Mar., 1892. 
PERMIAN BRECCIA OF LEICESTERSHIRE. 
53 
of volcanic origin, but much of the quartz shows a compound 
structure and resembles that from veins. Some, however, 
may have come from a gneiss or schist. Some bits of the 
felspar resemble that of a granitoid rock more than that of a 
lava. One fragment is composed of brown and white mica 
and quartz granules (the least abundant), Brown mica 
predominates, the flakes being about -002in. to '008in. long. 
Those of white mica sometimes attain to double this 
size, and are rather apt to be aggregated. As I am not able to 
assert that any constituent in its present condition is of clastic 
origin, I think the fragment is from a true schist. One or 
two gneissoid fragments contain a grain of zircon, one 
possibly some zoisite. Tiny but well developed crystals of 
brown mica are not rare in some of the fragments. I believe 
that this rock is largely composed of the debris of very 
ancient rocks. (95.) From Measham, a small round pebble 
about fin. long, of the peculiar quartz-felspar grit which I 
have described from the Trias.* To this formation I think 
the pebble more probably belongs. 
VIII. —Distribution of the Bock Fragments; and Character 
of the Matrix. 
The distribution of the fragments does not suggest any 
special inferences. All the different classes of rocks which 
I have described are represented among the specimens from 
localities in the neighbourhood of Overseal. (129.) Among 
those from the place itself we find various rocks ; the basalt 
(64), one or two specimens of Charnwood type, a dark slaty 
rock (138), specimens of the rhyolitic conglomerate, such as 
(119), the quartzose grit (103), afelspathic quartzite (101), and 
fine-grained quartzite (100), also a sandstone (132), and other 
rocks probably Carboniferous. From Coton Park, in addition 
to the two large boulders of grit or sandstone (40, 41) and the 
quartzo-rhyolitic pebble (39), come a slickensided clay (75) and 
a sandstone, probably Carboniferous, also the banded argillite 
of Charnwood origin. From Woodville or its neighbourhood 
come a pebble, probably from Charnwood (82), a Carboni¬ 
ferous sandstone (97), with a hard Carboniferous clay (76), 
and a pebble of quartzo-felspathic grit (102), of uncertain age. 
From Wooden Box, a flinty argillite from Charnwood (81). 
From Oakthorpe, a breccia with a crinoid stem (147). FromMea- 
* Address to the Geological Section of the British Association, 
Birmingham, 1886, p. 612, T. G. Bonney. “ Geol. Mag.,” Decade 2, 
Yol. VII. (1880), p. 405, “Note on the Pebbles in the Bunter Beds 
of Staffordshire,” T. G. Bonney. 
