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Glacial geologic studies in the Southern Hemisphere (SH) mid-latitudes (40-54°S) indicate renewed glacial activity in southern South America (Patagonia) and New Zealand's (NZ) South Island starting at ∼7 kyr, the so-called neoglaciation. Available data indicate that neoglacial advances in these regions occurred during a rising trend in atmospheric CO and CH concentrations, lower-than-present but increasing summer insolation and seasonality contrasts. In this paper we examine the climatological context in which neoglaciations occurred through analysis of the complete Paleoclimate Modelling Inter-comparison Project (PMIP2) database of simulations at 6 kyr for the SH. We observe that the amplitude of the annual insolation cycle in the SH did not change significantly at 6 kyr compared to the pre-industrial values, the largest difference occurring in autumn (MAM, negative anomalies) and spring (SON, positive anomalies). The simulated changes in temperatures over the SH respond to the insolation changes, with a 1-2 month delay over the oceans. This results in a reduced amplitude of the annual cycle of temperature and precipitation over most continental regions, except over Patagonia and NZ, that show a slight increase. In contrast, large-scale circulation features, such as the low and upper level winds and the subtropical anticyclones show an amplified annual cycle, as a direct response to the increased/decreased insolation during the transitional seasons SON/MAM. In the annual mean, there is a small but consistent equatorward shift of the latitude of maximum wind speed of 1-3° over the entire SH, which results in a small increase of wind speed over the South Pacific and Atlantic Oceans north of ∼50°S and a widespread decline south of 50°S. PMIP2 simulations for 6 kyr, indicate that in the annual mean, the SH mid-latitudes were colder, wetter and with stronger winds north of about 50°S. These conditions are consistent with the observed neoglacial advances in the region, as well as with terrestrial paleoclimate records from Patagonia that indicate cooling and a multi-millennial rising trend in Southern Westerly Wind intensity starting at ∼7.8 kyr. [ABSTRACT FROM AUTHOR]

Understanding past sea levels is essential to respond to the challenges of climate change. In the Pacific and Tasman, sea level has been up to 1.5 m higher during the mid-Holocene, similar to the predictions of some global warming models. Within New Zealand the knowledge of sea-level movements, especially during the recent past is poor, with the last major investigation being conducted 20 years ago. This paper reviews the state of local understanding of higher sea levels and suggests regions for further study and new methods of analysis to understand the nature of sea-level change in New Zealand. [ABSTRACT FROM AUTHOR]

It is suggested that Bayesian statistical methods for radiocarbon data interpretation, already widely used in archaeology, also have potential to improve the dating of tephra layers and hence enhance their use for tephrochronology. By re-analysing data from a recently published paper in which the authors sought to identify the calendar date of the eruption of fourteenth-century AD Kaharoa Tephra, a key marker in New Zealand prehistory, it is shown that Bayesian methods can be used to draw together a coherent collection of radiocarbon data, undertake formal outlier detection, and include prior information. Regardless of the calibration curve adopted, the distribution of likely dates for the Kaharoa eruption is multimodal. By including prior information from wiggle-matched dendrochronology, the uncertainty on the estimate of the calendar date is reduced from a range of about 100 years to about 25 years (i.e., 648–623 cal. BP, with modes at 638 and 632 cal. BP). Using sensitivity analysis, however, it is shown that such estimates are affected by the quality and nature of the prior information available. As a result, we urge tephrochronologists to seek fastidiously both high-quality radiocarbon data and reliable stratigraphic sequences that might inform future geochronological model building. [ABSTRACT FROM AUTHOR]

On rocky tectonic coasts, data from Holocene marine terraces may constrain the timing of coseismic uplift and help identify the causative faults. Challenges in marine terrace investigations include: (1) identifying the uplift datums; (2) obtaining ages that tightly constrain the timing of uplift; (3) distinguishing tsunami deposits from beach deposits on terraces; and (4) identifying missing terraces and hence earthquakes. We address some of these challenges through comparing modern beach sediments and radiocarbon ages with those from a trench excavated across three terraces at Aramoana, central Hikurangi Subduction Margin, New Zealand. Sedimentary analyses identified beach and dune deposits on terraces but could not differentiate specific environments within them. Modern beach shells yielded modern radiocarbon ages, regardless of position or species, showing age inheritance and habitat is likely not an issue when dating shells on these terraces. By integrating terrace mapping, stratigraphy, morphology, and radiocarbon ages we develop a conceptual model of coastal uplift and terrace formation following at least two, possibly three, earthquakes at 5490–5070, 2620–2180, and 950–650 cal. yr bp. A high step and time gap between the upper two terraces raises the possibility that at least one intervening terrace is completely eroded. The trench exposure also showed that terrace stratigraphy may differ from that inferred from surface geomorphology, with apparent beach ridges being of composite origin and draping of younger beach deposits on the outer edge of a previous terrace. Dislocation modelling and comparison of marine terrace and earthquake ages from ~4 km south and ≤ 73 km north confirms that the most likely earthquake source is the nearshore, landward‐dipping, Kairakau Fault. Alternative sources, such as multi‐fault ruptures of the Kairakau‐Waimārama faults or Hikurangi subduction earthquakes, and/or a combination of the two are also possible and should be examined in future studies. [ABSTRACT FROM AUTHOR]

Augustus Hamilton (1853-1913) was a New Zealand ethnologist and naturalist who amassed a significant collection of fossils, mostly of birds, during his career. Today, those fossils are housed in the Museum of New Zealand Te Papa Tongarewa (NMNZ). While some fossils have been catalogued and integrated into the collection of the NMNZ, a large part remained unsorted and uncatalogued. The present study brings an integrated view of Hamilton's collection at the NMNZ, highlighting the most significant fossils. In total, there are 3692 specimen lots collected by Hamilton in the NMNZ representing a large sample of taxa and a wide range of locations around Aotearoa New Zealand. Most fossils are of Holocene age and belong to birds. The collection includes type specimens, circa 250 specimen lots belonging to extinct species, and specimens belonging to otherwise poorly represented species in natural history collections. We hope that our study makes Hamilton's fossils visible and more readily available for future research. [ABSTRACT FROM AUTHOR]

Abstract: This paper applies meta-analysis techniques to a database of 401 14C-dated Holocene fluvial units in New Zealand. We use the database to produce a probability-based reconstruction of Holocene river behaviour at a national and regional scale. Records of river activity in northern (North Island) and southern (South Island) New Zealand are compared with independent hydro-climate proxy records that reflect regional, tropical and polar influences on Southern Hemisphere climate. During the Holocene, 12 multi-centennial length episodes of river activity and flooding were identified in the North Island, and in the South Island record 11 periods exceed the mean relative probability of activity. These records show that episodes of river activity have exhibited a predominantly out-of-phase relationship, suggesting the relationship between ENSO and SAM, and the relative dominance of the two modes, may be influencing Holocene river activity in New Zealand. The emerging pattern in the South Island Holocene fluvial record is one of increased river activity in response to enhanced westerly atmospheric circulation associated with a predominance of trough regime synoptic type (negative SAM-like circulation). In the North Island episodes of river activity are driven by increased meridional atmospheric circulation associated with blocking regime synoptic conditions (La Niña-like and positive SAM-like circulation). Analysis of floodplain sedimentation rates shows a rapid increase after ∼500 cal yr BP following the arrival of humans and the beginning of widespread deforestation. Regional climate complexity in New Zealand presents opportunities for palaeoclimate reconstruction, with the New Zealand fluvial 14C-database ideally placed to fill geographical gaps in the long-term hydrological record. [Copyright &y& Elsevier]

Abstract: Positive deviations from linear sea-level trends represent important climate signals if they are persistent and geographically widespread. This paper documents rapid sea-level rise reconstructed from sedimentary records obtained from salt marshes in the Southwest Pacific region (Tasmania and New Zealand). A new late Holocene relative sea-level record from eastern Tasmania was dated by AMS14C (conventional, high precision and bomb-spike), 137Cs, 210Pb, stable Pb isotopic ratios, trace metals, pollen and charcoal analyses. Palaeosea-level positions were determined by foraminiferal analyses. Relative sea level in Tasmania was within half a metre of present sea level for much of the last 6000yr. Between 1900 and 1950 relative sea level rose at an average rate of 4.2±0.1mm/yr. During the latter half of the 20th century the reconstructed rate of relative sea-level rise was 0.7±0.6mm/yr. Our study is consistent with a similar pattern of relative sea-level change recently reconstructed for southern New Zealand. The change in the rate of sea-level rise in the SW Pacific during the early 20th century was larger than in the North Atlantic and could suggest that northern hemisphere land-based ice was the most significant melt source for global sea-level rise. [Copyright &y& Elsevier]

Abstract: Diverse terrestrial palynomorph assemblages of Pleistocene to Recent age have been recovered from mainly marine sediment cores along the eastern New Zealand margin. These assemblages record a range of environmental changes including climate, deforestation, reforestation, rates of erosion, sediment provenance and age, volcanic activity, Polynesian and European settlement, strength and direction of ocean currents, astronomical cyclicity, and other major events many of which can be correlated with shorter onshore terrestrial sequences. As such, pollen yields valuable information on the dynamic New Zealand landscape, which is of particular relevance to a source-to-sink approach. This paper provides an integrated summary of published and unpublished late Pleistocene palynological studies off eastern North Island, New Zealand that gives context for an analysis of cores within and marginal to the Waipaoa Sedimentary System. Pollen assemblages faithfully reflect the last glacial vegetation dominated by grass- and shrub-land species together with elevated Tertiary pollen from enhanced erosion of the regolith. The glacial termination and Holocene were marked by establishment of podocarp forest, a mid-Holocene disappearance of sediment-trapping mangroves, and introduction of distal pollen with establishment of coastal current systems under rising sea level. These natural signals are overprinted by abrupt changes in pollen species caused by volcanic eruptions. Finally, endemic forest and shrub pollen were markedly reduced with human colonisation, associated land use changes and introduction of exotic species. [Copyright &y& Elsevier]

Coasts in tectonically active regions face varying threat levels as land subsides or uplifts relative to rising sea levels. We review the processes influencing relative sea-level change in New Zealand, and the geological context behind ongoing land movements, focussing on major population centres. Whilst Holocene sea levels have been reconstructed using a variety of techniques, recent work uses salt-marsh microfossil assemblages to reconstruct relative sea-level changes over the past few centuries. For the twentieth century, these proxy-based studies often show enhanced rates of sea-level rise relative to tide-gauge observations. The effects of tectonic subsidence must be considered, alongside vertical and dating uncertainties in the sea-level reconstructions. Global Positioning Systems (GPS) observations for the past few decades show that vertical land movement (VLM) may be influencing rates of relative sea-level rise. However, the short period of GPS observations, during which trends and rates have varied at some localities, raises questions over the longer-term contribution of VLM to sea-level change over the past few centuries and for future projections. We argue that high-resolution palaeo-sea-level reconstructions from salt-marsh sedimentary sequences can help to answer these questions regarding the interplay between sea-level change and VLM at key locations. [ABSTRACT FROM AUTHOR]

The Wairarapa Valley possesses strong ecological, economic and cultural heritage in New Zealand; however, it has also been extensively modified by human land-use practices. Despite the value of the Wairarapa Valley's natural heritage, little has been done to quantify anthropogenic impacts. We integrate ‘paleo’ and modern analyses of sediment deposition and assess major changes in Lake Wairarapa's depositional environment. Accumulation rates and grain-size statistics indicate that a major natural disturbance occurred at 2.5 cal kyr BP, whereas charcoal counts register the regional impact of Polynesian forest clearing and GIS analysis quantifies the reduction of Lake Wairarapa's surface area following the Lower Wairarapa Valley Development Scheme. Critically, areas with historically slow accumulation rates are now depositional zones and areas with historically high accumulation rates are now losing sediment. This study illustrates how recent modifications to New Zealand lakes can be set in a long-term context, enabling direct comparisons between the impacts of human and natural processes. [ABSTRACT FROM AUTHOR]

Three paleo-embayments on the southwest side of the uplifted Ahuriri Inlet, Hawkes Bay, contain complex interfingering sequences of Holocene terrestrial and saltmarsh peat and intertidal shelly sand and mud. We use 295 foraminiferal samples from 45 short cores (up to 8 m deep) to reconstruct the paleoenvironmental history of the bays. We infer that the strongest influence on their paleoenvironmental history was 8–10 m of net tectonic subsidence since 7.3 ka, which provided the accommodation space for sediment deposition prior to the c. 1.5 m of uplift in the AD 1931 Hawkes Bay Earthquake. Much of the subsidence appears to have occurred in eight large co-seismic events (0.4–2 kyr recurrence time) which caused marine transgressions of varying amounts into each bay. Sea-level changes (eustatic and isostatic) have been a secondary driver over the middle–late Holocene with an interval (c. 2.6–1.7 ka) of widespread erosion or slow sedimentation, caused by a sea-level fall of c. 1 m following the middle Holocene highstand. The interval of fastest sedimentation and maximum marine transgression occurred within the last 1 kyr and was driven by increased tectonic subsidence, rising sea level and enhanced compaction of thicker sequences of Holocene sediment, particularly peat. The supply of fluvial mud and cliff-eroded sand was the main, relatively constant source of clastic sediment. Airfall and reworking of three pumiceous tephras had a minimal impact on the paleoenvironments of the bays. [ABSTRACT FROM PUBLISHER]

Pollen and spore analysis is the most successfully used palaeobotanical discipline for reconstructing Holocene vegetation and climate history throughout the world. Subantarctic islands are very specific areas. They are located in the circum-Antarctic Southern Ocean in latitudes that are under strong influence of the southern westerly winds, and are characterised by a treeless, phanerogam-poor flora. Palynological research on many of these islands has resulted in diverging conclusions about how to infer climate history from pollen data. In this study we compare pollen data with macrofossil data on the one hand, and the palaeoenvironmental history based on a multiproxy record on the other hand, of two peat sequences from two different subantarctic islands, South Georgia and Île de la Possession (Îles Crozet). We conclude that palynology must be used with caution as a proxy for climate change on these islands, especially when no other proxy data are available. The upland–lowland principle, as it has been applied in pollen studies in the South Indian Ocean islands, results in erroneous conclusions about climate change on Île de la Possession. More palaeoclimatic multiproxy and pollen studies, in combination with pollen–vegetation relationship studies, can, however, contribute to a more reliable model of how to interpret pollen data in the Subantarctic. We want to stress that our conclusions are only based on Holocene records. Consequently, the question remains if palynology can be used as a palaeoclimatic proxy when climatic changes were more pronounced such as during the last glacial–interglacial transition. [ABSTRACT FROM PUBLISHER]

Three new species: Opalia (Pliciscala) flemingi (late Nukumaruan-early Castlecliffian, OIS 71-29?, Wanganui); Kuroshioturris putere (Opoitian-Waipipian, Westland and Hawke's Bay), Antimelatoma waimea (Kapitean-Opoitian, Westland); two new genera: Cryptofusus (Turbinellidae) for New Zealand species formerly referred to Pleia Finlay (Australian); Onoketoma (Conidae, Raphitominae) for 'Insolentia' solitaria King, bathyal Nukumaruan, Palliser Bay. Xymene (sensu stricto; separated again from Axymene, Xymenella and Zeatrophon) is useful biostratigraphically in near-shore facies: X. drewi (Hutton) (based on Marwick's lectotype), Mangapanian-late Nukumaruan; X. expansus (Hutton), late Nukumaruan-early Castlecliffian (to OIS 19); X. plebeius (Hutton), OIS 17-Recent. New fossil records from Pleistocene (OIS 7) deposits at Hokianga Harbour, Northland: Agnewia tritoniformis (Blainville), Hydatina physis (Linne), Philine tepikia Rudman. Other biostratigraphically useful species: Zeatrophon bonneti (Cossmann) (Nukumaruan-OIS 9; 7?); Aeneator delicatulus Powell, Buccinulum caudatum Powell (both OIS 25-19, 17?). New synonymy: Otahua Marwick, 1948 = Bedeva Iredale, 1936; Cominella (Eucominia) marlboroughensis Powell = C. elegantula (Finlay), Nukumaruan-Recent; Antiguraleus Powell, 1942=Propebela Iredale, 1918; Antiguraleus depressipirus (Beu) = Propebela ula (Watson); Oenopota Morch, 1853 is possibly an earlier name for Liracraea Odhner, 1924, but Liracraea is retained; Antimelatoma ahiparana and A. otagoensis of Powell = A. buchanani (Hutton); Tritonoturris Dall, 1924=Asperdaphne Hedley, 1922; most Australasian 'Asperdaphne' species are assigned to Pleurotomella Verrill. Taxonomy revised: Cirsotrema zelebori (Dunker); Opalia (Nodiscala) nympha (Hutton) (Mangapanian-Nukumaruan); Acirsa cookiana (Dell, 1956) (OIS 23-Recent); Cominella (Eucominia) incisa (Hutton), Nukumaruan, Hawke's Bay; Euthria pangoides (Beu), Waipipian; Iredalula striata (Hutton), Kapitean(?)-Castlecliffian (-OIS 11) distinguished from I. alticincta (Murdoch & Suter), Nukumaruan-Recent; Ponderia zealandica (Hutton) (OIS 13-Recent); Amalda (Baryspira) olsoni Beu, Nukumaruan; Kuroshioturris angustata (Powell), Mangapanian-Recent; Austrotoma aguayoi (Carcelles) (Recent, SW Atlantic); Struthiolariopsis ferrieri (Philippi), Cretaceous, Quiriquina, Chile (Conoidea); Mitrellatoma angustata (Hutton), Nukumaruan; Gymnobela gypsata (Watson), Recent, E New Zealand, removed from Paracomitas; Paracomitas protransenna (Marshall & Murdoch) (Nukumaruan), P. gemmea (Murdoch) (Castlecliffian) and P. augusta (Murdoch & Suter) (=P. augusta powelli Dell; Recent); Aoteadrillia wanganuiensis (Hutton) (=chordata Suter and many other synonyms; Nukumaruan-Recent), A. finlayi (Powell) and A. apicarinata (Marshall & Murdoch) (Nukumaruan); Bulla quoyii Gray (OIS 7-Recent); Bulla australis Ferussac, Atlantic,=B. mabillei Locard; Philippia lutea (Lamarck), Nukumaruan-Recent. [ABSTRACT FROM AUTHOR]

Three new species: Grandicrepidula hemispherica (Nukumaruan, S Hawke's Bay), Pelicaria granttaylori (Mangapanian-early Nukumaruan, Wanganui - Hawke's bay), Pelicaria arahura (Waipipian-early Mangapanian, Westland and Hawke's Bay). Drawings of marine species in Smith's (1874) three plates of New Zealand molluscan types are republished. Further Australian molluscs in Wanganui Basin: Sabia australis (Lamarck), Clanculus plebejus (Philippi), both early Nukumaruan. Further northern New Zealand mollusc in Wanganui Basin: Stephopoma roseum (Quoy & Gaimard), OIS 13, 9. Distinctive gastropods extinct at end Nukumaruan: Struthiolaria frazeri (Hutton), Taxonia suteri (Marwick). Taniella planisuturalis (Marwick) (Opoitian-Nukumaruan, southern NZ) and Trivia (Ellatrivia) zealandica (Kirk) (Nukumaruan, Hawke's Bay-Wanganui; Castlecliffian, North Canterbury) occur in Castlecliffian (OIS 15?) rocks at Whakatane. Cantharidella tessellata (A. Adams) and Risellopsis varia (Hutton), formerly Haweran, are recorded from Nukumaruan and Castlecliffian rocks, respectively. New fossil late Nukumaruan-early Castlecliffian records listed from Mikonui-1 offshore well, Westland, include Malluvium calcareum (Suter) and 10 other species. Other biostratigraphically useful gastropods: Calliostoma (Maurea) nukumaruense (Laws) (Mangapanian-OIS 17); Argobuccinum pustulosum (Lightfoot), Semicassis labiata (Perry) (both earliest in OIS 7). New synonymy: Zeacumantus perplexus (Marshall & Murdoch) = Z. lutulentus (Kiener); Pelicaria vermis (Martyn) = all named Nukumaruan-Recent forms (other than P. rugosa (Marwick) and P. granttaylori n. sp.); Trivia flora Marwick = T. zealandica Kirk. Taxonomy revised: Zelippistes benhami (Suter) (OIS 13 & 9 at Wanganui), distinguished from Lippistes and Separatista; Stiracolpus species, informally; Maoricrypta profunda (Hutton), Waipipian-early Castlecliffian (- OIS 19); M. radiata (Hutton) (= incurva Zittel, = hochetteriana Woods, = wilckensi Finlay), (Middle Miocene?) Tongaporutuan-Opoitian; Eunaticina cincta (Hutton), holotype illustrated. [ABSTRACT FROM AUTHOR]

Barrier islands in sheltered settings are rare coastal geomorphic features. Here we present a case study of controls on the evolution of Tapora Island, North Island, New Zealand. Tapora Island is an active barrier island located opposite the entrance to the Kaipara Harbour on a high-energy coast. Subsurface facies form an aggradational barrier island succession from subtidal to subaerial elevations. This facies succession, combined with surface samples and geomorphic and geologic relationships, indicates that Tapora Island is the most recent barrier island at this location in the estuary and forms part of a prograded coast opposite the entrance. Wave data indicate that ocean swell waves penetrate the inlet for approximately 2 hours either side of high tide and are capable of transporting sand onto the island. The combined effects of swell waves, abundant sediment supply, and exposed aspect are the critical factors that have formed the barrier island. Despite the ''sheltered' estuarine setting, Tapora Island has formed under conditions that are more akin to open ocean coasts. The origin and development of Tapora Island broadly conforms to the accumulating barrier island model. [ABSTRACT FROM AUTHOR]

Composition of pre-settlement vegetation communities in the semi-arid Central Otago lowlands has been one of New Zealand's longstanding ecological puzzles. Uncertainty is due largely to a paucity of fossil data. Here, we provide new evidence for pre-settlement vegetation in the region based on analyses of plant macrofossils from 15 late Pleistocene and Holocene lowland sites. The assemblages represent two habitat types: wooded or partially wooded intermontane basin-floor wetlands, and low forest and/or shrubland habitats in the Kawarau and Clutha River gorges. In both habitat types, plant communities appear to have been predominantly woody, with significant components of herbaceous dicotyledons but few grasses. Both habitats seem to have undergone major post-settlement vegetation transformation. Several presently common taxa were rare or absent before human settlement, but others (including threatened spring annuals), now rare or extinct in the region, were formerly more common. [ABSTRACT FROM AUTHOR]

New Zealand Plio-Pleistocene bivalves revised: Limopsis, oysters, Pecten, Mactra (Maorimactra), Oxyperas, Lutraria, Austrovenus, Barnea, Myadora. Recent Indo-West Pacific Lutraria species are reviewed; the Red Sea-East African species L. (Lutraria) turneri Jousseaume resembles L. grandis (Hutton) (adopted in place of the junior homonym L. solida Hutton). Six new species proposed: Saccella maxwelli (Nukumaruan-Recent; known previously as S. bellula (A. Adams)); Limopsis turnbulli (Castlecliffian, OIS 15-20, SW Fiordland); Mactra (Maorimactra) marwicki (late Nukumaruan); M. (Maorimactra) carteri (early Castlecliffian, OIS 45?-19); Paphies delta (early Castlecliffian, OIS 31?-17); Myadora fortecosta (Kapitean-Opoitian). Further Indo-West Pacific warm-water migrants to New Zealand: Chama ruderalis Lamarck (Kapitean-Nukumaruan; = C. huttoni Hector, = C. pittensis Marwick); Lutraria (Psammophila) vellai (Beu) (late Nukumaruan); probably the two New Zealand late Neogene Ctenoides species. Further temperate migrant from the Atlantic: Lutraria (Lutraria) grandis. New synonymy: Xenostrobus Wilson = Limnoperna Rochebrune; Pecten novaezelandiae (Reeve) = all other New Zealand Pecten names; Serratina eugonia (Suter) = S. charlottae (E. A. Smith); Oxyperas komakoensis (Carter) = O. elongata (Quoy & Gaimard); Austrovenus stutchburyi (Wood) varies clinally over New Zealand, = A. aucklandica Powell, = A. crassitesta Finlay; Dosinia (Austrodosinia) horrida Marwick = D. anus (Philippi) (Nukumaruan-Recent); Panopea wanganuica Powell = P. smithae Powell (Nukumaruan-Recent); Myadora stephaniae Carter = M. waitotarana Powell (Waipipian-Nukumaruan). Distinctive bivalves extinct at the end of Nukumaruan time: Glycymeris shrimptoni Marwick, Patro undatus (Hutton), Lutraria (Lutraria) grandis, L. (Psammophila) vellai, Paphies crassiformis (Marshall & Murdoch), Eumarcia plana Marwick, Dosinia (Raina) nukumaruensis Marwick, Myadora waitotarana. Ennucula Iredale is used for Cenozoic and Recent Nuculominae; the application of Leionucula Quenstedt is unclear. Saccostrea glomerata (Gould) is used in place of S. circumsuta (Gould). Protothaca crassicosta (Deshayes) (formerly Haweran-Recent) is recorded from Opoitian rocks. Pecten novaezelandiae appeared below Potaka Tephra (1.0 Ma) during OIS 29 or earlier in eastern New Zealand, but just above the Brunhes-Matuyama transition (0.78 Ma, early OIS 19) in Wanganui Basin. Oxyperas elongata and Barnea similis (Gray) changed anagenetically through late Miocene-Pleistocene time; earlier forms are conspecific with Recent ones. Tawera Marwick is restored as a genus. Purpurocardia Maxwell is compared with Glans Megerle von Muhlfeld and Glyptoactis Stewart, and all are retained. Limnoperna huttoni (Suter) became extinct during OIS 13, Barytellina crassidens Marwick during OIS 9 or younger. Pholadidea tridens (Gray) (OIS 23 & 5a) and Ostreola virescens (Angas, 1868) are recorded fossil. [ABSTRACT FROM AUTHOR]

Three trenches excavated across the central portion of the right-lateral strike-slip Wairau Fault in South Island, New Zealand, exposed a complex set of fault strands that have displaced a sequence of late Holocene alluvial and colluvial deposits. Abundant charcoal fragments provide age control for various stratigraphic horizons dating back to c. 5610 yr ago. Faulting relations from the Wadsworth trench show that the most recent surface rupture event occurred at least 1290 yr and at most 2740 yr ago. Drowned trees in landslide-dammed Lake Chalice, in combination with charcoal from the base of an unfaulted colluvial wedge at Wadsworth trench, suggest a narrower time bracket for this event of 1811-2301 cal. yr BP. The penultimate faulting event occurred between c. 2370 and 3380 yr, and possibly near 2680 ± 60 cal. yr BP, when data from both the Wadsworth and Dillon trenches are combined. Two older events have been recognised from Dillon trench but remain poorly dated. A probable elapsed time of at least 1811 yr since the last surface rupture, and an average slip rate estimate for the Wairau Fault of 3-5 mm/yr, suggests that at least 5.4 m and up to 11.5 m of elastic shear strain has accumulated since the last rupture. This is near to or greater than the single-event displacement estimates of 5-7 m. The average recurrence interval for surface rupture of the fault determined from the trench data is 1150-1400 yr. Although the uncertainties in the timing of faulting events and variability in inter-event times remain high, the time elapsed since the last event is in the order of 1-2 times the average recurrence interval, implying that the Wairau Fault is near the end of its interseismic period. [ABSTRACT FROM AUTHOR]

A continuous ∼ 5280 calendar (cal.) yr long cryptotephrostratigraphic record of a peat core from northern New Zealand demonstrates that cryptotephra studies can enhance conventional tephra records by extending the known distribution of ash fall and enabling re-assessment of volcanic hazards. A systematic sampling strategy was used to locate peaks in glass-shard concentrations and to determine loci of individual geochemical populations, and a palynological method involving spiking samples with Lycopodium spores was adapted to facilitate accurate counting of glass-shard concentrations. Using glass-shard major element compositions, and a core chronology based on eight AMS 14C ages and two visible macroscopic tephra layers, Taupo Tephra (Unit Y) (1688–1748 cal. BP) and Tuhua Tephra (6800–7230 cal. BP) (2σ-age ranges), four cryptotephras were correlated with known eruptions: Whakaipo (Unit V) (2743–2782 cal. BP), Stent (Unit Q) (4240–4510 cal. BP), and Unit K (4970–5290 cal. BP), erupted from Taupo Volcanic Centre, and Whakatane Tephra (5470–5600 cal. BP) erupted from Okataina Volcanic Centre. Mixed glass populations were found in the core, most likely an artefact of post-depositional remobilization of shards vertically (both up and down) in the peat or on its surface by wind, or a result of closely spaced eruption events, or a combination of these. A secondary glass population identified within the macroscopic Taupo Tephra was tentatively attributed to either an earlier phase within that eruption or to mixing with a slightly older Taupo-derived eruptive or (less likely) a currently unknown Okataina-derived eruptive. These results indicate that, in the absence of continuous cryptotephrostratigraphic analysis, a peak in shard concentrations may not in itself be indicative of the 'true' stratigraphic (ie, isochronous) level of a tephra layer. For cryptotephra studies of peat cores, we recommend (1) using a detailed sampling strategy for the analysis of distal tephra-derived glass to detect and account for any mixed populations and possible vertical spread of glass shards through the peat, and (2) analysing more shards from larger samples to help 'capture' sparsely represented cryptic andesitic tephra deposits. [ABSTRACT FROM AUTHOR]

Lichenometric dating studies using the yellow-green Rhizocarpon subgenus at the Eugenie, Hooker, Mueller and Tasman Glaciers in Mt Cook National Park, Southern Alps, New Zealand, reveal a 'Little Ice Age' maximum during the mid-eighteenth century (around AD 1725–1740). Lichenometric dating curves, constructed for Mueller Glacier in a preliminary study, were modified using local control points at the other glaciers. Modification was necessary because of variations in local ecological conditions. The 'Little Ice Age' chronology is similar for three out of the four glaciers studied. All except Tasman Glacier underwent a major glacier front oscillation directly following the 'Little Ice Age' maximum. After a slow but constant retreat during the second half of the eighteenth and the first half of the nineteenth centuries, the glaciers experienced major readvances during the second half of the nineteenthcentury (around AD 1860 and 1890/95), and during the early decades of the twentieth century. Tasman Glacier, as the exception, returned to its 'Little Ice Age' maximum frontal position during the late nineteenthcentury, overtopping pre-existing 'Little Ice Age' moraines, and therefore preventing detailed dating of these moraines. Differences in dating from previous lichenometric studies may be due to the different methods used. [ABSTRACT FROM AUTHOR]

Auckland Island is a small uninhabited Subantarctic island south (c.51°S) of the New Zealand mainland. It is the southernmost outpost of tall forest in the southwest Pacific. Pollen analysis of two closely adjacent peat cores near tree-line documents climate change and forest dynamics during the Lateglacial and Holocene. After the retreat of glaciers before 15 000 14 C yr BP, mountain tundra communities dominated on mineral soils under a cooler (c.3°C lower) climate than now. By 11 000 14 C yr BP, a transition to Chionochloa antarctica grassland and peaty soils was complete, and by 10 000 14 C yr BP shrub/grassland became dominant. Forest tree species (Metrosideros umbellata, Dracophyllum longifolium and Raukaua simplex) spread slowly from 10–000 14 C yr BP, but did not form tall forest until 5500–4000 14 C yr BP, despite southern ocean temperatures being warmer in the early Holocene. We suggest that warm, cloudy, low-radiation environments inhibited forest growth during the early Holocene in this intensely oceanic setting, through promoting saturated soils and reducing net photosynthesis. It was only in the later Holocene, when increased westerly windflow brought sunnier, although cooler and windier, climates, that forest expansion occurred on sheltered lowland sites. The forest at the study site collapsed to scrub at least twice within the last 2000 years, most likely because of extended periods of saturated soils. [ABSTRACT FROM AUTHOR]

Pollen diagrams from four sites along an altitudinal sequence on Mt Hauhungatahi support fossil wood data (Ogden et al., 1997) in suggesting a fluctuating Holocene tree-line not exceeding the altitude reached in the early Holocene. Tree-line forest at 1340–1390 m during the periods 10 100–7500 and 5400–3800 cal. BP was associated with patchy Subalpine scrub communities above and below this altitude. Rapid decline of this Halocarpus-Phyllocladus forest at c. 7500 cal. BP, and again c. 3800 cal. BP was probably due to volcanism. During 7500–5400 and 3800–1718 cal. BP tree-line forest was replaced by Subalpine scrub. The failure of forest to replace scrub during these two periods implies a long-lasting influence of the event which destroyed the forest, a continuation of disturbance events, or changed environmental conditions. After the Taupo volcanic eruption (1718 cal. BP) expansion of Libocedrus indicates an upwards movement of forest species into Subalpine scrub, followed by a decline. Volcanism has probably affected the vegetation of Mt Hauhungatahi directly and indirectly (through effects on soil drainage) throughout the Holocene. Results are consistent with increased climatic variability since 7500 cal. BP, and support the hypothesis that disturbance events can have persistent long-term effects on community composition and species distribution patterns. [ABSTRACT FROM AUTHOR]

One straw stalactite and three stalagmites from the Waitomo district of North Island, New Zealand, were examined for stable isotopes of oxygen and carbon with a view to interpreting their palaeoclimate signal. Dating was by uranium series and AMS [sup 14]C for the stalagmites and by gamma-ray spectrometry for the straw. Records were thus established for about 100 years for the straw and 3.9, 10.1 and 10.2 ka for the stalagmites. The range of variability in δ[sup 18] Oc and δ[sup 13] Cc this century is about two-thirds of that experienced over the entire Holocene, and is most simply explained in terms of the oceanic source area of rain. Stable isotope variations in three stalagmites show some general similarities, but have significant differences in detail, which underlines the necessity to base palaeoclimatic interpretations on more than one speleothem record. The δ[sup 18] Oc of each stalagmite varies positively with temperature, indicating the dominance of the ocean source of evaporation in determining the isotopic composition of precipitation and hence speleothem calcite in the Holocene. This conclusion is contrary to that of other authors working in New Zealand, who identified a negative relationship between δ[sup 18] Oc and temperature, while examining time periods extending across the Last Glacial Maximum. It is concluded here that, whereas the ice volume effect dominates the large climatic shifts of glacial-interglacial amplitude, the oceanic source effect becomes more important during the period of relatively stable sea level during the Holocene. Results also indicate a late-Holocene altitudinal effect of 0.2‰ δ[sup 18] Oc per 100 m and an associated temperature relationship of about 0.26‰ per °C. The average of two records identifies the postglacial climatic optimum to lie in the interval from prior to 10 ka BP to 7.5 ka BP, when δ[sup 18] Oc values were up to 0.6‰ less negative than present, implying an average annual mean temperature that was up to 2.3°C warmer. The average of three speleothem records for the last 3900 years reveals the coldest period of the Holocene to have occurred about 3 to 2 ka BP, when δ[sup 18]Oc values were typically 0.4‰ more negative than present and average temperatures may have been 1.5°C cooler. Mean annual temperature variability of about 2°C was sometimes experienced in little more than 100 years. [ABSTRACT FROM AUTHOR]