Thermoluminescence dating of late Quaternary dune sand, Manawatu/Horowhenua area, New Zealand: A comparison with¹⁴C age determinations

Abstract

Samples of dune sand from two previously described sections in the southwestern North Island have been dated by the thermoluminescence method. At the fIrst site, KoputaroaPhase dune sand immediately underlying Aokautere Ash (= Oruanui Ash 14C dated at c. 22 590 yr B.P.) was dated at 24 200 ± 3700 yr. At the second site, Holocene dune sand was dated at 3000 ± 500 yr. Factors influencing the error limits of the thermoluminescence dates are discussed. The results confirm that coastal dunes were migrating inland during the last stadial of the Otira Glaciation and indicate that the thermoluminescence method could usefully be applied in the dating of upper Quaternary deposits in this region.

A pluvial episode identified in arid Australia during the Medieval Climatic Anomaly

“…Sampling was concentrated on stratified high-energy beach deposits collected from each 2 -3 m excavation using stainless steel tubing. OSL ages were obtained by measuring equivalent doses using single sand-sized quartz grains, and a full description of sample preparation and analysis techniques is provided in Cohen et al (2011;2012) and Gliganic et al (in press) with procedures for the multi-grain TL outlined in Shepperd and Price (1990). A 90 m grid-cell digital elevation model (DEM) was used to construct lake-floor morphology and hypsometry Leon and Cohen, 2012) and we have assumed negligible lake-floor deflation since the MCA lake-filling episode.…”

The source, age, and stabilisation of the Koputaroa dunes, Otaki‐Te Horo, New Zealand

“…1). The relative position of these dunes suggests they are not as old as those to the north (Shepherd & Price 1990); hence, the present investigation and application of luminescence dating.…”

“…In the Horowhenua-Manawatu area, the Koputaroa dunes are no closer than 5 km from the coast and extend up to 25 km inland. Using radiocarbon, thermoluminescence (TL), and infrared stimulated luminescence dating, and sedimentological analysis, their relative stratigraphic position, origin, and age have been postulated (Cowie 1963;Shepherd 1985;Shepherd & Price 1990;Duller 1996). Pollen analysis of these dunes shows they formed during cool climatic conditions, most likely during a late stage of 5 18 O stage 2 (Mclntyre 1963).…”

“…The degree of soil development led Cowie (1963) to conclude that they were between 10 000 and 20 000 yr old. Shepherd & Price (1990) obtained a TL date of 24 000 ± 3700 yr for a sample of Koputaroa dune sand taken from Paiaka Road, Horowhenua (Fig. 2).…”

Late Quaternary evolution of a playa margin at Lake Frome, South Australia

“…In order to further test the validity of our TL chronology in the specific playa marginal setting at Lake Frome, we additionally analysed four paired samples from different sedimentary environments with single grain OSL techniques. Overall, the good agreement between both techniques suggests that our largely TL based chronological framework is reliable TL dating was conducted at the University of Wollongong, and used a combination of the regeneration and the additive dose methods following the procedure described in Shepherd and Price (1990). Samples were wet sieved to separate the 90-125 μm quartz grain size fraction which was chemically treated in dilute HCl and etched in HF to remove the outer grain coating as well as other material containing TL created by short range alpha particles.…”