페이지 이미지

Section of the Northern extremity of Mount Sirlun, near Ablottalad, from E. to W. bearing S. (not drawn to scale?)

1. Very compact and voiy hard Cornean rock, composed of a paste of white feldspar and grey hornsbone in intimate combination. The joints and exposed surfaces are smooth and have a quartzy glimmering. In the paste there is often a partial separation of white feldspar in spots of a dnll white colour. Splinters of the white spots can be roundod on their edges before tho blowpipe, but the grey paste of the rock appears to be more refractory, though there is certainly a softening of the mineral compound and a slight smoothing of sharp edges after long exposure to heat. It is a bed of very considerable thickness, stratified and much jointed.

2. White quartzite in a brecciated state, the pieces being recomonted together by a grey fcldspathose paste. It appears as if the bed had been broken after its formation and tho fragments reunited by a feldspathoso paste.

3. Very heavy, chocolate-coloured, clay-stone, with bands of quartzito.

4. Indurated clay, with round nodules, tho sizo of a boon, of a black mineral having the lustre of jet, whitening to a milk-white colour beforo tho blow-pipe, and finally melting with difficulty on thin edges; it belongs probably to the hypersthene group. Tho clay itself is grey, smooth and meagro.

5. Chloritic clay; grey, very smooth and soft to tho touch ; hardness of slate. It is full of ninute round grains of a semi-transparent mineral, grey like the clay, but a little darker. The clay becomes white and meagre before the blow-pipe; it is unaffected by muriatic acid, and does not form a pasty mass with water, either before or after grilling.

6. Limestone, at first extremely arenaceous and argillaceous, and presenting particles of dirty blue and brown colour. It becomes gradually conglomeratic and at the samo time thin-bedded, the layers being made of layers of pebbles of limestone cemented by a calcareous sandy cement; the top of tho layer appears to have been worn flat by the action of the wares, before tho deposit of the next stratum took place, the pebbles appearing as sections on tho surface of the bed. The next layer is a muddy limestone containing a few flat atliyris, remarkable especially for three internal raisod lines or ribs proceeding from the beak as far as the middle of the valve. But these sholls are in a very bad state of preservation. This layor is only two feet thick, and is succeeded by another equally thin and containing numerous debris of gasteropods and corals. Then comes a black, sometimes blue-black limestone, extremely foetid. The bluer portions are crossed by white lines intersecting each other in all directions and containing only debris of fossils.

The limestone forms altogether a bed of about thirty feet, when it is out by a fault whioh causes it to bo repeated, and a succession of faults directod W. N. W. to E. S. E. kocps tho samo limestone on tho surface for more than half a mile, it becomes finally covered by uuinmulitic limestone.

This Mount Sirbun forms the loft side of the Abbottabad valley. Following the slopes of this hill, wo find beds of quartrite, similar to No. 2 of the above section, reappearing three or four times in shert antiolinals; above it are bods of limestone containing a few fossils, principally casts of gasteropoda. This limestone is often strongly oolitic in structure, but presents also the very unusual appearance of resembling beds of travertin which had been entombed in a calcareous mud after their formation, so that the cavities of the travertin have become filled up with a limestone less hard than the original deposit. I have usually regarded these beds as fresh-water origin near a low coast, and referred them, in a general and provisional way, to the Jurassic; of course this is doubtful.

70. On the lower road from Marree to Abbottabad, near the village of Sayd Kote, great disturbances are observed, and rocks of a geyserian nature make their appearance about half way between Sayd Kote and the Dowr river. They are principally a chocolatecoloured sandstone, becoming coated by weathering on the surface as well as in the joints, with a shining dark incrustation. It is much jointed and breaks in prismatic blocks. A great quantity of dark boulders of this rock may be seen in the bed of the river Dowr. It appears to be similar to some variety of dust-rock or sandy ash or earthy ash seen in Kashmir. It is capped by a bed of quartzite composed of large, opaque, angular grains of quartz, jammed together and cemented by a feldspathose white paste of which there is very little. Angular grains of black augite are sparingly disseminated in the rock. Under the brown sandstone is seen a thick bed of crumbling clay slate, very dark and foliated. This is the lowest bed seen. These three beds, viz., slate, sandstone and quartzite conform together in their dip and are capped by a patchy limestone of doubtful age, and interbedded with grey soft slate. There is much kunkur near the locality.

At Sayd Kote the limestones are wonderfully disturbed: beds having the appearance of Kothair limestone and containing a great number of gasteropods and cyaihophyllides are seen repeatedly, as the road crosses nearly perpendicular beds which are much faulted. Nummulitic limestone appears to cover in directly the carboniferous (?) beds??

Again on the upper road from Murree to Abbottabad, at the bottom of the ravine under Doonga Gully, volcanic or rather geyserian rocks are to be seen. They consist of a very white and friable rock composed of acicular minute crystals of albite easily fusible before the blow-pipe and pressed and entangled together; there does not appear to be any cement to bind the small crystals together; the rock has a coarsely saccharine aspect and can easily be crumbled between the fingers. It rises in vertical and contorted bands, from half an inch to two and a half feet thick, amongst sands and disintegrated shales. It assumes very many remarkable colours, being sometimes flesh-coloured or reddish, and at other places azure-blue; its general colour is, however, snow-white; where it is blue, the shales near it are of the same colour. It is interbedded with thin beds of tufaceous limestone which have probably found their way there by infiltration. It is covered in by a rubanneous and dark slate, much disturbed, extremely cleaved and jointed and falling into small angular pieces. This slate appears similar to that seen near Syad Kote, and the feldspathose rock is intrusive. These two roeks are at the bottom of the ravine, on a fault, and form a little mound by themselves. There are no rocks to be seen in immediate relation to them, and the beds of the sides of the ravine appear to be entirely nummulitic.

From the examples given of volcanic rocks in Hazara, it seems evident that that district has participated in the great volcanic accumulation which preceded the carboniferous epoch, and that it has also been disturbed at a later date by intrusive volcanic action of a local and geyserian character.

71. Of Chumba, Kulu aud Kunawar, districts which occupy the hilly tracts south of the extension of the Pir Punjal chain towards the Sutlej, I know nothing.

72. Kashmir is continued to the south-east by the highlands of Lahnl and Spiti which are situated in the same Himalayan parallel, viz., between the Pir Pnnjal chain or parallel and that of the Ser and Mer. Spiti has been pretty often visited by geologists, and wo know that carboniferous and Jurassic fossils were brought thence by Dr. Gerard. Liassic fossils have also been found there. As for crystalline rocks, M. Marcadieu mentions much granite, and Captain W. E. Hay, granite penetrated by huge veins of ter-sulphuret of antimony and "other metals." Gypsum is reported as extremely abundant in Spiti, forming, it is said, whole mountains; and here I would mention again that several hot springs are found in close vicinity to these gypseous beds.

But I must draw back here, and leave the ground to Dr. Stoliczka who has been for some time studying the geology of Spiti with great care and is preparing a work on the subject. Dr. Stoliczka has found in Spiti rocks of the following ages: Silurian, Carboniferous, Triassic (?), Liassic, Oolitic and Cretaceous. I have said before that most of the fossils from Spiti represented in Dr. Royle's Illustrations, are to bo found in the Jurassic rocks of Sheikh Bodeen.

73. The great chain of Ser and Mer (called by Capt. R. Strachey, between the Sutlej and the Kali, the chain of Snowy Peaks, and by Cunningham, the western Himalaya or central chain of the Himalaya) appears to be, as far as I have been able to ascertain, made up of granite, gneiss, and other rocks of the plutonic and metamorphic groups. From the Nanga Parbat (26,629 ft.) to near the Sojji La pass, (11,300 ft.) the range is, I believe, mostly granite ; it is traversed by the road of Skardo via Guzais, and Mr. Drew informs me that the range, (which here forms the southern boundary of the Deosai plain) is "chiefly granite, partly schist." The plain of Deosai is a singular plain or steppe entirely covered with debris and loose stones; it is tolerably flat, considering how it is situated, and has perhaps once been the bed of a gigantic glacier. It is surrounded by granitic mountains on the southern and western sides; the north end is bounded by mountains of schist and slate, and the eastern side is closed in by granitic hills which gradually pass, over Drass and Kurgyl, into volcanic rocks.

Ji we cross the Ser and Mer chain by the Sojji La, from Kashmir into Drass, we find near Baltal, a village on the Kashmir versaut of the pass, that the carboniferous limestone ceases and is succeeded by beds of very coarse and micaceous slaty shales, often very sandy and always very thin-bedded. The specimens I possess of this rock show it to be identical with the sandstone and sandy coarse shales seen in the Zebawan and there interbedded with ash, agglomerate and slate. This rock goes on to nearly the top of the pass, where it becomes a dark and hard slate, having a metamorphic appearance. Then limestone reappears and is seen as far as Drass; it rests the whole way, as far as can be seen, on volcanic rocks and azoic slate. It is pro bnbly continuous, through Sooroo, with beds of limestone seen between Moolbek and Khurbu.

I do not know what sort of rock forms the summit of the Kun Non or Serand Mer Peaks (23,407 ft.) but their north-eastern slope and spurs are composed of gneiss and schist; these mctamorphic rocks extend as far as the Sojji La, where they are graduating into beds of the coarse slaty shales described above on the north of the road it is continued by beds of slate and of sandstone extremely micaceous and resting on mica-schists, of which some specimens effervesce powerfully with acids. Beds of metamorphic white marble are also seen, but the great bulk of the mountains between Tillail and the Deosai is made up of granite, shist and mica-slate.

Following the great chain to the S. E. we find it crossed by several passes of which the Bara Lacha (16,505 ft.) and the Parting la (18,794 ft.) are the most celebrated and frequented. Mr. Marcadieu describes these passes as being principally through granitic rocks; but unfortunately Mr. Marcadieu does not seem to have enjoyed much his visit to these " belles horreurs" and he gives us little geological information, but many complaints, about these " delights of Satan," as he calls the mountains.

South-east of the Sutlej, the chnin continues to be mostly granitic. It is studded with noble peaks, Porgyul (22,700, ft.)Baldang (21,400 ft.) Kamet (25,000) and Nanda Devi (25,700, ft.) all of them made up of granite, gneiss, and schist. But I must refer the reader to Captain B. Strachey's paper " on the geology of part of the Himalaya mountains,"* for the mountains south-east of the Sutlej.

74. Having crossed the Scr and Mer Parallel, we find ourselves in the great trough between this chain and that of the Kailas peak (which I shall call for convenience sake the Kailas chain) and we may hardly call this trough a valley, considering that it is a plateau from 10 to 12,000 feet high abovo the level of the sea; and yet it is a valley between the two great parallels which tower over it by some 10,000 feet more. It comprises the districts of Deosai, Soroo and Brass, Ladak proper, Zanskar, Rukshu and in the S. E. the great plateau of Tibet through which runs the Sutlej and inhabited by the Huudes. This last or south-eastern portion of the trough is toler* Proceedings of the Geological Society of London, Juno, 1851.

« 이전계속 »