Turkmen Republic

TURKMEN REPUBLIC, a constituent member of the U.S.S.R., created in 1924. Area 171,384 sq.m. Pop. (1933) 1, 268,90o. Boundaries, the Caspian Sea to the west, Iran and Afghanistan to the south, the Uzbek S.S.R. to the east and Kazakstan, with the Kara-Kalpak A.S.S.R. to the north. The oasis of Khiva, incorporated in the Uzbek S.S.R. forms an island of separate territory in the north-east.

The changes in the course of the Jaxartes (Syr-darya) and the Oxus (Amu-darya), and the supposed periodical disappearance of Lake Aral, are problems in geography and it is here that we must look for a clue to the physical changes which trans formed the Euro-Asiatic Mediterranean—the Aral-Caspian and Pontic basin—into a series of separate seas, and desiccated them, powerfully influencing the distribution of flora and fauna, and centuries ago compelling the inhabitants of Western and Central Asia to enter upon their great migrations.

A

mountain chain, comparable in length to the Alps, separates the deserts of the Transcaspian from the highlands of Khorasan. It begins in the Krasnovodsk peninsula of the Caspian, under the names of Kuryanyn-kary and Great Balkans, whose masses of granite and other crystalline rock reach an altitude of some 5,35o ft. Farther south-east they are continued in the Little Balkans (2,00o ft.) and the Kopepet-dagh or Kopet-dagh. The latter rises steep and rugged above the flat deserts over a stretch of 600 m. In structure it is homologous with the Caucasus chain; it appears as an outer wall of the Khorasan plateau, and is separated from it by a broad valley, which, like the Rion and Kura valley of Transcaucasia, is drained by two rivers flowing in opposite direc tions—the Atrek, which flows north-west into the Caspian, and the Keshef-rud, which flows to the south-east and is a tributary of the Murghab. On the other side of this valley the Alla-dagh (Aladagh) and the Binalund border-ranges (9,00o to i I,000 ft.) fringe the edge of the Khorasan plateau. Descending towards the steppe with steep stony slopes, the mountain barrier of the Kopet dagh rises to heights of 6,00o-9,000 ft. to the east of Kyzyl-arvat,

while the passes which lead from the Turkmen deserts to the val leys of Khorasan are seldom as low as 3,500, and usually rise to 5,000, 6,000 and even 8,500 ft.

While the Alla-dagh and Binalund border-ranges are chiefly composed of crystalline rocks and metamorphic slates, overlain by Devonian deposits, a series of more recent formations—Upper and Lower Cretaceous and Miocene—crops out in the outer wall of the Kopet-dagh. The mountains of Asia which stretch towards the north-west continued to be uplifted at a geologically recent epoch. Quarternary deposits have an extensive development on its slopes, and its foothills are bordered by a girdle of loess.

The loess terrace, called Atok ("mountain base"), i o to 20 TM in width, is very fertile ; but it will produce nothing without irri gation, and the streams flowing from the Kopet-dagh are few and scanty. The winds which impinge upon the northern slope of the mountains have been deprived of all their moisture in crossing the Kara-kum—the Black Sands of the Turkmen desert ; and even such rain as falls on the Kopet-dagh (ioi- in. at Kyzyl-arvat) too often reaches the soil in the shape of light showers which do not penetrate it. Where the mountain streams run closer to one another, as at Geok-tepe, Ashkhabad, Lutfabad and Kaaka, the villages are more populous, and the houses are surrounded by gardens, nourished by irrigation.

North of this narrow strip of irrigated land begins the desert— the Kara-kum—which extends from the mountains of Khorasan to Lake Aral and the plateau of Ust-Urt, and from the Caspian to the Amu-darya, interrupted only by the oases of Mery and Tejefi. But the terrible shifting sands, blown into barkhans, or elongated hills, sometimes 5o and 6o ft. in height, are accumulated chiefly in the west, where the country has more recently emerged from the sea. Farther east the barkhans are more stable.