42 GEOLOaY. 



Kotos tlio geology of the district, especially the gravel at Well Hill, 

 which Prof. Prestwich described as Marine and of Glacial age. 



Ward, J. C. The Glaciation of the Southern part of the Lake- 

 District and the Glacial Origin of the Lake-Basins of Cumberland 

 and Westmoreland. Quart. Journ. Geol. Soc. vol. xxxi. pp. 152- 

 166, pi. vii. (map and sections). 



Supplementary to papers in vols, xxix., xxx. At the period of 

 maximum glaciation the glaciers were more or less confluent, forming 

 an ice-sheet which moved S. and S.E. over the lower ridges. Some 

 striations crossing watersheds at high levels and in passes or cols, were 

 doubtfully referred to floating ice, supporting the supposition that the 

 submergence exceeded 2000 feet. The moraines belong to the second 

 period of glaciation, the glaciers of which wore not confluent, but 

 occupied the heads of all the principal valleys. Some mountain-tarns 

 are due, wholly or in part, to moraines ; others are wholly due to glacial 

 erosion. The larger lakes, lying in true rock-basins, are but shallow 

 grooves in the bottoms of the valleys ; their depth is small as compared 

 with the thickness of the ice, and they are probably due to glacial 

 erosion. W. T. 



. On the Granite, Granitoid, and Associated Metamorphic 



Rocks of the Lake-District. Quart. Journ. Geol. Soc. voL xxxi. 

 pp. 568-602, plates xxx., xxxi. 

 Part 1. 0)1 the Liquid-cavities in the Quartz-hearing Bocks of the 

 Lake- District, pp. 568-589. — Deeply-formed granitic or granitoid rocks 

 must have been subjected to pressure from two causes : — Downward 

 jpressure^ caused by the weight of overlying rocks ; Surplus or Outward 

 pressure, acting from below. A microscopic examination of the rock 

 enables us to estimate the total amount of pressure ; this is determined 

 by the relative size of the liquid- cavities and their vacuities. Exami- 

 nation in the field informs us of the greatest amount of downward 

 pressure which can have been exerted ; the diff'erence, if any, gives the 

 amount of outward pressure. Probably none of the granitoid rocks of 

 the Lake-district were consolidated at a greater depth than 30,000 feet, 

 whilst the total pressures represent 35,000 to 52,000 feet. The Skid- 

 daw and Eskdale granites were formed respectively at a maximum 

 depth of 30,000 and 22,000 feet; they both indicate large surplus 

 pressure, which probably acted outwards and effected elevation, contor- 

 tion, and metamorphism. The Shap granite, consolidated at a maximum 

 depth of 14,000 feet, shows much surplus pressure; it probably repre- 

 sents an immature volcanic vent. The volcanic rocks of the Lower 

 Silurian series were not produced from the granites in question ; the 

 granites are of more recent date, and their microscopic structure indicates 

 that the outward pressure was not relieved by volcanic action. The 

 mean pressure obtained for Lake-district granites is nearly the same as 

 that for Cornish granite. 



Part 2. On the Eskdale and Shap Granites and their associated 

 Metamorphic Bodes, pp. 590-602. — It appears that the granites were 



