viewing distances and other factors affect the colors seen. 
The "viewing distance" of the aerial photographs of the 
field area was approximately 10,000 feet, This is a cone 
sistent factor, whereas viewing distances of the ground 
observer may vary considerably. Certain formations within 
the Paleozoic sequence have characteristic over-all colors, 
which may be seen from a ground viewing distance exceeding 
11 miles, Color transparencies (35 mm.) taken from similar 
viewing distances recorded the same color differences, and 
these color differences were also visible on low-altitude 
high-angle oblique aerial color photographs (taken Nove 
ember 10, 1955), 
Problem 5 
A persistent marker bed of bright orange color 
(field and photograph) was noted within the Furnace Creek 
formation, Other such beds might be found, although rock 
types and correlative colors are not generally persistent 
within the formations of Tertiary age. 
Problem 6 
Exposures of basalt in the southeast part of the 
area and within the formations of Tertiary age are shown on 
the color aerial photographs. Steel-blue and rust-red colors 
predominate in the basalt at Ryan, in contrast to the deeper 
red and olive-green tones that characterize basalt found 
Within the Artist Drive and Furnace Creek formations. The 
basalt cap at Ryan thins to the north from a thickness of 
about 500 feet to less than 3 feet within a distance of 3i 
miles, Direct tracing methods cannot be used in correlation 
as transverse faults offset the basalt at Ryan and may have 
Juxtaposed 1t with older basalt layers of comparable thickness. 
Color differences may aid in determining the magnitude of the 
faulting involved; they may also aid in determining the extent 
of the basalt flow at Ryan. 
FIELD STUDIES TOWARD OBJECTIVE 2 
Field studies toward objective 2, the study of 
ground colors and their relationship to colors as seen at a 
distance and/or recorded upon color film, were undertaken 
concurrently with field studies directed to objective 1, 
Data related to certain environmental factors that influence 
the observer!s visual impressions of color were collected