The Glen Roy Area Through Time

QUATERNARY
THE “ICE AGE”
2.4 million years ago up to and including
recent times
Present day to 1,500 years ago. Increased land improvements and forest clearance. Enhanced slope erosion and gully
formation.
6,000 years ago. Start of significant woodland clearance by human activity.
10,000 years ago. Establishment of woodland.
11,500 years ago. Climate warms very rapidly. Glaciers melt and ice-dammed lakes in Glen Roy, Glen Gloy and Spean drain
for the last time. Landslides and rockfalls occur due to stress release and ground thawing.
12,500 years ago. Climate becomes extremely cold again at the start of Loch Lomond Stadial. An icefield forms in the
West Highlands. Glaciers from this icefield block the drainage in Glen Roy, Glen Goy and Glean Spean, allowing formation of
ice-dammed lakes and the Parallel Roads.
14,700 years ago. Climate warms rapidly, with summer temperatures comparable to those of today. Glaciers retreat
rapidly.
22,000 years ago. A vast sheet of ice covers all but a few mountain tops and extends at least 100km west of the Scottish
mainland.
29,000 years ago. Climate cools and the last major ice sheet glaciation (Late Devensian) begins.
2.4 million to 29,000 years ago. Many glacial episodes with short warmer (interglacial) intervals. Erosion by ice sheets
and mountain glaciers.
NEOGENE
2.4 to 24 million years
Tropical conditions are widespread, although the climate cools as the Ice Age approaches.
PALEOGENE
24 to 65 million years
The North Atlantic Ocean continues to widen. Active volcanoes on Skye, Mull and Rum pour out great volumes of lava.
CRETACEOUS
65 to 142 million years
Sea levels are higher than today. Warm, shallow, temperate seas fringe the low-lying land, with chalk deposited across
Scotland, but later removed by erosion.
JURASSIC
142 to 206 million years
Opening of the North Atlantic Ocean begins. Climate is warm and humid. Sea levels are considerably higher than today.
TRIASSIC
206 to 248 million years
Scotland is located in near-equatorial latitudes, in a similar position to sub-Saharan Africa today, and desert conditions are
widespread.
PERMIAN
248 to 290 million years
Desert conditions prevail across Scotland. Violent earthquakes rock the land.
CARBONIFEROUS
290 to 354 million years
Scotland sits astride the equator.
DEVONIAN
354 to 417 million years
The high mountains created by the colliding continents are rapidly eroded and debris carried to lower ground by streams
and rivers. Movements on the Great Glen Fault produce a zone of broken rock. The Ben Nevis volcano is active!
SILURIAN
417 to 443 million years
The earth continues to move as Scotland collides with Baltica (Norway and Sweden) and Avalonia (England). A mountain
chain (the Caledonian Mountain Belt) as high as the Himalayas is created as a result of these collisions.
ORDOVICIAN
443 to 490 million years
The ancient sands and muds, laid down in Precambrian times, are cooked and squashed as they become deeply buried
within the earth’s crust.
CAMBRIAN
Scotland moves north from a position close to the South Pole!
PRECAMBRIAN
545 to 3,500 million years
Great thicknesses of sands and muds are deposited. These are later altered to form the bedrock of the Glen Roy area.