CONTENTS. VII 



CHAPTER V. 



PHYSICAL AND GEOLOGICAL DESCBirTION OF THE COUNTKV FKOM TUB INITIAL POINT ON TUE PACIFIC TO TUE JUNCTION OF THE GILA 



AND COLOKADO. 



Pago. 



I. General physical features of the coimtry , 78 



Streams and water-courses 81 



Lakes and lagoons 83 



II. Geology and mineral productions 83 



Tertiary formation 85 



Natural terraces and table summits.. 86 



Desert formation 87 



Mineral productions of Southern California 88 



Introductory note of Major W. H. Emory 31 



Extract of report of Assistant Arthur Schott 92 



Tertiary shore 92 



Volcanic vents .... ... 92 



Solfataras 94 



Clavij ero' s Accounts of Lower California. 91 



Volcanism through the Gulf Basin 95 



Changes in the physiography of the country 97 



Mountain rupture 98 



Summary 100 



GEOLOGY AND PALEONTOLOGY. 



GEOLOGY AKD PALEONTOLOGY OF THE BOUNDARY, BY JAMES HALL, OF ALBANY, NEW YORK. 



Letter to W. H. Emory, United States commissioner, briefly rcTiewing sources of information and present state of 



knowledge of the geology of the west 10 1-106 



Observations upon the character and geological age of the specimens of rocks and minerals submitted for exami- 

 nation from the collections of the survey 106-112 



Specimens collected on the route from the Pacific coast eastward, including the tertiary of the coast and the 

 metamorphic rocks of the Cordilleras ; the tertiary of the great plain east of the Cordilleras, and the meta- 



morphic rocks of the isolated mountains in the great plains . 113-119 



Observations on the carboniferous limestone of the boundary survey collections, and its relations with the carbon- 

 iferous limestones of the Mississippi valley 122-125 



Observations upon the cretaceous strata of the United States with reference to the relative position of the fossils 



collected by the boundary commission 126-138 



Eemarks upon the tertiary formation ; Cretaceous formation ; Carboniferous formation ; Devonian and Silurian 



formations ; newer igneous and metamorphic rocks ; older metamorphic rocks 139-140 



DESOBIPTION OF CBETACBOCS AND TEIITIABY FOSSILS, BY T. A CONBAD. 



Polypi - 144-146 



Bivalves 147-156 



Univalves 167-159 



Tertiary fossils 160-163 



Appendix 164-165 



