GEOLOGICAL IILSTORV OF NORTHEASTERN PERSIA. 233 
ILLUSTRATIONS OF THE GEOLOGICAL HISTORY OF NORTHEASTERN PERSIA. 
Although the portion of Iran which I traversed embraces but a small part of 
the entire basin, it affords illustrations of many phenomena characteristic of the 
entire region. These fall into groups illustrating, respectively, (i) the non-climatic 
or more strictly geological historj' of Iran during the Tertiary- and Quaternary eras ; 
(2) the physiographic results produced by an arid climate during the same time ; 
and (3) the effects produced by climatic changes during the Quatemarj- era. Each 
of these groups will be considered in its relation to certain theoretical generaliza- 
tions, and in relation to the geographic aspect of the countr)-. The following 
illustrations of the geological history pertain first to the character and conditions 
of uplift of the mountains on the northeastern border of Persia ; second, to the 
nature and appearance of the north-and-south break which separates the Persian 
and Sistan basins ; and, third, to the conditions of warping and deposition in the 
numerous subsidiary basins. 
THE MOUNTAINS OF KHORASAN. 
The term Khorasan is applied administratively to all northeastern Persia from 
Astrabad to the northwestern corner of Baluchistan. In a n:ore restricted .sense it 
is the name of the mountainous northeastern corner of the coinitr\' centering about 
Meshed as a capital. As thus limited Khorasan is one of the most prosperous 
provinces of Persia, thanks to the considerable number of mountains which rise to 
the height of 10,000 feet or more ; yet the prevailing aspect is one of sterility. 
The mountains are very scantily covered with soil, and support merely a few weeds 
and bushes and an ephemeral growth of grass in spring. Cultivation is almost 
confined to the valley bottoms and is dependent entirely on irrigation. Each village 
is an oasis in the midst of a desert, but compared with other parts of Persia the 
oases are large and numerous, and are often of great beauty, with their fringes of 
poplars and orchards. 
This favored province of Persia consists of four parts. On the north lies the 
broad mountain mass of Kopet Dagh, running northwest and southeast, and fonning 
the boundary' between Persia and the Russian province of Transcaspia. South of 
Kopet Dagh lies the so-called valley of Meshed, a narrow cigar-shaped basin or 
depression. This is bounded on the south by the Binalud range, which runs from 
the Afghan border northwestward parallel to Kopet Dagh as far as Kuchan, and 
then turns southwestward until it joins the Elburz Mountains southeast of the 
Caspian vSea. Within the great arch of the Binalud range lies the fourth division 
of Khora.san, the little-known basins of Isferayin, Jaga-tai, and Nisliapur, together 
with the mountains which hem them in. South of all stretches the fearful desert 
of the Dasht-i-Kavir or Dasht-i-Lut. 
KOPET DAGH. 
If the line of the Caucasus IMouutains be projected acro.ss the Caspian Sea it 
reappears in the low, isolated, and half-buried ranges of the Great and Little 
Balkhans. Toward the southeast these mountains become broader and higher, and 
rise into the distinct range of Kopet Dagh, or Kopet Mountain, which, with an 
