File:The Quarterly journal of the Geological Society of London (12512005023).jpg

1853..
HARKNESS KIRKCUDBRIGHT SILURIANS.
183
..2 "li
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Mary. A little to the east of this place the grits are traversed by
veins of sulphate of barytes. At Port Mary the Silurians again
make their appearance, and in the course of the small burn are seen
dipping S.S.E. at an angle of 55°.
Immediately west from Port Mary the grits
reappeai', and run along the coast to Abbey
Burnfoot ; where the silurians are seen, having
a north inclination at Guthries Pool. Up the
Netherlaw Glen, from whence the burn flows,
the inclination of the silurians is the reverse of
what occurs at Guthries Pool, being to the
south at an angle of 50°.
^ ^ ^^^' £ From Abbey Burnfoot westward the grits
again occur, and occupy the coast to Nether-
law. Here they consist of red-coloured beds
containing rounded and angular fragments of
quartz and silurian rock, and have a southerly
dip, at an angle of 1 7°, which is the prevailing
dip of the carboniferous equivalents in this
county.
At Netherlaw Point commence the series of
silurian rocks which it is the object of this paper
more particularly to notice. Some of these have
been more or less fully described in a former
paper* ; but the relation they bear to the de-
posits constituting the great mass of the silu-
rians of the South of Scotland has not yet
been shown. Near the summit of the headland
the silurian strata are covered by the carbo-
niferous grits, but the point of contact between
the two formations is not seen ; they consist
of 1. (uppermost) Shale and sandstone; 2.
Vl ^^.%. Sandstone; and 3. Graptolite Shale.
No. 1 comprise, in the Upper part, — light-
grey shales (with calcareous nodules), alter-
nating with light-grey sandstones, in beds
rarely exceeding a foot in thickness. The un-
der-surface of the sandstone is ripple-markedf
(as seen at Netherlaw and Gipsey Points).
This sandstone at Gipsey Point is much coarser
than that at Netherlaw Point, of which it is a
repetition, and it contains fragments of quartz
and jasper, and a fragment also of syenite was
found in it by the author, similar to the syenite

• See Quart. Joum. Geol. Soc. vol. vii. p. 54.
  

t These ripple-marks are not of the waved form which usually occurs on
ripple-marked sandstone, but consist of irregular hollows and sinuous elevations,
often terminating abruptly. A similar ripple-mark occurs on the under-surface
of the red sandstones near Annan, Dumfriesshire, where they lie on beds of day.
See Quart. Joum. Geol. Soc. vol. vi. p. 397.
5* "^