REPORT OF COMMISSION VII 
GVII-25 
tial oil structures within northern Alaska have been structure-contoured at 
scales as large as 1:10,000. This work was accomplished in spite of a paucity of 
outcrops, but with widespread tundra cover. Some aspects of this work are 
described by W. A. Fischer in “Photogeologic Studies in Arctic Alaska and 
Other Areas.” 
Other sedimentary rock studies have been completed in the Colorado Plateau 
area, western United States, where structures and distribution of rock types have 
been mapped at a scale of 1:24,000. Here rock exposures are excellent and per 
mit such recognition of detail that stratigraphic thicknesses in many areas have 
been measured with sufficient accuracy to allow isopachous maps to be com 
piled with an isopachous interval of ten feet. The isopachous maps show strati 
graphic thickness variations that may be significant with regard to uranium 
mineral deposition. Correlation studies in part of the petroliferous Tertiary Fasin 
of northeastern Utah have also been completed. Beds as thin as five feet have 
been mapped over wide areas. 
Photogeologic mapping of heavily forested parts of Alaska has been accom 
plished at scales of 1:8,000 to 1:250,000 depending on the objectives of the 
study. Large-scale mapping has been done in mine areas and potential dam 
site areas; small-scale mapping has been carried out in other areas at scales of 
1:62,500 to 1:250,000. In these studies the mapping of structures like faults and 
shear zones was the primary objective. In some sparsely forested areas surficial 
deposits have been mapped at a scale of 1:250,000. 
Instruments and procedures used in these photogeologic studies have been 
described by W. A. Fischer in “Photogeologic Instruments Used by the U. S. 
Geological Survey,” and by R. G. Ray in “Photogeologic Procedures in Geo 
logic Interpretation and Mapping.” 
ACTIVITY IN GEOMORPHOLOGY 
The largest British project involving interpretation of a geomorphological 
character is at present being undertaken by Hunting Aerosurveys in Jordan. 
Though the ultimate object of the survey is mapping vegetation units through 
out the country, the present operations consist mainly in the preparatory land 
classification mapping, based largely on geological and geomorphological cri 
teria. Much of the work is being carried out by photographic interpretation 
methods, though the definition of the classification types is based in considerable 
measure on detailed field investigations by ecologists and geologists in all parts 
of Jordan. Illustrations based on the preliminary stages of this project were 
used by Dr. V. C. Robertson in a paper read to the Photogrammetric Society 
entitled “Aerial Photography and Proper Land Utilization” (Photogrammetric 
Record, Vol. 1, No. 6). An interesting example of a correlation between vegeta 
tion forms and geology, which has been proved on the ground and traced by 
photographic interpretation methods in Jordan, is provided by the way in 
which, in the West Central woodland scarp area of the country, oaks are found 
on the limestone and marl areas, whereas the juniper occurs on the sandstones. 
In England a paper on “The Value of Air Photographs in the Analysis of 
Drainage Patterns” was given to the Photogrammetric Society in March 1953 
by Dr. S. H. Shaw; this included details of investigations on this subject in the 
Lake Nvasa region (Photogrammetric Record, Vol. 1, No. 2). 
During the reporting period, the U. S. Geological Survey, in cooperation 
with the Corps of Engineers, U. S. Army, has also engaged in field studies of the 
geology and vegetation of Alaska with particular reference to the relationship 
between permafrost, land forms, and vegetative cover. A major aim has been