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tine crop out to the west of the road. The shales have become very ferruginous near the junction and are very highly contorted and folded.
103. After his work on the water supply of certain areas in Baluchistan, Dr. A. L. Coulson returned to South Waziristan for a short period of field-work in late January and early February, 1937, before his visit to the Makarwal area in the Trans-Indus Salt Range. Conditions during his time in Waziristan were far from suitable for field-work owing to increasing disaffection amongst the tribes, and on the completion of his economic investigations at Makarwal, Dr. Coulson's further field-work in the Agency was stopped.
Dr. Coulson worked on sheets 38 H/15 and L/3 and the results of his short survey confirm his conclusions given in last year's General Report.1 He made additional collections of Tertiary fossils from the Kirthar rocks north of the Shahur Tangi, north-west of Chagmalai Post (32° 20′ 70° 5'), amongst which Mr. H. M. Lahiri has provisionally identified Amblypygus sub-rotundus (Dunc. and Slat.) and species of Assilina and Alveolina. The Kirthar limestones. and shales are developed east of the Mastang Algad, south of Chagmalai Post, where they are faulted against Middle Siwalik rocks to the east and underlain, apparently conformably, by Laki shales and grits.
These Laki strata continue southwards through sheets 38 L/4 and 39 1/1 and 2 to the Shirani country west of Dera Ismail Khan, where they have been correlated with the Ghazij shales of Baluchistan.2 They extend at least as far north as Kotkai (32° 25′ : 70° 2') in South Waziristan, where Ranikot rocks make their first appearance. Dr. Coulson is unable to state how far north from Kotkai the Laki strata continue or whether the Kirthar overlap on to the Ranikot. In his previous season's work, he found Neocomian belemnites in situ in the bend of the Shuza Algad a quarter of a mile south-east of hill 3314 (32° 32′ : 70° 6′), and the sub-Kirthar rocks accordingly are confined to the small area east of the northward continuation of the Mandanna Kach fault, between the left-hand bank of the Shuza and the Kirthar-capped ridge.
1 Rec. Geol. Surv. Ind., 72, Pt. 1, pp. 22-23, 23-24, 71-75, (1937).
2 E. Vredenburg, op. cit., XXXIV, pp. 87, 182, (1906); XXXVI, p. 252, (1908).
Op. cit., 72, p. 72, (1937); L. M. Davies, Nature, 139, No. 3514, pp. 414-415, (1937).
Additional belemnites collected by Dr. Coulson during his present field season have been sent to Dr. Spath for examination. The results to hand confirm Dr. Coulson's views that the belemnites from Haidari Kach (32° 21′ 69° 59′), immediately underlying the Shahur Tangi Pab sandstones, may be of a slightly higher horizon in the Neocomian that those from the Danawat shales near Sarwekai Fort (32° 16′ 69° 54′), Nai Kach (32° 23′ 70° 4′) and other places.
Dr. Coulson now considers that the thick limestones associated with the Danawat shales, as at Sura Ghar (32° 18′ 69° 55'), are more probably also of Lower Cretaceous age rather than lithological variants of the Pab sandstones.
104. Dr. Coulson is now convinced as a result of his examination of the specimens collected by him during his preliminary traversel in February, 1936, that the massive limestone
forming Zer Ghar (32° 59' 70° 6'), 2 miles east of Miram Shah, in North Waziristan, should be correlated with the Takht limestone of the Shirani country, three miles west of Mughal Kot (31° 26′ : 70° 5′), and the Bobai (32° 18′ : 69° 39′) limestone of South Waziristan. Both are more bituminous than the Upper Jurassic (Callovian) limestone of Sheikh Budin (32° 18′ : 70° 49) with which he also correlates them.
105. In March, 1937, after work in South Waziristan had been stopped by tribal unrest, Dr. A. L. Coulson paid a visit to the Cherat
(33° 49′ : 71° 53′) area (sheet 38 0/13) in the Nowshera tahsil of the Peshawar district, a brief summary of the geology of which has been given by Griesbach.2 Dr. Coulson's work was in the nature. of a reconnaissance survey, carried out under police escort in the regions bordering the disturbed tribal area of the Tirah. His mapping, however, brings out the complicated structure of the Cherat area. !
Peshawar district, N.-W. F. P.
The general strike of the rocks is E. N. E. and the Cherat ridge, on which the hill-station has been built, is the northern limb of an anticline which has foundered by strike-faulting. The oldest rock in the anticline is apparently a limestone of possible Jurassic age which crops out near Mir Kalan (33° 49' 71° 57') and north of Jalala Sar (33° 47′ 71° 51′). It is overlain by a series of several
1 Rec. Geol. Surv. Ind., 72, Pt. 1, p. 71, (1937),
a Op. cit., XXV, Pt. 2, pp. 93-99, (1892).
hundreds of feet of shales and sandstones, possibly Cretaceous in age, the apparent thickness of which is greatly increased by strikefaulting. Dr. Coulson, however, found no belemnites in these beds.
The next higher rock in the sequence is the massive bituminous limestone with abundant comminuted foraminiferal remains, so far unidentifiable, which forms the main part of the Cherat ridge. Foundered parts of the crest of the anticline are formed of this limestone, which Dr. Coulson correlates with the Dunghan limestone of Laki age. It is the same limestone as Cotter's Hill Limestone1 in the Attock district of the Punjab across the Indus river. The southern limb of the anticline is covered by a mass of Recent deposits to the south of which is a large stretch of Upper Tertiary rocks, striking north and south, and apparently extending into sheet 38 0/14.
Dr. Coulson noted two outcrops, three-quarters of a mile N. N. E. of Jalala Sar and a quarter of a mile south-east of the Post Office, of a peculiar slickensided basic rock, of specific gravity 3·19, which is igneous in origin. Sections of this rock show it is now mostly serpentine, but such structure as remains indicates the rock was originally a tachylite. The faulting and isoclinal folding are postMurree and have affected this basic rock. Its relations with the rocks at Jalala Sar are masked; also, below the Post Office, it occurs between the Dunghan limestone and a quartzite of the Cretaceous beds and the secondary iron-oxide present prevents one from being able to determine whether or not it is intrusive into the limestone. It is probably an offshoot of the Tertiary basic igneous complex of Waziristan2 and Baluchistan.
The Dunghan limestone is succeeded by a series of shales with lenticular limestones, at times algal and containing unidentifiable fossils, which are similar to Griesbach's Dag beds. As a result of the overfolding and faulting to which the area has been subjected, the relations of these Dag beds are at times difficult to interpret, but Dr. Coulson thinks that they are perfectly conformable with the Dunghan limestone and that they represent the Chharat series. However, he could find no representatives of the Nummulite Shale, the uppermost stage of Pinfold's3 Chharat series.
1 Mem. Geol. Surv. Ind., LV, Pt. 2, pp. 93-95, (1933).
2 Rec. Geol. Surv. Ind., 72, Pt. 1, p. 74, (1937).
Op. cit., XLIX, Pt. 3, pp. 144-145, (1918).
The Dag beds are succeeded by typical Murree rocks which occupy most of the area between Dag (33° 51′: 71° 49′) and Cherat. These generally dip very steeply S. S. E. towards the hill-station, forming an isoclinal syncline which succeeds the Cherat anticline. North of the Murrees, the Dag beds, Dunghan limestone and Cretaceous rocks again appear in the form of an anticline, the southern limb of which is strike-faulted. It is also faulted to the north by a strike-fault of very large throw against highly contorted slates and schists which Dr. Coulson correlates with the Attock slates.
In the latter part of March and in early April, 1937, Dr. A. L. Coulson commenced the geological survey of part of the newly created Mardan district of the North-West Frontier Province adjacent to the Buner tract of Swat near Rustam (34° 21' 72° 17'), working on sheets 43 B/3, 7 and 8. He had previously collected interesting specimens of porphyries from Shahbazgarhi (34° 14′ 72° 9′) and other localities near this area, which he has described elsewhere.1
Mardan district, N.W. F. P.
The chief rock cropping out in the area is a biotite-granite, sometimes containing hornblende. This occupies a large area on sheet 43 B/7 and the new road which was being constructed from Rustam to Swat by the Ambela Kandao (34° 23′ 72° 26') gave good opportunities for studying it. The rock is of the Engadine granite type and contains 74-30 per cent. of silica. The relations of this possibly Mesozoic granite, which Dr. Coulson has termed the Buner granite as it crops out largely in that tract of Swat, to the Malakand muscovite-granite (see page 41) and the soda-granite suite of the Khyber and the Mardan district, have not yet been ascertained. It is generally unfoliated, weathering into rounded tors, though at times foliation is strongly developed. Certain exposures are very coarse-grained, but the texture of the granite varies greatly within small distances. The rock contains numerous small roof pendants of hornfels rock belonging to the series of schists, thin limestones and amphibolitic rocks into which it has apparently been intruded. Greisenised rocks occur near the junction with the schists south of Kulian Darra (34° 22' 72° 20').
The exact age of this series of schistose rocks, which are profusely intruded by epidiorites and amphibolites, is not at present known. They probably belong to the infra-Trias and the associated
1 Proc. Nat. Ins. Sci., Ind., II, No. 3, pp. 103-111, (1936).
basic rocks to the Carboniferous-Trias Panjal trap series. The associated basic rocks apparently do not cut the granite, though inclusions of basic rocks in this were noted by Dr. Coulson along the Ambela Kandao road.
Reference has been made in the economic section of this report (see page 30) to the excellent deposits of marble at Ghundai Tarako (34° 13′ : 72° 25′). This altered limestone is presumably the same Carboniferous limestone that occurs at Shahidmena (34° 9′: 71° 17') in the Mullagori country and in the Khyber Pass. So far Dr. Coulson has had no opportunity of studying its relations with the schistose series. It is also intruded by basic igneous rocks, though not so profusely as at Maneri (34° 8' 72° 28').
Dr. Coulson has so far noted no occurrences of the Buner granite on sheet 43 B/3, but the schistose series and the massive limestones apparently crop out in force in that area.
106. After the conclusion of his work in the Hazara district of the North-West Frontier Province, Dr. A. L. Coulson paid a visit of inspection to Mr. P. C. Das Hazra in the Udhampur district of Jammu. He then made a preliminary traverse up the Liddar valley of Kashmir before commencing his work on the northern slopes of the Pir Panjal on sheets 43 J/4, 8 and 12 and 43 K/5 in the Baramula and Uri districts of Kashmir, where he worked from late May to the middle of August, 1937.
Dr. Coulson's work was undertaken with a view to joining up Mr. D. N. Wadia's work in the Punch jagir of Kashmir with that officer's maps of parts of the Baramula and Uri districts and the unpublished reconnaissance mapping of parts of the Gulmarg area by Mr. C. S. Middlemiss. Another season's work yet remains to be done.
Baramula and Uri districts, Kashmir.
Dr. Coulson is still uncertain whether or not representatives of the Salkhala series occur in the northern part of his area near Nambalan (34° 9′ 74° 19'), but microscopic examination of the schistose rocks occurring here would appear to indicate that they are really highly altered tuffs of the upper part of the Panjal trap
Apart from these possible, but doubtful, Salkhalas, the oldest rocks in the area are the Lower Palæozoic Dogra slates which crop out in force in the south-western part of sheet 43 J/8 and the northwestern part of sheet 43 K/5, stretching from the Baramula district