Saturday, May 31 • 11:30am - 12:00pm
(Research and Technical Studies Session) Elemental identification of pigments used in traditional bark paintings from Arnhem Land, Groote Eylandt, and the Tiwi Islands

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Harvard Art Museums are undertaking a major investigation into traditional bark paintings from Arnhem Land, Groote Eylandt and the Tiwi Islands; locations in the Northern Territory of Australia. This study is focusing on the pigments used by Aboriginal artists and is the first major analytical survey of bark paintings from the late 19th to 20th century.

These naturally occurring pigments contain a wide range of elements in varying amounts, characteristic of pigment types such as ochres, clays and mineral blacks. An earlier study conducted at the University of Western Australia demonstrated that laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) can be used to group pigments from various regions around the Australian continent according to the distribution of trace elements. Our study focuses on the trace element differences in a more closely defined region of Australia, namely the Northern Territory. To identify the pigments we are using LA-ICP-MS alongside complimentary techniques, including scanning electron microscopy (SEM), Raman and Fourier transform infra red (FTIR) spectroscopy.

The samples in this study include natural deposits of pigments, obtained from recorded historical expeditions and collected directly by the authors in consultation with local artists, as well as approximately 200 samples from 50 bark paintings collected from galleries and museums from Canberra, Sydney and Melbourne. The paintings were all chosen because they used traditional methods and materials and spanned over 100 years, with the location and date of painting being known for some examples. For instance, Melbourne University’s sampled paintings all come from the same community on Groote Eylandt and date to 1941-1945. A sample of each paint color present was collected to provide a statistically valid database of the range of natural pigments available from the 1870s to 1980s. The opportunity to compare samples from paintings with samples of natural raw materials from sites around Arnhem Land, Groote Eylandt and the Tiwi Islands provides us with a unique opportunity to trace the geographical origin of the pigments. It is anticipated that this will shed new light on the movements of raw materials through trade.

Initial results from a small selection of paint samples have illustrated subtle differences in elemental composition. This has given us the ability to differentiate between pigments of the same color with different mineral compositions, and identify regional differences within black pigments. Groote Eylandt has large manganese ore deposits and samples of black pigment from the region are uniquely rich in manganese. Variation in manganese content has also been observed in red and yellow pigments from different regions and may indicate use of different shades, as observed elsewhere with natural sienna or umber pigments. The study is ongoing and will be included in the catalogue for an upcoming exhibition at Harvard Art Museums opening in January 2016.

avatar for Georgina M. Rayner

Georgina M. Rayner

Associate Conservation Scienctist, Straus Center for Conservation and Technical Studies
Georgina Rayner is the Associate Conservation Scientist at the Straus Center for Conservation and Technical Studies, Harvard Art Museums. Prior to this role Georgina was the Andrew W. Mellon Postdoctoral Fellow in Conservation Science at the same institution. Georgina holds a Masters... Read More →


Andrew J. Shortland

Cranfield Forensic Institute, Cranfield University

Katherine Eremin

Patricia Cornwell Senior Conservation Scientist, Harvard Art Museums
Katherine Eremin is the Patricia Cornwell Senior Conservation Scientist at the Straus Center for Conservation and Technical Studies at the Harvard Art Museums. Katherine studied Natural Sciences at the University of Cambridge and received a PhD in metamorphic petrology from the University... Read More →
avatar for Narayan Khandekar

Narayan Khandekar

Director, Straus Center for Conservation and Technical Studies, Harvard Art Museums/Straus Center for Conservation and Technical Studies
Narayan Khandekar leads the Straus Center’s conservation and research activities, as well as those for the Center for the Technical Study of Modern Art. Specializing in the scientific analysis of paintings and painted surfaces, he has published extensively on the subject. His laboratory... Read More →

Rita Giannini

Cranfield Forensic Institute, Cranfield University

Saturday May 31, 2014 11:30am - 12:00pm PDT
Seacliff A-B