106 Transactions. 
Авт. 8.— Fossiliferous Limestone at Dowling Bay. 
By Н. I. Fiytay, M.Sc., and Е. Н. McDowarr, M.Sc. 
[Read before the Otago Institute, 8th November, 1921 ; received by Editor, 5th December, 
1921 ; issued separately, 8th February, 1923.] 
Plate 11. 
THE occurrence of a limestone at Dowling Bay has long been known, but 
no fossils have yet been recorded from it. A few species were found on 
the occasion of a visit of the Otago University geology class, and, at the 
suggestion of Dr. Benson, we undertook to make as complete a collection 
of fossils as possible, and to describe the locality. 
The place was visited by Blair (1879), who found five seams of lime- 
stone which he stated might be of use for building purposes. Analysis, 
however, showed that varying amounts of sand (from 3 to 28 per cent.; 
were present, and the rock has been rejected as a source of lime, though it 
has been used for building-stone in Port Chalmers. 
ere is no record of any other examination of the locality till it was 
inspected by Morgan (1919). He found the strikes ranging from S. 30° W. 
to W. 10° N., with westerly and northerly dips of from 25° to 60°. He 
also noticed the extreme variation in the composition of the rock. ; 
s may be seen from the map, the outcrops of sedimentary deposits 
are limited on one side by the coast-line, and on the other by an over- 
lying series of basalt-flows. The marine beds have been exposed by the 
removal of the basalt by erosion, and except along the sea-border are 
almost completely covered with soil. It is thus difficult to determine 
the line of separation between the basalt and the calcareous sandstone, 
but a series of springs was taken as giving evidence of the dividing-line. 
Fossils were obtainable only from a road-cutting at the western end of. 
Dowling Bay, the remainder of the fossiliferous strata being obscured by 
two masses of landslip rubble and soil. The Limopsis-bearing limestones, 
which are the most prominent parts of the outcrop, were found to dip 
about W. 10° N. at angles varying from 36° to 45°. The fossiliferous layers 
are scattered through a thickness of about 160 ft., with no well-defined - 
order of occurrence. The limestone varies largely in appearance and 
character from a hard grey to a softer black rock, and in small laminae 
is even of a shaly character. The Limopsis bands are up to 1ft. m 
thickness, while those in which Flabellum and Turritella are abundant 
have a thickness in some cases of several feet. 
In a cliff on the road between the two heaps of rubble, blue-grey 
calcareous sandstones are seen to rest on the fossiliferous beds, and these 
in turn on yellow sandstone like that at Caversham. Here the dip of the 
grey limestone is 35°. From the second rubble-heap to the mass of 
phonolite at Otafelo Point the sandstone is yellow, unfossiliferous, and 
stands in high cliffs, though without much sign of stratification. Те. 
beds here appear to dip vertically, and it was noticed that this displaced 
_ stone is in line with the fault that cuts off the phonolite. The phon 
adjacent to the faults is fractured and broken, especially the northern - 
‘mass at Otafelo Point. oe 
