118 
NATURE 
[ ¥une 10, 1886 
The first volume of M. Moushketoff's “ Turkestan ” 
consists of two parts. The first is an analysis of all 
explorations made in Turkestan up to 1884; and, the 
literature of the subject being scattered in periodicals, 
it will be of great value for the geographer. All the 
Russian and English explorations are mentioned, and the 
chief of them briefly analysed. The second part contains 
a description of the journeys of the author in the “ Turan 
or Aral basin,” including Samarkand, the western out- 
skirts of the Tian-Shan, the valley of Ferganah, the 
western outskirts of the Pamir and Alay region, the valley 
of the Amu-daria from Termez to Khiva, and the Kyzyl- 
kum sands. A summary concludes the volume, which is 
accompanied by a novelty that will agreeably surprise 
geologists, namely, a geological map of Russian Turkestan, 
on a scale of 67 miles to an inch. Another map, on a 
scale of 20 miles to an inch, is in course of preparation, 
that now published being only intended to show the 
extension and limits of four great geological sub- 
divisions: the Post-Tertiary deposits; the Tertiary, 
together with the Chalk, Jurassic, and Trias; the 
Primary, including the Archean crystalline slates ; and 
the unstratified crystalline rocks (granites, porphyries, 
diabases, and so on). Of course, it is regrettable that 
the Secondary deposits could not be separated from the 
Tertiary; but we must wait for the appearance of the 
promised map on a larger scale. 
As to the conclusions arrived at in this volume, we 
may remark at once that the personal inclinations of the 
author being chiefly directed to petrography on the one 
hand, and dynamic geology on the other, these two 
departments have received most attention ; while Prof. 
Romanovsky, being a well-known paleontologist, has 
devoted his chief attention and wide practical knowledge 
to the discrimination of the different subdivisions of the 
sedimentary deposits explored by him. M. Romanovsky 
having published almost every year very valuable reports 
on his summer’s work, his researches are embodied in M. 
Moushketoff’s work, so that each is complementary to 
the other. 
Nearly the whole of the Aral basin (and we have seen 
that the author includes under this name the wide tracts 
east and south-east of Lake Aral) is covered by Chalk, 
Tertiary, and Post-Tertiary deposits ; the remaining por- 
tion, that is, no more than one-twentieth of the area, 
being occupied by crystalline unstratified rocks, meta- 
morphosed slate, and Paleozoic deposits which appear 
from below the above. A mere glance at a topographical 
map of the region would be sufficient to indicate their 
extent—all the hills rising amidst the wide steppes being 
built up of Paleozoic or Archeean rocks. The Devonian 
limestones of the mountains Urda-bashi and Karatash ; 
the syenites, diabases, and crystalline slates of the Mogol- 
tau, Kochkar-ata, and Karnak mountains ; and the De- 
vonian and Carboniferous limestones of the Kazy-kurt 
hills are in this category. Some gold, silver-and-lead 
ores, copper, as also almandine and beryl, are found in 
these mountains. It is interesting also to notice that the 
crystalline rocks in the Paleeozoic islands scattered amidst 
the steppes are much more metamorphosed than the 
corresponding rocks in the Tian-Shan mountains. They 
have obviously been long subject to the influence of water, 
which once covered what is now the steppe region. 
Jurassic deposits are the next geological formation 
found in the East Aral basin. ‘The lowest strata seem, 
however, to belong to the Rheetic subdivision—the few 
remains of plants which they contain being some of them 
Jurassic, while others should be recognised as Rhaetic, 
and the third Triassic. They contain no traces of marine 
origin, and only one fresh-water shell, the Anadonta 
boroldaica, Romanovsky. It must therefore be concluded 
that throughout the Triassic and Jurassic periods nearly 
all Turkestan was a land having on its borders numerous 
lakes containing sweet or brackish water. These Jurassic 
deposits appear only on the borders of the East Aral 
basin: namely, on the Baidam and Saram rivers, and in 
Ferganah ; in the west they are known on the Mangi- 
shlak peninsula (Caspian). Everywhere they contain 
most valuable deposits of coal. We may add that the 
geologist will thus find, in the Aral basin, the well-known | 
geological feature so characteristic of the structure of 
East Siberia and Manchuria. 
Chalk and Tertiary deposits are widely spread. They 
constitute the bottom of nearly all the basin, and reach a 
thickness of 2000 feet in Ferganah, and 5000 feet in 
the Hissar region. ‘Two systems of dislocation are pretty 
well observed amidst these deposits which are folded in 
two chief directions: north-east (60°) and north-west 
(60°). This observation of M. Moushketoff is well worthy 
of notice. We thus find, on the outskirts of the hilly 
tracts of Asia, the two great systems of upheavals which 
are so characteristic of Asia: the system of ridges and 
plateaux running from south-west to north-east, which 
we have found appearing with such persistency in the 
East Siberian hilly tracts ; and the north-western direc- 
tion, which appears predominantly in South-West Asia. 
The Chalk deposits show great variety of structure; 
sandstones, limestones, and marls predominating. As to 
their fossils, they appear at some places in immense 
masses, but the number of species is mostly limited. 
According to M. Romanoysky, the Upper and Middle 
Chalk are represented there: the former, very rich in 
oysters, is closely akin to the Senonian of Europe; it is 
much developed on the outskirts of the Tian-Shan, espe- 
cially in Ferganah, but it changes its characters (Senonian 
Ammonites making their appearance) farther west, in the 
lower parts of the Amu-daria. The Middle Chalk, which, 
however, it is difficult to separate from the former, has a 
still wider extension. The Chalk contains a number of 
useful minerals; namely, phosphorite, gypsum, naphtha, 
ozokerite, and sulphur. 
The Tertiary deposits are so closely connected with 
the Chalk deposits that it is often difficult to separate 
them from one another; they are still poorer in fossils 
(excepting those on the northern and western shores of 
Lake Aral, as yet unexplored), especially towards the 
east, as we approach the Tian-Shan, In this last region 
we have, as is known, the Eocene deposits, consisting for 
the most part of deep-sea deposits of Nummulite sand- 
stones. They are covered with Lower and Middle Oligo- 
cene, very much like the German and Belgian Tertiary 
deposits, and these last in their turn disappear under 
Miocene limestones and Sarmatian clays. 
The Tertiary deposits of the Tian-Shan contain, on the 
contrary, very little or no clays, and chiefly consist of 
conglomerates and sandstones. S me of them date from 
ee 
