352 PROCEEDINGS OP THE GEOLOGICAL SOCIETY. [JuilG 19, 



often stratified in such thin layers that many hundreds of them go 

 to the inch, and which were without doubt formed in lakes amongst 

 huge ice-masses. 



In ascending from the level of the sea to the slopes of the Southern 

 Alps there are many sections in the banks of the river which show 

 well the gradual retreat of the Postphocene glaciers ; in some other 

 localities, on the other hand, there is ample evidence offered to us that 

 there has been an advance of the glaciers during more recent times, 

 since the broad river-beds were formed. Thus, to give only one 

 instance, three miles from the present terminal face of the Francis 

 Joseph glacier, we meet a moraine curving across the shingle-bed of 

 the Waiau river, which is here more than a mile wide, and by which 

 this newer moraine has been destroyed in many spots, through which 

 its structure has become visible. An examination of these beds 

 reveals the important fact that the channel of the Francis Joseph 

 glacier was cut deeply into the ranges during their deposition, 

 as we find many blocks of truly metamorphic rocks mixed up with 

 those derived from the summit of the Southern Alps. Finally, I 

 beg to point out that glacier-lakes are not altogether missing on the 

 western side of the Southern Alps proper : a few of them, like lakes 

 Brunner and Kanieri, are dammed up by enormous morainic accu- 

 mulations ; others, from the descriptions given to me by trustworthy 

 miners, appear to be true rock basins, some of which I hope to visit 

 in the course of next autumn. 



7. On the Chemical Geology of the Malveen Hills. 

 By the Eev. J. H. Timins, F.G.S., M.A. 



In the year 1861, I commenced an examination of the rocks com- 

 posing the Malvern Hills ; and the results of the analyses of some 

 of the eruptive rocks, taken from various parts of the chain, were 

 published in the Edinburgh New Philosophical Journal, vol. xv. pp. 

 1-7. Since then, a minute and accurate description of the structure 

 of these hiUs has been given by my friend Dr. Harvey B. Holl (Quart. 

 Journ. Geol. Soc. vol. xxi. p. 72), to which I shall have to refer, in 

 the course of this paper, for a more particular account of the physical 

 geology of the district under investigation. I have also had the 

 advantage of visiting the hiUs with him, and, with his assistance, I 

 have been able to make many valuable additions to my collection of 

 specimens of the various rocks for analysis. 



In the present communication I propose to examine the rocks with 

 a view to the discovery of the sources from which they have been 

 derived, and the chemico-physical processes which have resulted in 

 their development, confining myself more especially to the consider- 

 ation of those which appear to be, wholly or in part, the products of 

 eruptive action, whether they occur as intrusive masses, lava-flows, 

 or beds of ash mechanically deposited. Those of which the mate- 

 rials were originally furnished by the decomposition and disintegra- 



