scholarly journals University of Waikato Radiocarbon Dates I

Radiocarbon ◽  
1987 ◽  
Vol 29 (2) ◽  
pp. 263-301 ◽  
Author(s):  
Alan G Hogg ◽  
David J Lowe ◽  
Chris H Hendy
Keyword(s):  
New Zealand ◽  
Radiocarbon Dating ◽  
Late Quaternary ◽  
Scintillation Counting ◽  
University Staff ◽  
Radiocarbon Dates ◽  
Postgraduate Students ◽  
The North ◽  
National University ◽  
Vacuum Systems

The radiocarbon dating laboratory at Waikato was established in 1975, primarily as a research tool in the fields of geomorphology, volcanology, tephrostratigraphy, coastal studies, and paleolimnology, to cope with the increasing supply of late Quaternary lake sediment, wood, peat, and shell samples submitted by University staff and postgraduate students undertaking research in the North Island of New Zealand. The method employed is scintillation counting of benzene using the procedures and vacuum systems designed by H A Polach for the Australian National University (ANU) Radiocarbon Dating Research Laboratory (Hogg, 1982). This date list reports on samples submitted by University of Waikato researchers and assayed in the Waikato laboratory mainly between 1979 and 1985. Other dates on material submitted by individuals working in other organizations in New Zealand, and overseas, are to be reported later.

An Archaeomagnetic Study of Hangi Stones in New Zealand

2021 ◽  
Author(s):  
◽  
Rimpy Kinger
Keyword(s):  
New Zealand ◽  
Radiocarbon Dating ◽  
Principal Component ◽  
Blocking Temperature ◽  
Radiocarbon Dates ◽  
The North ◽  
Sw Pacific ◽  
Archaeomagnetic Dating ◽  
Show Evidence ◽  
Temperature Spectra

<p>Burnt or fired archaeological artefacts often retain a record of the magnetic field in which they were last heated and cooled. Over the past four years we have collected oriented hangi stones from 10 archaeological sites spread across the North and South Islands of New Zealand. The stones vary in lithology from andesites, originating from the central North Island volcanoes, favoured by Maori for their durability and with remanent magnetization up to 30 A/m, to sandstones and schists from the main axial ranges, with magnetizations as weak as 10-4 A/m. Radiocarbon dating of charcoal fragments retrieved from amongst the stones indicates that the sites span from ca. 1400 AD to the present.  In all cases, we have independently oriented and retrieved several stones, and we have made several samples from each stone, either by drilling (standard cylindrical samples) or sawing (pseudo-cubes) in the laboratory. We have calculated site mean palaeomagnetic directions (Dec between 1.5o and 19.6o and Inc between -52.2o and -68.3o) from principal component analysis of thermal demagnetization and alternating field demagnetization data, discarding the data of stones that show evidence of disturbance after cooling. The directions are in good agreement with recently published palaeosecular variation records from lake sediments. We have carried out palaeointensity experiments using the Coe/Thellier method with pTRM and tail checks, and with selection criteria modified to the situation. Palaeointensities range from 50μT to 77μT. Rock magnetic experiments contribute to our understanding of the mineralogy, domain state and blocking temperature spectra.  We compare our data with predictions of the global field models ARCH3k and gufm1, and suggest that the addition of our new data will improve these models for the SW Pacific region for the most recent time period. Archaeomagnetic measurements are also used to date hangi sites by matching the palaeo-direction to an established archaeomagnetic dating model, NZPSV1k. Archaeomagnetic dating is used to resolve ambiguities in the calibration of radiocarbon dates, and shows up inconsistencies due to unreliable source material for radiocarbon dating. Archaeomagnetic dating and radiocarbon dating results are combined to give the best estimates of the best age of the hangi sites.</p>

An Archaeomagnetic Study of Hangi Stones in New Zealand

2021 ◽  
Author(s):  
◽  
Rimpy Kinger
Keyword(s):  
New Zealand ◽  
Radiocarbon Dating ◽  
Principal Component ◽  
Blocking Temperature ◽  
Radiocarbon Dates ◽  
The North ◽  
Sw Pacific ◽  
Archaeomagnetic Dating ◽  
Show Evidence ◽  
Temperature Spectra

<p>Burnt or fired archaeological artefacts often retain a record of the magnetic field in which they were last heated and cooled. Over the past four years we have collected oriented hangi stones from 10 archaeological sites spread across the North and South Islands of New Zealand. The stones vary in lithology from andesites, originating from the central North Island volcanoes, favoured by Maori for their durability and with remanent magnetization up to 30 A/m, to sandstones and schists from the main axial ranges, with magnetizations as weak as 10-4 A/m. Radiocarbon dating of charcoal fragments retrieved from amongst the stones indicates that the sites span from ca. 1400 AD to the present.  In all cases, we have independently oriented and retrieved several stones, and we have made several samples from each stone, either by drilling (standard cylindrical samples) or sawing (pseudo-cubes) in the laboratory. We have calculated site mean palaeomagnetic directions (Dec between 1.5o and 19.6o and Inc between -52.2o and -68.3o) from principal component analysis of thermal demagnetization and alternating field demagnetization data, discarding the data of stones that show evidence of disturbance after cooling. The directions are in good agreement with recently published palaeosecular variation records from lake sediments. We have carried out palaeointensity experiments using the Coe/Thellier method with pTRM and tail checks, and with selection criteria modified to the situation. Palaeointensities range from 50μT to 77μT. Rock magnetic experiments contribute to our understanding of the mineralogy, domain state and blocking temperature spectra.  We compare our data with predictions of the global field models ARCH3k and gufm1, and suggest that the addition of our new data will improve these models for the SW Pacific region for the most recent time period. Archaeomagnetic measurements are also used to date hangi sites by matching the palaeo-direction to an established archaeomagnetic dating model, NZPSV1k. Archaeomagnetic dating is used to resolve ambiguities in the calibration of radiocarbon dates, and shows up inconsistencies due to unreliable source material for radiocarbon dating. Archaeomagnetic dating and radiocarbon dating results are combined to give the best estimates of the best age of the hangi sites.</p>

Geodetic strain and the deformational history of the North Island of New Zealand during the late Cainozoic

1987 ◽  
Vol 321 (1557) ◽  
pp. 163-181 ◽  
Keyword(s):  
New Zealand ◽  
Subduction Zone ◽  
East Coast ◽  
Late Quaternary ◽  
Plate Boundary ◽  
Boundary Zone ◽  
Metamorphic Belt ◽  
Volcanic Region ◽  
The North ◽  
Plate Boundary Zone

The subduction zone under the east coast of the North Island of New Zealand comprises, from east to west, a frontal wedge, a fore-arc basin, uplifted basement forming the arc and the Central Volcanic Region. Reconstructions of the plate boundary zone for the Cainozoic from seafloor spreading data require the fore-arc basin to have rotated through 60° in the last 20 Ma which is confirmed by palaeomagnetic declination studies. Estimates of shear strain from geodetic data show that the fore-arc basin is rotating today and that it is under extension in the direction normal to the trend of the plate boundary zone. The extension is apparently achieved by normal faulting. Estimates of the amount of sediments accreted to the subduction zone exceed the volume of the frontal wedge: underplating by the excess sediments is suggested to be the cause of late Quaternary uplift of the fore-arc basin. Low-temperature—high-pressure metamorphism may therefore be occurring at depth on the east coast and high-temperature—low-pressure metamorphism is probable in the Central Volcanic Region. The North Island of New Zealand is therefore a likely setting for a paired metamorphic belt in the making.

Testing the Accuracy of 14C Age Data from Pollen Concentrates in the Yangtze Delta, China

Radiocarbon ◽  
2014 ◽  
Vol 56 (1) ◽  
pp. 181-187 ◽  
Author(s):  
Chunhai Li ◽  
Yongxiang Li ◽  
George S Burr
Keyword(s):  
Radiocarbon Dating ◽  
Liquid Scintillation ◽  
Scintillation Counting ◽  
Yangtze Delta ◽  
Plant Materials ◽  
Radiocarbon Dates ◽  
Ams Radiocarbon Dating ◽  
14C Age ◽  
Climate Events ◽  
Age Determinations

In order to test the accuracy of accelerator mass spectrometry (AMS) radiocarbon dating of pollen, 8 samples of pollen concentrates and 4 bulk organic samples were collected and analyzed from trench T1041 at the Tianluoshan site, Yuyao city, Zhejiang Province. This site was chosen because a reliable chronology had been previously established there based on radiocarbon dates of plant materials. The pollen concentrate samples were measured using AMS 14C and the 4 bulk organic samples were measured by liquid scintillation counting (LSC). The pollen concentrates and bulk organic samples yield ages that are a few hundred years to thousands of years older than those from plant materials, respectively. Contributions from reworked sediments can explain the older ages for the pollen concentrates and sediment organic dates. This study suggests that caution must be exercised when discussing millennial- or centennial-scale climate events based on chronologies that are controlled by age determinations of pollen concentrates.

scholarly journals Further Developments in On-Line Computing and Radiocarbon Dating At the British Museum

Radiocarbon ◽  
1980 ◽  
Vol 22 (2) ◽  
pp. 455-460 ◽  
Author(s):  
A D Hewson ◽  
J A Hall
Keyword(s):  
Research Laboratory ◽  
Radiocarbon Dating ◽  
Liquid Scintillation ◽  
Full Range ◽  
British Museum ◽  
Scintillation Counting ◽  
Hewlett Packard ◽  
Radiocarbon Dates ◽  
On Line ◽  
Reporting Procedures

In November 1973 the British Museum Research Laboratory acquired a Hewlett Packard 2100A mini-computer for the storage, calculation and retrieval of scientific measurements made on museum objects. A part of the computer's work is the calculation of radiocarbon dates based on the liquid scintillation counting of 14C activities. A system of programs and files has been developed and has been in daily use since August 1974 (Hall and Hewson, 1977).This paper describes changes and improvements to the system to make it more flexible so that it now provides the full range of facilities required by an active 14C laboratory. The reporting procedures in particular have been restructured in the light of experience. The paper will be of interest to all laboratories that have, or hope to have, access to similar mini- or micro-computers.

University of Granada Radiocarbon Dates I

Radiocarbon ◽  
1982 ◽  
Vol 24 (2) ◽  
pp. 217-221 ◽  
Author(s):  
Cecilio González-Gómez ◽  
Juan de D López-González ◽  
María Domingo-García
Keyword(s):  
Liquid Scintillation Counting ◽  
Radiocarbon Dating ◽  
Liquid Scintillation ◽  
Scintillation Counting ◽  
Pure Oxygen ◽  
Radiocarbon Dates

The Radiocarbon Dating Laboratory of The Granada University was established to support the work of archaeologists and geologists. The method of dating is benzene synthesis and liquid scintillation counting developed by a number of investigators (Polach and Stipp, 1967; Tamers, 1969; Pietig and Scharpenseel, 1966) with sample combustion in pure oxygen (Switsur, 1974).

A late Quaternary moraine sequence dated by rock weathering rinds, Craigieburn Range, New Zealand

1993 ◽  
Vol 30 (9) ◽  
pp. 1861-1869 ◽  
Author(s):  
K. E. Ricker ◽  
T. J. Chinn ◽  
M. J. McSaveney
Keyword(s):  
New Zealand ◽  
Oxygen Isotope ◽  
Late Quaternary ◽  
Rock Weathering ◽  
Radiocarbon Dates ◽  
Oxygen Isotope Record ◽  
Isotope Record

Basins draining the Craigieburn Range, New Zealand, preserve a nearly complete late Quaternary moraine sequence. There are no radiocarbon dates, but moraine ages were determined by weathering-rind dating using thicknesses of rinds on surface-exposed sandstone boulders. Periods of expanded glaciers occurred 0.53, 0.66–2.5, 2.8–4.2, 5.9–9.7, and 16 thousand calendar (sidereal) years ago. Earlier periods of expanded glaciers in the region are dated by inference, largely from the ocean oxygen-isotope record, at 21–23.3, 25.5, and 56–70 ka.

scholarly journals Quaternary palaeoceanography and palaeogeography in northern Denmark: a review of results from the Skagen cores

1996 ◽  
Vol 43 ◽  
pp. 22-31
Author(s):  
Karen Luise Knudsen ◽  
Keld Conradsen ◽  
, Susanne Heier Nielsen ◽  
Marit-Solveig Seidenkrantz
Keyword(s):  
North Atlantic ◽  
Late Quaternary ◽  
Climatic Changes ◽  
Last Interglacial ◽  
North Atlantic Region ◽  
Atlantic Region ◽  
Radiocarbon Dates ◽  
Marine Deposits ◽  
The North ◽  
Late Weichselian

Palaeoenvironmental reconstructions from the Skagen record contribute to the understanding of Late Quatemary climatic changes and variations in the oceanographic circulation pattem in the entire North Atlantic region. The Skagen cores penetrated c. 192 m of Quatemary sediments comprising two marine Late Quaternary records: A 7 m marine unit (185.3-178.3 m) comprised the entire last interglacial, including its lower and upper transitions (Late Saalian-Eemian-Early Weichselian), while the upper 132 m of marine deposits covered the last about 15,000 years from the Late Weichselian through the Holocene, including the Pleistocene-Holocene transition. Results from the study of lithology, foraminifera, stable isotope measurements and radiocarbon dates are reviewed while emphasizing the most important contributions to the general understanding of the North Atlantic Quatemary history

scholarly journals Yale University Geology and Geophysics Radiocarbon Dates I

Radiocarbon ◽  
1977 ◽  
Vol 19 (1) ◽  
pp. 138-141 ◽  
Author(s):  
Y Nozaki ◽  
K K Turekian
Keyword(s):  
Liquid Scintillation Counting ◽  
Radiocarbon Dating ◽  
Liquid Scintillation ◽  
Scintillation Counting ◽  
Yale University ◽  
Radiocarbon Dates ◽  
Geochemical Parameters ◽  
Natural Tracer

A radiocarbon dating system has been established at the Department of Geology and Geophysics, Yale University. Liquid-scintillation counting of benzene described by Noakes et al (1965) and Polach and Stipp (1967) is used. The operation of the original Yale Radiocarbon Laboratory, based on counting CO2 gas, was suspended in 1969. The present facility is operated as part of the geochemical laboratories of the Department of Geology and Geophysics. The operation is small, geared to solving geochemical problems, through the use of radiocarbon as a dating tool and as a natural tracer in combination with other geochemical parameters. The facility will collaborate on significant archaeologic and geologic problems. However, it will not be a facility to which samples are submitted routinely. We believe that commercial facilities and other laboratories dedicated to such kinds of operation are better suited to handling such diversity and volume of samples.

scholarly journals University of Granada Radiocarbon Dates V

Radiocarbon ◽  
1991 ◽  
Vol 33 (3) ◽  
pp. 367-373 ◽  
Author(s):  
Cecilio Gonzalez-Gomez ◽  
Purificacion Sanchez-Sanchez
Keyword(s):  
Liquid Scintillation Counting ◽  
Radiocarbon Dating ◽  
Liquid Scintillation ◽  
Scintillation Counting ◽  
Boiling Temperature ◽  
Liquid Scintillation Spectrometer ◽  
Radiocarbon Dates ◽  
Standard Acid ◽  
Basic Procedure ◽  
The University

This paper includes some determinations of archaeological, art and palaeobotanical samples from Spain and Portugal, obtained at the University of Granada Radiocarbon Dating Laboratory, mostly from 1986 to 1988. Pretreatment of charcoal and wood samples is a standard acid-basic procedure using 8% HC1 and 2% NaOH at boiling temperature. The collagen of bone samples is obtained by the Longin (1971) method.The method of dating is benzene synthesis and liquid scintillation counting as previously reported (González-Gómez, López-González & Domingo-García 1982; González-Gómez, Sánchez-Sánchez and Domingo-García 1985; González-Gómez, Sánchez-Sánchez and Villafranca-Sánchez 1986, 1987).14C activity was measured in a Packard Tri-Carb Mod 4640 liquid scintillation spectrometer, using 20 ml low 40K counting vials with 5 ml benzene and 10 ml PPO-toluene as scintillator with a background of ca. 9 cpm. Efficiency was approximately 70% using the part of spectrum above the end point of tritium.

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