Selective reburial: a potential approach for the in situ preservation of waterlogged archaeological wood in wetland excavations

This paper reviews the degradation, preservation and conservation of waterlogged archaeological wood. Degradation due to bacteria in anoxic and soft-rot fungi and bacteria in oxic waterlogged conditions is discussed with consideration of the effect on the chemical composition of wood, as well as the deposition of sulphur and iron within the structure. The effects on physical properties are also considered. The paper then discusses the role of consolidants in preserving waterlogged archaeological wood after it is excavated as well as issues to be considered when reburial is used as a means of preservation. The use of alum and polyethylene glycol (PEG) as consolidants is presented along with various case studies with particular emphasis on marine artefacts. The properties of consolidated wood are examined, especially with respect to the degradation of the wood post-conservation. Different consolidants are reviewed along with their use and properties. The merits and risks of reburial and in situ preservation are considered as an alternative to conservation.

Download Full-text

In situ polymerisation of isoeugenol as a green consolidation method for waterlogged archaeological wood

Scientific Reports ◽

10.1038/srep46481 ◽

2017 ◽

Vol 7 (1) ◽

Cited By ~ 14

Author(s):

Emily McHale ◽

Calin C. Steindal ◽

Hartmut Kutzke ◽

Tore Benneche ◽

Stephen E. Harding

Keyword(s):

Archaeological Wood ◽

Waterlogged Archaeological Wood

Download Full-text

Even Visually Intact Cell Walls in Waterlogged Archaeological Wood Are Chemically Deteriorated and Mechanically Fragile: A Case of a 170 Year-Old Shipwreck

Molecules ◽

10.3390/molecules25051113 ◽

2020 ◽

Vol 25 (5) ◽

pp. 1113 ◽

Cited By ~ 1

Author(s):

Liuyang Han ◽

Xingling Tian ◽

Tobias Keplinger ◽

Haibin Zhou ◽

Ren Li ◽

...

Keyword(s):

Cell Wall ◽

Cell Walls ◽

Intact Cell ◽

Nitrogen Adsorption ◽

Wet Chemistry ◽

Archaeological Wood ◽

Waterlogged Archaeological Wood ◽

X Ray Scattering ◽

Crystallite Structure ◽

Cell Wall Mechanics

Structural and chemical deterioration and its impact on cell wall mechanics were investigated for visually intact cell walls (VICWs) in waterlogged archaeological wood (WAW). Cell wall mechanical properties were examined by nanoindentation without prior embedding. WAW showed more than 25% decrease of both hardness and elastic modulus. Changes of cell wall composition, cellulose crystallite structure and porosity were investigated by ATR-FTIR imaging, Raman imaging, wet chemistry, 13C-solid state NMR, pyrolysis-GC/MS, wide angle X-ray scattering, and N2 nitrogen adsorption. VICWs in WAW possessed a cleavage of carboxyl in side chains of xylan, a serious loss of polysaccharides, and a partial breakage of β-O-4 interlinks in lignin. This was accompanied by a higher amount of mesopores in cell walls. Even VICWs in WAW were severely deteriorated at the nanoscale with impact on mechanics, which has strong implications for the conservation of archaeological shipwrecks.

Download Full-text

An in situ Raman spectroscopic method for quantification of polyethylene glycol (PEG) in waterlogged archaeological wood

Holzforschung ◽

10.1515/hf-2019-0238 ◽

2020 ◽

Vol 74 (11) ◽

pp. 1043-1051

Author(s):

Åke Henrik-Klemens ◽

Katarina Abrahamsson ◽

Charlotte Björdal ◽

Alexandra Walsh

Keyword(s):

Polyethylene Glycol ◽

Spectroscopic Method ◽

Calibration Model ◽

Efficient Treatment ◽

Raman Spectroscopic ◽

Archaeological Wood ◽

Validation Set ◽

Impregnation Period ◽

Polymer Impregnation

AbstractThe weakened microstructure of archaeological wood (AW) objects from waterlogged environments necessitates consolidation to avoid anisotropic shrinkage upon drying. Polymer impregnation through submergence or spraying treatments is commonly applied, and for larger and thicker objects, the impregnation period can stretch over decades. Thus, for efficient treatment, continuous monitoring of the impregnation status is required. Today, such monitoring is often destructive and expensive, requiring segments for extraction and chromatographic quantification. This study proposes an in situ Raman spectroscopic method for quantification of polyethylene glycol (PEG) in waterlogged AW. A calibration model was built on standards of PEG, cellulose powder, and milled wood lignin using orthogonal partial least squares (OPLS). The OPLS model had a strong linear relationship, and the PEG content in wood of varying degrees of degradation could be determined. However, the accuracy of the model was low with a root mean square error of prediction of 11 wt%. The low accuracy was traced to the heterogeneity in the calibration and validation set samples with regard to the small probing volume of the confocal instrumental setup.

Download Full-text

New trials in the consolidation of waterlogged archaeological wood with different acetone-carried products

Journal of Archaeological Science ◽

10.1016/j.jas.2011.06.012 ◽

2011 ◽

Vol 38 (11) ◽

pp. 2957-2967 ◽

Cited By ~ 28

Author(s):

Gianna Giachi ◽

Chiara Capretti ◽

Ines D. Donato ◽

Nicola Macchioni ◽

Benedetto Pizzo

Keyword(s):

Archaeological Wood ◽

Waterlogged Archaeological Wood

Download Full-text

A Full-Ocean-Depth Sampler for Hadal Microbes Based on Multistage Membrane Filters With In-Situ Preservation

Marine Technology Society Journal ◽

10.4031/mtsj.55.2.10 ◽

2021 ◽

Vol 55 (2) ◽

pp. 25-34

Author(s):

Jiawang Chen ◽

Weitao He ◽

Peng Zhou ◽

Jiasong Fang ◽

Dahai Zhang ◽

...

Keyword(s):

Ribonucleic Acid ◽

Gene Pool ◽

Special Structure ◽

High Quality ◽

Mariana Trench ◽

Membrane Filters ◽

In Situ Preservation ◽

Microbial Samples ◽

Flow Pump

Abstract In order to obtain high-quality microbial samples from the hadal zone, which has a depth of over 6,000 m, a full-ocean-depth sampler with the function of in-situ filtration and preservation was developed. A flow pump and several membrane filters were used for in-situ filtration under the sea. With a multistage filtering structure, the microbes can be initially screened according to their sizes. To avoid the degradation of microbial ribonucleic acid (RNA), a special structure was designed to inject the RNAlater solution into the samples immediately after the filtration. The sampler was tested in our laboratory and deployed during Mariana TS-15 in 2019. It was installed on a hadal lander of Shanghai Ocean University and deployed at MBR02 (11.371°N, 142.587°E, 10,931 m) in the Mariana Trench. A total of 20 L of in-situ seawater was filtered, and membranes with pore sizes of 3 and 0.2 μm were preserved. The study is expected to provide important support for the establishment of a hadal microbial gene pool.

Download Full-text