Culbin's landscape: changes through time
How the Moray coastline was formed
The rocks on which this Moray coastline is founded were created near the equator some 250 million years ago.
The nearby dune sandstone ridge at Burghead was formed when this area was a red-hot desert. Fossilised in this sandstone layer you can still follow the footprints of Cynodont reptiles and early dinosaurs where they roamed across the dunes. Cynodonts were mammal-like reptiles which survived the Permian and Triassic eras and into the early Jurassic, 208 million years before the present.
In fact this area has seen many landscapes, including tropical lakes, deserts and ice-age glaciers. The history of the area is written into its coastline. Fossil fish (such as those discovered by early local palaentologist Hugh Miller) tell of a warm and arid Scotland, lying south of the equator on the shores of a great lake that extended north to where Orkney and Shetland lie today.
The impact of the ice age
Changes in land and sea level have formed many coastal features seen today. Around 18,000 years ago, the area was covered by a vast ice-sheet. As the climate warmed and the ice melted, relieving the land of its crushing weight, it began to rise - and it is still recovering today!
Further meltwater from the ice sheets of Europe and North America caused a rise in sea-level, rapidly overtaking that of the land. Eroded cliffs and banks set back from the sea, such as those at Culbin and Spey Bay, mark previous shorelines.
Eventually the sea-level rise slowed and was overtaken by the land, re-exposing tracts of coastal flat-land, such as the Conon valley. Much of the land used today for agriculture, transport, housing and industry once lay under water.
Lichen on a shingle ridge. Culbin forest, MorayshireCulbin is not just made up of sweeping dunes of sand. You can also look for long, straight shingle ridges, particularly noticeable where they cross paths and their multi-coloured pebbles have been polished by the action of feet.
Shingle ridges here were created 5,500 years ago. Offshore shingle began life as rocks broken up by glaciers, rumbling downwards until rivers eventually swept them out to sea. This shingle was then swept inland in great straight banks across the dunes as sea-levels rose when the ice-sheets melted.
Look out for these long shingle ridges where they cross Culbin’s footpaths: they have been colonised by grey-green lichen and often form a band of polished pebbles underfoot where they cross paths. Culbin pebbles are noticeably rounded and smooth, proof of the aggressive tidal action in the past.
Among the Culbin shingle you will find few samples of sedimentary rocks such as sandstone: that is the softest stone found in the area and is the one which tends to have been first to be ground down into sand. These pebbles tend to be much harder rock: grey and pink granites, often showing bands of strata, and white crystalline quartzes, some containing agates.
The sheer variety of stones found here also proves their glacial origins, with fragments of rock from many different sources and eras all being dashed together and crushed in the headlong plunge of the river of ice.
Immense storms have as recently as the early 18th century forced the river Findhorn to change its course eastwards by mounding sand across its mouth. The course of the old river used to flood in winter, creating ‘winter lochs’ and today areas of birch trees within the forest still show where the old river course ran.
Human evidence of the changing coastline
Detail from one of the shell middens at Culbin forest, MorayshireSand dune systems are one of the hardest landscapes to read in terms of archaeology because of the sand’s tendency to mix up layers. However, one feature is noticeable: the shell middens - which would logically have been located within easy reach of the shoreline where shells were gathered - are now found over ½ km further inland.
One butte dune is covered in pot-stones which cracked when used to boil water 3,500 years ago. Then the dune would have been at a junction between a river-mouth and the sea; now it is much further inland and the river has changed its course.
Read more about Culbin’s human timeline or Culbin's early people. There's more information about the Moray coast on the Moray Firth Partnership website.