416 REPORT—1899, 
E.S.E. of the edge of the boulder clay, and rises gradually to W.N.W. 
The angle measured by Abney Level from opposite side of Alexandra 
Quarry is from 2°-5 to 6°0 (average 4°°25) to E.S.E. (Photographs 
1, 2, 3). But the surface undulates (Photographs 7, 8). 
5. Slope of Surface of Drift along Section (Photograph 3). 
6. Strike and Dip of Cleavage of Slates.—N. 30 E., 95°-98° to 8. 
of E. Dip of Bedding of Slates.—25°-30° 8.8.E. or 8., but undulating. 
7. Thickness of Drifts along Section.—25 ft. maximum, thinning 
towards hill-top (Photographs 1, 2, 3, 4,11). The sections which will 
remain at present will show the varying thicknesses in the quarries. 
8. General Nature of the Drifts.—Their general characters have been 
often described. Towards the N.W. are sands, sandy loam, and gravel, 
with shells, boulder clay coming on above them towards the 8.E. 
(Photographs 1, 2, 3). 
9. Position of Boundary of Sandy Group and Boulder Clay.—The 
junction at the surface between the quarries is about 1,000 ft. from the 
hill-top. 
Fic. 2.—Contortions in Sands below Boulder Clay. 
I. Mynydd Mawr Eurite 
2. Welslr Felsite 
‘3. Benmaenmawr Diorite 
WE 
/ronm pan 
Section at x (in fig. 3) on Elevation. 
10. Character of the Sandy Grouwp.—The beds may be described as 
sand and yellow loam with gravelly streaks and pockets containing shells. 
The shell fragments were found on November 5 only in the gravel, none but 
the finest crumbs having’ been seen in the sand and loam (a, p. 419). The 
bedding is very irregular, and even here and there curved (Photograph 1), 
but contortion has only been observed near the junction with the over- 
lying boulder clay ((, p. 419). 
11. Characters of the Boulder Clay.—This is a good, typical, tough, 
strong, unstratified till, such as is mostly found in mountain districts, 
dark grey in colour and full of stones (Photograph 4). The stones 
are for the most part of moderate size, but some up to 34 and 3 ft. (the 
visible part) occur. They are subangular and well striated. There seems 
to be a general slight upward inclination of the longer axes of the stones 
to E.S.E. or E. The longer axis of the large boulder mentioned pointed 
W. 20 8.-E. 20 N., and its eastern end was a little lifted. Nearly all 
the stones observed were of N. Welsh origin, the riebeckite eurite of 
Mynydd Mawr being very abundant, but one pebble of a granite foreign to 
