The Scourian orogeny was an

orogeny Orogeny is a mountain building process. An orogeny is an event that takes place at a convergent plate margin when plate motion compresses the margin. An ''orogenic belt'' or ''orogen'' develops as the compressed plate crumples and is uplifted t ...

mountain building event 2.6 billion years ago during the

Archean The Archean Eon ( , also spelled Archaean or Archæan) is the second of four geologic eons of Earth's history, representing the time from . The Archean was preceded by the Hadean Eon and followed by the Proterozoic. The Earth Earth ...

before the beginning of the Laxfordian orogeny (or potentially overlapping with the beginning of the Laxfordian. The orogeny is marked by northwest-southeast trending folds south of

Laxford Laxford is a remote area in the far Northwest Highlands of Scotland around the River Laxford which runs northwest from Loch Stack to Laxford Bay. This bay is an inlet of Loch Laxford, a sea loch and Special Area of Conservation. The river is wel ...

in northwest Scotland. The event affected the

Lewisian gneiss The Lewisian complex or Lewisian gneiss is a suite of Precambrian metamorphic rocks that outcrop in the northwestern part of Scotland, forming part of the Hebridean Terrane and the North Atlantic Craton. These rocks are of Archaean and Paleopr ...

. Rubidium-strontium dating indicated Scourian metamorphism took place between 2.6 and 2.7 billion years ago{{cite book , year=1977, title= Precambrian of the Northern Hemisphere, url=https://archive.org/details/precambriannorth00salo, url-access=limited, publisher=Elsevier,
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References

Archean orogenies Geology of Scotland