GEOLOGICAL HISTORY OF NORTHEASTERN PERSIA. 245 
glomerates, ver>' slightlj- consolidated, and to all appearance of comparatively recent 
origin. The shales are rather brightly colored, greenish-white, red, etc. . . . 
The beds near the river are contorted and sometimes vertical ; farther away they 
become more horizontal and appear to pass up into the alluvial beds of the great 
plain to the northward." 
Elsewhere (/;, pp. 493-494) Blanford speaks of red shales, or ferruginous shales 
and sandy beds, sometimes banded red and white, and often much decompo.sed, 
which lie in tilted positions against the limestone of the mountains on the edge of 
the basins west of Kirman and seem to lia\'e been brought to their present positions 
by faulting and folding. From the description it seems as though these beds must 
closely resemble those of Hajistan. 
SUMMARY. 
The facts set forth above, so far as they warrant any conclusion, suggest that in 
Eastern Persia the lower strata of the basins are generally greenish shales, which are 
now exposed along the edges of the basins where they have been extensively warped 
and compressed. Above them occur reddish silts containing more or less sand and 
g\'psum and warped like the underlying shales, although to a less extent. In certain 
places toward the top of the series the red strata alternate with green clays. Above 
all lie the deposits of silt and gravel which are to-day accumulating. Although 
these different strata show varying degrees of warping along the edges of the basins, 
it is noticeable that toward the centers they approach the horizontal position. It 
is probable that in the centers of many of the basins an uninterrupted series of 
strata has been deposited from the time of the post-Cretaceous uplift of the country" 
until now. At first a shallow sea or large lakes probably occupied the central 
portions of Iran and allowed the deposition of the green shales. Later, as the great 
basin was broken into smaller basins, the larger bodies of water gave place to 
smaller ones, and these, under the influence of a drj- climate, gave place to playas 
or shallow salt lakes where the prevailing deposits were reddish silts. Still the 
process of deepening the basins and decreasing their area went on, with the result 
that the green shales were more highly warped and the red deposits were also 
uplifted along the borders of the basin and were exposed to erosion. Meanwhile 
the superficial deposits which now cover the plains were laid down and the country 
assumed its present form. It is not to be supposed that ever)' basin has gone 
through exactl)' the same process, or that a single process has everywhere taken 
place at the same time. Accidents have intervened. At Zorabad the damming of 
the Heri Rud formed a lake and greatly altered the course of events. At Sistan, 
and probably elsewhere, a series of lakes appears to have occupied the basin during 
the glacial period. Nevertheless the general course of events was a gradual progress 
from larger basins to smaller basins, and from subaqueous to subaerial deposition. 
