Tobermory Geology Granite

An igneous rock that is coarse grained and overall light colored.

Tobermory geology granite.

Skip to main content. Now only seen to the north of mull. Granite has a felsic composition and is more common in recent geologic time in contrast to earth s ultramafic ancient igneous history. This mineral composition usually gives granite a red pink gray or white color with dark mineral grains visible throughout the rock.

The main folding and metamorphism of moine and dalradian rocks occurred. California department of conservation. Over geological time it has undergone enormous changes. Mull has not always been in its present position and form.

The pink caledonian granite at the western end of the ross of mull has been worked as a building stone and features locally in iona cathedral. It forms from the slow crystallization of magma below earth s surface. Mull s oldest rocks formed way south in the southern hemisphere and mull in common with the british isles has gradually drifted northwards to its present day position. Iona is covered in erratic boulders that is great lumps of granite that have been carried westwards by the glaciers that once covered the area.

Glacial erratic boulders of granite are found in iona scouring of the rocks by ice is clear in many places. All the errratics are found west of the granite not east thereby indicating the direction of ice flow. Felsic rocks are less dense than mafic and ultramafic rocks and thus they tend to escape subduction whereas basaltic or gabbroic rocks tend to sink into the mantle beneath the granitic rocks of the continental cratons. On the shore of loch na keal a feature called p forms can be seen channels cut in the rock by glaciers.

It may also be found in the lighthouses at skerryvore and ardnamurchan point and much further afield in the albert memorial and blackfriars and westminster bridges in london. Granite is composed mainly of quartz and feldspar with minor amounts of mica amphiboles and other minerals. Major movements of the moine thrust and the great glen fault t h ec al do nio rg y. But in the parlance of the natural stone industry the definition of granite is expanded to include all igneous rocks as well as many metamorphic rocks like gneiss and schist.

In geology granite is one specific thing. Intrusion of the ross of mull granite.