Whether one’s interests are practical, historical, acquisitive, esthetic, philosophical or scientific, the geological features of the Connecticut Valley possess the variety to gratify them all. One must indeed be blind if he cannot find something of interest—a hobby—even a profession in the geological display spread before him in central Massachusetts. Let it not be thought that this little volume tells the whole story. On the contrary, its authors expect to have a difficult time justifying their sins of omission, more particularly because many of the omissions have been conscious and deliberate. But they trust they have left for the reader a wealth of features which he can make his own by right of discovery. For it will not take him very long to penetrate the fourth dimension of geologic time more deeply and intimately than is possible in the pages of a book. Footnotes [1]The figures denote the distance in miles from the starting point to the feature mentioned. General Index “P” indicates plate following page number indicated A Agglomerate, 22 P, 24, 36, 72, 84 Albite, 109 Albite granite, 116 Allanite, 88, 110 Alluvial fans, Triassic, 19, 28, 43, 46 Alluvial plain, 3, 21 Alluvial wash, 25, 43 Amphibole, 110 Appalachian disturbance, 42 Argillite, Leyden, 64 Arkose, 114 Arkose, “first” sandstone, 86 Ash, volcanic, 28, 66, 71 Augite, 110 Autunite, 110 Azurite, 64 B Bank, undercut, 2 Barite, 30, 63, 108 Basalt, 72, 115 Basalt, columns, 71 Basin, Triassic, 27, 43 Batholith, 32 Beaches, sloping south, 49 Bedrock, depth, 10 Biotite, 109 Block mountains, 25 Boulders, striated, 21 Brickyards, 4, 69 C Calcite, 64, 108 Calendar beds, 69 Cambrian, 37, 38 Canyon, Little Westfield River, 61 Carboniferous period, 33, 42 Carboniferous swamps, 34, 42 Caves, Sunderland, 55 Chalcopyrite, 64, 108 Channel scars, 79 Chicopee shale, 18 Chlorite, 110 Cinder cone, 25 Cirque, 10 Clay, 4 Clay beds, 69 Clay, distorted, 6, 66 P, 70 Clay stones, concretions, 70 Clays, banded, 4, 6 Clays, record climate, 69 Climate, Triassic, 23 Coal, 33 Coal basin, 34, 42 Coal swamps, Carboniferous, 33, 40 Coal, Triassic, 22 Coherent rock, effect, 12 Columns, basaltic, 60 Concretions, 70 Conglomerate, 20, 25, 28, 54, 56, 99, 113 Conglomerate, boulder, 21 Conglomerate, Devonian, 35 Conglomerate, Mt. Toby, 54 Conglomerate, Triassic, 19, 21 Contact, conglomerate with crystallines, 59 Crater, 25 Cretaceous period, 17, 46 Cretaceous sediments, 16 Crops, 7 Cut-banks, 11