Bulletin - United States Geological Survey, Issue 597

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Page 12 - ... Massachusetts and Rhode Island, by BK Emerson. 1917. 289 pages, 10 plates, 2 text figures. In preparing this treatise and the accompanying geologic map the author endeavored to use all the material available. A large part of the area is described from the results of his own studies, which began in 1871. The State of Massachusetts presents a perfect illustrative section across the Appalachian Mountain system in an area where it culminates in variety and complexity, about midway in its great sweep...
Page 88 - The accumulation of sediments was interrupted by an eruption of lava through a fissure in the earth's crust, which opened along the bottom of the basin. The lava flowed east and west on the bottom of the bay, as tar oozes and spreads from a crack, and solidified in a sheet which may have been 2 or 3 miles wide and about 400 feet thick in its central part. This is the main sheet, or Holyoke diabase.
Page 115 - From this point on, therefore, an attempted classification into families and orders seems futile. Genus Platypterna E. Hitchcock E. Hitchcock 1845, p. 25 ; 1858, p. 83. Lull 1904 A, p. 515. Generic Characters. — " Bipedal, tridactyl, plantigrade or digitigrade, generally with a broad, rounded heel. Digits narrow without pad impressions and but rarely showing distinct claws " (Lull). Platypterna deanii E. Hitchcock Ornithoidichnites deanii E. Hitchcock 1841, p. 493, pi. 42, figs. 31, 32. Platypterna...
Page 55 - ... few thin lenses of slate. At some places along the southern margin of the basin its base is a slaty or sericitic quartzite but at most places it is a coarse ill-sorted conglomerate containing some pebbles or small bowlders more than a foot through. " Dorchester slate member. — This member is named from the Dorchester district of Boston, where it is exposed at several places. It consists of red and purple slates, in part crossbedded, interbedded with sandstone and fine-pebble conglomerate. The...
Page 117 - Length of step, 1,224 mm. Width of trackway, ?35O mm. Digit I is straight, the others curve inward. • Genus Plesiornis E. Hitchcock E. Hitchcock 1858, p. 102. Lull 1904 A, p. 521. Generic Characters. — " Bipedal or ?quadrupedal, digitigrade, tridactyl [or tetradactyl] forms, digits terminated by blunt or pellet-like claws. Small forms of doubtful affinity
Page 106 - As a matter of fact no fewer than three genera and five species of dinosaurs, one species of phytosaur and two species of aetosaurs are known, making four genera and seven species, including that which Emerson and Loomis were describing at the time of their writing, while the actual number of bone remains from the Connecticut valley exceeds this record of different forms. The northernmost...
Page 129 - At present it appears probable that these fragments have been detached from a very extensive submerged Tertiary formation, at least several hundreds of miles in length, extending along the outer banks, from off Newfoundland nearly to Cape Cod, and perhaps constituting, in large part, the solid foundations of these remarkable submarine elevations.
Page 116 - E. Hitchcock 1848, pp. 184-185 ; 1858, p. 81. Lull 1904 A, p. 518. Generic Characters. — " Bipedal, leptodactylous, tridactylous. Toes curved, the lateral ones more or less outward and upward behind, so as to be keel-shaped. Digitigrade, rarely showing a heel" (Lull). Argoides minimus E. Hitchcock Ornithichnites minimus E. Hitchcock 1836, p. 325, fig. 9. Ornithoidichnites isodactylus E. Hitchcock 1841, p. 496, pi. 45, figs. 38, 39. Ornithoidichnites minimus E. Hitchcock 1841, p. 496, pi. 45, fig....
Page 183 - Petrology of the alkali granites and porphyries of Quincy and the Blue Hills, Massachusetts, Proc.
Page 56 - ... settle this point. THE CAMBRIDGE SLATE MEMBER.1 Emerson describes the Cambridge slate as follows: "The Cambridge slate, named from Cambridge, where it has been encountered in many excavations, consists of perhaps 3,500 feet of slate, shale, argillite, and some interbedded sandstone, and at or near the top about 40 feet of greenish and yellowish quartzite. Beds here and there are composed of reworked tuff. The formation is of rather uniform lithologic character, and appears to have been deposited...

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