On Rocks and Minerals from the Karakoram Himalayas. 481 



mineral resembling a pyroxene seems to be present. On the whole, 

 after consulting many analyses of rocks and minerals, we venture to 

 suggest that this rock may v e composed of a lime garnet,* a potash 

 jadeite, a mineral of the scapolite group, and a little pyroxene (or, 

 possibly, even wollastonite or pectolite). It is more probably a vein 

 product, for the low percentage of alumina seems to exclude the pos- 

 sibility of a felspathic euphotide. 



(4.) Geographical Distribution of the Rocks. 



Mr. Conway's collection commences with some specimens from the 

 Jhelam Valley below Barramula. These are a limestone and slates, 

 not unlike some which occur in the Secondary series of the Alps. 

 The next specimens are from Gurai, in the side valley north of the 

 Tragbal Pass. These (fallen blocks) are granite and diorite. Ad- 

 vancing thence up the valley of the Kishanganga and the Burzil 

 Valley, fphyllites,t a -("conglomerate and then a fgranite were 

 collected, and fallen blocks, near Mapnun, furnished a slate and a 

 serpentine. Descending from the Burzil pass towards the Astor 

 Valley, fhornblende diorite and tchlorite schist were found ; in 

 fallen blocks diorites and a micaceous gneiss ; and one water-rolled 

 specimen of argillite, Near Astor, two varieties of gneiss were 

 obtained from boulders. Below Astor, a fdiorite on the west of the 

 river, and apparently also on the east, and fallen blocks of horn- 

 blendite on the west, a fgarnetiferous gneiss (near Parri), common as 

 big boulders down the valley ; and then fgrannlite and ffine-grained 

 gneiss (these two abundant by. the roadside). The strikes and dips 

 recorded by Mr. Conway in some cases may be planes of jointing 

 rather than of bedding, and in crystalline masses they are most 

 probably to be reckoned as results of pressure. Down to this part 

 of the Astor Valley, the strikes vary from 15 W. of N. to 10 E. of K, 

 the dips varying from 80 eastward to vertical. From the lower part 

 of the valley, and from below Hatu Pir come fmicaceous gneisses, 

 and fdiorite at Ramghat. In the valley the strikes vary from N.N.E. 

 to nearly N.E., the dips being on the south-eastern side from 

 30 to 45, while below Hatu Pir the strike varies between 10 N. or 

 S. of E., the dips being 33 on the southern side. 



The first specimens brought by Mr. Conway from the valley of the 

 Indus come from the neighbourhood of Bunji. They are fgranite, 

 hornblendite, decomposed diabase, and micaceous gneiss. The next 

 specimens are representatives of the Bagrot Valley ; its stream enters 



* The constituents of the greater part of the rock are so feebly double-refracting 

 that a fair quantity of an isotropic mineral, if disseminated in granules, might easily 

 elude discovery. 



t Specimens marked thus f were obtained in situ. 



