198 
THE JURASSIC PLANT BEDS OF ROSEBERRY 
TOPPING. 
H. HAMSHAW THOMAS, M.A., F.G.S. 
AT the present time there is an excellent opportunity for 
. studying an exposure of very great importance to those 
interested in fossil-plants. The beds which have recently been 
exposed near the summit of Roseberry Topping almost rival 
the famous Gristhorpe bed in the beauty and variety of the 
plant-remains in them. The hill, which forms a landmark 
well-known in North Yorkshire, is a conical outlier, consisting 
of Lias capped by a small group of Estuarine rocks. Owing 
to mining operations, part of the massive sandstone capping 
has slipped down, carrying with it the underlying beds and 
forming a scree below. In this way the beds forming the 
summit of the hill have become exposed, and have provided 
ample material in the scree from which fossils can be collected. 
On the south side of the exposure the massive sandstone 
appears to rest directly upon the Upper Lias, in which 
Ammonites are very rare, though a single fragment, probably 
of Ammonites communis, has been seen. At the northern 
end of the exposure, however, there are eight or ten feet of 
black and yellow shales between the Lias and the sandstone. 
These appear to be quite conformable with the underlying 
strata, but thin out as we pass northwards. The beds have 
not yet been carefully traced between the north and south 
ends of the exposure owing to the disposition of the scree 
material and to the great risk from falling blocks. The plant 
beds have been found on the other side of the hill and also 
on the main escarpment about half a mile away towards 
Hutton. They appear to be absent from the southern face 
of the escarpment towards Easby. Probably here, as at 
Marske, the plant layers are of somewhat local occurrence, such 
as might have been produced by the filling in ‘of a lake or 
lagoon on the rising land surface.. The character of the sedi- 
ment, when traced laterally, varies from a fine black shale 
to a micaceous shaly sandstone, and this may point to the 
same conclusion. 
The distribution of plant remains in these beds seems to 
offer some points of interest, One form, Eqgutsetites Beant, is 
very abundant, and is found almost everywhere, but most of 
the others are very limited in their horizontal and vertical 
distribution. They are never indiscriminately mixed, but in 
one place the shale is full of Zamites gigas fronds, together 
with some Anomozamites, and a short distance away Nuilssonia 
mediana is most abundant, with Ctenis falcata and Elatides 
twigs. In these blocks a narrow layer contains many Ginkgo 
Naturalist, 
