1918.] The N.Z. Journal of Science and Technology. 
171 
DEPARTMENTAL REPORTS. 
Notes on the Geology of the Cheviot District. 
By J. Henderson, D.Sc-., Mining Geologist, Geological Survey Department. 
Introduction. 
In May, 1917, the writer spent a few days in the Cheviot district, and 
hurriedly examined the section exposed near the mouth of Jed Stream 
and thence southward along the coast to Port Robinson. The following 
is a list of publications that deal with this district:— 
1871. Sir J. von Haast, On the Geology of the Amuri District, in 
the Provinces of Nelson and Marlborough, Rep. Geol. Explor. 
during 1870-71, No. 6, pp. 40-44. 
1877. F. W. Hutton, Report on the Geology of the North-east Portion 
of the South Island from Cook Strait to the Rakaia, Rep. Geol. 
Explor. during 1873-74, No. 8, pp. 38, 47, 48, 55. 
1883. A. McKay, On a Deposit of Moa-bones near Motunau, North 
Canterbury, Rep. Geol. Explor. during 1882, No. 15, pp. 78, 79. 
1902. A. McKay, Report on the Recent Seismic Disturbances within 
Cheviot County, Northern Canterbury, and the Amuri District 
of Nelson, New Zealand. 
General Geology. 
The oldest rocks of the district are the greywackes and argillites that 
form the highest points of the Cheviot Hills, Mounts Caverhill (1,320 ft.) 
and Maccoinnich (1,099 ft.). The main area of these beds, which litho¬ 
logically closely resemble those that form the chief part of the Southern 
Alps, is bounded on the south by the valley of Jed Stream. The rocks, 
however, again appear from beneath the concealing strata at Port Robinson 
in the form of a fault breccia containing large angular boulders of greywacke, 
of all sizes up to 12 ft. across, set in a scanty matrix of soft dark pug. 
Many of the boulders are shattered, and others have polished slickensided 
faces. The breccia extends along the shore southwards as far as the old 
slip. Beyond this point it is overlain by soft horizontally bedded sand¬ 
stones. Toward the headland on the south side of Port Robinson these 
sandstones form steep grassy slopes, the shore itself being protected against 
the waves by greywacke boulders. But whether these latter have been 
derived from the rock in situ, either solid or breccia, or whether they have 
been transported by the waves from Port Robinson, the exploration under¬ 
taken was insufficient to determine. 
Immediately north of the breccia just described, soft sandy claystones 
are exposed for a few chains along the shore. These beds, which are dark- 
coloured, are covered with a yellowish efflorescence, and some layers contain 
numerous nearly spherical concretions up to 2 ft. in diameter. The beds 
dip gently northward; but the whole exposure, which is not more than 
10 chains in length, lies between two powerful faults, so that it is impos¬ 
sible from this section to determine the relative position of these rocks 
on stratigraphical grounds. According to von Haast, they form part of 
the series which closes with the Amuri limestone, and which he states 
outcrops north of Jed Stream. 
