Atlas of igneous rocks and their textures

W.S. MacKenzie, C.H. Donaldson and C. Guilford

Longman Scientific 8c Technical Copublished in the United States with John Wiley & Sons, Inc., New York Contents

Preface

A cknowledgements

Part 1 The textures of igneous rocks (Numbers refer to photographs - not to pages)

Introduction

Crystallinity 1-9

Granularity

Terms referring to what the aided and unaided eye can or cannot see 10-14 Terms indicating absolute ranges of grain size 15-17 Terms indicating relative size of crystals 18-22

Crystal shapes

Terms indicating quality of the development of faces on crystals 23-25 Terms indicating three-dimensional crystal shape General three-dimensional terms Specific three-dimensional terms Skeletal, dendritic and embayed crystals , 26-30 Parallel-growth crystals , • 31-32 Sieve-textured crystals 33 Elongate, curved, branching crystals 34- 37 Pseudomorphs 38

Mutual relations of crystals (and amorphous materials)

Equigranular textures 39-43 Inequigranular textures Seriate texture 44 Porphyritic texture 45 Glomeroporphyrilic texture 46-47 Spilite Poikilitic texture 48-51 Gabbro Ophitic texture 52-57 Teschenite Interstitial textures 58-63 Lssexite Dolerite Oriented, aligned and directed textures 64-66 No rite Trachytic texture 64 66 Anorthosite Trachytoid texture 67 69 Parallel-growth texture see 31-32 Comb texture (comb layering) 70 71 Orbicular texture (orbicular layering) sec 104 Intermediate rocks Intergrowth textures Consertal texture 72 73 Boninite Micrographic texture (or graphic, if visible with the naked eye) 74- 76 Granophyric texture 76-77 Diorite Myrmekitic texture . 78 Tonalite Intrafasciculale texture 79 Kentallenite Lamellar and bleb-like intergrowths 80 83 Monzonile Dacite Symplectite texture 84- 85 Granodiorite Radiate textures Spherulitic texture 86-88 Syenite Variolitic texture 89 Shonkinite Radiate intergrowth 90 Overgrowth textures Skeletal or dendritic overgrowths 91 Acid rocks Corona texture 92 94 Crystal zoning , 95 102 Pantellerite Banded textures (banding) 103-104 Granite Comb layering, orbicular texture, and occllar texture 105 Alkali granite Cavity textures . : Vesicular texture 106 107 Amygdaloidal texture 108 Miarolitic texture 109 Alkaline and miscellaneous rocks Lilhophysa or (stone-ball) texture — Phonolite Leucite phonolite Nosean leucite phonolite Pseudoleucite phonolite Blairmorite Nepheline syenite Part 2 Varieties of igneous rocks Malignite (Numbers refer to photographs - not to pages) Sodalite syenite • Ncphelinite Ijolite Introduction Urtite Basanite Tephrite Olivine meiililite Ultrabasic rocks Leucitite Fergusite Dunite I'O M incite Peridotite 1" Alnoite Kimberlite H2 Mafurite Garnet peridotite Fitzroyite Pyroxenite '14 Wyomingite Komatiite "5 Madupite Meymechite "6 Carbonatite Hornblendite "7 Chondrite (meteorite) Achondrite (meteorite)

Basic rocks

Basalts Appendix var. Tholeiitic , ' 118 var. Alkali olivine basalt 119 Preparation of a thin section of rock var. Lunar low-Ti basalt 120 var. Lunar high-Ti basalt 121 References var. Picritic basalt 122 var. Ankaramite 123 Index