b 



610 EEPORT— 1886. 



former, however, appears to me the more prohable source. They also contain 

 fragments of felspar still recognisable, flakes of mica, and possibly a little schorl. 

 The frequent occurrence of crystalline quartz as a secondary formation in these 

 sandstones is a point of much interest, but has no relation to my present inquiry. 

 The breccias near Appleby, Kirkby Stephen, &c., which I have not seen, indicate 

 that at this time, not distant, masses of Carboniferous limestone, and of earlier 

 Palaeozoic rocks, were undergoing denudation ; but it appears to me improbable 

 that the finer materials of the sandstones were furnished by any rocks in the 

 vicinity. 



The Permians of the central area offer a rich field for future work. For the 

 materials of the sandy beds I should conjecture a distant source, but for the pebbles 

 in the conglomerates, and the fragments in the breccias, we need not ti'avel very 

 far afield. The Lower Carboniferous Measures contributed limestone and chert, 

 the former being especially abundant in the conglomerates, but the ' vein-quartz, 

 jasper, slates, and hornstone,' mentioned by some observers, indicate that yet 

 earlier rocks furnished their contingent, while of the igneous materials I will 

 speak dh-ectly. I shall pass ver}' briefly over the breccias, so well displayed, 

 for instance, on the Clent and Lickey hills, at no great distance from this town, 

 because I trust we shall have presented to us, in the course of this meeting, a 

 sample of the rich harvest which is awaiting explorers. Earlier investigators 

 looked towards Wales for the origin of these fragments ; we shall, I believe, learn 

 that the majority are more probably derived from rocks which, though now 

 almost bid from view, exist at no great distance. Some of the more compact 

 traps may have come from the old rhyolites, which, by the labours of your 

 geologists, have been detected in situ beneath the Lickey quartzite, while we may 

 venture to refer the ' red syenite ' and ' red granite ' to outcrops of crystalline 

 rocks of Malvernian age. These breccias have been regarded as proving the exist- 

 ence of glaciers in the Lower Permian age. It is, of course, possible that floating 

 ice has been among the agents of transport, but after carefully examining the 

 specimens in the museum of the Geological Survey, on which glacial striae are 

 asserted to occur, I am of opinion that the marks are due to subsequent earth- 

 movements. On only one specimen did I recognise glacial striation, and this pebble 

 is so difl'erent from the rest that I think it must have come from drift, and not from 

 the Permian beds. 



No less interesting are the Permian breccias of Leicestershire. These have 

 attracted the attention of an indefatigable local geologist, Mr. W. S. Gresley, and 

 to his kindness I am indebted for the opportunity of examining both rock specimens 

 and slices. As might be expected, fragments, which I have no hesitation in 

 referring to the Chamwood series, are not wanting, though hitherto they have not 

 occurred in any abundance ; but perhaps the most interesting member is a tolerably 

 hard conglomerate, containing rather abundantly pebbles of a speckled grit and 

 of a compact 'trap.' Microscopic examination of this conglomerate, which varies 

 from a fairly coarse puddingstone to a grit, shows that the above-named speckled 

 grit is composed of small and rather angular fragments of quartz, associated with 

 grains of brownish and greenish material, which may be in some cases decomposed 

 bits of a rather basic lava, in others possibly a glaucoiiite of uncertain origin. 

 But the ' trap ' pebbles are yet more interesting. These are. the more numerous, 

 and are commonly well rolled. They probably belong, roughly speaking, to one 

 species, but exhibit many varieties. In a single slide I have seen at least six, 

 perfectly distinct. Some are indubitably scoriaceous, others full of microliths of a 

 plagioclastic felspar, others almost black with opacite, others mottled brown 

 devitri6ed glasses, more or less fluidal in structure. Probably they belong to the 

 andesite group, with a silica percentage not very far away from sixty. In none 

 have I observed any signs of crushing or cleavage, so that I cannot refer them to 

 the Charnwood series, but conjecture that they are relics of volcanoes later in age 

 than the great earth movements which affected that series, though I cannot connect 

 them with the more basic post-carboniferous outbreaks of which we have indica- 

 tions at Whitwick and elsewhere. Quartz grains also occur, and some of these 

 exhibit a rather peculiar ' network ' of cracks which is characteristic of this mineral 



