310 Geological Society : — 



GEOLOGICAL SOCIETY. 



[Continued from p. 230.] 



. December 17th, 1873. — Prof. Ramsay, F.R.S., Yice-President, 

 in the Chair. 



The following communications were read : — 



1. " Observations on some features in the Physical Geology of the 

 Outer Himalayan region of the Upper Punjab, India." By A. B. 

 Wynne, Esq., E.G.S. 



The district of the Upper Punjab described by the author con- 

 sists of crystalline, granitoid, syenitic, and schistose rocks far in 

 among the hills, succeeded by slates and limestones, possibly of 

 Silurian age, unconformable overlain by Triassic and perhaps older 

 rocks, which are in their turn unconformably succeeded by a series 

 of mutually conformable Jurassic, cretaceous, and nummulitic lime- 

 stones and shaly beds. These secondary and Tertiary beds, which are 

 chiefly limestones, are called the " Hill Limestones." Beyond these 

 comes a zone of hills and broken plains, composed of sandstones, clays, 

 and conglomerates, of great thickness and of Tertiary age (Eocene 

 and Miocene), which the author calls the " Murree beds." This belt 

 passes generally along the whole southern foot of the Himalayas, 

 from Assam to Afghanistan. In the district described by the 

 author it is bounded on the south by the Salt Range, beyond which 

 stretch the deserts of the Punjab and Sind. 



The outer Tertiary belt presents a gradation towards the hill 

 character. Among the rocks of the Murree zone there are harder 

 beds than elsewhere ; limestones occasionally appear, sometimes 

 like those of the hill-beds, and the Hill Nummulitic limestones may 

 have alternated in their upper part with the Murree beds. The 

 nummulitic limestones of the Salt Range, containing large Bivalves 

 and Gasteropoda, were probably of shallow- water origin, whilst the 

 diminutive organisms of the Hill Nummulitic limestone inhabited 

 greater depths. 



Contortion of the strata is a common feature of the country, 

 affecting some of the newest Tertiary beds so as to place them in a 

 vertical position, and almost everywhere throwing the rocks into 

 folds, producing in many ca^es inversions of the strata. 



The author compares these rocks with those of the Simla area 

 described by Mr. Medlicott, who found there two strong uncon- 

 formities, namely, between his Siwalik and Nalum, and ISTalum and 

 Subathu groups, and regarded the whole of the beds of the outer 

 Tertiary detrital zone from the base of the Subathu group upwards 

 as discordant to the Himalayan or Hill-series and to each other. 



The junction of the newer Tertiaries with the rocks forming the 

 higher hills of the outer Himalaya, both in the Simla area and in the 

 outer Punjab, is marked by disturbance, distortion, and inversion or 

 abnormal superposition in the Tertiary strata along the contact. 



