And here at least four principal ranges or groups of ranges admit of being discriminated, namely the Astin-tagh, the Chimen-tagh, the Kalta-alaghan and the Arka-tagh, all belonging to the mountainous country which borders on the north the actual plateau region of Tibet.
Another law appears to distinguish the hydrography of at any rate the great latitudinal valleys of the Arka-tagh and the Chimen valley (north of the Chimen-tagh): the streams flow close under the foot of the range that shuts in each individual valley on the north.
Whereas both the mountains and valleys of the Astintagh and of the Akato-tagh (the next large range to the Astin-tagh on the south) are arid and desolate in the extreme, smitten as it were with the desiccating breath of the desert, those of the Arka-tagh and beyond are supersaturated with moisture, so that, at any rate in summer, the surface is in many parts little better than a quaking quagmire.
On the Arka-tagh even the moss, the last surviving representative of the flora, disappears entirely.
Farther west, lying between the Muzluk-tagh and the Arka-tagh, is the lake of Achik-kol (13940 ft.), 162 m.
The next great parallel range is the lofty and imposing Arka-tagh, the Przhevalsky Range of the Russian geographers, which has its eastward continuations in the Marco Polo Range (general altitude 1 5,75 0 - 16, 2 5 0 ft.) and Gurbu-naiji Mountains of Przhevalsky.
The Arka-tagh 1 is the true backbone of the Kuen-lun system, and in Central Asia is exceeded in elevation only by the Tang-la, a long way farther south, this last being probably an eastern wing of the Karakorum Mountains of the Pamirs region.
Of great length, the Arka-tagh, which is a mountain-system rather than a range, varies greatly in configuration in different parts, sometimes exhibiting a sharply defined main crest, with several lower flanking ranges, and sometimes consisting of numerous parallel crests of nearly uniform altitude.
The Arka-tagh ranges do not culminate in lofty jagged, pinnacled peaks, but in broad rounded, flattened domes, a characteristic feature of the system throughout.
These Arka-tagh mountains are built up, at all events superficially, of sand and powdery, finely sifted disintegrated material.
But the relations in which these detached mountain-masses stand to one another and to the Arka-tagh behind them have not yet been elucidated.
In the vicinity of the Ullughmuz-tagh there exist numerous indications of former volcanic activity, the eminences and summits frequently being capped with tuff, and smaller fragments of tuff are scattered over other parts of the Arka-tagh ranges.
The difference in altitude between the lowest, most northerly range, the Lower Astin-tagh, and the most southerly of the Arka-tagh ranges amounts to nearly 7500 ft.
With one exception, namely the climb out of the Kum-kol valley to the Arka-tagh, the first three steps are 1 This is the correct form, Arka-tagh meaning the Farther or Remoter Mountains.
The biggest ascent is that from the Kalta-alaghan to the Arka-tagh, namely, nearly 1850 ft.
Lower, than the valley to the north of it, and consequently the climb up out of it to the first (on north) of the Arka-tagh valleys amounts to no less than 2900 ft.
Hence these ten parallel ranges of the middle Kuen-lun system may be grouped in three divisions - (1) the more strictly border ranges of the Upper and Lower Astin-tagh and the Akatotagh; (2) the three ranges of Chimen-tagh, Ara-tagh and Kaltaalaghan, which may be considered as forming a transitional system between the foregoing and the third division; (3) the Arka-tagh, which constitute the elevated rampart of the Tibetan plateau proper.
After crossing the Kara muren davan in the Arka Tagh, they Dutreuil de entered the lake region of north Tibet and followed a Rhins and general southerly direction across low ranges of hills F., Grenard, 1893-1894.
South of Cherchen, and after crossing the Arka Tagh took an easterly course between that range and the S ven Ifedln, western continuation of the Kokoshili range till he 896=1908.
He made crossings of the lofty Arka Tagh and other parallel ranges to the south (running east and west).
Gebal, now Jebeil), Arka, 80 m.