Landforms and geology of granitee terrains/ Twidale, C.R.

Table of Contents; Preface and acknowledgements; 1 Characteristics and foundations 1.1 Typical land forms and landscapes 1.2 Previous work 1.3 Occurrences of granite 1.4 Granite - definition and composition 1.5 Physical characteristics 1.6 Orthogonal fracture systems 1.7 Fractures and drainage patterns 2 Sheet fractures and structures 2.1 Terminology 2.2 Description and characteristics 2.3 Theories of origin 2.3.1 Exogenetic explanations 2.3.2 Endogenetic explanations 2.4 Summary 3 Weathering 3.1 Definition and significance 3.2 Physical disintegration 3.3 Chemical alteration 3.4 The course of weathering in granite 3.5 Controls of weathering 4 Plains - the expected granite form 4.1 Weathering and surfaces of low relief 4.2 Plains of epigene (subaerial) origin 4.2.1 Rolling or undulating plains 4.2.2 Pediments 4.2.3 Relationship between pediment and peneplain 4.3 Etch plains in granite 4.4 Very flat plains 4.5 Multicyclic and stepped assemblages 4.6 Exhumed plains 4.7 Summary 5 Boulders as examples of two-stage forms 5.1 The two-stage or etching mechanism 5.2 Boulders - morphology and occurrences 5.3 Subsurface exploitation of orthogonal fracture systems 5.4 Tectonic and structural forms 5.5 Types of peripheral or marginal weathering 5.6 Causes of peripheral weathering 5.7 Evacuation of grus 5.8 Boulders of epigene origin 5.9 Summary 6 Inselbergs and bornhardts 6.1 Definitions and terminology 6.2 Bornhardt characteristics 6.3 Theories of origin 6.3.1 Environment 6.3.2 The scarp retreat hypothesis 6.3.3 Tectonics and structure: faulting and lithology 6.3.4 Variations in fracture density 6.3.5 Differential subsurface weathering and the two-stage concept 6.4 Evidence and argument concerning origins of bornhardts 6.4.1 Contrasts in weathering between hill and plain 6.4.2 Incipient domes 6.4.3 Subsurface initiation of minor forms 6.4.4 Flared slopes and stepped inselbergs 6.4.5 Regional and local patterns in plan 6.4.6 Coexistence of forms associated with compression/shearing 6.4.7 Topographic settings 6.4.8 Occurrence in multicyclic landscapes 6.4.9 Fracture-defined margins 6.4.10 Age of inselbergs and bornhardts 6.5 Exhumed bornhardts and inselbergs 6.6 Antiquity and inselberg landscapes 6.7 Summary Other granitic residuals and uplands 7.1 Isolated residuals 7.1.1 Nubbins 7.1.2 Castle koppies 7.1.3 Large conical forms or medas 7.1.4 Towers and acuminate forms 7.2 Massifs 7.3 Regions of all slopes topography 7.4 Discussion 8 Minor forms developed on steep slopes 8.1 Flared slopes 8.1.1 Description and characteristics 8.1.2 Origin 8.1.3 Changes after exposure 8.2 Fretted basal slopes and other variants 8.3 Scarp-foot weathering and erosion, and the piedmont angle 8.4 Rock platforms 8.4.1 Description 8.4.2 Origin 8.5 Scarp-foot depressions 8.5.1 Description 8.5.2 Origin 8.6 Flutings or grooves 8.6.1 Description 8.6.2 Origin 8.6.3 Surface or subsurface initiation? 8.6.4 Inversion 9 Minor forms developed on gentle slopes 9.1 Rock basins 9.1.1 Description 9.1.2 Nomenclature 9.1.3 Origin 9.1.4 Differentiation of major types 9.1.5 Evacuation of debris 9.1.6 Rate of development 9.2 Plinths and associated blocks and boulders 9.2.1 Description 9.2.2 Origin 9.3 Pedestal rocks 9.3.1 Terminology 9.3.2 Origin 9.4 Gutters or runnels 9.4.1 Terminology 9.4.2 Description 9.4.3 Origin 9.5 Rock levees 9.6 Rock doughnuts 9.6.1 Description 9.6.2 Origin 9.6.3 Evidence and argument 9.7 Fonts 10 Caves and tafoni 10.1 General statement 10.2 Caves associated with corestones and grus 10.3 Caves associated with fractures 10.4 Tafoni 10.4.1 Description 10.4.2 Process 10.4.3 Stages of development 10.4.4 Case-hardening and other veneers 10.5 Speleothems 11 Split and cracked blocks and slabs 11.1 Split rocks 11.1.1 Description 11.1.2 Origin 11.2 Parted and dislodged blocks 11.3 Dislocated slabs 11.3.1 A-tents 11.3.2 Overlapping slabs 11.3.3 Displaced slabs 11.3.4 Chaos 11.3.5 Wedges 11.3.6 Origin of the forms 11.3.7 Relationship of A-tents and pressure ridges 11.4 Polygonal cracking 11.4.1 Description 11.4.2 Previous interpretations 11.4.3 Evidence 11.4.4 Explanations 11.5 Tesselated pavements 12 Zonality, azonality and the coastal context 12.1 Introduction 12.2 Lithological zonality and azonality 12.3 Climatic zonality and azonality 12.4 The coastal context 13 Retrospect and prospect Author Index; Location Index; Subject Index.