Local Rocks

Within easy reach of Glasgow there lies a rich variety of igneous, sedimentary and metamorphic rocks. These rocks were laid down during a period of over 500 million years, starting in the Neoproterozoic period (1000 to 541 Ma) and finishing in the Triassic period (252 Ma to 201 Ma). (A chronostratigraphic chart describing the internationally agreed geological time scale can be found here.)

The map below shows the rock types that are found in the extended Glasgow area, and the key to the right describes the symbols used in the map. Below the map are two panels. The left panel contains links to pages describing the rock cycle, the three different rock types (igneous, sedimentary and metamorphic) and rock-forming minerals. The right panel contains links to pages describing twelve sites in the extended Glasgow area. These links can also be accessed by moving the mouse pointer over the pins on the map. When the pointer is above a pin, a hint with the site name is shown, and the page describing the site can be opened by clicking the mouse button.

Rouken Glen Fossil Grove Corrie Burn Dumbarton Rock Ardmore Point Balmaha Aberfoyle Ballantrae Heads of Ayr Corrie Shore Drumadoon Lochranza District

Key

 

Sedimentary Rocks

1s Mudstone, sandstone, limestone  Middle-Upper Triassic
2s Stewartry Group, sandstone, breccia, conglomerate  Lower Permian
3s Coal Measures Group, mudstone, sandstone, coal  Upper Carboniferous
4s Clackmannan Group, sedimentary cycles  Lower-Upper Carboniferous
5s Strathclyde Group, sedimentary cycles  Lower-Upper Carboniferous
6s Inverclyde Group, sandstone, siltstone, mudstone  Lower Carboniferous
7s Stratheden Group, sandstone, conglomerate  Upper Devonian
8s Strathmore Groups, sandstone, conglomerate, mudstone  Lower Devonian
9s Arbuthnott- Garvock Group, sandstone, conglomerate  Lower Devonian
10s Lanark Group, sandstone, conglomerate  Silurian-Devonian
11s mudstone, siltstone, sandstone  Middle Silurian
12s Hawick Group, wacke  Lower-Middle Silurian
13s Gala Group, wacke  Lower Silurian
14s Shinnel and Glenlee Formations, wacke  Middle-Upper Ordovician
15s Leadhills Supergroup, wacke  Middle-Upper Ordovician
16s Portpatrick and Glenwhargen Formation, wacke  Middle Ordovician
17s Kirkcolm Formation, wacke  Middle Ordovician
   
 

Igneous Rocks

18i Felsic igneous intrusives  Palaeogene
19i Dolerite and tholeiitic basalt  Carboniferous-Permian
20i Midland Valley Sill Complex, quartz- dolerite  Upper Carboniferous
21i Strathclyde Group, mafic lava and tuff  Lower Carboniferous
22i Felsic intrusion  Upper Silurian-Devonian
23i Mafic lava and tuff  Silurian-Devonian
24i Ballantrae Ophiolite Complex- serpentenite  Lower Ordovician
25i Balcreuchan Group basaltic lava, agglomerates  Lower Ordovician
   
 

Metamorphic Rocks Dalradian Supergroup

25m Southern Highland Group, psammite, pelite  Neoproterozoic-Cambrian
26m Metamorphosed lava and tuff  Neoproterozoic
27m Argyll Group, psammite, semi- pelite, pelite  Neoproterozoic
 

Minerals, Rocks & Fossils

Selected Sites

Central Belt

  • Corrie Burn

    Sedimentary and volcanic rocks of Lower Carboniferous age and evidence for the Campsie Fault.

  • Dumbarton Rock

    A basalt plug which is the only remaining evidence of the volcano which existed on this site 330-340 million years ago.

  • Fossil Grove

    Beautifully preserved fossil tree stumps and roots from the Carboniferous period in Glasgow's Victoria park. 

  • Rouken Glen

    Sedimentary rocks from the Carboniferous period and evidence of the Quaternary glaciation.

Loch Lomond Area

  • Aberfoyle District

    The relationships between the Dalradian block and the Midland Valley; details of the structure and stratigraphy of the Highland Border Complex; recumbent folding in Upper Dalradian rocks.

  • Ardmore Point

    Stratigraphy and sedimentation of the Lower and Upper Devonian; the angular unconformity which separates them. 

  • Balmaha

    The Highland Boundary Fault, which separates the Highlands from the Lowlands, with metamorphic rocks to the north and sedimentary rocks to the south.

Ayrshire & Arran

  • Ballantrae District

    An association of serpentenite, chert and pillow lavas that represents an ophiolite suite.

  • Corrie Shore

    Succession of Carboniferous rock types and junctions of the Carboniferous with the Devonian and the Permian.

  • Drumadoon

    A Palaeogene quartz-feldspar-porphyry sill displaying massive columnar jointing, with members of the Palaeogene dyke swarm.

  • Heads of Ayr

    A large deeply-eroded volcanic vent of Lower Carboniferous age.

  • Lochranza District

    Dalradian schists, Hutton's classic unconformity and Permian sandstones and breccias.