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to about 10 ft. in thickness. At many points brecciation of the shale and calcareous bands accompanied the intrusion, and the dyke material at places is a breccia with many marl and limestone fragments cemented in a sandy matrix. The limestone and shale blocks in the dykes range from a fraction of an inch up to about 2 ft. through, and they may be abundant in or entirely absent from the dykes and sills. These dykes are best exposed at Hurunui Mouth, where the marl in the section along the south bank at the river mouth is invaded by sandstone dykes and sills and is unconformably overlain by sandstone containing a band of phosphatic nodules at the base, or a coarse basal conglomerate with a few phosphatic nodules. The conglomerate consists mainly of fragments of Amuri limestone or the mailv beds underlying it, and. boulders of the sandstone breccia dykes intruding the marly beds. The mapping shows that the marl intruded by sandstone dykes at the Hurunui Mouth is the equivalent of the chalk marl of other areas, and is the bed that underlies and grades into the Amuri limestone rock type. Dr. Finlay examined a specimen from this marl at the Hurunui Mouth and identified a micro-fauna identical with that of the marly limestone beneath the typical Amuri stone at Port Robinson and characteristic of the Hampden beds, Otago. The typical cuboidal jointed Amuri limestone ranges from a few feet to 50 ft. thick in the area so far mapped, and it is succeeded by a nodular phosphatic band with a glauconitic sandy matrix. Cookson Beds. —Localized volcanicity followed the deposition of the chalk marl in the Waiau Survey District, where tuff, breccia, basaltic flows, and pillow lavas crop out close to the fault zone that extends from the Upper Waiau to Kaikoura. These volcanic rocks suggest instability along this zone in early Oamaruian time. Weka Pass Stone. —The equivalent of the Weka Pass stone within the subdivision grades from a calcareous sandstone or glauconitic sandstone to a massive crystalline limestone. The Isolated Hill limestone of the annual report for 1931 is correlated with the Weka Pass stone. At Isolated Hill and Mount Cookson tuffaceous bands are interbedded with it, indicating that volcanicity continued to the Ototaran. South of Amuri Bluff the Weka Pass stone is a banded sandy limestone with thin interbedded glauconitic sandstone bands, and north of the Bluff it resembles somewhat the Amuri limestone. Grey Marl.—Calcareous mudstone with abundant fucoids is the equivalent of beds known as Grey Marl beyond the subdivision. It is apparently conformable with the Weka Pass stone at Amuri Bluff. Elsewhere in the subdivision sandstone and glauconitic sandstone interbedded with argillaceous sandstone represent the grey marl. No rocks corresponding with the Grey Marl were recognized in the Waiau Survey District, but should they be present, they are included in the Sugar-loaf beds of the 1931 annual report. The Sugar-loaf beds are disconformable to the Isolated Hill limestone. The age of the sandstone that unconformably overlies the marl at the Hurunui Mouth is debatable. It truncates the Weka Pass glauconitic calcareous sandstone along the lagoon front; and its equivalent in the south limb of the Gore Bay syncline is probably the sandstone that disconformably overlies the Weka Pass glauconitic calcareous sandstone about 12 ft. above the contact of that rock with the Amuri limestone. The sandstone overlying this 'disconformity is associated with fucoid-rich mudstones, a rock-type considered by Speight and Jobberns characteristic of the Grey Marl. But these writers considered the sandstone above the unconformity at Hurunui Mouth the equivalent of the Mount Brown Beds. Mount Brown Beds. —Mount «Brown Beds, consisting of shelly conglomerate bands and sandstones, unconformably overlie the grey marl in the Cheviot basin, and at the Trig, two and a half miles west of Domett they rest on the Amuri limestone. The Sugar-loaf beds which yielded faunas that place them in the Awamoan and Hutchinsonian stages, are the equivalent of the Mount Brown Beds. Bourne Conglomerate and Sandstones. —Since 1931 the Bourne conglomerate and interbedded mudstones and sandstones have been mapped over an extensive area, and the suggestion in the annual report for that year, that the huge rocks of the coarser facies were derived from newly formed fault scarps is inadequate to account for its distribution. The coarse conglomerates represent the shallow-water beds of an extensive Pliocene transgression. These conglomerates, sandstones, and mudstones truncate all the older rocks. Their equivalents are the Greta Beds of the Waipara and Weka Pass district,* the Great Hundalee Conglomerate of Jobberns,f and in all probability the Great Post-Miocene Conglomerate which McKay has described,J and the Great Marlborough Conglomerate of Thomson.§ Highjield and Lyndon Beds.—Tilted gravels occupy a considerable area east of the Hawkswood Range between Hawkswood Bluff and the Conway. Both the Highfield and Lyndon gravels appear to be represented in this area. The conglomerate in the Gore Bay syncline is tentatively correlated with the Bourne beds, but it may possibly be younger. Late Pleistocene and Recent. —High-level terrace gravels, loess, and raised beach gravels and sands constitute these deposits.

* Thomson, J. A. : " The Notocene Geology of the Middle Waipara and Weka Pass District, North Canterbury, New Zealand," Trans. N.Z. Inst., Vol. LII, pp. 322-415. f Jobberns, 6. : " The Raised Beaches of the North-east Coast of the South Island of New Zealand," Trans. N.Z. Inst., Vol. 59, 1928, pp. 508-570. J McKay, A. : Id. 1890. § Thomson, J. A. : " The Great Marlborough Conglomerate," Seventh Ann. Rep. N.Z. Geol. Survey, 1913, p. 123.

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