CONTENTS. 



Page 



Letter of transmittal xv 



Preface x\ ii 



Part I. — General geology oi^ the Narhagansett Basin, by N. S. Shaler. 



Chai)ter I. — Position and surface relations of the Narragansett Basin, and tbe rocks it contains. 7 



General features - 7 



Strati grapliical and erogenic relations 10 



Eesults of the action of orogenic forces 20 



Overthrust phenomena 23 



Dike rocks of the hasin *.. 27 



Chapter II.— Physical history of the hasin 30 



Eelation to marine and atmospheric erosion and deposition 30 



Ageof Carhoniferous I'ocks of the basin 36 



Original relation of the Narragansett Basin to the sea 37 



Original distribution of the east Appalachian coal field .---.. 38 



Ancient margin of the basin 40 



Eelati%"e erosion of east and west Ai^palachians 40 



Recent changes of level 46 



General statement concerning base-leveling 47 



Cycles of deposition 49 



Arkose deposits of the basin 50 



Relation of arkosesto erosion 55 



Record value of conglomerates 59 



Red color of the Cambrian and the Carboniferous 62 



Chapter III. — Glacial history of the Narragansett Basin 64 



Carboniferous conglomerates 64 



Last Glacial period 67 



Amount of erosion - 71 



Chapter IT. — Economic resources of the basin 77 



Soils - 77 



Coals 79 



Condition of the beds 80 



Characteristics of the coals 82 



Conditions of future economic work 85 



Iron ores: Iroii Hill deposit - 88 



Part II.— Geology of tub northern and eastern portions op the Narragansett Ba«;in 



BY J. B. WOODWORTH. 



Chapter x.— The problem ot stratigraphic succession 99 



Repetition of lithological characters 100 



Transition of lithological characters 100 



Effects of igneous intrusions 101 



Metamorphism 101 



Folding and faulting 101 



Denudation 101 



