CHAPTER XLIII

The Bosses and Sheets of Gabbro

Petrography of the Rocks--Relations of the Gabbros to the other members of the Volcanic series--Description of the Gabbro districts--Skye 327

## CHAPTER XLIV The Bosses and Sheets of Gabbro in the Districts of Rum, Ardnamurchan, Mull, St. Kilda and North-East Ireland. History of the Gabbro Intrusions 349

## CHAPTER XLV The Acid Rocks

Their Petrography--Their Stratigraphical Position and its Analogies in Central France 364

## CHAPTER XLVI Types of Structure in the Acid Rocks--Bosses 378

## CHAPTER XLVII The Acid Bosses of Mull, Small Isles, St. Kilda, Arran, and the North-East of Ireland 395

## CHAPTER XLVIII The Acid Sills, Dykes and Veins 430

## CHAPTER XLIX The Subsidences and Dislocations of the Plateaux 447

## CHAPTER L Effects of Denudation 455

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