Jeffrey Parr

AMS dating of ancient plant residues from experimental stone tools: a pilot study

Andrea Yates et al. — Sun, 05 May 2013 22:01:20 PDT

Residue analyses on stone artefacts have contributed to resolving functional questions in stone tool research. Although identifying the function of tools through the analysis of their micro-residues is possible, the establishment of a sound numerical chronology for stone tools lacking a clear stratigraphic sequence, such as surface scatters, remains a challenge. While radiocarbon dating of blood residue on stone artefacts has been published previously (Loy 1987, 1990, 1993; Loy et al., 1990; Nelson et al.1986), this paper reports on an experiment designed to assess the possibility of directly dating residues on stone artefacts by accelerator mass spectrometry (AMS) based radiocarbon measurements. Innovative with this approach is (1) the use of mid and late Holocene pre-dated plant material (wood and peat), processed with contemporarily manufactured stone flakes under controlled laboratory conditions and (2) the use of very small carbon masses (less than 22 μg) for radiocarbon dating. The ¹⁴C results of the wood residues are in excellent agreement with the original sample, whereas the ¹⁴C results of the peat residues yield a wider age variation as expected due to the inhomogeneity of the material, but nevertheless, provided dates within an expected age range. Preliminary results demonstrate the feasibility of dating very small amounts of plant residue on lithics directly when contaminants are confined.

Phytolith occluded carbon and silica variability in wheat cultivars

Jeffrey F. Parr et al. — Tue, 11 Dec 2012 19:06:28 PST

Phytolith Occluded Carbon (PhytOC) has recently been demonstrated to be an important long-term terrestrial carbon fraction. The aim of this study was to examine the rates of silica accumulation and carbon bio-sequestered within the silica phytoliths of the leaf and stem material of wheat (Triticum sp.) cultivars. The phytolith content of 53 wheat cultivars sourced from 25 countries around the world and grown on a single trial site was first isolated and the PhytOC content then determined. The data shows that the phytolith occluded carbon content of the wheat cultivars ranged from 0.06% to 0.60% of dry leaf and stem biomass: a range of 1,000%. The data also demonstrates that it is the efficiency by which carbon is encapsulated within silica rather than the quantity of silica accumulated by the plant that is the most important factor in determining the relative PhytOC yields. The potential phytolith carbon bio-sequestration rates in the leaf and stem components of these wheat cultivars ranged up to 0.246 t-e-CO2 ha−1y−1. These phytolith carbon bio-sequestration rates indicate a substantial potential (~50 million t-e-CO2 y−1) exists for increasing the rate of secure carbon bio-sequestration in wheat crops using existing cultivars.

Raman, infrared and XPS study of bamboo phytoliths after chemical digestion

Kym M. Watling et al. — Tue, 11 Dec 2012 19:06:27 PST

Raman, infrared and X-ray photoelectron spectroscopies have been used to examine the effect of various chemical digestion methods on the composition of bamboo phytoliths. Intact bilobate phytoliths, suitable for interrogation by Raman microprobe analysis, were isolated by a microwave wet ashing technique using hydrogen peroxide with nitric and hydrochloric acids. The occluded phytolith carbon presented evidence of cellulose, lignin and carboxylic acids. Nitrate from the nitric acid used in the digestion was observed in homogenized samples of the isolated phytoliths; in addition to nitrogen of plant origin occluded within the phytolith, which was observed as amine nitrogen and ammonia. Intact bilobate phytoliths were not observed following an exothermic hydrogen peroxide/sulfuric acid digest, suggesting that these structures ruptured during this digestion procedure. The silicate network was significantly altered during isolation using the exothermic hydrogen peroxide/sulfuric digest, with surface hydroxyls undergoing condensation to form a SiO3 ring structure

Green geosequestration: secure carbon sequestration via plant silica biomineralisation

Leigh A. Sullivan et al. — Wed, 15 Sep 2010 16:53:00 PDT

Forensics report

Jeffrey F. Parr et al. — Tue, 24 Aug 2010 16:23:36 PDT

Phytolith-occluded carbon and the long-term soil organic carbon sequestration potential

Leigh A. Sullivan et al. — Mon, 23 Aug 2010 21:26:12 PDT

Holocene vegetation dynamics in West New Britain, PNG

William E. Boyd et al. — Mon, 23 Aug 2010 21:26:11 PDT

Sugarcane the champion crop at carbon sequestration

Jeffrey F. Parr et al. — Tue, 18 May 2010 21:57:11 PDT

Dr Jeff Parr and Professor Leigh Sullivan, both researchers from Southern Cross University and Plantstone Pty Ltd in Lismore NSW, have recently discovered that a process that occurs naturally in plants (especially grasses such as sugarcane), plays an important role in countering CO2 emissions and global warming.

This process is termed plantstone carbon and is also referred to as phytolith occluded carbon. Their research shows that plantstone carbon has been extracting 300 million tonnes of CO2 per year from the atmosphere and storing it securely in soil for thousands of years.

Pleistocene colonisation of the Bismarck Archipelago: new evidence from West New Britain

Robin Torrence et al. — Tue, 18 May 2010 21:57:10 PDT

The geological and archaeological signatures at the site of Kupona na Dari on the Willaumez Peninsula, West New Britain provide important new data about human colonisation of the Bismarck Archipelago. Analyses of the stratigraphy and weathering of paleosols and manuports, when combined with fission track, radiocarbon, and luminescence dating, indicate that the site was first occupied at about 35-45,000 years ago. During the whole period of occupation, people were exposed to a series of volcanic events which varied in terms of their potential impacts on the local environment. A PIXE-PIGME characterisation study of the obsidian artefacts at the site demonstrates that from the earliest period stone resources were acquired from outcrops located across a relatively large region. When compared with Early-Middle Holocene assemblages from nearby localities, the Pleistocene stone tool technology differs in only a few minor respects. From this analysis we infer that groups were mobile in both periods, but slightly different strategies for the procurement and maintenance of the stone tools were required for the more extensive ranges exploited during the Pleistocene. The interdisciplinary study of Kupona na Dari concludes that colonisation comprised a long term process of settling into this volcanically active environment. Due to variability in the environments that people encountered, the pattern of colonisation may not have been similar across the entire Bismarck Archipelago.

Archaeobotany in Australia and New Guinea: practice, potential and prospects

Tim Denham et al. — Tue, 18 May 2010 20:54:11 PDT

Archaeobotany is the study of plant remains from archaeological contexts. Despite Australasian research being at the forefront of several methodological innovations over the last three decades, archaeobotany is now a relatively peripheral concern to most archaeological projects in Australia and New Guinea. In this paper, many practicing archaeobotanists working in these regions argue for a more central role for archaeobotany in standard archaeological practice. An overview of archaeobotanical techniques and applications is presented, the potential for archaeobotany to address key historical research questions is indicated, and initiatives designed to promote archaeobotany and improve current practices are outlined. ,

Once, twice maybe, but not three times: Reheating xanthorrhoea australis resin - not viable

Jeffrey F. Parr — Tue, 18 May 2010 20:54:10 PDT

Hafting is a process in which a handle is attached to a stone tool adding to its functionability andlor ease of use. This was nonnalIy achieved by using a resinous plant exudate as a fIxative (Flood 1995:270) which was heated and then fashioned into place (Cribb and Cribb 1982:89). The resin may also have been reinforced with other materials such as grass, beeswax and fme sand (Cribb and Cribb 1982:89). A large range of stone tools have retained evidence of hafting in the fonn of resins long after separation or deterioration of handles due to taphonomic processes. These tools range in function from utilitarian and ceremonial uses to articles of trade. For example, backed blades, Bondi points, some eloueras, burrens and ground-edged axes were used to carry out a range of woodworking and food procurement tasks (McBryde 1975; McCarthy 1976; Kanuninga 1977; Morwood and L'Oste Brown 1994; Flood 1995). Alternatively,leilira blades and Kimberley points often served important roles in ceremonial events and the latter is known as a signifIcant item of trade (Tindale 1965; McCarthy 1976).

Deposition of plant silica, a long-lived soil fraction containing easily quantifiable carbon

Jeffrey F. Parr et al. — Tue, 18 May 2010 17:45:00 PDT

Management of silica biomineralisation in crops to enhance soil carbon sequestration in agro-ecosystems

Leigh A. Sullivan et al. — Tue, 18 May 2010 17:44:59 PDT

Morphometric and visual fossil phytolith identification using a regionally specific digital database

Jeffrey F. Parr — Tue, 18 May 2010 17:44:59 PDT

The identification of Xanthorrhoea resins by starch morphology: Prospects for archaeological and taxonomic applications

Jeffrey F. Parr — Tue, 18 May 2010 17:44:58 PDT

For Australian Aboriginal people plant resins have played an important role in both trade and the manufacture of hafted tools. In particular, the resins of theXanthorrhoea species were widely distributed and favored resources. The aim of this pilot study was to: (1) determine if starch grains were present in all of theXanthorrhoea resin samples examined, and (2) determine the feasibility of discriminating between resins of differentXanthorrhoea species by the morphological attributes of their starch grains. The results established that starch grains were present within all of theXanthorrhoea species resins that were examined. Moreover, for the purpose of identifying resins from within this genus the preliminary results suggest that starch grains have sufficient differences in attributes to allow discrimination between species. The results suggest that further research into the morphological attributes of starch grains in resins may prove to be an efficient and cost-effective means by which species identification could be achieved for small portions of archaeological resin samples.

Sugarcane phytoliths: Encapsulation and sequestration of a long-lived carbon fraction

Jeffrey F. Parr et al. — Tue, 18 May 2010 17:44:57 PDT

The potential to reduce emissions from agriculture and increase the amount of carbon captured in soils is currently being examined by researchers in a number of countries. This paper describes a process of carbon capture and long-term storage using silica phytoliths and, provides the results of a study of this process on newly planted and ratooned sugarcane varieties. Our results indicate that a) there was significant variation in the phytolith occluded carbon (PhytOC) content of different varieties, b) this did not appear to be directly related to the quantity of silica in the plant but rather the efficiency of carbon encapsulation by individual varieties and c) it was possible to accurately quantify this carbon fraction prior to its incorporation into soil. The carbon content of the varieties tested under the particular suite of environmental conditions for which they were grown ranged from 0.12 te-CO2 ha-y−1 to 0.36 te-CO2 ha-y−1. This PhytOC process provides an approach which reduces emissions from agriculture for the long-term (millennia), as opposed to many other soil organic carbon fractions that may decompose over a much shorter time. Moreover, the ability to quantify PhytOC prior to its incorporation into the soil will provide a distinct practical advantage for the quantification of this carbon form over other soil carbon fractions in emerging emissions trading and offset markets.

Morphological characteristics observed in the leaf phytolith of select gymnosperms of Eastern Australia

Jeffrey F. Parr et al. — Tue, 18 May 2010 17:44:57 PDT

Starch in resins

Jeffrey F. Parr — Tue, 18 May 2010 17:44:56 PDT

Increasing long term soil carbon sequestration in agriculture and forestry

Leigh A. Sullivan et al. — Tue, 18 May 2010 17:44:54 PDT

Terrestrial carbon sequestration is fundamental to the global carbon cycle and is being utilised to counter increases in anthropogenic carbon dioxide emissions. Although soil organic carbon dominates the terrestrial carbon cycle in terms of total quantity, the long term sequestration of soil organic carbon in the Holocene was relatively low (<1 % of net primary production). Consequently there is a viewpoint that soil has a low carbon storage potential and hence only a relatively minor role to play in countering anthropogenic carbon dioxide emissions. Long term (decades to millennia) soil organic carbon sequestration mechanisms are currently thought to be mainly due to the physical protection of chemically recalcitrant organic matter within clays. Recent research is presented here to show that some forms of soil organic carbon (e.g. that occluded in phytoliths) are not readily physically accessible to the agents responsible for decomposition and that these forms also play a major role in long term soil organic carbon sequestration. Phytoliths (literally ‘plant rocks') are silicified features that form as a result of biomineralization within plants. The occlusion of carbon within phytoliths has been recently found to be an important process in the long-term sequestration of terrestrial carbon (Parr & Sullivan, 2005). Moreover, relative to the other soil organic carbon constituents, the carbon occluded in phytoliths (PhytOC) is highly resistant against decomposition. Although comprising < 10 % of the total carbon pool in contemporary topsoils (with ages of < 200 years), the resistance of this carbon fraction against decomposition processes resulted in this carbon fraction comprising 70 % of the total carbon pool in the buried topsoils after decomposition for 3,000 years in soils under grasslands. The carbon in phytoliths is sequestered over the geological time scale rather than the anthropological. Experimental and modelled data presented here indicates that the long term carbon sequestration potential of soil can be increased considerably in areas under managed vegetation (e.g. crops) by the adoption of simple agronomic and silvicultural practices.

Geochemical analysis of fragments of burnt and impressed cay

William E. Boyd et al. — Tue, 18 May 2010 17:44:53 PDT