28 PROF. T. G. BONNE Y ON THE NAKBOROUGH DISTRICT. [Feb. 1 89 5, 



The resemblance in the groundmass of the rock in the two pits 

 between Narborough and Huncote and in that south of Enderby — ■ 

 this being granular instead of ' quasi-ophitic ' and distinctly more 

 minute in structure than in the other localities — is interesting, and 

 suggests that the former pits also may be near the boundary of an 

 intrusive mass. 1 It is also worth noting that the micrographic 

 structure, so characteristic of the ' syenites ' of the Forest district, is 

 absent from these masses. An indication of it perhaps may be 

 traced in one or two of the specimens, but this is so slight that I 

 may venture to say that the structure is as characteristically absent 

 here as it is present in the other district. This group of rocks 

 evidently occupies an intermediate position between fine-grained 

 varieties of syenite and diorite, inclining rather to the latter, and 

 being sufficiently quartziferous to bring them near to the border of 

 granites and tonalites. 



More interesting results have followed from the enlargement of 

 the quarry in the outcrop on the lower ground south-east of Enderby 

 village. 2 The section formerly exposed at the south-eastern side of 

 the pit is no longer visible, probably being concealed by debris, but 

 new junctions have been disclosed by the advance of the quarry 

 westwards. These were shown me by the manager, Mr. A. 11. 

 Marston, to whom I am indebted for giving me not only every 

 facility for examining them, but also some valuable information. 

 The ' slate,' he said, had proved to be wedge-like in plan, the axis 

 running roughly W.N.W., and he thought that its extremity must 

 have been almost reached. 3 The mass also was wedge-like in 

 section, the northern slope being the steeper one. Hence it was 

 enveloped, so far as could be seen, by the ' S5 r enite.' I examined 

 actual junctions of the two rocks (in 1893) and obtained specimens. 

 In one place the syenite thrusts a short blunt tongue into the 

 ' slate,' at another it slightly contorts the latter. This in one part 

 is much indurated and almost ' flint}'',' but it is generally somewhat 

 fissile, the cleavage probably being anterior to the intrusion. I have 

 examined under the microscope two specimens of the sedimentary 

 rock, one showing an actual junction, the other from the flinty- 

 looking variety, perhaps 2 or 3 feet from the intrusive mass. In 

 the former the sedimentary part appears to be made up of specks of 

 opacite and ferrite, tiny yellowish granules and minute flakes of 

 mica, partly brownish to olive-tinted, partly colourless ; the latter 



1 At present our information is hardly sufficient to serve as a basis for 

 speculation, but we may anticipate that the area of buried crystalline rocks in 

 this district is considerably larger than that marked by their outcrops, and that 

 the slate may be looked for on the southern side of the pits between Narborough 

 and Huncote. 



2 Quart. Journ. Geol. Soc. vol. xxxiv. (1878) p. 227. In the second line of 

 p. 228, south is miswritten or misprinted for north (better ' more northern '). 



3 The appearances in 1893 suggested that he was right in this opinion. In 

 1894, however, though the pit had been carried some yards farther back, the 

 end of the mass had not been reached. Still, so far as I could judge, it did not 

 rise so high from the floor or cover so wide a space. 



