A Reconnaissance of Parts of Northwestern New Mexico and Northern Arizona (Google eBook)

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U.S. Government Printing Office, 1910 - Geology - 88 pages
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Page 78 - I), 5 3£ inches in diameter and one-fourth inch thick, having a 3-inch stem, which is cemented in a drill hole in solid rock, in the wall of some public building, in a bridge abutment, or in other substantial masonry structure.
Page 77 - Marshall, RB Results of spirit leveling in Delaware, District of Columbia, Maryland, and Virginia. 1896 to 1909. inclusive.
Page 78 - Credit is given to the various level men directly in charge under the heading of each list. The office work of computation, adjustment, and preparation of lists was done mainly by SS Gannett, geographer, and DH Baldwin, topographer, and since 1907 under the general direction of EM Douglas, geographer. Classification.
Page 77 - The office work of computation, adjustment, and preparation of lists was done mainly by SS Gannett, geographer, under the general direction of EM Douglas, geographer. Classification. — The elevations are classified as precise or primary, according...
Page 79 - ... statement of the elevation. It is assumed that engineers and others finding these bench marks so stamped in the field will communicate with the director of the United States Geological Survey in order to obtain the accepted elevation to hundredths or thousandths of a foot. Any person finding bench marks in the following lists mutilated or destroyed will confer a favor by notifying the Director. United States Geological Survey, Washington, DC PRECISE LEVELING.
Page 77 - Va., is recent work and did not form part of the data involved in the net adjustment, but an adjustment has been made of this line and corrections made to the primary leveling in agreement. All results of spirit leveling in this State previously published by the United States Geological Survey and all later work are included in this report, readjusted, and rearranged by quadrangles. Descriptions and elevations of bench marks are given for 48 counties, furnishing vertical control for nearly half the...
Page 78 - The elevations under precise leveling were determined by lines run either in both forward and backward directions or by simultaneous double-rodded lines, a highgrade level and rated rods being used and special precautions being taken in observation and reduction to correct error and make the results continuously good; elevations under primary leveling were determined mostly by single lines run with the Y level, precautions being taken against only the principal sources of error and depending upon...
Page 11 - Asterocalamitcs scrobiculatus and the single minute fern pinnule, is more or less macerated and obscure, the collection consisting chiefly of drift-rounded or comminuted and more or less macerated bits of stems, roots, and bark, of no value except as showing that they fall within the epoch of vascular or woody plants (post-Silurian). The material is not of a nature or state of preservation to justify anything like a close correlation. The plant beds are Carboniferous. It is probable that they belong...
Page 5 - QUADRANGLES. The elevations in the following list are based on an aluminum tablet stamped "635 ERIE'' placed in the Soldiers' Home, at Erie, Pa., the elevation of which is now accepted as 636.179 feet above mean sea level.
Page 59 - ... thickness of over forty feet which near the top contain bands of flags or sandstone impregnated with iron. Usually one of these layers at least is fossiliferous and has been termed the Gasteropod zone. Among the fossils so far identified in this bed are the following : Ostrea translucida, Exogyra 1 Farther to the westward this band reposes on the Dakota Sandstone or may perhaps be said to form a part of it.

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