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PROFESSOR T. J. JEHU AND DR ROBERT CAMPBELL ON 
VI. Paleontology of the Beds. 
The great majority of the fossils noted are in Professor Jehu’s collection. A few 
are in the collection of the Geological Survey and these were found by Mr D. Tait, 
kindly sent by Dr Flett, Assistant Director of the Survey, at Professor Jehu’s 
request, to search for specimens. The interest of the fossils lies not so much in their 
nature as organisms, but rather in the light they throw on the age of the rocks ; that 
is to say, their importance is stratigraphical rather than palaeontological. The 
localities at which fossils have been found- are indicated on the map (Plate VI). 
I. The Lower or Black Shale and Chert Series. 
No undoubted organic remains have been recorded from the black shales. This 
is probably due to the intense movement they have undergone, resulting in the 
production of well-marked fiaser structure. 
“ Ghosts” of graptolites have been noted in the less altered bands of black shale, 
but these are too shadowy to be regarded with confidence as fossils. It is probable, 
however, that the carbonaceous material which gives the shales their black colour, 
and causes them to stain the fingers, is an indication of the presence of life in the 
waters under which the sediments accumulated. 
The fossils which have been obtained occur in beds of pale grey, somewhat 
muddy cherts and cherty shales, 1 to 4 inches in thickness. The principal fossili- 
ferous locality is on the south-east side of the Bofrishlie Burn, about 400 yards 
north-west of Arndrum. Here the belt of Highland Border Rocks is very narrow, 
the width being only a little over 100 yards. The cherty beds and associated black 
shales are sharply folded along nearly vertical axial planes, and frequently the folds 
have snapped, resulting in small overthrusts (Plate V, fig. 2). Sometimes the chert 
beds and black shales are so crushed together as to be intermixed or to form a 
breccia of angular fragments. The cherty beds are traversed frequently to such an 
extent by joints, small faults, and minute veins of quartz as to render it extremely 
difficult to split the rock along the planes of lamination. 
Another exposure of cherty beds yielding fossils occurs on the same horizon 580 
yards further north-east, measuring along the strike of the belt. This spot is 
situated on the top of the ridge of black shales and cherts, north-west of a sharp 
bend in the course of the Bofrishlie Burn. 
Again a few fossils were obtained from nearly pure chert beds on the hill-top 
just above and north-west of the road where the old aqueduct of the Glasgow Water- 
works crosses the valley opposite the Drum of Clashmore. 
