Dharamsala 

                A Guide to Little Lhasa in India

  These zones are-- 

( 1) An outer or Sub-Himalayan zone composed of sediments for the most part of Tertiary age, but including also some sub-recent deposit.".

(2) A central or Himalayan zone comprising most of the Dhaula Dhar. This is composed of granite and other crystalline rocks and a group of unfassiliferous  sediments of unknown age.

The following table shows the classification and the more important sub-divisions, the details of which have been worked out in the Kalka-Simla area :-

                                     Tertiaey  Rocks.

 Aryan Group.- The Teriary rocks extend from the Siwalik Range in the Hoshiarpur District to the base of the Dhaula Dhar. They are composed of conglomerates, sandstones, red and purple clays and shales and in this District yield very few fossils.

Siwalik Series.- The outer hills are chiefly conglomerates, sandstones and soft earthy beds of the Siwalik series, with a general strike roughly parallel to the Dhaula Dhar. Two main faults have been traced throughout the system from near the banks of the Sutlej in Hamirpur Distt to the Gurdaspur border. The more northerly fault passes close to Jwalamukhi, Kotla and Nurpur and the southern appears to go through Bharwain ( on Hoshiarpur - Kangra boundary) and then across the Beas to about Pathankot. As compared to similar faults to the east of the Sutlej these faults exhibit considerable uniformity, as they can be traced in remarkably straight lines or very flat curves across the Kangra District and through the Jammu Hills into the Jhelum District, they are constantly connected with more or less steep ridges formed of the hard lower rocks on the up- throw side of the fault, always more or less steeply inclined. Away from the line of distrubance newer strata, generally conglomeratic, come,in and the dip flattens to the horizontal, forming the Jaswan dun and the two principal duns of Kangra proper. Rocks of the same stratigraphical series show considerable differences in lithological character if traced from one end of the District to the other.

   Sirmur Series.-

The Sirmur series (the Sabathu group of Medlicott ) outcrops as a narrow band along the foot and lower slopes of the Dhaula Dhar. Its various stages denominated in the table above are really representative of the series in the tract east of the Sutlej and it does not appear that these stages have so far been discriminated in Kangra proper. The station of Dharmsala is situated on a sandstone spur of this formation. Here the system exhibits an anticlinal fold, the strata on each side of which are deepy inclined, A fault separates this series from the Siwalik series further south, and it was approximately along this fault that the epicentrum line of the 1905 earthquake lay       Between the rocks of the Sirmur series and the older rocks of the Himalayan zone occurs a well marked fault known generally as the main boundary, which extends along the base of the Himalayas. Dharmsala itself stands on rock of the Sirmur series and the main boundary here occurs at Devi da Galla, the "neck" a short distance from Dharmkot. From here in one direction it passes close to Bhagsunath and then along the base of the main ridge a short distance to the south of the Kaniara Slate quarries. In the other direction it bends off more to the west through about Drini and on into Chamba.

The rocks on the northern side of the boundary fault consists or limestones, and metamorphous shales, slates and schists , with the gneissose core of the main ridge. All these are utterly devoid of any indications or fossils.

The limestones and slates arc identified as one of the same series as the Krol limestones in the Simla area. Their age was previously considered to correspond roughly to the Triassic of England but later opinion inclines strongly to the belief that they are much more ancient and apparently of about pre-Cambrian age so that an enormous period of time separates them from the Tertiary rocks across the fault.

The structure of the western portion of the Dhaula Dhar has been studied in great detail by the late Lieutenant-General C .A. McMahon, and the Chamba Gazetteer ( 1904 Chapter I-A.) gives his findings which may be accepted with respect to the Kangra portion of the Dhaula Dhar. These findings, based largely on a detailed microscopic examination of the rocks, are that the main core of the range is a   gneissose granite which apparently has been subject to great pressure and shows flow structure. It has intruded into the older rocks   at a comparatively recent date which is placed by the General as about the end of the Eocene or the commencement of the Miocene period of the Tertiary epoch. This classic research finally disposed of the old theory that the  gneissose core represented some extremely ancient sedimentary rock which has been metamorphosed and rendered crystalline by the immense pressure to which it had been subjected. 

Mr. Middlemiss in his report on the 1905 earthquake indicates the following salient features or the geology or the District which may be connected with the liability to earthquakes :--The Tertiaty rocks in the Dharmsala area and to a lesser extent in the Dehra Dun area, form deep bays into the ancient Himalayan mass, they are very thick beds and have accumulated comparatively recently in geological history at a very rapid rate so that a condition of unequilibrium has been set up in the earth 's crust in these areas; the epicentrum in the Kangra arca seems to have lain roughly along the fault between the Siwalik and the Sirmur series and not along the "main boundary," also the steepness of the immense wall of rock constituting the Dhaula Dhar may have added to the instability.