Geological evolution of Britain (option T4): the main tectonic events and orogenies (Caledonian, Variscan, Alpine), the changing palaeogeography and palaeolatitude of Britain through the Phanerozoic, and the rocks and structures these events produced.

Take the orogenies in order and link each to its structures, because the marks track named events and their effects.

The Caledonian orogeny (Ordovician to Devonian) resulted from the closure of the Iapetus Ocean and the collision that joined the northern and southern parts of Britain. It produced the folded and faulted, regionally metamorphosed rocks of Scotland, the Lake District and Wales, with a strong north-east to south-west structural grain and granite intrusions.

The Variscan (Hercynian) orogeny (Carboniferous to Permian) resulted from collision to the south. It folded and faulted the rocks of south-west England and south Wales, with tight, often overturned folds and thrusts verging north, and emplaced the south-west England granites with their tin and copper mineralisation.

The Alpine orogeny (Cenozoic), the distant effect of the Africa-Europe collision, gently folded the younger rocks of southern England, producing structures such as the Weald and the London and Hampshire basins, and faulting.

So three orogenies, Caledonian, Variscan and Alpine, successively deformed Britain, each with a characteristic style and grain.

Markers reward the Caledonian (Iapetus closure, NE-SW grain, metamorphism and granites), the Variscan (southern collision, north-verging folds, SW granites) and the Alpine (gentle folding of southern England), each with its structures.

Track Britain's drift northward and link each climate-sensitive rock to its latitude, because that is the evidence.

Britain has drifted steadily northward through the Phanerozoic, from southern high latitudes in the early Palaeozoic to its present temperate northern position.

The evidence is the climate-sensitive rocks. Ordovician and Silurian marine rocks formed at high southern latitudes. By the Carboniferous, Britain lay near the equator, shown by tropical coal swamps and warm-water limestones. In the Permian and Triassic it lay in the hot, dry subtropics, shown by desert sandstones (with dune cross-bedding) and evaporites. Younger Jurassic and Cretaceous rocks record warm seas as Britain continued north.

So the succession of glacial, tropical, desert and temperate indicators up the column records Britain drifting north through the climate belts, consistent with plate-tectonic reconstructions.

Markers reward steady northward drift, and the use of Carboniferous coals and limestones (equatorial), Permo-Triassic desert sandstones and evaporites (subtropical) and the overall climate sequence as evidence.