earth science

North Atlantic Craton

North Atlantic Craton 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 North Atlantic Craton rather than just read about it. In short: The North Atlantic Craton (NAC) is an Archaean craton exposed in southern West Greenland, the Nain Province in Labrador, and the Lewisian complex in northwestern Scotland. The NAC is bounded by the Nagssugtoqidian orogen to the north and the 1.8–1.87 Ga Ketilidan–Makkovik mobile belt to the south.

Key takeaways

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

Reference excerpt

The North Atlantic Craton (NAC) is an Archaean craton exposed in southern West Greenland, the Nain Province in Labrador, and the Lewisian complex in northwestern Scotland. The NAC is bounded by the Nagssugtoqidian orogen to the north and the 1.8–1.87 Ga Ketilidan–Makkovik mobile belt to the south. The latter can be linked to the Lewisian-Malin boundary in Scotland, which in turn can be linked to the Transscandinavian Igneous Belt in Baltica. Palaeoproterozoic mobile belts surround the continental blocks and cratonic fragments of the NAC. Throughout the Mesoproterozoic, Neoproterozoic, and Mesozoic (1350–550 Ma), when these blocks still formed a coherent craton, repeated continental extension resulted in lithospheric thinning. The NAC finally broke up at c. 60 Ma with the opening of the Labrador Sea. Ultramafic magmatism has occurred continuously in the NAC for almost 3 billion years, but kimberlite-producing magmatism has only occurred in two stages: in the Neoproterozoic (c. 600–550 Ma) in the northern NAC and in the Jurassic (c. 200–150 Ma) in the southern NAC. Magmatism during the Neoproterozoic was caused by either the opening of the Iapetus Ocean, lithospheric thinning along a fracture zone, or the appearance of a mantle plume. A rift system that developed during the Mesozoic began to fraction the NAC, and the initial stages of the break-up of the NAC produced the kimberlite and carbonatite deposits along the Labrador Sea. In Greenland the NAC is primarily made of tonalite–trondhjemite–granodiorite orthogneisses separated and obscured by supracrustal belts, anorthosite complexes, and granite intrusions. A series of terranes have been distinguished in Greenland: north of the Frederikshåb Isblink Glacier. The Akia, Isukasia, and Kapisilik terranes probably collided c. 2950 Ma in the Isukasia orogeny, although events are masked by Neoarchaean overprinting. The Færingehavn, Tre Brødre, and Tasiusarsuaq terranes merged c. 2800–2700 Ma in the Tasiusarsuaq orogeny, although these terranes were affected by Neoarchaean folding and deformation. In the Kapisilik orogeny c. 2650–2580 Ma terranes around the Godthåbsfjord, mostly north of Nuuk, were accreted along the Iivinnguit fault. South of Frederikshåb Isblink the Paamiut and Neria blocks probably collided c. 2850–2830 Ma in the Paamiut orogeny. They in turn collided with the Sioraq block and Tasiusarsuaq terranes 2760–270 Ma in the Tasiusarsuaq orogeny.

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Worked examples

Example 1 — a first encounter with North Atlantic Craton

Start with the simplest possible case. Write down what North Atlantic Craton 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 North Atlantic Craton 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 North Atlantic Craton 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 North Atlantic Craton

In research: North Atlantic Craton 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 North Atlantic Craton 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: North Atlantic Craton is common in secondary-school and first-year university syllabi. It links to neighbouring topics Cratons, Geology of Greenland, Geology of Newfoundland and Labrador, so understanding it makes those chapters shorter.
In everyday life: Look for North Atlantic Craton 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 North Atlantic Craton in 20 minutes

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

Frequently asked questions

What is North Atlantic Craton in simple terms?

Why does North Atlantic Craton 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 North Atlantic Craton?

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 North Atlantic Craton.