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Tutamoe Series. —Tutamoe microfaunas are recorded by Dr. Finlay from mudstones somewhat lower than the first marked sandstone bands of the Tutamoe. The more characteristic lutamoe consists of bands of hard sandstone interbedded with mudstones. The sandstones vary in texture from coarse to fine, and there are occasional conglomerate bands. These sandstones have usually a calcareous cement and contain abundant AmpMstegina. The upper part of the Tutamoe consists of softer grey sandstones. Mapiri Series.—Bands of pumiceous white sandstone occur at the base and are covered by mudstones similar to those of the Ihungia. Economic Geology. The hard Tutamoe sandstones have been quarried for road-making purposes at Frenchman's Cap and beside the Pourerere Road about 140 chains north-east of Omakere Station. These quarries are no longer worked. Near Roundaway Station on the Pourerere Road there is an old gas-spring which gave a regular discharge for one year after the Murchison earthquake. Earthquake traces 8 ft. to 9 ft. deep were found on this site at the time of the Napier earthquake, and occasional slight discharges of liquid mud still occur. There is a very large deposit of bentonite along the coast east of Clareinch Station and north ot Poanui Point. Samples taken from this deposit indicate the presence of high-grade material. OREPUKI SUBDIVISION. By R. W. Willett. Field-work was commenced in the Orepuki Subdivision in November, 1939, and by March, 1940, an area of some 180 square miles had been mapped in detail, comprising the entire Longwood Survey District. Adverse weather conditions and heavily bushed country greatly hampered the of the survey. Spccial attention was given to a detailed examination of the Orepuki oil-shale deposits, this work being assisted by seismic and magnetic surveys. Topography and Structure. The outstanding topographic feature of the area is the Longwood Mountains, a rounded, flat-topped mass, extending north and south through the eastern part of Longwood Survey District. They range in height from 2,300 ft. to 2,850 ft. Near the northern end the headwaters of the Waiineamea River rise in a low saddle between the Longwoods and Hekeia or Bald Hill, a rounded isolated knob in the extreme north of the area. To the west they are fla-nked by low flat-topped hills and ridges and extensive river terraces. Along the western base of the Longwoods the Waimeamea River flows south to Te Wae Wae Bay and separates the main mountains from the foothills to the west. Towards the south the Longwood Mountains terminate in a group of low hills occupying the Pahia-Riverton area and forming the coast-line —namely, Round Hill, Pahia Hill, Ruahine Hill, and Oraka Hill. In the Orepuki area an extensive terrace extends from the coast to the base of the Longwoods, a distance of about three miles. This terrace extends north along the base of the Waihoka foothills and joins the terraces of the Waiau valley, and eastward skirts the coastal hills as far as the Aparima River. In the lower Waiau Valley are well-preserved and extensive terraces at heights of 35 ft., 50 it., and 85 ft. that skirt the base of the foothills and the edge of the Waiau River's flood-plain. These terraces meet the coastal terraces at a point a mile north-west of the mouth of Grindstone Creek and form a cliff some 170 ft. high. The streams have cut fairly wide channels in the higher terra.ee (85 ft.) and have entrenched themselves in narrow cha,nnels in the lower terraces. This rejuvenation ol the streams can be seen to advantage where the terraces merge, a narrow, deep channel cut in the bottom of the wide upper gully. The coastal terrace extends from Waiau mouth to Monkey Island at the southern end of Te Wae Wae Bay, and ranges in height from 40 ft. to 170 ft, Remnants of a coastal terrace, 30 ft. to 45 ft. in height, can be seen around the headlands and bays between Pahia Point and Colac Bay. Generally the terrace rises from a wide wave-cut platform, which, south of Orepuki, is a prominent feature of the coast-line. The wave-cut platform is always covered with a veneer of rounded igneous boulders, with here and there partly consumed stacks and several almost-stacks. In several places beach gravels are to be found on the terrace remnants. The wave-cut platform is in weathered igneous rocks, except in Te Wae Wae Bay, where the harder sandstanes of the Orepuki Series form the platform. Likewise, in the case of the coastal terrace where the soft Orepuki Series have eroded away, the cliffing has been continued on the weathered igneous complex, large unweathered cores being left as boulders resting on a wave-cut platform. In the past the rapid retreat of the cliffs, composed ol 11011resistant clays and sandstones, has been responsible for the rejuvenation of the main streams, such as the Grindstone Creek, Deep Creek, Waimeamea River, Taunoa Stream, Falls Creek, and Kemp Creek. The structure of the area is by no means clear, especially in the Orepuki district, where exposures of the Tertiary beds are few. The evidence suggests that the Tertiary beds were laid down on a comparatively level surface cut on the igneous complex, and later folded into a series ol synclines and anticlines along a north-south axis. The hypothesis is supported by evidence obtained from geophysical surveys. The Tertiaries were then reduced to a gentle sloping erosion surface, upon which the Orepuki Series was deposited. Along the contact of the Tertiary rocks and the igneous complex, the dips on the basal coal-measures are fairly regular, and, near Orepuki, there is nothing to support the suggestion that it is a fault contact, nor is there any evidence of an overlap on to the granite. The Orepuki Series extend over the Tertiary surface and overlap on to the igneous complex, resting on the fairly

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