Geophysical Abstracts 152 January-March 1953

GENERAL GEOPHYSICAL EXPLORATION 57
Some support is found for the view that the Earth's present inner core is
more likely to consist of an accumulation of iron and denser materials than of
ultrabasic rock that has undergone a second pressure transformation. Support is
also found for the view that the density gradients of model B require a pro­
gressive change of composition with increase of depth in the inner core. The
hypothesis that the inner core is solid is strengthened. Strong support is given
to Elsasser's argument against the presence of large amounts of compressed
hydrogen in the central core. P. E. B.
14376. Bullen, K. B. Cores of terrestrial planets: Nature, v. 170, no. 4322, p.
363-364, 1952.
Earth models with an iron core as postulated by Urey, with a core due to
pressure modifications as proposed by Ramsey, and a core partly of nickel iron
and partly of modified ultrabasic rock as suggested by Bullen are compared,
using data on Venus, Mars, and Mercury. H. C. R.
GENERAL GEOPHYSICAL EXPLORATION
14377. Lahee, Frederick H. Field geology (5th ed.), 883 p., New York, McGraw
Hill Book Company, 1952.
Gravity, magnetic, seismic, and electrical methods of exploration are outlined
in chapter 23 (69 pages). M. C. R.
14378. Joesting, H. R. Geophysics Annual review 1952: Mining Engineering,
v. 5, no. 2, p. 151-155, 1953.
The outstanding discoveries, advances and trends in geophysics during 1952,
with emphasis on mining and engineering geophysics, are outlined. Informa­
tion was obtained from about 75 correspondents in all parts of the world except
the U.S.S.R. satellite countries. If. C. R.
14379. Garcia Rojas, Antonio. Exploration work in Mexico: Geophysics, v. 18,
no. 1, p. 188-200, 1953.
Oil exploration in Mexico has been intensified since 1940 so that, at present,
the number of crews per million barrels of oil produced is approaching that of
the United States. There are now 20 geologic parties, 20 seismic parties, 4
gravity-meter parties and 1 electrical party operating in Mexico. The number
of wildcats per million barrels of oil produced, however, is far below that of the
United States, although there has been a sharp increase since 1945. Most of the
work has been done in the Gulf Coast area. Geophysical methods are credited
with finding a very large percentage of new oil fields. Pemex employs gravity
measurements locate regional trends and some local anomalies, followed by
detailed seismic work. Electrical methods are used successfully to locate shallow
fracture zones. L. C. P.
14380. Pot, R. Well logging and testing techniques applied to reservoir analysis:
Canadian Min. Metal Bull., v. 45, no. 480, p. 208-212, 1952.
This paper reviews the principal testing methods which are available to the
petroleum engineer to aid in the prediction of the potential productivity of an
oil well. The methods mentioned are coring, formation testing, electrical well
logging, radiation well logging, bottom-hole pressure measurements, and sam-