VI CONTENTS. 



Part II — Continued. 



Chapter I. — The problem of stratigraphic succession — Continued. Page. 



Glaciation 102 



Submergence - 103 



Absence of artificial excavations 103 



Chapter II. — The pre-Carboniferous rocks 104 



Algonkian period 101 



Blackstone series 104 



Cumberland quartzites 106 



Ashton schists 107 



Smithfield limestones 107 



Cambrian period 109 



Lower Cambrian 109 



Middle Cambrian (unrepresented) 109 



Upper Cambrian 109 



Silurian period (unrepresented) 113 



Chert pebbles 113 



Chapter III. — The igneous rocks of the border of the basiu 114 



Granitic rocks 114 



Plympton felsites 116 



Granite-porphyry 1 17 



Other rocks 117 



Gabbro hills of Sharon 118 



Chapter IV. — The Carboniferous basin 119 



General structure of the basin 121 



Maps of the boundary of the basin 124 



Boundary of the basin on the north and east 125 



From Cranston to the Blackstone River 125 



From Blackstone River to Sheldonville 127 



Connection between the Narragansett and Norfolk County basins 127 



Sheldonville cross fault 127 



From Sheldonville to Foolish Hill 127 



Foolish Hill fault 128 



From Foolish Hill to Brockton 128 



From Brockton to North River 129 



Shumatuscacant fault 129 



From North River to Lakeville 129 



From Lakeville to Steep Brook 130 



Inliers 130 



North Attleboro inlier 131 



Nemasket granitite area 131 



Summary 131 



Chapter V. — The Carboniferous strata 133 



Determination of horizons within the basin 133 



Means of determining superposition 133 



Tabular view of the strata in the Narragansett Basin 134 



Formations below the Coal Measures 135 



Pond ville group 135 



Basal arkose beds 135 



Foolish Hill exposures 135 



North Attleboro exposures 135 



Pierces Pasture in Pondville, Norfolk County Basin 135 



Absence of basal granitic conglomerates ■ 136 



Geographical conditions indicated by the basal arkose 137 



Absence of iron oxides in the basal arkose 138 



Absence of carbonaceous matter along northern margin 139 



Extent of arkose zone 139 



