Starting from the Amur river and reaching along the eastern margin of the Gobi desert towards the sources of the Hwangho, it merges into the Altyn-tagh and the Kuen-lun, forming the northern face of the vast Tibetan highlands which are bounded on the south by the Himalaya.
In 1876 he visited the Lop Nor and discovered the Altyn Tagh range.
His fourth journey in 1883-1885 was to Sining (the great trade centre of the Chinese borderland), and thence through northern Tibet (crossing the Altyn Tagh to Lop Nor), and by the Cherchen-Keriya trade route to Khotan.
Longitude, which culminates in the Altyn Tagh, and extends eastwards in a continuous water-divide to the Nan Shan mountains, north of the Koko Nor basin.
ALTYN-TAGH, or Astyn-Tagh, one of the chief constituent ranges of the Kuen-lun in Central Asia, separating Tibet from east Turkestan and the Desert of Gobi.
Although the use of the name is thus restricted in geographical usage, the mountain system so designated does, as a fact, extend eastwards as far as the great depression of Tsaidam (say 95° E.), though it is uncertain whether its direct orographical continuation eastwards is to be identified with the Astin-tagh, or, as F.
Western Kuen-lun and Astin-tagh) is throughout double; and this " twinning " of the mountain-ranges, as also of the intermont lake-basins among the Kuen-lun ranges, is a peculiar feature of the Tibetan plateau.
The names given to them are the Kilian or Kiliang, the Khotan and the Keriya Mountains in the more northerly range and the Raskem or Raskan, the Sughet and the Ullugh-tagh Mountains in the more southerly range.
Dutreuil de Rhins on his journey in 1890-1895, gives the names the Altyn-tagh and Ustun-tagh, though he names no less than six parallel ranges altogether.
Now as Altyn-tagh 2 is an accepted, though in point of fact erroneous, name for Astin-tagh, it is clear that Grenard considers the main Kuen-lun ranges to be continued directly by the Astin-tagh.
Etymologically the correct form is Astin-tagh or Astun-tagh, meaning the Lower or Nearer Mountains.
Ustun-tagh, which appears on Stieler's map as an alternative name for Altyn-tagh, means Higher or Farther Mountains, and though not used locally of any specific range, would be appropriately employed to designate the higher and more southerly of the twin border-ranges of the Tibetan plateau.
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.
Although these several ranges, or systems of ranges, differ considerably in their orographical characteristics, the following description will apply generally to the entire region from the Astin-tagh southwards to the Arka-tagh.
In the western parts of the system they mostly go to feed the Kara-muren or the Cherchen-darya, while farther east they flow down into some larger self-contained basin of internal drainage, such as the Achik-kol, the two lakes Kara-kol, or the Ghaz-kol, and even yet farther east make their way, some of them into the lakes of the Tsaidam depression or become lost in its sands or in those of the Kum-tagh desert on the north, or go to feed the headstreams of the great rivers, the Hwang-ho (Yellow River) and the Yangtsze-kiang (Blue River) in the south.
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.
The wild camel approaches the north outliers of the Astin-tagh, but rarely, if ever, ventures to enter their fastnesses.
On the Arka-tagh even the moss, the last surviving representative of the flora, disappears entirely.
In the eastern Astin-tagh a variety of wild tea (chay, mountain tea) is used by the Mongols.
Gold is obtained in very small quantities in a few places in the Astin-tagh and the Kalta-alaghan.
The Astin-tagh, although it occupies a similar position to the twin ranges of the Western Kuen-lun, in that it forms the outermost escarpment or border-ridge on the north of the Tibetan plateau,would appear in the opinion of the most competent judges (e.g.
The passes in the Lower Astin-tagh range from altitudes of 10,150 to 10,700 ft., and in the Upper Astintagh at 11,770 to 15,680 ft.
But there exists a striking difference between the crests of the Astin-tagh and those of the ranges which give rise to the gigantic ridge and furrow arrangement on the Tibetan plateau.
" Here in the Astin-tagh the mountains, like those in the Kuruk-tagh, 2 are indeed severely weathered, but they always consist, from base to summit, of hard rock, bare and barren, most frequently piled up in eccentric, rugged masses, denticulated, pinnacled crests and peaks.
This gives rise to the great morphological difference, that in the former regions, the Astin-tagh and the Kuruk-tagh, the products of disintegration are almost always carried away by the wind, and so disappear; no matter how powerful or how active the disintegration may be, none of the loosened material ever succeeds either in gathering amongst the mountains or in accumulating at their foot.
3 The twin ranges of the Astin-tagh are fairly equivalent in point of magnitude and regularity; but while the Lower Range, on the north, sensibly decreases in altitude towards the east,the Upper Range, on the south, maintains its general altitude in a remarkable way, and is gapped by steep, wild, deeply incised transverse glens directed towards the north, and generally fenced in by dark precipitous walls of rock.
4 The next parallel range on the south, the Akato-tagh, and the valley which separates it from the Astin-tagh, are equally arid and waterless.
This range of Akato-tagh, the Altun Range of Carey, is the same as that which on the map of the Russian general staff bears the name Chimen-tagh.
Like the Astin-tagh it stretches towards the E.N.E., and, like it, appears to be built up of granite and schists, but its crest is greatly denuded, so that it is a mere crumbling skeleton protruding above the deep mantle of disintegrated material which masks its flanks.
The latitudinal valley that intervenes between the Akato-tagh and the next great range on the south, the Chimen-tagh, slopes for the most part eastwards, from 12,500 ft.
Nevertheless the Akato-tagh is only of secondary importance in the general Kuen-lun system, being nothing more than a central ridge running along the broad Kakir valley that separates the Astin-tagh from the Chimentagh.
The latter range, the Chimen-tagh, is identical in its western parts with the Piazlik-tagh and in the east must be equated with the Tsaidam chain of Przhevalsky; and it is probably continued westwards by the range which the Russian explorers call the Moscow Range or the Achik-tagh, running north of the Achik-kol and, according to Przhevalsky, connecting on the west with the Tokuz-davan.
The Chimen-tagh rises into imposing summits, some rounded, some pyramidal in outline, which are capped with snow, though the snow melts in summer.
Hence its slopes are not so arid as those of the Akato-tagh and the Astin-tagh.
Snow falls all the year round on the Chimen-tagh, even in July, and water is abundant everywhere.
The range is crossed by passes at 1 3,97 0, 13,230 and 13,760 ft., and the Piazlik-tagh by a pass at an altitude of 13,640 ft.
The next important range, still going south, is the Kalta-alaghan, Carey's Chimen-tagh Range, Przhevalsky's Columbus Range and the range which is variously designated (e.g.
This last is, however, properly the name of a short secondary range which rises along the middle (ara = middle) of the valley between the Chimen-tagh and the Kalta-alaghan.
The Ara-tagh is crossed by a pass at an altitude of 14,345 ft.
This range appears to be linked on to the Tokuz-davan by the Muzluk-tagh, in which there are passes at 16,870 and 15,450 ft.
It is possible however that the Muzluk-tagh belongs more intimately to the Chimen-tagh system, that is, to the Moscow or Achik-kol ranges.
Indeed Bogdanovich considers that the Tokuz-davan, the Muzluktagh, the Moscow Range and the Chimen-tagh form one single closely connected chain, in which he also places Przhevalsky's isolated peak of Mount Kreml (15,055 ft.).
Sven Hedin, whilst agreeing that this may possibly be the true conception, inclines to the view that the Achik-kol Range dies away towards the E., and that the Chimen-tagh and the Kalta-alaghan merge westwards into the border-ranges that lie north of the Muzluk-tagh and the Tokuzdavan.
Tibet, the Kalta-alaghan does not decrease, but it increases in elevation towards the east, where, like the Chimen-tagh, it abuts upon and merges in the ranges that border Tsaidam on the south.
The floor of the valley consequently slopes away in both directions, like the Chimen valley between the Akato-tagh and the Chimen-tagh; and in so far as it slopes westwards towards the Kum kol lakes it differs from nearly all the other great latitudinal valleys that run parallel with it, because they slope generally towards the east.
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.