border of the formation are dated be from the Late Eifelian to the Early Givetian, while the central and western portions were dated to be from the Late Eifelian to the Early Famennian.

Paleoenvironment When it was deposited, the Pimenteiro Formation was a shallow marine environment under the influence of currents and storm waves, as well as fluvio-deltaic influences. The Passagem Member has been proposed to be influenced by episodic floods. During the Mid to Late Devonian, the formation was situated below the antarctic circle, its fauna being part of the endemic Malvinokaffric Realm. It haboured a diverse fauna of invertebrates such as trilobites, brachiopods, ostracods, bivalves, gastropods, hyolithids, and tentaculids, as well as fish, like elamobranches and acanthodians. Plant remains are also found, as well as ichnofossils.

Fossil Content

Flora

Arthropods

Echinoderms

Brachipod

Conulariids

Tentaculites

Annelids

Molluscs

Fishes

Ichnofossils

References

Illustrations

Worked examples

Example 1 — a first encounter with Pimenteira Formation

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

In research: Pimenteira 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 Pimenteira 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: Pimenteira Formation is common in secondary-school and first-year university syllabi. It links to neighbouring topics Devonian Brazil, Eifelian Stage, Famennian Stage, so understanding it makes those chapters shorter.
In everyday life: Look for Pimenteira 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 Pimenteira Formation in 20 minutes

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

Frequently asked questions

What is Pimenteira Formation in simple terms?

Why does Pimenteira 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 Pimenteira 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 Pimenteira Formation.