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VOL. XV. (3) EXCURSION—LAVERNOCK 181 
Not all the component beds of the Upper Rheetic are present at 
Lavernock. From some cause the gritty beds of the White Lias rest 
directly upon a much fissured surface of those Upper Rhetic marls 
which are usually seen immediately beneath the Lstherza-bed. The 
Members were able to examine some of these fissures, which were 
filled in with gritty material like that composing the bed above. The 
White Lias (Plate vi., fig. 2) is very poorly developed at Lavernock, 
but the surfaces of the thin limestone-beds are covered with fossils such 
as Dimyodon intusstriata (Emmrich), Zima valoniensis, Defrance, Pro- 
tocardium rheticum (Merian), Plicatula Hettangiensis, Terquem. Above 
all the White-Lias limestones are some marly shales similar to those 
seen in the Watchet District. Pale brown Paper-Shales succeed and 
mark the commencement of the Liassic Series. The great mass of 
limestones with shaly partings are most regularly-bedded, and well- 
exposed in the Point (Plate vii., fig. 1). 
The third limestone above the Paper-Shales commences a series 
of four limestone-beds locally known as the ‘‘ Washers,” which are 
extremely persistent in this part of Glamorganshire. The great mass 
of grey shale known as the ‘‘Lavernock Shales” belongs to. the 
Angulata-Zone and contains Cardinia ovalis (Stutchbury), a fosssil 
_common in the equivalent beds at Down Hatherley, near Cheltenham. 
Inaccessible, at the top of the section, are seen the limestones of the 
Bucklandt-Zone. 
Numerous fossils were observed by the Members on the surfaces 
of the limestone-beds which successively cropped out in the shore. 
Thus older and older strata appeared, and the Rheetic was again seen 
at St. Mary’s Well Bay. 
The section here is very important. The top-beds of the ‘‘ Tea- 
green and Grey Marls” are extremely fossiliferous, By the Geological 
Survey the line between the Rheetic and Keuper is drawn at the top 
of these fossiliferous marls, but the palzeontological evidence before 
the Members showed that without doubt the division-line must be 
drawn lower down, and at the base of these fossiliferous strata, or Sully 
Beds.* (Plate VII., fig. 2). 
A very interesting fault was studied here, and the Sully Beds were 
seen bent round against the ‘‘ Dolomitic Conglomerate” (Plate VII., 
fig. 2). 
‘ Ne a more detailed investigation of the ‘‘ Dolomitic Con- 
glomerate,” the Members had tea at Swanbridge Farm, and returned 
to Dinas Powis Station. 
Col. D. O’C. Raye was elected a Member. 
r L, Richardson, Quart. Journ. Geol. Sec., vol. lxi. (1905), pp. 386, 387, 394, 395, 410-414. 
