Kawhia Harbour Research Articles

A giant Oligocene fossil penguin from the North Island of New Zealand

ABSTRACT Penguins (Sphenisciformes) have arguably the most complete and continuous fossil record of any avian clade, offering an ever-improving understanding of penguin phylogeny, biogeography, and the evolution of wing-propelled diving. Yet, our knowledge of the precise body proportions of stem-group penguins remains poor due to a dearth of articulated specimens. Here, we describe Kairuku waewaeroa sp. nov., a new giant penguin species from the Glen Massey Formation (Whaingaroan stage, 34.6–27.3 Ma). The holotype skeleton, discovered in Kawhia Harbour, North Island, New Zealand, is one of the most complete skeletons of a giant penguin yet uncovered. Our phylogenetic analysis recovers a clade uniting the New Zealand endemics Kairuku waewaeroa, Kairuku waitaki, and Kairuku grebneffi, which is supported by synapomorphies including a stout femoral shaft and tibiotarsi with a distinctly convex medial condyle. Kairuku waewaeroa is unique among stem penguins in having elongate tibiotarsi, revealing a new long-legged stem penguin body plan. The discovery of Kairuku waewaeroa contributes yet another penguin species to an Oligocene avifauna for Zealandia that is replete with giant birds.

Lepidium peregrinum (Brassicaceae)—a new addition to the New Zealand flora

Lepidium peregrinum (Brassicaceae) is recorded for the first time in New Zealand, where it was collected from O Wiwi Ku, an island in Kawhia Harbour, western North Island. Although native to eastern Australia, L. peregrinum was initially described from plants collected wild in the United Kingdom. This and other European occurrences are believed to have arisen from seed trapped within sheep fleeces imported from Australia. It is suggested that the sole New Zealand occurrence also results from the importing of goods directly from Sydney, New South Wales, to Kawhia by Maori during the 1830s to 1860s. A description of L. peregrinum based on New Zealand specimens is provided. The biostatus of L. peregrinum is reviewed and, despite being treated as naturalized, it is concluded that the species poses no threat to the indigenous New Zealand flora. As a threatened Australian plant, recommendations are made about the conservation management of the species in New Zealand.

Flank Margin Cave Development in Telogenetic Limestones of New Zealand

Coastal limestone outcrops, typically with advanced levels of diagenetic maturity (i.e., are telogenetic carbonates), were ex­amined on NorthIsland (Raglan Harbour, Kawhia Harbour, Napier, and Waipu Cove) and SouthIsland (Pohara, Paturau River, Punakaiki, Kakanui, and Kaikoura), New Zealand, to de­termine if flank margin caves, produced by mixing dissolution, were present. In coastal settings, caves in carbonate rock can be the outcome of pseudokarst process, primarily wave erosion, as well as karst processes not associated with freshand sea-water mixing suchas epikarst features and conduit-flow stream caves. Flank margin caves were successfully differentiated from other cave types by the following criteria: phreatic dissolutional mor­phologies at the wall rock and chamber scales; absence of high-velocity, turbulent-flow wall sculpture and sediment deposits; and lack of integration of adjacent caves into a continuous flow path. The active tectonics of New Zealand creates a variable sea-level situation. The relatively short time of sea-level stability lim­its the size of the New Zealand flank margin caves compared to tectonically-stable environments, suchas the Bahamas, where glacioeustasy alone controls sea-level stability. Uplift events can be identified as slow and steady when the flank margin caves are uniformly elongated in the vertical direction, and episodic when the flank margin caves show widening and tube develop­ment at discrete horizons that cut across rock structure. New Zealand flank margin caves contain information on uplift dura­tion and rates independent of other commonly used measures, and therefore can provide a calibration to other methods.

A coniferous tree stump of late Early Jurassic age from the Ferrar Basalt, Coombs Hills, southern Victoria Land, Antarctica

An upright, partly rooted tree stump preserved within a late Early Jurassic basalt flow of the Ferrar Group, Coombs Hills, is described from southern Victoria Land, Antarctica. The wood structure allows the tree to be identified as a conifer (possibly Podocarpaceae) that from the stump diameter of 35–40 cm was c. 24 m tall. The possibly transported tree may have survived the lava flow because the stump was waterlogged or already mineralised. Conifers of similar age (early Middle Jurassic) are known from fossil forests at Curio Bay and Kawhia Harbour in New Zealand, and this discovery extends the known distribution of forests living in moderately warm, humid climates at very high southern latitudes during the late Early Jurassic.

Isotopic evidence for Late Jurassic–Early Cretaceous climate change

Strontium-, oxygen- and carbon-isotope ratios have been determined from Late Jurassic–Early Cretaceous belemnites from the Volga Basin, Russia, and Kawhia Harbour, New Zealand. 87Sr/ 86Sr ratios derived from well-preserved belemnites from the Volga Basin support a Middle Tithonian age derived from the analysis of the endemic ammonite fauna. The Kawhia Harbour section records a gradual rise in 87Sr/ 86Sr values and in comparison with the published 87Sr/ 86Sr curve suggests that the lower part of the section is latest Oxfordian in age, whilst the upper part of the section correlates well with the biostratigraphic correlation suggestion of an Early–Middle Tithonian age. Although the published strontium calibration curve shows a degree of scatter, our new data confirm the uniform rise in 87Sr/ 86Sr values from the Late Jurassic into the Early Cretaceous. Such an increase may result from either a decrease in mid-oceanic ridge spreading and/or an increase in weathering rates and flux of radiogenic strontium, although a eustatic drop in sea level and concurrent Western Cordillera uplift suggests that weathering may have been the controlling factor of Late Jurassic seawater strontium-isotope composition. Palaeotemperatures derived from the well-preserved belemnite δ 18O carb values from the Volga Basin indicate that the Middle Volgian (Late Kimmeridgian) was warm (∼14–20°C), followed by a slight cooling and a subsequent gradual increase to the Jurassic–Cretaceous boundary. The δ 18O carb values from New Zealand (located at a palaeolatitude of ∼80°S), if interpreted in terms of palaeotemperature, indicate a high degree of variability. Such variability may not be related to palaeotemperature, but to changes in oceanic chemistry resulting from the formation and dissolution of an ice-sheet and/or snow during the Oxfordian–Kimmeridgian. Carbon-isotope trends for the Late Jurassic show a fall in values from the Oxfordian with lowest values occurring in the Early–Middle Tithonian, before rising but without reaching values obtained in the Oxfordian. The overall low δ 13C carb may be related to a global increase in continental weathering and/or upwelling of cooler oceanic water enriched in oxidised organic carbon ( 12C-enriched).

Synonymy and stratigraphic ranges of Belemnopsisin the Heterian and Ohauan Stages (Callovian‐Tithonian), southwest Auckland, New Zealand

Belemnopsis stevensi, Belemnopsis maccrawi, and Belemnopsis sp. A (Challinor 1979a) are synonymous; B. stevensi has priority. New belemnite material from Kawhia Harbour and Port Waikato, together with graphical study methods, indicates that many small fragmentary specimens associated with B. stevensi in the lower part of its stratigraphic range are probably the same taxon. B. stevensi has been found only in the Middle and Upper Heterian Stage (Lower Kimmeridgian) at Kawhia and only in the Lower Ohauan Stage (Upper Kimmeridgian) at Port Waikato. This apparently disjunct distribution is attributed to poor exposure in the relevant sections. Belemnopsis kiwiensis n.sp., Belemnopsis cf. sp. B, Belemnopsis sp. B, Belemnopsis sp. D, and Belemnopsis spp. are associated with B. stevensi near the lowest known point in its stratigraphic range. The distribution of stratigraphically useful belemnites within the Heterian and Ohauan Stages is: Conodicoelites spp. (Lower Heterian; correlated with Lower Callovian); Belemnopsis annae (Lower and Middle Heterian; Lower Callovian/Lower Kimmeridgian); Belemnopsis stevensi (Middle Heterian/Lower Ohauan; Kimmeridgian); Belemnopsis keari (Upper Heterian; Kimmeridgian); Belemnopsis trechmanni (Upper Ohauan; Upper Kimmeridgian/Middle Tithonian). The apparently extreme range of Belemnopsis annae remains unexplained. Klondyke Sandstone (new) is recognised as the basal member of Moewaka Formation (Port Waikato area).

New Jurassic Ammonitina from New Zealand: Bathonian‐Callovian Eurycephalitinae

Several new ammonite assemblages are described from the uppermost Temaikan and basal Heterian regional stages of New Zealand, Auckland Province, consisting mainly of the east Pacific Eurycephalitinae (Family Sphaeroceratidae). Four successive faunas are distinguished in the upper Awakino valley: all include the Andean genus Araucanites, here occurring with both sex‐morphs. Fauna 1 includes Araucanites awakino n. sp., Iniskinites cf. crassus Riccardi & Westermann, and Xenocephalites grantmackiei Westermann & Hudson ?/m × Lilloettia aff. steinmanni (Spath) ?/M—latest Bathonian; Fauna 2 includes Araucanites postawakino n. sp. and Xenocephalites cf. stipanicici Riccardi et al.—Early/earliest Callovian; Fauna 3 with Araucanites ponganui n. sp., Iniskinites gr. cepoides (Whiteaves), and Choffatia gr.furcula (Neumayr)—Early Callovian; Fauna 4 with Araucanites spellmani n. sp.—? Middle Callovian. The Oraka Sandstone at Kawhia Harbour is now placed entirely in the uppermost Bathonian and Lower Callovian (i.e., with Faunas 1 and 2). Ammonites previously identified with Kimmeridgian taxa—that is, "Epimayaites”, “Epicephalites”, and "Subneumayria"—are now classified as microconchs of Araucanites and with macroconchs of Lilloettia and Iniskinites. The superjacent Ohineruru Formation contains a typically Indo‐Pacific fauna of Late Oxfordian to Early Kimmeridgian age, based on Sulaites heteriensis (Stevens) [ex Idoceras], a close relative of S. gerthi Oloriz & Westermann from New Guinea, and, above, Paraboliceras macnaughti (Stevens) [ex Kossmatia]. The interval Upper Callovian to Middle Oxfordian cannot be documented by ammonites in New Zealand, suggesting a hiatus between Oraka and Ohineruru Formations, marked by the Captain King's Shellbed. Other useful index fossils are forms of the bivalve Retroceramus. The first occurrence of R. galoi (Boehm) defines the base of the Heterian regional stage, but its New Zealand occurrence is much earlier than in Indonesia (Middle Oxfordian). Furthermore, first occurrence is diachronous according to ammonite biostratigraphy even in Auckland Province, that is, between Faunas 3 and 4 in Awakino valley and in Fauna 2 at Kawhia Harbour. Regional and local facies control is indicated. On the other hand, Fauna 2 includes R. stehni Damborenea known from the Early/earliest Callovian of the Andes.

Vegetation communities of a high palaeolatitude Middle Jurassic forest in New Zealand

Fossil evidence of a high southern palaeolatitude (approximately 75–78° South) Middle Jurassic (Temaikan) forest from Gondwana is investigated from the Murihiku Supergroup exposed at Kawhia Harbour, North Island, New Zealand. Horizons of fossilised tree stumps, preserved in growth position and rooted within coal-rich layers at bedding contacts, are exposed within cross-bedded medium-grained sandstone on the present-day shore platform. Interbedded siltstone and fine-grained sandstone contain terrestrial palynomorphs, fossilised leaves and other macroflora material (including cones and seeds). The sediments are interpreted as three fluvial facies ( vegetated bar top, major sheet flood and channel fill and migration) within a sandy braided river palaeoenvironment. The fossil flora suggest the original vegetation was multi-layered and dominated by gymnosperms and ferns. Lycopods, bryophytes, fungi and algae also grew on the forest floor and in bar top pools. A model of plant communities is presented reflecting changing habitats up the side of interdistributary bars. The model is based on stratigraphically successive taphocenoses within vegetated bar top facies and the preferred growing conditions and life forms of comparable modern relatives. Lycopods and bryophytes on the saturated channel banks became less frequent higher up the bar on the damp, partially drained soil preferred by ferns and cycad trees. Favouring the drier bar top, arborescent gymnosperms thrived around probably ephemeral pools containing lycopods, bryophytes and algae. The characteristics of this fossil forest at Kawhia Harbour compare well to a similar Middle Jurassic site at Curio Bay in South Island, New Zealand, and other high southern palaeolatitude fossil floras from the late Mesozoic. A humid, warm climate with high average annual rainfall and large storms is interpreted from the Kawhia Harbour fossil forest for the New Zealand Middle Jurassic. These palaeoclimatic conditions are comparable to the modern mesothermal zone.

Belemnite biostratigraphy of the New Zealand Late Jurassic Mangaoran (Early Puaroan) Substage and the Puaroan Stage revisited

Hibolithes arkelli Stevens, H. marwicki Stevens, and H. mangaoraensis Stevens are common fossils with partly overlapping stratigraphic ranges in the Mangaoran Substage, of the Late Jurassic Puaroan Stage. Studies based on samples from known stratigraphic positions in the Kawhia Harbour sequence provide data for comparative purposes. The three species are similar in several measurable features. Mean values differ only slightly, and dispersions are partially concurrent. The specific identification of fragmentary specimens may be difficult, and that of pre‐adult fragments particularly so. The stratigraphic proximity of the morphologically similar Upper Ohauan Hibolithes kaimangoensis Challinor is a complicating factor. The stratigraphic succession of H. arkelli, H. marwicki, and H. mangaoraensis can be demonstrated in several sections in the Kawhia and Port Waikato regions. Hibolithes arkelli grantmackiei Challinor, currently used to define the base of the Puaroan Stage, is a composite taxon some members of which are here re‐identified as H. arkelli and H. mangaoraensis. The remainder are re‐described as Hibolithes sp A. Its morphology and stratigraphic range are poorly known and the species is unsuitable as a stage boundary marker. Hibolithes arkelli regularly appears near the base of the Puaroan Stage as presently defined and a formal re‐definition based on that taxon is proposed. Although this alters the faunal basis of the stage, the position of its base remains unchanged.

Geology and geochemistry of Gannet (Karewa) Island, Tasman Sea: A rift‐related nephelinitic tuff ring

Gannet (Karewa) Island is a small (0.06 km2) island situated in the Tasman Sea, northwest of Kawhia Harbour, western North Island, New Zealand. It consists of well indurated, palagonitic tuff and lapilli tuff with subordinate scoriaceous basalt bombs and blocks (Karewa Volcanic Formation) which are considered to represent the eroded remnants of a tuff ring. Evidence for this includes such features as cross‐bedded coarse ash units, lensoidal beds, U‐channels, and impact sag structures. Juvenile bombs and blocks consist of fine‐grained olivine nephelinite, comprising microphenocrysts of olivine and acicular clinopyroxene, set in a devitrified glassy groundmass. Accidental lithic fragments are abundant and include ultramafic xenoliths (up to 5 cm), sedimentary rock fragments (15 cm), and hornblende andesite crystal tuff (20 cm). The island has previously been mapped as part of the Alexandra Volcanics, but the major and trace element abundances and isotopic composition indicate that it has lower SiO2 (40–42%) and higher TiO2 (3.2–3.5%), MgO (14–16%),Nb(110–125 ppm), Zr(307–343 ppm)andLREE abundances, and lower 87Sr/86Sr (0.7030) and relatively higher SNd (+6.8) compared with the alkaline intraplate basaltic fields of Okete, Ngatutura, or South Auckland, or the convergent margin basalts of the Alexandra Volcanics and Egmont. Juvenile olivine nephelinite bombs have been dated by K‐Ar determination at 0.51 ± 0.05 Ma, much younger in age than the nearby Alexandra Volcanics (2.74–1.60 Ma) or offshore middle‐late Miocene volcanics. Gannet Island is located approximately above the Taranaki Fault, which is shown on offshore seismic profiles as extending northwards, parallel to the coast off western North Island. Movement on the Taranaki Fault, which forms the eastern boundary of the North Taranaki Graben, ceased in the late Miocene. Since the Pliocene, this region of western North Island has been in extension, and hence Gannet Island is interpreted on geochemical constraints and tectonic position to be an isolated rift‐related volcano. This supports the interpretation that the North Taranaki Graben formed as a back‐arc rift rather than an actively spreading back‐arc basin. The nephelinites of Gannet Island, and also those in the South Auckland volcanic field, which have similar ages, lie just to the northwest of the limit of seismic activity on the subducting Pacific plate, and are probably close to the most distal expression of the contemporary plate boundary.

Belemnites from the upper Ohauan stage at Kawhia Harbour, New Zealand

Abstract At least five belemnite species, of mostly Middle Tithonian age, are present in the upper Ohauan Kinohaku Siltstone at Kawhia Harbour, New Zealand. Two are previously undescribed. They and three known taxa are described using modern methods. Belemnopsis aucklandica trechmanni is present through most of the upper Ohauan, Hibolithes minor (Hauer), Hibolithes kaimangoensis n. sp., Hibolithes otekensis n. sp., and Hibolithes (formerly Belemnopsis) spathi (Stevens) occur near the top of the stage.

Jurassic Pholadomyidae (Bivalvia) from New Zealand and New Caledonia

Abstract Fossil bivalves of the family Pholadomyidae are described from Jurassic sequences of the Murihiku T errane of New Zealand (Murihiku Supergroup) and New Caledonia (Baie de St‐Vincent Group). Four new species and two new subgenera are erected: Pholadomya (Pholadomya) oretiensis n. sp., Hettangian‐Sinemurian (Aratauran local stage); Pholadomya (P.) beaumontensis n. sp., probably Aalenian‐Callovian (Temaikan); Pholadomya (Kanakimya) uitoe n. subgen. et sp., Aalenian‐Callovian (Temaikan); and Pholadomya (Moewakamya) hudsoni n. subgen. et sp., Oxfordian (Heterian). An isolated specimen from the type Temaikan sequence (c. Aalenian), Kawhia Harbour, does not warrant formal naming but is closely related to P. oretiensis. Neither of the new subgenera is yet recognised elsewhere but an exhaustive review of relations within this large genus is long overdue. P. oretiensis and P. teaumontensis show some similarities with contemporary English species, but this is not thought to imply any particularly close evolutionary relationship. The presence of P. beaumontensis in strata in western Southland previously mapped as Permian supports earlier evidence from absolute dating and palynology for the Barretts Conglomerate being of Jurassic age.

Two new belemnites from the lower Ohauan (?middle Kimmeridgian) Stage, Kawhia Harbour, New Zealand

Abstract Dicoeliles kowhaiensis Challinor n. sp. and Belemnopsis rarus Challinor n. sp. are described from the middle Kowhai Point Siltstone at Kawhia Harbour. D. kowhaiensis is sparsely distributed; B. rarus, as the name suggests, is rare. Most specimens studied were not found in situ and are damaged and incomplete.

Recognition and distribution of HeterianBelemnopsisin south-west Auckland

Belemnopsis annae, Belemnopsis maccrawi, and Belemnopsis keari are characteristic taxa of the Heterian stratotype at Kawhia Harbour, New Zealand. When morphological criteria are used, their recognition elsewhere can be difficult. Contrasts in body form are slight, and when collections consist of fragmentary specimens or of juveniles there is a strong possibility of misidentification. Statistical procedures based on apical line positions and on cross sectional shape provide a simple method of recognition. Supporting stratigraphic evidence is available. The succession of taxa present in the Heterian stratotype can be recognised in the Port Waikato region, and two of them are shown to be widely distributed in south–west Auckland.

Proposal to redefine the puaroan stage of the New Zealand jurassic system

Abstract Buchia plicata occurs in the uppermost levels of the Puaroan stage, but was used by Marwick to define the base of the Puaroan. Modern research has thrown doubt on the basal Puaroan occurrences of B. plicata and indicated a need for redefinition of the Puaroan stage. Benthic fossils are sparsely distributed adjacent to the Ohauan-Puaroan boundary and the remains of non benthic forms, in particular belemnites, offer the greatest promise of providing a faunal basis for the boundary. Fossil1 collections from topmost Ohauan and basal Puaroan strata indicate that a homotaxial faunal succession of belemnite guards is present in several sections in south-west Auckland. The belemnite Hibolithes arkelli grantmackiei Challinor appears consistently near the base of most sections and is an appropriate fossil with which to define the base of the Puaroan Stage. Faunal correlation between Puaroan sections at Kawhia Harbour and Port Waikato can now be made with reasonable confidence and stratigraphic continuity b...

Variation inHibolithes arkelli arkelli—2

Abstract Multivariate statistical tests on random samples of the belemnite Hibolitbes arkelli arkelli Stevens drawn from localities at Puti Point (Kawhia Harbour) and Ngapohoi Stream (east of Kawhia Harbour) show that the measurement vectors of certain parameters are highly likely to be from populations with different variance-covariance matrices. The vectors of means are different too, although no individual measurement produces a significant mean difference. The evidence is strong that the Puti Point specimens are from a population which is clearly different from the population found at Ngapohoi Stream. The means, standard deviations, and correlations of the measured variables were studied in detail. The main conclusion is that there is a significant age difference in the two populations and that the Ngapohoi Stream sample was collected from beds which are geologically older that those at Puti Point. Statistical differences between samples are of an evolutionary nature; differences within samples are at least partly ontogenic.

Biostratigraphy of the Ohauan and Lower Puaroan stages (Middle Kimmeridgian to Lower Tithonian), Port Waikato region, New Zealand, with description of a newBelemnopsis

Abstract Biostratigraphy of the Ohauan and lower Puaroan stages in the Port Waikato region is described with particular reference to belemnite content. Hibolithes arkelli Stevens and Hibolithes marwicki marwicki Stevens, both characteristic taxa of the lower Puaroan at Kawhia Harbour, are recorded from the Port Waikato sequence for the first time. Belemnop.ris stevens; n. sp. is described from lower Ohauan strata. Correlation with the coastal section at Kawhia Harbour is possible on a biostratigraphical basis but lithological correlation is more difficult. Faunal elements are similar to those described from Kawhia Harbour but some elements are missing. This factor, together with reduced stratigraphic distances between some faunal range-zones, suggests that an ullconformity or condensed sequence occurs within the Ohauan/basal Puaroan part of the Port Waikato sequence. The base of the Ohauan stage at Port Waikato is relocated 200–250 m above its previously mapped position. The base of the Puaroan stage is r...

A fossil penguin bone from Kawhia, New Zealand

Abstract The two ends of a femur similar in size to that of Archaespheniscus lowei Marples, but possibly representing an unnamed small ,pecies of Palaeeudyptes, from the Whaingaroan Stage of Motutara Point, Kawhia Harbour, are the first Tertiary penguin fossils recorded from the North Island of New Zealand.

Hokonui Stratigraphy of the Awakino-Mahoenui area, South West Auckland

Summary Trias-Jura rocks of the Awakino-Mahoenui area constitute part of the western limb of the Kawhia Syncline in its southern-most exposure. The syncline is approximately meridional in alignment and pitches northwards at a low angle. Strata have dips varying from nearly vertical in the west of the area to about 15° east at the top of the succession in the east. The strata form the Herangi Range which originated as a north-south fold or the peneplained surface resulting from the post-Hokonui orogeny. This fold is believed to be faulted on its western edge, but while this is also the case on the eastern limb farther north, in the Awakino-Mahoenui area faulting seems not to have occurred at the surface. The oldest beds exposed are 7,000 ft of Oretian (lower Carnian) which are believed to be the equivalent of 2,100 ft of strata above the Moeatoa conglomerate at Marakopa. These are followed conformably by 2,200 ft of Otamitan strata (Carnian), 1,800 ft to 2,300 ft of Warepan (Norian), 2,800 ft of Otapirian (Rhaetian), 2,500 ft of Aratauran (Hettangian-Sinemurian), about 2,000 it of Ururoan (Pliensbachian-Toarcian), about 4,000 ft of Temaikan (Bajocian-Oxfordian), and 4,300 ft of Heterian (Kimeridgian), giving a total of 14,000 ft of Triassic and 12,000 it of Jurassic strata. Beds of. Heterian age make up a greater thickness than in other North Island localities. On the south shore of Kawhia Harbour there are some 500 ft of beds, including Temaikan, between the type Temaikan and the black, gritty sandstone of Totara Peninsula, whereas below the Palmer Creek Shellbed (the same horizon as the black sandstone) there are 3,500 ft of Heterian strata. The sediments are mainly bedded sandstones and siltstones, with scattered and widespread tuffaceous material. True conglomerates are rare and thin, but grits are more common. Carbonaceous beds occur in the Otapirian and Heterian and accompany thin coals in the Oretian, but no non-marine beds typical of the type Temaikan sequence were observed in strata of Temaikan age. Calcareous beds are found at various levels in the Jurassic sequence but only Aratauran strata were found to contain microfossils. Marine fossils are widespread and allow closer subdivision of some stages. Warepan beds contain numerous forms of Monotis whose stratigraphic distribution enables four subdivisions to be recognized in the area. M. richmondiana is found in the older beds; M. calvata. is confined to the upper Warepan; while middle Warepan strata contain a very varied fauna including forms recognized by Trechmann (1918) and others recorded from New Caledonia (Avias, 1953). The Otapirian Stage is divided after Campbell (1956) although his basal fauna was not recognized in the area. Ururoan beds are divided into those containing Pseudaucella (Pliensbachian) and those with Dactylioceras (Toarcian). This ammonite was not found, but the fauna enables ready correlation wi'th the beds containing it at Ururoa Point.

Borehole survey of North Island Ironsands from New Plymouth to Kaipara Harbour

Summary A reconnaissance survey in 1949 indicates that on the beaches between the mouth of the Mokau River, 56 miles north of New Plymouth, and the township of Muriwai, 35 miles north-west of Auckland City, there is available over 600 million tons of magnetically recoverable ironsand assaying 58% Fe. The most important deposit, that near Lake Taharoa, just south of Kawhia Harbour, ccntains some 173 million tons of ironsand in concentrations varying from 41% Fe in dune sands to 87% Fe in beach concentrates.