CONTENTS 



PAGE 



List of illustrations 9 



Preface 13 



Introduction 15 



The rocks 15 



Sedimentary rocks 16 



Origin of materials 16 



Consolidation of materials 22 



Chemical sediments 24 



Organic sediments. 24 



Places of deposition 24 



Continental deposits 24 



Littoral deposits 26 



Marine deposits 26 



Description of clastic rocks.- 27 



Conglomerates 31 



Breccias 33 



Sandstones 33 



Shales, lime mudrocks etc 36 



Limestones and dolomites 37 



Structures of sedimentary rocks 39 



Original structures 39 



Structures due to deformation 49 



Unconformities and disconformities 57 



Age relations of sedimentary rocks 59 



Igneous rocks 62 



Structures in igneous rocks 71 



Relative age of igneous rocks 72 



Metamorphic rocks 72 



Conditions of life in the sea today 75 



Bathymetric or vertical range 77 



Life in pelagic and abyssal realms 81 



Geographical range 85 



Struggle for existence in littoral realm 90 



Effects of tides 90 



Effects of currents 92 



Effects of waves 94 



Effects of varying temperature 99 



Effects of variability in salinity 102 



Conflict between animals themselves 108 



Competition within the species 113 



Factors dangerous to eggs and larvae 114 



Plant and animal associations along the shore 115 



Rocky shores 118 



Sandy bottoms 143 



Muddy bottoms 162 



5 



