Geology

 

Dumfries and Galloway on the Move

4,600 million years ago our world formed.

Volcanic eruptions, land movement and mountain building continually changed the face of the globe over the next 3,000 million years.

500 million years ago an ancient ocean called Iapetus began to close as Southern Ireland and England broke free from their landmass near to the South Pole and gradually moved north to collide with Scotland and Northern Ireland.

It wasn’t until about 250 million years ago that Britain began to separate from the American continent and only 23 million years ago when it finally came to where we are now.

Evidence in the rocks record the climatic changes and geological processes Scotland experienced as it shifted across the globe. Ancient mountains, volcanoes, deep oceans, deserts, cold and temperate seas, tropical swamps, rivers, warm seas and oceans full of plant and animal life, plus 470 million years of Ice Ages are recorded here in Dumfries and Galloway.

 The landscape between the Southern Uplands to the north and The Solway Firth to the south, are directly influenced by the underlying rocks.  

There are three types of rock; Igneous rocks have their origins in volcanoes: Sedementary rocks have origins in river, lake and ocean deposits: Metamorphic Rocks originate when sedimentary, igneous and other metamorphic rocks are affected by heat and pressure. Throught the region a wealth of rock varieties can be found, for example:

Igneous Rocks;
– Granite from Criffel;
– Microgranite from Abbingdon and Glenhead;
– Basalt lava flows in the Dalveen Pass;
– Diorite, Dolerite and Gabbro around Thornhill, Kirkconnel and the Southern Upland Fault.

Sedementary Rocks;
– Permian Red Sandstone around Thornhill and Dumfries;
– Black Shale, Conglomerate from the Upper Nithsdale Valley;
– Mudstone, Coal, Seatearth around Kirkconnel;
– Limestone full of Fossils and Mudstone along the Solway coastal pathways;
– Glacial, river and lake deposits of Pebbles and Gravel in the Scar and Shinnel River Valleys.

Metamorphic Rocks;
– Slate in the small quarries of the Dalwhat, Shinnel and Scar Valleys;
– Diabase at the contact zone between Coal and Diorite at Sanquhar.

If you would like more information on the geology of Dumfries and Galloway see the Publications slot on this website for some great books. 

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