Depositional environment of the Branch Sandstone and correlative sequences: Late Cretaceous changes in relative sea level in the East Coast Basin of New Zealand

<p>The Branch Sandstone is located within an overall transgressive, marine sedimentary succession in Marlborough, on the East Coast of New Zealand’s South Island. It has previously been interpreted as an anomalous sedimentary unit that was inferred to indicate abrupt and dramatic shallowing. The development of a presumed short-lived regressive deposit was thought to reflect a change in relative sea level, which had significant implications for the geological history of the Marlborough region, and regionally for the East Coast Basin. The distribution and lithology of Branch Sandstone is described in detail from outcrop studies at Branch Stream, and through the compilation of existing regional data. Two approximately correlative sections from the East Coast of the North Island (Tangaruhe Stream and Angora Stream) are also examined to provide regional context. Depositional environments were interpreted using sedimentology and palynology, and age control was developed from dinoflagellate biostratigraphy. Data derived from these methods were combined with the work of previous authors to establish depositional models for each section which were then interpreted in the context of relative sea level fluctuations. At Branch Stream, Branch Sandstone is interpreted as a shelfal marine sandstone, that disconformably overlies Herring Formation. The Branch Sandstone is interpreted as a more distal deposit than uppermost Herring Formation, whilst the disconformity is suggested to have developed during a fall in relative sea level. At Branch Stream, higher frequency tectonic or eustatic sea-level changes can therefore be distinguished within a passive margin sedimentary sequence, where sedimentation broadly reflects subsidence following rifting of the Tasman Sea. Development of a long-lived disconformity at Tangaruhe Stream and deposition of sediment gravity flow deposits at Angora Stream occurred at similar times to the fall in relative sea level documented at the top of the Herring Formation at Branch Stream. These features may reflect a basin-wide relative sea-level event, that coincides with global records of eustatic sea level fall.</p>

Depositional environment of the Branch Sandstone and correlative sequences: Late Cretaceous changes in relative sea level in the East Coast Basin of New Zealand

<p>The Branch Sandstone is located within an overall transgressive, marine sedimentary succession in Marlborough, on the East Coast of New Zealand’s South Island. It has previously been interpreted as an anomalous sedimentary unit that was inferred to indicate abrupt and dramatic shallowing. The development of a presumed short-lived regressive deposit was thought to reflect a change in relative sea level, which had significant implications for the geological history of the Marlborough region, and regionally for the East Coast Basin. The distribution and lithology of Branch Sandstone is described in detail from outcrop studies at Branch Stream, and through the compilation of existing regional data. Two approximately correlative sections from the East Coast of the North Island (Tangaruhe Stream and Angora Stream) are also examined to provide regional context. Depositional environments were interpreted using sedimentology and palynology, and age control was developed from dinoflagellate biostratigraphy. Data derived from these methods were combined with the work of previous authors to establish depositional models for each section which were then interpreted in the context of relative sea level fluctuations. At Branch Stream, Branch Sandstone is interpreted as a shelfal marine sandstone, that disconformably overlies Herring Formation. The Branch Sandstone is interpreted as a more distal deposit than uppermost Herring Formation, whilst the disconformity is suggested to have developed during a fall in relative sea level. At Branch Stream, higher frequency tectonic or eustatic sea-level changes can therefore be distinguished within a passive margin sedimentary sequence, where sedimentation broadly reflects subsidence following rifting of the Tasman Sea. Development of a long-lived disconformity at Tangaruhe Stream and deposition of sediment gravity flow deposits at Angora Stream occurred at similar times to the fall in relative sea level documented at the top of the Herring Formation at Branch Stream. These features may reflect a basin-wide relative sea-level event, that coincides with global records of eustatic sea level fall.</p>

Compensation for Marine Ecological Damage: From ‘Tasman Sea’ to ‘Sanchi’

The research on marine ecological compensation is aimed to protect the marine environment and sustainably utilize marine ecosystem services, and is an important institutional instrument for coordination of the relationships among environmental, economic and other social interests. The legal mechanism of marine ecological compensation should be an important way to effectively deal with the contradictions (for examples: the value loss of marine ecosystem services, destruction of marine biodiversity, etc.) in marine eco-environmental protection. This paper firstly introduces the case of the “Sanchi” ship accident, which is regarded as the first collision case of a tanker carrying gas condensate in world shipping history, and also provides a detailed analysis of the “Tasman Sea” ship case which is regarded as the first compensation claim for marine ecological damage in China, and makes some related discussions on marine ecological compensation concerning the two cases. Then, the paper probes into the research theme from four aspects: China’s legislative deployment, the legal connotation of marine ecological damage (including the current legal status of compensation claims, subjects of compensation claims, the compensation scope and the evaluation system.), major challenges in legal practice, and remediation of marine ecological damage in China. Finally, the paper provides some suggestions on marine ecological damage compensation for the final settlement in the “Sanchi” case, and tries to explore the future trend of the research theme based on the China’s marine strategy.

Late Quaternary vegetation and climate history reconstructed from palynology of marine cores off southwestern New Zealand

<p>Little is known about how mid-latitude Southern Hemisphere terrestrial vegetation responded during glacial terminations and the warmer phases of the Late Quaternary, especially beyond the last glacial cycle where records are commonly fragmentary and poorly-dated. The timing, magnitude and sequence of environmental changes are investigated here for terminations (T) I, II and V and their subsequent warm interglacials of MIS 1, 5e and 11 by direct correlation of terrestrial palynomorphs (pollen and spores) and marine climate indicators in marine piston cores MD06-2990/2991 recovered from the East Tasman Sea, west of South Island, New Zealand. The climate there is strongly influenced by the prevailing mid-latitude westerly wind belt that generates significant amounts of orographic rainfall and the proximity of the ocean which moderates temperature variability. Chronological constraint for the cores is provided by δ¹⁸O stratigraphy, radiocarbon chronology and the identification of two widespread silicic tephra horizons (25.6 ka Kawakawa/Oruanui Tephra (KOT); ~345 ka Rangitawa Tephra (RtT)) sourced from the central North Island. Similar vegetation changes over the last two glacial cycles at MD06-2991 and in the adjacent nearby on land record of vegetation-climate change from Okarito Bog permit transfer of the well resolved Marine Isotope Stage (MIS) chronology to Okarito for the pre radiocarbon dated interval (~139-28 ka). Placing both sequences on a common age scale nonetheless assumes there is minimal lag between pollen production and final deposition on the seafloor. However, the timing of Late Pleistocene palynomorph events and KOT between independently dated marine and terrestrial sedimentary sequences are found in this study to be indistinguishable, which supports the direct transfer of terrestrially derived ages to the marine realm and vice versa. Vegetation change in southwestern New Zealand is of similar structure during T-I and T-II, despite different amplitudes of forcing (i.e., insolation rise, CO₂ concentrations). In a climate amelioration scenario, shrubland-grassland gave rise to dominantly podocarp-broadleaf forest taxa, with accompanying rises in mean annual air temperature (MAAT) estimated from Okarito pollen typically synchronous with nearby ocean temperatures. The T-II amelioration commenced after ~139 ka in response to increasing boreal summer insolation intensity, with prominent ocean-atmosphere warming over the period from ~133-130 ka. In contrast, northern mid-high latitude paleoclimate records display cooling over Heinrich Stadial 11 (~135-130 ka), and are prominently warm from ~130-128 ka, while southwestern New Zealand and the adjacent ocean displays cooling. Such millennial-scale climate asynchrony between the hemispheres is most likely a result of a systematic, but non-linear re-organisation of the ocean-atmosphere circulation system in response to orbital forcing. The subsequent MIS 5e climatic optimum in Westland was between ~128-123 ka, with maximum temperatures reconstructed in the ocean and atmosphere of 2.5°C and 1.5°C higher than present. Similarities revealed between land and sea pollen records in southwestern New Zealand over the last ~160 ka offer confidence for assessing vegetation and climate for older intervals, including T-V/MIS 11, for which no adjacent terrestrial equivalents currently exist. Vegetation change over T-V is similar to T-II and T-I, with southern warming antiphased with northern mid-high latitude cooling. Tall trees and the thermophilous shrub Ascarina lucida define interglacial conditions in the study region between ~428-396 ka. East Tasman Sea surface temperatures rose in two phases; 435-426 ka (MIS 12a-MIS 11e) and 417-407 ka (MIS 11c climatic optimum), reaching at least ~1.5-2°C warmer than present over the latter. Similarly, Ascarina lucida dominance over MIS 11c is akin to that displayed during the early Holocene climatic optimum (11.5-9 ka) in west-central North Island, where MAAT average ~3°C higher today. This contrasts markedly with the dominance of the tall tree conifer Dacrydium cupressinum for the Holocene (MIS 1) and last interglacial (MIS 5e) in southwestern New Zealand. Biogeographic barriers are proposed to have inhibited the migration of species from more northerly latitudes better adapted to warmer climatic conditions over MIS 5e and MIS 11.</p>

Late Quaternary vegetation and climate history reconstructed from palynology of marine cores off southwestern New Zealand

<p>Little is known about how mid-latitude Southern Hemisphere terrestrial vegetation responded during glacial terminations and the warmer phases of the Late Quaternary, especially beyond the last glacial cycle where records are commonly fragmentary and poorly-dated. The timing, magnitude and sequence of environmental changes are investigated here for terminations (T) I, II and V and their subsequent warm interglacials of MIS 1, 5e and 11 by direct correlation of terrestrial palynomorphs (pollen and spores) and marine climate indicators in marine piston cores MD06-2990/2991 recovered from the East Tasman Sea, west of South Island, New Zealand. The climate there is strongly influenced by the prevailing mid-latitude westerly wind belt that generates significant amounts of orographic rainfall and the proximity of the ocean which moderates temperature variability. Chronological constraint for the cores is provided by δ¹⁸O stratigraphy, radiocarbon chronology and the identification of two widespread silicic tephra horizons (25.6 ka Kawakawa/Oruanui Tephra (KOT); ~345 ka Rangitawa Tephra (RtT)) sourced from the central North Island. Similar vegetation changes over the last two glacial cycles at MD06-2991 and in the adjacent nearby on land record of vegetation-climate change from Okarito Bog permit transfer of the well resolved Marine Isotope Stage (MIS) chronology to Okarito for the pre radiocarbon dated interval (~139-28 ka). Placing both sequences on a common age scale nonetheless assumes there is minimal lag between pollen production and final deposition on the seafloor. However, the timing of Late Pleistocene palynomorph events and KOT between independently dated marine and terrestrial sedimentary sequences are found in this study to be indistinguishable, which supports the direct transfer of terrestrially derived ages to the marine realm and vice versa. Vegetation change in southwestern New Zealand is of similar structure during T-I and T-II, despite different amplitudes of forcing (i.e., insolation rise, CO₂ concentrations). In a climate amelioration scenario, shrubland-grassland gave rise to dominantly podocarp-broadleaf forest taxa, with accompanying rises in mean annual air temperature (MAAT) estimated from Okarito pollen typically synchronous with nearby ocean temperatures. The T-II amelioration commenced after ~139 ka in response to increasing boreal summer insolation intensity, with prominent ocean-atmosphere warming over the period from ~133-130 ka. In contrast, northern mid-high latitude paleoclimate records display cooling over Heinrich Stadial 11 (~135-130 ka), and are prominently warm from ~130-128 ka, while southwestern New Zealand and the adjacent ocean displays cooling. Such millennial-scale climate asynchrony between the hemispheres is most likely a result of a systematic, but non-linear re-organisation of the ocean-atmosphere circulation system in response to orbital forcing. The subsequent MIS 5e climatic optimum in Westland was between ~128-123 ka, with maximum temperatures reconstructed in the ocean and atmosphere of 2.5°C and 1.5°C higher than present. Similarities revealed between land and sea pollen records in southwestern New Zealand over the last ~160 ka offer confidence for assessing vegetation and climate for older intervals, including T-V/MIS 11, for which no adjacent terrestrial equivalents currently exist. Vegetation change over T-V is similar to T-II and T-I, with southern warming antiphased with northern mid-high latitude cooling. Tall trees and the thermophilous shrub Ascarina lucida define interglacial conditions in the study region between ~428-396 ka. East Tasman Sea surface temperatures rose in two phases; 435-426 ka (MIS 12a-MIS 11e) and 417-407 ka (MIS 11c climatic optimum), reaching at least ~1.5-2°C warmer than present over the latter. Similarly, Ascarina lucida dominance over MIS 11c is akin to that displayed during the early Holocene climatic optimum (11.5-9 ka) in west-central North Island, where MAAT average ~3°C higher today. This contrasts markedly with the dominance of the tall tree conifer Dacrydium cupressinum for the Holocene (MIS 1) and last interglacial (MIS 5e) in southwestern New Zealand. Biogeographic barriers are proposed to have inhibited the migration of species from more northerly latitudes better adapted to warmer climatic conditions over MIS 5e and MIS 11.</p>

Ocean and Terrestrial Response to a Pleistocene Warm Interglacial (MIS11) as Revealed by Pollen and Dinoflagellates from Marine Sediment Cores, South Island, New Zealand

<p>The response of the surface ocean and terrestrial climate in the New Zealand region to interglacial Marine Isotope Stage (MIS) 11 (423-380ka) is documented, using assemblages of fossilised marine algae (dinoflagellate cysts, or dinocysts) and spores/pollen from terrestrial plants, analysed from marine sediment cores. This work is underpinned by studies on the modern distribution of dinocysts, factors that influence their accumulation in marine sediment, and the use of dinocyst assemblages to quantify past sea surface temperature (SST). In the first of the modern-process studies, a dataset of modern sea-floor dinocyst assemblages from the Southern Hemisphere is collated, including new observations from the SW Pacific. Variations in the assemblages are related to environmental gradients. Cluster analysis reveals distinct biogeographic assemblage zones, individual taxa indicative of specific water masses are identified, while ordination of the databases indicates that the assemblages vary most with changes in SST. A second modern process study reports on the dinocyst assemblages from two time-incremental sediment traps (3 years of data) moored north and south of the Subtropical Front in the ocean east of New Zealand. This study provides observations of seasonal and inter-annual variability of dinocyst flux to the deep sea, which are used to identify possible biases in the sea-floor dinocyst assemblages. Observations from these first two studies are used in a systematic analysis of the strengths and weakness of using dinocyst assemblages to quantify SST in the SW Pacific. The best transfer function performance achieved was a root mean squared error of 1.47˚C, for an artificial neural network model, and the benefits in considering a range of model results are also established. Fossil records that document the oceanographic and terrestrial response to MIS11 are developed from two areas around New Zealand; (i) dinocysts assemblages are collected from the east Tasman Sea, from giant piston cores MD06-2987, -2988, and 2989, and (ii) dinocysts and pollen assemblages are analysed from Deep Sea Drilling Project (DSDP) Site 594, from the east of New Zealand. Dinocyst assemblages confirm that SST in the east Tasman Sea was ~2-3˚C warmer than the present during late MIS11 (415-400ka), while SSTs were slightly below modern levels during an early phase (428-415ka). Two assemblage – based productivity indices suggest that the elevated SSTs during MIS11 were accompanied by lower rates of primary productivity in the east Tasman Sea study area than the present. As in the east Tasman Sea, two distinct phases of MIS11 are recognised in both the dinocyst and pollen assemblages at DSDP 594. The dinocyst assemblages of late MIS11 are similar to, but qualitatively represent warmer waters than the Holocene. The succession of pollen assemblages during MIS12-11 is very similar to that observed during the previous two interglacials at this site (MIS1 and MIS5), with two notable variations: (i) the deglacial vegetation succession during MIS11 was prolonged, and (ii) the pollen assemblage representing the warmest forest type was also present for longer (ca. 15ky) than later interglacials. Changes in the pollen record during MIS11 at DSDP 594 correlate more closely to SST variations in the east Tasman Sea than to ocean variations at DSDP 594, suggesting that the eastern ocean had only limited influence on conditions on the adjacent landmass during MIS11.</p>

Ocean and Terrestrial Response to a Pleistocene Warm Interglacial (MIS11) as Revealed by Pollen and Dinoflagellates from Marine Sediment Cores, South Island, New Zealand

<p>The response of the surface ocean and terrestrial climate in the New Zealand region to interglacial Marine Isotope Stage (MIS) 11 (423-380ka) is documented, using assemblages of fossilised marine algae (dinoflagellate cysts, or dinocysts) and spores/pollen from terrestrial plants, analysed from marine sediment cores. This work is underpinned by studies on the modern distribution of dinocysts, factors that influence their accumulation in marine sediment, and the use of dinocyst assemblages to quantify past sea surface temperature (SST). In the first of the modern-process studies, a dataset of modern sea-floor dinocyst assemblages from the Southern Hemisphere is collated, including new observations from the SW Pacific. Variations in the assemblages are related to environmental gradients. Cluster analysis reveals distinct biogeographic assemblage zones, individual taxa indicative of specific water masses are identified, while ordination of the databases indicates that the assemblages vary most with changes in SST. A second modern process study reports on the dinocyst assemblages from two time-incremental sediment traps (3 years of data) moored north and south of the Subtropical Front in the ocean east of New Zealand. This study provides observations of seasonal and inter-annual variability of dinocyst flux to the deep sea, which are used to identify possible biases in the sea-floor dinocyst assemblages. Observations from these first two studies are used in a systematic analysis of the strengths and weakness of using dinocyst assemblages to quantify SST in the SW Pacific. The best transfer function performance achieved was a root mean squared error of 1.47˚C, for an artificial neural network model, and the benefits in considering a range of model results are also established. Fossil records that document the oceanographic and terrestrial response to MIS11 are developed from two areas around New Zealand; (i) dinocysts assemblages are collected from the east Tasman Sea, from giant piston cores MD06-2987, -2988, and 2989, and (ii) dinocysts and pollen assemblages are analysed from Deep Sea Drilling Project (DSDP) Site 594, from the east of New Zealand. Dinocyst assemblages confirm that SST in the east Tasman Sea was ~2-3˚C warmer than the present during late MIS11 (415-400ka), while SSTs were slightly below modern levels during an early phase (428-415ka). Two assemblage – based productivity indices suggest that the elevated SSTs during MIS11 were accompanied by lower rates of primary productivity in the east Tasman Sea study area than the present. As in the east Tasman Sea, two distinct phases of MIS11 are recognised in both the dinocyst and pollen assemblages at DSDP 594. The dinocyst assemblages of late MIS11 are similar to, but qualitatively represent warmer waters than the Holocene. The succession of pollen assemblages during MIS12-11 is very similar to that observed during the previous two interglacials at this site (MIS1 and MIS5), with two notable variations: (i) the deglacial vegetation succession during MIS11 was prolonged, and (ii) the pollen assemblage representing the warmest forest type was also present for longer (ca. 15ky) than later interglacials. Changes in the pollen record during MIS11 at DSDP 594 correlate more closely to SST variations in the east Tasman Sea than to ocean variations at DSDP 594, suggesting that the eastern ocean had only limited influence on conditions on the adjacent landmass during MIS11.</p>

Sequent Economies in Kuku: A Study of a Rural Locality in New Zealand

<p>Today, the majority of travellers journeying in the North Island of New Zealand, from Wellington to points north, e.g. Palmerston North or Wanganui, travel the length of the Horowhenua coastal plain, which sole routeway is bordered by the Tararua foothills to the east and by the Tasman Sea to the west. At a point some 52 miles north of the capital city and approximately 4 miles south of Levin, the motorist passes over a white bridge near which stands a dairy factory, and at a distance, a Maori meeting house. At the end of the mile-long stretch of State highway, an elevated by-pass affords a view of fenced paddocks, closely-cultivated fields, a railway line and a river. (See frontispiece.) As such scenes are common on many lowland pockets of the North Island of New Zealand, they mean little to the average traveller who crosses the Ohau River and pursues his northward course.</p>

Sequent Economies in Kuku: A Study of a Rural Locality in New Zealand

<p>Today, the majority of travellers journeying in the North Island of New Zealand, from Wellington to points north, e.g. Palmerston North or Wanganui, travel the length of the Horowhenua coastal plain, which sole routeway is bordered by the Tararua foothills to the east and by the Tasman Sea to the west. At a point some 52 miles north of the capital city and approximately 4 miles south of Levin, the motorist passes over a white bridge near which stands a dairy factory, and at a distance, a Maori meeting house. At the end of the mile-long stretch of State highway, an elevated by-pass affords a view of fenced paddocks, closely-cultivated fields, a railway line and a river. (See frontispiece.) As such scenes are common on many lowland pockets of the North Island of New Zealand, they mean little to the average traveller who crosses the Ohau River and pursues his northward course.</p>

Planktic Foraminifera-Based Sea Surface Temperature Estimates and Late Quaternary Oceanography off New Zealand's West Coast

<p>Planktic foraminiferal assemblages were used to investigate the paleoceanography of the Eastern Tasman Sea over the last 480 kyrs (Marine Isotope Stages 12-1). One hundred and sixty-two faunas (96 picked and identified as part of this project (MIS 12-6) added to 66 census counts from Dr. M. Crundwell (MIS 6-1)) have been assembled from Marion Dufresne piston core MD06-2986 (~43˚ S. off New Zealand‟s west coast, 1477 m water depth). Faunal changes through the last five glacial-interglacial cycles are used to track surface water mass movement. Glacial periods are dominated by the eutrophic species Globigerina bulloides, with significant contributions from the temperate species Globoconella inflata. Temperate species Neogloboquadrina incompta and Gc. inflata dominate interglacials, with the former dominating the warmer parts and the latter dominating the cooler parts of the interglacials. Modern Analogue Technique (MAT) and an Artificial Neural Network (ANN) were used to estimate past sea surface temperatures (SST) based on the foraminiferal census counts data (23 species, ~46,000 specimens). SSTs show that MIS 12 was the longest, sustained cold period, while the coldest temperature was recorded in MIS 5d (~8º C). Interglacials MIS 11 and 5e are the two warmest stages of the record, with SSTs reaching ~18.5º C, about ~2º C warmer than present day. We find that contrary to either the western Tasman Sea or offshore eastern New Zealand, the eastern Tasman Sea has been fairly isolated from any major influx of subpolar or subtropical species carried in with surface water from either high or low latitude sources. Subtropical taxa abundance (Globigerinoides ruber, Neogloboquadrina dutertrei (D), Globigerinoides sacculifer, Globigerinella aequilateralis, Sphaeroidinellopsis dehiscens, Truncorotalia truncatulinoides (D), Beella digitata) is low (average ~0.6%) and only prominent during peak interglacials. Subantarctic taxa abundance (Neogloboquadrina pachyderma, Neogloboquadrina dutertrei (S)) is low (average ~5.1%), but significant, particularly in glacial periods. Comparison of faunal and SSTANN data along with ratios of Nq. pachyderma:Nq. incompta (previously referred to as coiling ratios of Nq. pachyderma) and absolute abundance of planktic productivity (a productivity proxy) suggest that the STF migrated northwards towards the site in all glacial periods, and may have moved over the site in MIS 12 and possibly MIS 5d. A latitudinal SSTANN 25 comparison between offshore eastern and western New Zealand reveals that MD06-2986 (~43º S) is most similar (~0.5º C) to ODP Site 1125 (~42º S). On the contrary, ODP Site 1119 (44º S) is ~5º C cooler than MD06-2986. This comparison highlights the significant changes in surface water masses off eastern New Zealand that exist in such a short span of latitude because of the influence of a complex submarine topography.</p>