. The geology of the Oamaru district, North Otago (Eastern Otago division). The limestone is in places so fine-grained as to resemblelithographic stone. It contains fossils, but no recognizable forms could be extracted,on account of the hardness and shattered condition of tlic rock. The strike of the beds, so far as can be judged from the short exposure (Plate X),is about north-west - south-east. The dip is about north-east (true), at angles varyingfrom 12° to 17°. The conglomerate is about 8 ft. thick, and consists of rounded and semi-roundedpebbles of basalt set in a calcareous tuff matrix.
. The geology of the Oamaru district, North Otago (Eastern Otago division). The limestone is in places so fine-grained as to resemblelithographic stone. It contains fossils, but no recognizable forms could be extracted,on account of the hardness and shattered condition of tlic rock. The strike of the beds, so far as can be judged from the short exposure (Plate X),is about north-west - south-east. The dip is about north-east (true), at angles varyingfrom 12° to 17°. The conglomerate is about 8 ft. thick, and consists of rounded and semi-roundedpebbles of basalt set in a calcareous tuff matrix. Some angular pieces of basalt arealso present. At the base of the conglomerate, and resting on the inclined edges ofthe tufaceous limestone (bed d), there is a thin horizontal bed of fine lithographiclimestone, varying from 1 in. to 6 in. thick. Some 8 or 10 yards south of the old quarry excavation the conglomerate isfaulted down to the level of the limestone by a small fault, which is seen a few yardsbehind the overhanging ledge of conglomerate, as shown in Fig. Fiu. 22.—) of Hltchinsons guARRV. a. Yellowish-red and purple tuffs with limestone lenses. d. Basaltic conglomerate, 8 ft thick. b. Hutchinson Quarry hmestone and tuffs. e. Glaueonitie greensands, c. Horizontal band of limestone, from 1 in. to Om. tluck. /. Surface clays and silts. 61 The thickness of greensands as exposed 9 yards south of the quarry excavation isabout 18 ft. The U)\ver 12 it. consists of greyish-cohjured .laiu-onitic greensands crowdedwith Pachiiniufjati juiiki (Hutt.) and Rhizothyiis rhizoida (Hutt.). They also contain manymolluscs, ecliiiioderm spines and plates, corals, and cup-sliai)ed bryozoans. The clawsof a [)()werful crab, Bahonin plates, fragments of cetacean bones, a)id fish-teeth are alsopresent. The molluscs collected from greensands (Lower Hutcliinsonian .stage) include— AnciJJd papillata (Tate). Pcclen hutc/iitisoni Hutt. Polinices (jihb
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectgeology, bookyear1918
