The Flamborough Quaternary Research Group
South Landing 3-12-2009.
Key Hole left hand side -
1- (top) Coarse chalk gravels with apparent dip of 8 degrees to left. The
largest chalk clasts are 20 x 16cm, 16 x 9, 32 x 42; the average size is 13 x 8
cm
2 - "chalk wash" upper 74cm fine, lower 50 cm finer [sample - 1209SL] with an
apparent dip of 34 degrees to left. Not indurated.
3 - 40cm layer of coarser chalk gravel. Largest clast 20 x 5cm; many are 8-10cm
x 3cm
4 - "chalk wash"
both chalk gravel layers have about 2 percent erratics. The erratics are
quartzite, yellow quartz, grey sandstone and grey flint. The chalk clasts are
larger than the erratics and the larger ones are sub-angular.
In the chalk gravel cliff to the right of South Landing -
There is about 2 percent erratics in the gravels and a vague coarsening upwards
to each poorly defined unit, The units can be seen from a distance but the bases
are hard to see close up.
Larger clasts are - 29 x 27cm, 26 x 16, 32 x 12, 34 x
13, 27 x 16 and 39 x 16. Average sizes are
5 x 6, 7 x 5, 8 x 4 and 5 x 8. Some are
imbricated into the cliff.
There is a laryer of coarser material above this layer
-- the larged clasts are - 48 x 12 cm, 46 x 24, 23 x 20, 35 x 16, 35 x 26, 42 x
10, 36 x 6
and 33 x 32. Average size is about 10 cm
diameter. They are sub-angular to sub-rounded. There is one erratic of brown
layered sandstone 30 x 18cm.
At TA23146 69319 - coarse chalk gravel 1-2 percent erratics with silty sand
above.
TA23139 69258. Large calcrete block to the right of South Landing. Two smaller
ones down beach. The suite of erratics is very similar to that of the Devensian
Tills. Including - black flint, jasper, porphyries, calcite, Cheviot porphyries
and Larvikite (Rodger has specimen of this). The chalk clasts in the calcrete
are frost shattered but the fragments have not been dispersed.
Left side of South Landing.
Gravels overlying the in situ Chalk; it is clast
supported in places. The matrix at the base is very iron rich. The Chalk clasts
are often flattened and sub-rounded. In places they dip about 15 degrees into
the cliff. Erratics make up about 15 percent of these gravels. There is evidence
of cryoturbation about 2/3 of way up and at the top of the gravels, The larger
chalk clasts are 8 x 22cm, 6 x 20, 6 x 17, 4 x 23 and 8 x 18, but there is every
size up to that. The erratics include -
black flint, quartz, yellow quartz, grey flint,
orange sandstone, brown sandstone, grey sandstone, porphyry, quartzite and
jasper.
{fieldwork report by Mike Horne}
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