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July 7 found us heading from Fort William through the Northern Highlands to the Isle of Skye. In one day we went from the oldest, most altered rocks of Scotland to some of the youngest. Our tour of the Isle of Skye allowed us to see Tertiary-aged lava flows, dikes, volcanic centers, as well as granite and gabbro intrusions (the Red Hills and Black Cuillins). The castles and villages were beautiful, too!

Our first stop was Eilean Donan Castle, one of the most photographed castles in the world. With good reason. See a higher resolution photograph here.

Isle of Skye was accessible only by ferry until a few years ago. A toll bridge now connects the Isle with the Scottish mainland.

The granitic Red Hills of the Cuillins come into view shortly, and then the craggy Black Hills, composed of gabbro. The Black Hills are among the most rugged mountains of the British Isles.

A winding drive along the coast and through the hills brought us to the small village of Portree, the capital city of the Isle. It lies at the western end of a spectacular bay bounded by basaltic cliffs. Gaelic is still spoken and used on the Isle, and most of the signs provide translations.

After lunch (and shopping, as if we were tourists or something), we continued north onto the Trotternish Peninsula. The Old Man of Storr was visible for miles.

The scenery, carved out of Mesozoic and early Cenozoic volcanic rocks, seemed to grow more dramatic. We stopped for a few moments at a beautiful coastal overlook...

See another high resolution view here

And what do we find? An ugly old rock quarry! We RAN to investigate! It was carved out of zeolite-bearing basalt. We were thrilled...

At Mealt Falls, the water tumbles over the basalt cliffs almost directly into the sea.

See two other views of the area around the falls

It was a bit windy....

The rest of our tour of Isle of Skye can be found on the next page, found by clicking here.

Geologic Notes:

The Isle of Skye is divided into three provinces. On the Sleat Peninsula, rocks of the Lewisian and Torridonian groups are seen. We passed through exposures of these rocks soon after crossing the bridge at Kyle of Lochalsh.

The northern peninsulas of the Isle (the Duirinish, Waternish, and Trotternish) are composed of Jurassic sediments covered by plateau basalts erupted from dikes and fissures in earliest Tertiary time (60-65 mya). The lava layers are 2,000 feet thick in places, and where exposed along shorelines, form spectacular cliffs and columns (Storr Rock is a 180 foot high example).

The spectacular alpine scenery north of Broadford and south of Sligachan results from the exposure of plutons of granite (Red Hills) and dark gabbro (Cuillin Hills). These intrusions are slightly younger than the plateau basalts. These rocks form the highest and most rugged mountain scenery on the island.

The Tertiary volcanic activity in the Isle of Skye and in other parts of the British Isles was tied to the opening of the Atlantic Ocean in latest Mesozoic and early Cenozoic time. The crust was stretched and thinned and numerous normal faults developed, allowing partial melting to take place in the uppermost mantle. Lavas followed the faults to the surface, in some cases escaping as fissure flows.

In other cases, very hot basaltic magmas actually melted the overlying continental crust, causing the formation of granitic magmas, such as those in the Red Hills. The granite weathers differently than gabbro, and the Red Hills have a decidedly smoother aspect.

As always in Scotland, glacial activity played a huge role in shaping the landscape, and the Isle of Skye is no exception. In the Cuillins, corries, horns and arêtes are common, and ground moraines are present all around the flatter parts of the island.