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PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [June 25, 



by superior force to that which the Oolitic beds could offer in resist- 

 ance, eventually produced the phenomenon at Linksfield. 



Upon the first cursory view of the strata above described, it is 

 naturally supposed, that the intercalated Boulder-clay, lying between 

 the Devonian limestone and the oolites, must be some bed of Con- 

 glomerate or Drift of the latter, and to which a slip of the upper 

 strata had imparted a striated character ; but the apparent identity 

 of the intruded mass with the superficial Drift or Boulder- clay of the 

 district forbids such an interpretation. However, to avoid perpetu- 

 ating a mistaken view of a fact sufficiently remarkable to be worthy 

 of record, whatever be its true explanation, I beg to lay before the 

 Society specimens taken by myself from the intruded mass. 



The specimens exhibited to the Society were taken from the bed 

 described above as being intercalated between the Oolites and Devo- 

 nian Limestone. Fragments of the latter rock, showing its polished 

 and striated surface, accompany the samples of the Clay-bed with its 

 included pebbles. Amongst these may be detected fragments be- 

 longing to the upper beds, as well as of the ordinary pebbles of the 

 Boulder Formation, which, with large erratics, are dispersed irregu- 

 larly through the clay, and these are not unfrequently marked with 

 grooves. There are also seams of a dark purple-tinted clay pervading 

 the intercalated mass, which, when seen on the face of the escarp- 

 ment, appear nearly horizontal, but, in the section at right angles to 

 it, are found to incline inwards at an angle of about 45°. These 

 seams are partly composed of what the natives call the "Cutley-clay," 

 which is the lower stratum of the incumbent series, and which seems 

 to have been thus displaced and carried forward by the intrusion of 

 the Boulder-clay. 



4. On the Geology of Part of the Himalaya Mountains and 

 Tibet. By Captain Richard Strachey, Bengal Engineers, 

 F.G.S. 



[Pl. XVI. XVII.] 



It is, I think, to Humboldt that we are indebted for the first correct 

 views of the general configuration of the surface of the central por- 

 tion of the great continent of Asia, and for the announcement that, 

 while the greater proportion of the area is comparatively low, the 

 high lands are confined within somewhat narrow limits. 



The elevated region is known to extend through nearly 30 degrees 

 of longitude, from the sources of the Oxus to those of the Hoang-ho, 

 the Yellow River of China. Its southern limits are tolerably well 

 Imown also, but we almost entirely depend upon Chinese geographers 

 for the information that we possess of its extension to the north. 

 The chain of mountains that, under the name of Himalaya, forms 

 the northern boundary of Hindostan, is in reality the southern face 

 of this great mass of elevated land, while its northern face in like 

 manner appears upon our maps as the range called Kouenlun. To 

 the south lie the plains of India, whose greatest elevation is not more 



