CONTENTS. 
PART I. 
The Geology of Spiti, with parts of Bashahr and 
RuPSHu. By H. H- Hayden, B.A., B.E., F.G.S., Deputy 
Superintendent, Geological Survey of India. (With 18 
plates.) 
Page. 
Introduction ........... 1 
Chaptee I. — Previous accounts of the Geology of Spiti . . 5 
„ II. — Cambrian System ...... 8 
„ III.— Silurian System ....... 20 
„ IV. — Devonian (?), Carboniferous and Permian . • 33 
„ V. — Mesozoic Group ....... 60 
„ VI. -Rupsbu 92 
„ VII. — Igneous rocks ....... 97 
„ VIII.— Economic Geology 101 
„ IX. —Correlation with the Simla Series .... 103 
Subject Index . . . . 113 
Geographical Index .......... 123 A 
Bibliography ........... i 
List of Plates ........... viii 
PART II. 
The Geology of the Provinces of Tsan and U. in 
Central Tibet. By H. H. Hayden, B.A., B.E., F.G.S., 
Superintendent, Geological Survey of India. (With 15 
plates.) 
Page. 
Introduction ........... 123 
Chapteb I.— Physical Features , 123 
„ II. — The Crystalline zone ...... 138 
III. — Pre-Jurassic Sedimentaries ..... 140 
