Gravity data collected in New York by the U.S. Geological Survey during June, 1963

1963 ◽  
Author(s):  
Marvin Gene Simmons
Keyword(s):  
New York ◽  
Gravity Data ◽  
Geological Survey ◽  
The U.S

On: “GRAVITY AND AEROMAGNETIC EXPLORATION IN THE PARADOX BASIN,” BY NELSON C. STEENLAND (GEOPHYSICS, FEBRUARY, 1961, PP. 73–89)

Geophysics ◽  
1962 ◽  
Vol 27 (3) ◽  
pp. 398-398
Author(s):  
P. Edward Byerly
Keyword(s):  
Gravity Data ◽  
Geological Survey ◽  
Effective Density ◽  
Isostatic Compensation ◽  
Paradox Basin ◽  
The U.S

Following are some comments concerning Dr. Steenland’s discussion of gravity data in Professional Papers 316-A and 316-C of the U.S. Geological Survey. Dr. Steenland’s cylinder calculations are entirely dependent upon the regional anomaly removed. He obtained an anomaly of −40 mgal over Paradox Valley, whereas we obtained a residual anomaly of −32 mgal. The bottom 4,000 ft of Dr. Steenland’s cylinder contribute −5 mgal to the anomaly. Dr. Steenland’s analysis supposes that the only effective density contrasts are those attributable to variations in salt thickness or isostatic compensation.

Silas Watson Ford: A Major But Little-Known Contributor to the Cambrian Paleontology of North America

1999 ◽  
Vol 18 (2) ◽  
pp. 246-263 ◽  
Author(s):  
Linda Hernick
Keyword(s):  
New York ◽  
North America ◽  
Master's Degree ◽  
Hudson River ◽  
Geological Survey ◽  
Personal Problems ◽  
Personal Library ◽  
New York Tribune ◽  
The U.S ◽  
Union College

Silas Watson Ford (1848-1895), telegrapher and paleontologist born in Glenville, New York, in 1848, made significant contributions to Cambrian paleontology from 1871 to 1888. The focus of his work was the allochthonous Taconic rock that lies east of the Hudson River in easternmost New York. His discovery of a ‘Primordial’ fauna in this region was instrumental in helping to resolve the uncertainty surrounding the age of this older portion of the Taconics. While most of his papers were published in the American Journal of Science, a series of seven papers on the ‘Silurian Age’ was published by the New York Tribune in 1879. For this work he was subsequently awarded an honorary master's degree by Union College.Ford was hired by his contemporary, Charles Doolittle Walcott (1850-1927), to work for the U.S. Geological Survey from 1884 to 1885. Highly regarded by James Hall (1811-1898), James Dwight Dana (1813-1895), Joachim Barrande (1799-1883), and many other prominent geologists of the time, he was often consulted for his expertise in collecting and describing Cambrian-age fossils.While Walcott's career continued to flourish, Ford faded into obscurity after 1888. Plagued by personal problems, he was forced to give up his personal library, his fossil collection, and finally, his career. He died in 1895 at the age of 47, with his passing virtually unnoticed by his professional colleagues.

Reexamination of the values used as constants in calculating rock density from borehole gravity data

Geophysics ◽  
1981 ◽  
Vol 46 (2) ◽  
pp. 208-210 ◽  
Author(s):  
Stephen L. Robbins
Keyword(s):  
Bulk Density ◽  
Research Program ◽  
Gravity Data ◽  
Geological Survey ◽  
Rock Density ◽  
The U.S

The U.S. Geological Survey has a research program in bore‐hole gravimetry (Mast, 1978, p. 17). As part of this program, I have been examining the accuracy of constants F and k used in the formula for determining in‐situ bulk density from borehole gravity data.

ACCURACY OF BOREHOLE GRAVITY DATA

Geophysics ◽  
1978 ◽  
Vol 43 (3) ◽  
pp. 538-542 ◽  
Author(s):  
James W. Schmoker
Keyword(s):  
Data Quality ◽  
Gravity Data ◽  
Geological Survey ◽  
Gravity Survey ◽  
Vertical Separation ◽  
Elapsed Time ◽  
Gravity Measurements ◽  
Period Data ◽  
The U.S

Repeated subsurface gravity measurements, obtained with the U.S. Geological Survey‐LaCoste and Romberg borehole gravity meter, were studied to determine the accuracy of the borehole gravity data, the dependence of accuracy upon elapsed time and vertical separation, and the precision of bulk densities calculated from borehole gravity measurements. The likelihood of poor interval gravity measurements increases sharply for vertical intervals greater than 150 ft, and increases approximately linearly with increasing time between readings. After a brief warmup period, data quality does not improve with the passage of time from the beginning of the survey. If the stations of a borehole gravity survey are separated by less than 70 ft, and the time between readings is less than 18 minutes, the gravity difference between two points in a borehole can be measured to ±10 μgals. For intervals greater than 20 ft, this is equivalent to a density error of [Formula: see text] or less.

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