29G 
THE GEOLOGIST. 
rectified in your next number. You have embodied a fool^note in the text, which 
makes it read that Dr. Fiedler's specimen was found on the confines of Holland 
by a shepherd, which was not the case. I merely noticed it as a fact of ocular 
demonstration of the formation of a fulgmite given in his work. — Yours, &c. 
"George D. Gibb." 
Geology of Wigton, Cumberland. — " Sir, — I shall be greatly obliged to any 
of your readers who can furnish me with information as to the geology of this 
neiglibom-hood, the varieties of fossils, and the localities in which they are most 
abundant.— I am, yom's respectfully, Frank Dymond, Brookfield, near Wigton, 
Cumberland." 
On a Pit-Section of Tertiary Strata at Woolwich. — By the Rev. 
T. G. Bonney, ^I. a., of Westminster. — " The following descriptions of a section of 
the lower tertiaries, at present exposed in a sandpit near Woolwich, may not be 
uninteresting to some of the readers of The Geologist. The pit is situated close 
to the road, between Charlton and Woolwich, and is divided by the railway. In 
fact, .strictly speaking, there are two pits ; one, the smaller, open to the road ; 
the other, on the other side of the railway. It is of this latter that I intend 
chiefly to speak. When I visited it two years ago, it was then deserted, but now 
a considerable section has been exposed by working for sand. The section 
exposed is as follows : — the measurements are only approximate, as I had no 
instruments — (1.) Soil, containing many roimded pebbles, more esjiecially in the 
lower part (2 ft.). (2.) Yellowish-grey sand, with irregidar rust-colom-ed streaks 
(5 ft.). (3.) Sand and rolled pebbles. In this there are a few tliin streaks or 
traces of shells (3 ft.). (4.) A mass of sliells and rounded pebbles. The shells 
here are iiregularly heaped together, as if by the action of the waves, just like a 
great shell-bank. Their quantity is so great that, at a short distance, the seam 
appears like a stratum of white rock. The shells are exceedingly brittle, and, 
consequently, it is difficult to procirre good specimens, although the number to 
choose from is enormous. I found about ten or eleven species, among which were 
Melania incquinata, Cerithina funatum, Melanopsis fasiformis, Natica, Nerida 
consobrica, N. (jlobulus, Pccluncidus, Ci/rena, &c. The pebbles in this seam are, 
perhaps, rather smaller than those above (2 ft.). (.5.) A small band of grey and 
yellow sand (3 or 4 inches), ((i.) Small pebbles, sand, and shells. The shells as 
before, but not quite so abundant. This stratum always formed a talus on the 
cliff (10 ft.). (7.) Bluish and dark clay (13 ft.). The last 7 feet composed of 
layers of different shades. The effect of "this part, when seen from a little distance, 
is very curious. The great number of parallel laminoe of different shades look as 
thougli the face of the cliff had been ruled with differently shaded inks. Shells 
are plentiful in this, but very difficult to olitain perfect, there are not so many 
varieties, api)arently, as above. The most plentiful are, Melania inequinata (large), 
Cerithium funatum, C>irena cordata, and C. cuneiformis ; the last very abimdant, 
lying horizontally with the valves closed, as though they had been engdphed 
while alive, or immediately after death. Oyster-shells also occur, especially in a 
seam about 2 feet from the bottom of the bed. They are frequently of consider- 
able size, and form conglomerated masses. (8.) Thi'ee seams of yellow sand, with 
thin clay partings. This sand, I am informed, is used for the moulds in casting 
brass (3 ft.). (9.) Grey sand, used m casting iron (12 ft.). Whitish sand, called 
the ' silver sand,' used in making potteiy. This bed is of gi-eat thickness, not 
less, I should think, than 50 feet. 
" The above section is made in a line nearly at right angles to the river, and the 
beds slope gi'adually upwards in that direction. In the other pit, by the roadside, 
the section parallel to the road, shows only beds 9, 10, 8, and perhaps part of 7. 
There also appeare to be a small seam of pebbles separating 9 and 8 ; but with 
regard to these I cannot speak ■n-ith certainty, as they were nigh up in the face 
of the cliff, and I had not time to make an accurate examination, indeed, I doubt 
whether it could be accomplished ^vithout some risk. In this place the chalk has 
been reached just below the level of the road. 
" The beds exposed m some other parts of the pits are a good deal bent ; in one 
place they appear to be bent over a projection of the white sand, which seems to 
nave formed a sort of mound or shoal. 
