Hugh Grenfell

Auckland Museum

Sudden changes in microfossils and lithologies in Holocene sediments of a former tidal inlet on the Hikurangi subduction margin provide evidence of 10 large earthquakes. Studies were focused in three former embayments where intertidal shelly sediment interfingers with freshwater and salt-marsh peat. Paleoelevation histories were reconstructed using...

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 t...

Foraminiferal faunas in 29 short cores (maximum depth 7 m) of estuarine and coastal wetland sediment were used to reconstruct the middle–late Holocene (last 7 ka) elevational history on the southern shores of Poverty Bay, North Island, New Zealand. This coast is on the southwest side of a rapidly subsiding area beneath western Poverty Bay. Modern A...

Canonical correspondence analysis indicates that the distribution of Neogene benthic foraminiferal faunas (>63 µm) in seven DSDP and ODP sites (500-4500 m water depth) east of New Zealand (38-51°S, 170°E-170°W) is most strongly influenced by depth (water mass stratification), and secondly by age (palaeoceanographic changes influencing faunal compos...

Four-hundred and fifty-nine species of marine biota (154 gastropods, 74 bivalves, 42 seaweeds, 40 foraminifera, 34 ostracods, 25 crabs and shrimps, 16 amphipods, 10 echinoderms, 10 chitons, 9 isopods, 9 polychaetes, 7 barnacles and smaller numbers of other groups) are recorded from a 4 km long stretch of coast around Whangapoua Beach, north-east Co...

[1] Investigations in long-term instrumental tidal records reveal that 20th century sea level along the coast of New Zealand is rising at 1.46 ± 0.10 mm/yr in agreement with the regional rates from southern Australia and Tasmania. We extend the advanced altimeter-gauge approach of combining satellite altimetry and tide gauge data with constraint eq...

Census counts (.63 mm) of 461 species in 361 samples are used as the basis for recognizing and mapping associations of deep-sea benthic foraminifera (50–5000-m depth) around New Zealand, southwest Pacific (28–60uS, 155uE–170uW). Fourteen faunal associations are identified by cluster analysis with five of these subdivided into 20 subassociations. Th...

Modern analog faunal distributions are increasingly being used in fossil foraminiferal studies to provide quantitative estimates of past environmental conditions, requiring an accurate assessment of modern taphonomic assemblages. A fundamental issue with such an approach is the differentiation of live versus dead foraminifera in the modern assembla...

At Shag River estuary, North Otago, New Zealand, parts of an Archaic moa-hunter occupation site (AD 1340–1410) lie beneath 50 cm of saltmarsh sediment at a modern elevation of 0.3 m below mean high water. Fossil saltmarsh foraminiferal assemblages in the overlying cored sediment provide high-tidal palaeo-elevation estimates (Modern Analogue Techniq...

The present study aimed to extract a sea-level history from northern New Zealand salt-marsh sediments using a foraminiferal proxy, and to extend beyond the longest nearby tide-gauge record. Transects through high-tidal salt marsh at Puhinui, Manukau Harbour, Auckland, New Zealand, indicate a zonation of dominant foraminifera in the following order...

Porangahau, southern Hawkes Bay, lies above the Hikurangi Subduction Zone in the transition zone between strong and weak plate interface coupling. This coastal area is unusual in the absence of uplifted Holocene coastal terraces or active fault traces. Holocene estuarine foraminiferal faunas in five short cores in the southern part of the Porangaha...

Planktic foraminiferal assemblages in a composite section from two cores (MD06-2989/2986) off the west coast of New Zealand's South Island (42–43.5°S) provide a 1myr (MIS 31–1) sea-surface temperature (SST) record (~3–4kyr resolution) in the Tasman Sea. A significant overall faunal change occurred near the end of the mid-Pleistocene Climate Transit...

Part 1. The Last Global Extinction in the Deep Sea During the Last Global Extinction (LGE) c. 20% (30 genera, 105 species) of cosmopolitan, mainly deep-sea (600–4000 m), benthic foraminiferal species (excluding unilocular taxa), belonging to seven families, became extinct. During this late Pliocene–middle Pleistocene interval (3.6–0.13 Ma), five fa...

Four hundred and eighty-one species of intertidal and shallow subtidal species are recorded from the Whananaki coast, east Northland. The dominant phylum is the Mollusca (360 species), which here has greater diversity than similar-sized areas on the North Island's west coast (150-238 species) or more sheltered east-coast harbours, such as Waitemata...

Three marine inlets across the southern Hikurangi margin, New Zealand, are investigated for evidence of palaeocoseismic subsidence, a signal associated with great subduction earthquakes. Microfossil analyses and radiocarbon-dated shells from core samples show that none of the sites have subsided since 2000 cal yr BP. Pauatahanui Inlet has remained...

This paper aims to establish whether contemporary salt-marsh foraminifera from eastern Tasmania are suitably related to elevation and can therefore be used to reconstruct past sea levels. A proxy reconstruction of recent sea-level change in Tasmania is potentially useful because in New Zealand a prominent early 20th century acceleration of sea-leve...

The shallow subtidal to intertidal sandy mudflats of an unusual, 6 km2, alternating tidal lagoon–brackish lake (Lake Onoke, New Zealand) has a remarkably consistent foraminiferal fauna dominated (.80%) by Miliammina fusca. During intervals when the gravel barrier across its mouth is closed, the salinity in the lake declines and the level may rise t...

Fossil foraminifera provide some of the most precise reconstructions of former Holocene sea-levels, but these are based on their narrow high tidal zonation. In this study we identify two foraminifera-based proxies for low tide levels in sheltered harbour or estuarine mudflats. One proxy is the increasing relative abundance of two calcareous foramin...

The shallow tidal Wairau coastal lagoons, New Zealand, are in a prime location for investigating the relative roles of tectonic and eustatic sea level on their palaeogeographic evolution. The Wairau lagoons are unique in New Zealand for their wide seasonal and tidal salinity range, from hyposaline (10—20 psu) to hypersaline (35—54 psu). Foraminifer...

This paper provides the first solid evidence in support of a century-old hypothesis that the mountainous Marlborough Sounds region in central New Zealand is subsiding. More recent hypotheses suggest that this may be a result of southward migration of a slab of subducted Pacific Plate causing flexural downwarping of the overlying crust in the vicini...

Taxonomy A total of 563 species is listed from deep water (>50 m) from the New Zealand Exclusive Economic Zone (EEZ). The 347 most common or distinctive species are fully illustrated and their diagnostic features outlined. Two new species are described: Ammoscalaria georgescotti n. sp. and Spiroplectammina carteri n. sp. When used in combination wi...

Ninety-five species and 19 genera of cosmopolitan, deep-sea benthic foraminifera belonging to the families Pleurostomellidae, Stilostomellidae and Nodosariidae, became extinct during the Late Pliocene–Middle Pleistocene. Only 50% of these (44 species) were present in the Pliocene or Pleistocene of the deep Mediterranean Sea (ODP Sites 654, 966, 967...

Ninety-five species and 19 genera of cosmopolitan, deep-sea benthic foraminifera belonging to the families Pleurostomellidae, Stilostomellidae and Nodosariidae, became extinct during the Late Pliocene-Middle Pleistocene. Only 50% of these (44 species) were present in the Pliocene or Pleistocene of the deep Mediterranean Sea (ODP Sites 654, 966, 967...

Uniquely in the Southern Hemisphere the New Zealand micro-continent spans the interface between a subtropical gyre and the Subantarctic Circumpolar Current. Its 20° latitudinal extent includes a complex of submerged plateaux, ridges, saddles and basins which, in the present interglacial, are partial barriers to circulation and steer the Subtropical...

The ecological impact from the establishment of dense intertidal beds of introduced Asian date mussels (Musculista senhousia) and cordgrass (Spartina alterniflora) in five northern New Zealand estuaries and harbours was documented in 2005–2006, using the fossil record of the shells of foraminifera, ostracods and molluscs in paired sediment cores an...

Uniquely in the Southern Hemisphere the New Zealand micro-continent spans the interface between a subtropical gyre and the Subantarctic Circumpolar Current. Its 20° latitudinal extent includes a complex of submerged plateaux, ridges, saddles and basins which, in the present interglacial, are partial barriers to circulation and steer the Subtropical...

One hundred and forty-eight species of benthic foraminifera are recorded from depths shallower than 80 m around the subantarctic Auckland (130 spp.) and Campbell (71 spp.) Islands, southwest Pacific. Comparisons with other circum-polar, subantarctic island groups suggest that they all have relatively low diversity, shallow-water benthic, foraminife...

Foraminiferal assemblages preserved in estuarine sedimentary sequences along the coast of South Otago, New Zealand, provide evidence for three Holocene fault-displacements and associated earthquakes within the 250 km-wide continental collision zone along the Australian-Pacific plate boundary. The modern analogue technique was used to estimate paleo...

Sixty-two species and 19 genera of elongate, cylindrical benthic foraminifera disappeared from the deep-sea in the south-east Atlantic (ODP Sites 1082 and 1083) and the Atlantic sector of the Southern Ocean (ODP Site 1088) during the Early and Middle Pleistocene as part of the global extinction of the families Pleurostomellidae, Stilostomellidae an...

Twenty percent (19 genera, 95 species) of cosmopolitan, deep-sea (500–4000 m), benthic foraminiferal species became extinct during the late Pliocene–Middle Pleistocene (3–0.12 Ma), with the peak of extinctions (76 species) occurring during the mid-Pleistocene Climate Transition (MPT, 1.2–0.55 Ma). One whole family (Stilostomellidae, 30 species) was...

The biodiversity and community structure of benthic foraminifera were estimated from 217 stations distributed in four geographic regions (north, south, east, west) around New Zealand. An analytical method accumulating sample values of species richness (S), the information function (H) and evenness (E) with increasing number of individuals (N) calle...

We investigate the combination of environmental factors that influence the distribution patterns of benthic foraminiferal tests (> 63 μm) in a topographically varied region crossed by both the Subtropical and Subantarctic Fronts, south-east of New Zealand. Seafloor sample sites, extending from outer shelf (50 m) to abyssal (5000 m) depths, are bath...

The microfossils in eight short sediment cores in Mahurangi Harbour, northern New Zealand, record major ecological changes since colonisation by Europeans. During the period of catchment deforestation (1850s-1900) these changes include increased sedimentation rates, decline of soft-shore molluscs, increased diatoms and seaward migration of brackish...

Twenty percent (19 genera, 95 species) of cosmopolitan, deep-sea (500-4000 m), benthic foraminiferal species became extinct during the late Pliocene-Middle Pleistocene (3-0.12 Ma), with the peak of extinctions (76 species) occurring during the mid-Pleistocene Climate Transition (MPT, 1.2-0.55 Ma). One whole family (Stilostomellidae, 30 species) was...

Northeast of New Zealand, nine benthic foraminiferal associations are recognized and mapped (50-3800 m depth) based on cluster analysis of faunal census data (> 63 mu m, 235 species, 56 samples). Similar associations are identified using cluster analysis based on the presence or absence of species. Canonical correspondence analysis shows that the a...

During the mid-Pleistocene Transition (MPT), 2 families, 14 genera and 41 species of benthic foraminifera (Extinction Group) declined in abundance (8-12 % of early Pleistocene benthic foraminiferal fauna) and finally disappeared at mid-bathyal depths in the Caribbean Sea (ODP Site 1000A, 916m depth), as part of the global extinction of at least 73...

Foraminiferal and diatom assemblages in 11 cores (3–7.5 m deep) of Holocene sediment from brackish marine Ahuriri Inlet in southern Hawke's Bay, New Zealand, provide a record of 8.5 m of subsidence followed by 1.5 m of uplift in the last 7200 cal years, in a region overlying the subduction zone between the Australian and Pacific Plates.Modern Analo...

Two short cores of late Holocene, low tidal, estuarine sediment from the sheltered fringes of the Auckland's Waitemata Harbor, New Zealand, record the following changes through time since human colonization: an abrupt decline and disappearance of marine molluscs, a major decline and virtual disappearance of ostracods, an abrupt decline in calcareou...

The pulsed decline and eventual extinction of 51 species of elongate, cylindrical deep-sea benthic foraminifera (Stilostomellidae, Pleurostomellidae, and some Nodosariidae) occurred at intermediate water depths (1145–2168 m, Sites 980 and 982) in the northern North Atlantic during the mid-Pleistocene transition (MPT, 1.2–0.6 Ma). In the early Pleis...

An open access copy of this article is available from the publishers website. The fossil foraminiferal faunas preserved in intertidal sediment in six cores document the impact of human activities on the ecosystems of the north-east arm of the Manukau Harbour, Auckland, New Zealand. They indicate that Polynesian forest clearance and horticulture had...

Benthic foraminiferal faunas from three bathyal sequences provide a proxy record of oceanographic changes through the mid-Pleistocene transition (MPT) on either side of the Subtropical Front (STF), east of New Zealand. Canonical correspondence analyses show that factors related to water depth, latitude and climate cycles were more significant than...

The pulsed decline and eventual extinction of 51 species of elongate, cylindrical deep-sea benthic foraminifera (Stilostomellidae, Pleurostomellidae, and some Nodosariidae) occurred at intermediate water depths (1145-2168 m, Sites 980 and 982) in the northern North Atlantic during the mid-Pleistocene transition (MPT, 1.2-0.6 Ma). In the early Pleis...

Fossil foraminiferal faunas were studied in four, short, late Holocene cores (two localities) from the low tidal, estuarine fringes of the Waitemata Harbour, which is surrounded by New Zealand's largest city, Auckland. All cores record similar major changes in their fossil content since the arrival of humans (ca. 1300 AD), with faunal changes conti...

The Bounty Trough, east of New Zealand, lies along the southeastern edge of the present-day Subtropical Front (STF), and is a major conduit via the Bounty Channel, for terrigenous sediment supply from the uplifted Southern Alps to the abyssal Bounty Fan. Census data on 65 benthic foraminiferal faunas (>63 μm) from upper bathyal (ODP 1119), lower ba...

Fossil foraminifera and diatoms are used to identify sudden, probably earthquake-related, elevational changes in three Holocene sedimentary sequences from the high-tidal fringes of Ohiwa Harbour, eastern Bay of Plenty, New Zealand. Modern analogue calibration sets of faunal and floral census data are used to estimate palaeosalinities and palaeotida...

Canonical correspondence analysis indicates that the distribution of Neogene benthic foraminiferal faunas (>63 μm) in seven DSDP and ODP sites (500–4500 m water depth) east of New Zealand (38–51°S, 170°E–170°W) is most strongly influenced by depth (water mass stratification), and secondly by age (palaeoceanographic changes influencing faunal compos...

In this study, morphometric analysis has been performed on 178 Ammonia specimens belonging to 12 different molecular types, plus non-sequenced type specimens of Ammonia beccarii and A. tepida. Molecular type distinction is based on phylogenetic analysis of 267 partial LSU rDNA sequences, obtained from 202 living Ammonia specimens, sampled in 30 loc...

Techniques for estimating tidal elevation and con” nement (proxy for salinity) using modern benthic foraminiferal census data from New Zealand harbours and lower-salinity estuaries are described and assessed for their utility for reconstructing the depositional settings of late-Holocene sequences. We describe a simple modern analogue technique for...

The Bounty Trough, east of New Zealand, lies along the southeastern edge of the present-day Subtropical Front (STF), and is a major conduit via the Bounty Channel, for terrigenous sediment supply from the uplifted Southern Alps to the abyssal Bounty Fan. Census data on 65 benthic foraminiferal faunas (>63 µm) from upper bathyal (ODP 1119), lower ba...

Paleobathymetric estimates based on fossil foraminiferal faunas play an important role in understanding the paleogeographic, structural, and burial history of New Zealand's most important hydrocarbon‐bearing sedimentary basin—the Taranaki Basin. Bathyal and abyssal estimates have large ranges of uncertainty, which might be improved using knowledge...

An open access copy of this article is available from the publishers website. Drillhole records of fossil Foraminifera and Mollusca, together with sparse tephra age control, document similar Holocene marine histories of two of Auckland's breached maars-Pukaki Lagoon, Manukau Harbour, and Onepoto Lagoon, Waitemata Harbour. Following eruption, both m...