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of the country, and partly to the baffling disintegrations of (he Nummulitic Limestone, actual contact sections were difficult to realize. With regard to the Kallar Kahar oasis, I have nothing of importance to add to what Mr. Wynne has written (p. 183). The Red Marl shows up at the surface on the south side of the lake, but elsewhere there are no clear sections, free from debris, that it would be worth while to describe.
The examination of the Vasnal oasis was entrusted to Mr. Datta. The following is a summary of the facts that he was able to glean. The Vasnal oasis. valley is a north and south irregular oval, opening into the lower country towards the north-west. It is three miles from the exposure of Red Marl in the neighbourhood of Bh.idror, and a greater distance from the Nurpur valley. The bottom of the depression is occupied by Red Marl, gypsum, and some few salt beds. On the north at Tirwa peak, on the east side, and on the south side it is hemmed in by cliffs of nearly horizontal Nummulitic Limestone, the junction being generally covered by the usual talus from the scarps above. The western side is more complicated, being interrupted by three faults running respectively E.—W., E.N.E.—W.S.W., and N.E.—S.W. At the south-west corner the Red Marl is in contact with, and underlies, the Purple Sandstone, which is much slickensidedi crushed, and faded in colour. The latter dips W. by S. and is overlaid by a regular' though badly exposed, ascending series of formations up to the Nummulitics.
The E.—W. fault separates this from the Nummulitic Limestone on the south side of the oasis. Traversing the line of contact of the Red Marl and Purple Sandstone for a quarter the length of the west side, the E.N.E.—W.S.W. fault is crossed, and the Red Marl successively comes in contact with a group of formations from the base of the Productus Limestone up to the Nahans, all of which strike obliquely agains the Red Marl in a N.N.E. direction. Underneath Tirwa the arrangement of the rocks is vague and difficult to follow. It has been described by Mr. Wynne in his memoir (p. 197) with a sketch-section. The latter is instructive as showing what a hopeless task it would be to reconcile the allure of the Red Marl at that place with a theory of it as an inert stratified rock.
The Vasnal inlier, therefore, is surrounded on all sides, except a quarter of its western side, by an abnormal line of junction—just such a one as an intrusive, or y«<wi-intrusive, rock would make for itself by bursting through a fissure, but which would be difficult to account for by a combined system of small faults.
The following account of the relation of the Red Marl and gypsum masses
_ . .. to the surrounding rocks in the neighbourhood of Ainwa
Sections near Ainwa. s. , ,. . . , ., ,
(Aninwa) is an abstract of the very interesting detailed notes
supplied me by Mr. Datta, who visited this locality alone.
In the plan, Plate IV, is seen the surface arrangement of these masses and bands, chiefly of gypsum, and with but little Red Marl in them. About 400 yards south of Ainwa (of map) gypsum is first found in bands from one to two feet thick, apparently intercalated with the Upper Tertiary (Nahan ?) sandstones and hardened clays, which are strongly impregnated with gypsum. The area in which they are found (indicated by the dotted oval in the plan) is disturbed as to its strike in relation to the prevailing N.W.—S.E. strike on either side of the area.
Between that area and the gypsum hill there are no regular bands of gypsum, but the clays of the Nahans are impregnated with it. The mass of gypsum forming the hill is peculiar, in that it appears on the north and west sides to rest on or against the Nahan Sandstones, whilst on the south it appears to lie on the alluvium. After allowing Tor a certain amount of surface slipping down the hillside, it remains probable that it passes downwards through or among the Tertiary Sandstones in the form of a "neck" or a series of closely approximating bands.
At the south-west corner of the hill there are two small isolated exposures of the gypsum which were doubtless originally connected with the larger mass. An isolated outcrop of Nummulitic Limestone S. by E. of the hill is an indication of irregular disturbance in this neighbourhood.
Mr. Datta remarks: "Not only are the Tertiary clays and sandstones occupying the valley in which Ainwa (of the map) is situated highly impregnated with gypsum, even when the beds show no sign of disturbance, but the whole tract of country in this neighbourhood exhibits an amount of gypsum in the rocks not observable elsewhere. Between the valley and Ainwa village (which is about a mile east of the valley), I found veins of gypsum in joints of the grey sandstone cutting obliquely through the bedding. It appears to me that the gypsum of the hill, and the gypsum bands in the disturbed area of the valley south of Ainwa (of the map) are contemporaneous; that the gypsum must have come up from below through a fissure or some other vent; that some of it forced itself along the bedding planes and became thus apparently interbedded with the clays and soft sandstones, but the main mass accumulated on the Tertiary clays and sandstones forming what is now a hill; and from the same source which gave rise to the hill, the neighbouring Tertiary beds became impregnated with the gypsum."
The gypsum bosses or bands south of the hill and marked on the plan as A, B, C, are of slightly different import. They mark a line of great faulting between the Nahan Sandstone to the north and an inverted series consisting of Boulder-bed and Speckled Sandstone to the south. Thus the gypsum, Boulder-bed, and Speckled Sandstone are in the same order as the middle limb of the sigma flexure on the west side of the Amb glen. It seems evident that the gypsum forming these lenticular masses was forced up along this line of dislocation. Mr. Datta states that there is hardly any Red Marl associated with the gypsum. Presumably, however, there is sufficient to identify the material as belonging to the Saline series.
Sketch Section No. 13, Plate IV, drawn along M. M. on the plan, is copied from Mr. Datta's notes. It illustrates the foregoing description, and in addition shows one of the gypsum masses D. E. F., which appear overlying the truncated edges of the Speckled Sandstone, &c. It was probably once connected with the protruded tongue A. B. C.
(j) Concluding hypothesis.
The nature of this paper as a mere collaboration of field work, written practically The intrusive theory in camp, and at a great distance from books of reference, not original, though not makes it impossible to treat fairly the views of other geonow accepted. logists on the subject of the origin and age of these salt-bear
ing beds. From the remarks made by Mr. Wynne in his memoir (pp. 12, 13, 15, 26,82,83) it will be seen that he was fully aware of, but unimpressed by the fact that inferences analogous to those drawn by me have been entertained by previous observers. Also I think there can be no doubt that modem geological thought as a whole does not in the least regard seriously such explanations as I have so far given or implied, and which I shall now embody in a single sweeping hypothesis. I believe the geologists of to-day are few, if any, who would extend the scheme of rock formations so as to include one coming in such a questionable shape as this. Hence I must rely on my own facts detailed before if I would drive home a conviction, even though it hi founded on an old idea.
Let me begin by pointing out that the area of the Salt Range presents some peculiarities of its own that may warrant us in looking for
Absence of metamor- , , ... ... _
phic rocks below the exceptional subterranean conditions in this region. For Cambrian strata. No instance, we now know, beyond possibility of dispute, that
the trilobite-bearing shales of Khusak fort date back into geological history almost as far as the present records can take us. But instead of these Lower Cambrian rocks resting on a Pre-Cambrian or Archean floor of gneissose or schistose rocks, we find them placidly reposing on a Purple Sandstone of much the same firmness and aspect as the Old Red Sandstone of England. The Purple Sandstone is totally devoid of metamorphism in the strict sense of the word. What is true of the lowest rock-group in this respect is of course true of all the succeeding younger formations. In addition to the absence of any metamorphic strata in the range, there is also wanting everything in the nature of a Slate series— there is not a slate in the whole country. Look where we will in the Salt Range, we can find no suggestion of the action of plutonic heat or deep-seated compression on the rocks from Palaeozoic times up to to-day.
Another instance illustrating peculiar subterranean conditions is, that through the
whole of the stratified rocks, which embrace so rich a fauna
No contemporaneous e „ . , . ,
or intrusive igneous o1 the Palaeozoic, Mesozoic, and Tertiary eras, there is no rocks from Cambrian single example of an igneous rock, neither in the form of times upwards. contemporaneous bedded lavas, &c, nor as dykes or pluto
nic masses.1 It needs no words to show the probable connection between this peculiarity and the absence of all metamorphism.
Shifting the aspect in which we regard this phase of the question, it is clear The subterranean that the subterranean magmas, whether liquid from molten magmas have remained or aqueo-igneous conditions, have remained sealed up sealed up. smce the time of the 0\fesi stratified rocks. Nothing of
those magmas has ever been drawn off by volcanic vents. Hence, all the gases, water substance, and other constituents, that in other parts of the world have found access to the surface during periods of eruption, have in this region never approached sufficiently near to the surface to make their escape.
It follows, therefore, that if we could bore through the crust of the earth, we should either let loose the slumbering magma beneath, or we should come upon a solidified layer representing the potential volcanic activity arrested and smothered
1 The only volcanic rock in situ in the Salt Range, in fact, is the Khewra trap found always associated with the Salt Marl. This peculiarity is commented on in Mr. Wynne's memoir (p. 83), and reference is also made to the like association of dolerites' and trachytes with the salt rocks of Hormuz in the Persian Gulf, described by Dr. Blanford (Rec, Geol. Surv. I. Vol. V, p. 4a).
before birth. Moreover, it would represent a potential volcanic activity that at some level or other beneath the surface had been continuously kept prisoner since the Cambrian epoch.
The question now suggested is, Can we see in the homogeneous structure and
„ composition of the Red Marl, in its freedom from all
The hypothesis or the * .... ....
Salt Marl as a scum or traces of sedimentation, in its signs of a derivative origin
secretion, resulting from bedded dolomitic strata, in its contained beds of salt
from a lonp-suppressed, , . . , .. . . , „< . .
potential, volcanic acti- an" gypsum, in its association with the Khewra trap, and in vity, which had become its anomalous quasj'-intrusive relations to other formations— ext,nct- can we see in all this the actual embodiment of such a
potential activity? Can we see in it anything of the nature of a scum, such as we might picture to ourselves as having partly secreted at the surface of an ancient untapped magma, and partly resulted from that secretion by induced changes in the overlying dolomitic strata?
If we can, we have but to give the substance a gently intrusive or injective impetus, followed by consolidation, some time during the Tertiary period, to account for all the otherwise perplexing circumstances under which the salt-bearing beds of the Panjab are found.
In such a hypothetical state I must reluctantly leave the enquiry for the present.
On Veins of Graphite in decomposed Gneiss (Laterite) in Ceylon1; by Dr. Johannes Walther, Jena. (Translated by R. B. FoOTE, F.G.S., Superintendent, Geological Survey of India.)
Graphite forms the most important mineral export from Ceylon; it is therefore all the more remarkable that up to the present no exact information is procurable concerning its geological occurrence. The statistical and economic relations of the Ceylon graphite were drawn up very fully in 1887 by A. M. Fergusson, the Editor of the great " Ceylon Directory," and laid "before the Ceylon Branch of the Roya I Asiatic Society ;s and to F. Sandberger we are indebted for valuable researches into the mineralogical condition of the Ceylon graphite;' while briefer remarks about the mineral are scattered in the literature of the island.
The last King of Kandy is reported to have already exported graphite; the Dutch Governor Ryklof van Goens made communications in 1675 about graphite veins in the lowland hills; Robert Knox referred to them in 1681, and the Scandinavian naturalist Thunberg wrote about them in 1777.
The most important mine in Kurungala belongs to De Mel, and lies at foot of the Polgola hill, which is said to consist almost entirely of graphite (?). The pit is
J Vide Zeitschr. d. Deutsch. Geolog. Gesellshaft, Jahrg., 1889.
* On plumbago, with special reference to the position occupied by the mineral in the com. merce of Ceylon.
• Neues Jahrbuch fOr Mineralogie, &c, 1887, II, 12.