GEOLOGY. 25 
The southern slopes of the ridge are on their basal half entirely covered with gravel, 
* C . m ^ aC6S even ex ^ends to the top, assuming here a thickness of from 10 to 15 feet, 
a I* 00 / i^ IC ^ r . aVe ^ ^ et ^ s are separated from the main range by a shallow depression, forming 
ow rit ge -which runs along the base of the higher one, and from which it is, even in the 
g i^ aace ’ clearl y discernible by its dark tint. The pebbles in the gravel are mostly of small 
ze an v ell river-worn; they are derived to a very large extent from grey or greenish 
caK ' s an( l shales, black or white limestone, more rarely of trap, basalt, and of gneiss. 
U* 1 t e exception of the last-named rock, all the others had been met with in situ in the 
ipei oyanda valley. The pieces of gneiss belong to a group of metamorphic rock which is 
. a y called Protogine. It is mainly composed of quartz and white or reddish orthoclase, 
. a comparatively small proportion of a green chloritic substance. The white felspar 
I } if gCncra Hy contains as an accessory mineral schorl, in short, rather thick, crystals. 
havTl SUl ^ equentl y aq - U( l c to the probable source from which the protogine pebbles might 
th’orn Artysh we marched, as already stated, northwards, up the Toyanda river, and for 
the f CS ^ ~~ m ^ os one was sru'prised to find nothing but the same Artysh and gravel deposits, 
ormer constantly dipping at a high angle to north by west, and the latter resting on 
,, 111 ln s ^ghtly inclined or horizontal strata ; while among the recent river deposits in 
„ e °f the valley itself the order of things appeared reversed. The gravels, having 
rs ^ yidded to denudation, here underly the clays derived from the Artysh beds, thus 
Preparing an arable ground for the agriculturist, whenever a favourable opportunity offers 
uiY ^ i° w miles south of Chung- terek, the laminated Artysh beds entirely disappear 
cc) 1 61 S ray cl> which from its greater consistency assumes here the form of a rather tough, 
a ^ aisc conglomerate. In the bend of the river the latter has a thickness of fully 200 feet, 
rare ero< ^ e< ^ ^y lateral rivulets into remarkably regular Gothic pillars and turrets. It is 
^ re 0 mee f with a more perfect imitation of human art by nature. The general surface of 
• (f _ ? gravel deposits is comparatively low, from 400 to 500 feet above the level of the river ; 
much denuded and intersected by minor streams and old water-courses. 
Kolctan range. 
Tekki range. 
Chung'terek . 
Mir%a-terek. 
Chakmdk range. 
Artysh •valley . 
Kashghdr t 
1 
Chakmdk. 
Guljabashi. 
Russian J Boundary . 
Purug-ju . 
Chadyr-kul. 
I a. l ; occas l°nally hardened into conglomerate, 
a. Yc ° ne gravel - 
Basalt re< ^^' s ^ san dy an ^ clay beds (Artysh beds). 
san dstones and conglomerates* red or white, with bands of 
5. ant ^ S re enstone rocks interstratified. 
Jmestone conglomerates. 
6. White dolomiti'c limestone. 
7. Dark semi-metamorphic schists and slates. 
8. Dark limestone. 
9. Blackish triassic limestone. 
10. Triassic ? greenish shales below the limestone. 
11. Palaeozoic shales, slates and sandstones. 
12. A band of white and reddish crystalline limestone. 
At a 
limestone 
Section from Kashghar to the Chadyr Lake. 
couple of miles north of Chung- terek the Koktan range begins with rather abrupt 
cliffs, rising to about 3,000 feet above the level of the Toyanda. Nearly in the mid- 
9 
