286 THE KASIN OF EASTERN PERSIA AND SISTAN. 
is broken into a breccia, and is baked, so that the upper portions resemble a mass 
of finely broken bricks cemented with brick dust. Kuh-i-Khoja is the remnant of a 
volcano (see fig. i68) which broke out under the lake, and in its efforts to find exit 
elevated the sediments of the lake bottom into a dome, which it covered with lava. 
Around the island thus formed the waves at once set to work, and have now under- 
mined and carried away all the dome except the central mass. Soon all the clays 
will be removed and merely a volcanic neck will remain. 
Similar volcanic outbursts are described by \'redenburg as having taken place 
in other parts of Sistan and throughout Baluchistan. Smith (a, p. 315) describes 
"a flat-topped, irregularly-shaped hill, called Kuh-i-Kuchah, somewhat smaller 
than but resembling the Kuh-i-Khoja." It lies between the Farah and Harud 
rivers, 8 miles west-northwest of the ruins of Peshawaran. (See jjlate 6, opposite 
p. 288.) This hill and others like it will doubtless repay close study when it shall 
be possil)le to travel freely in Afghanistan. 
Meanwhile there is one mountain, the Kuh-i-Chaku, on the northwestern shore 
of the Hamun-i-Sistan, which can be studied. It lies in the desert close to the 
Afghan border and is difficult of access, but it presents such wonderful sections that 
^^iniiiiiii^»iiiii|^jljjjjl __^^^^^^ Lake level 
Fig. 168. — Ideal cross-section of the Mesa of Kuh-i-Khoja. Heavily shaded portions = lava; lightly shaded 
portions = pink sill ; unshaded portions ^ green clay. 
it deserves months of study rather than the short week which I was able to give 
to it and to the surrounding countr)'. The mountain of Kuh-i-Chaku is a mesa 
like Kuh-i-Khoja, although nuich larger. The clays reach a thickness of 650 feet, 
and the lava cap 400. The broad top of the mesa presents a relief of from 100 to 
200 feet, and two breached craters inclosing hills of scoria can be made out. The 
upper layers of clay are baked, as at Kuh-i-Khoja, and most of the lower slopes are 
covered with talus, so that good sections are difficult to obtain directly on the side 
of the mountain. At the time of the volcanic eruptions which produced the 
mountain, however, the whole region was uplifted. South of Kuh-i-Chaku a 
slightly rolling monocline of uplifted clays descends gently for 30 or 40 miles to 
Bereng, and has been dissected by the waves to form the bluffs which have been 
described. Fine sections are exposed between Kuh-i-Chaku and Kharikha, where 
the bluffs reach a height of over 400 feet. 
LAKE DEPOSITS VERSUS PLAVA DEPOSITS. 
The accompanying diagram (plate 5) illustrates sections of lake deposits from 
various locations along the northwestern shore of the lake in the region of the Kuh-i- 
Chaku uplift, and from the southeastern bluffs along the edge of the Helmund delta 
in the district affected by the Kuh-i-Khoja uplift. The sections are arranged according 
to location. The position of each is marked on the map of Sistan by the appropriate 
letter, A being in the northwest comer, close to Kuh-i-Chaku. With the possible 
