PINE RESINS AND POTTERY SEALING: ANALYSIS OF ABSORBED AND VISIBLE POTTERY RESIDUES FROM CENTRAL NEW YORK STATE*

Analysis was performed on absorbed and visible residues from 21 New York State prehistoric pottery sherds dating from 2905 ± 35 bp (Intcal04) (1256–998 cal bc ) to 425 ± 40 bp (Intcal04) (1417–1626 cal ad ). The use of pine resin was detected in 10 of 12 absorbed residue samples and 11 of 17 sherds subjected to visible residue analysis. It seems likely that the pots were resin‐sealed to make them more impermeable, constituting the first chemical evidence of extensive resin‐sealing in North America. A comparison of the results of absorbed and visible residues from eight of the sherds indicates that the two kinds of residue provide complementary evidence of vessel use.     

TRACE ELEMENT GEOCHEMISTRY OF NATIVE COPPER FROM THE WHITE PINE MINE,MICHIGAN (USA): IMPLICATIONS FOR SOURCING ARTEFACTS*

Eighty-five samples of native copper from the White Pine mine in upper Michigan were analysed by neutron activation to document geochemical variability within a single locality. Silver, sodium, antimony and scandium contents vary by two orders of magnitude, whereas arsenic values vary by three orders of magnitude. This variability reinforces the need for provenance studies of artefacts to examine sufficient samples to test for heterogeneity within the source area. The White Pine suite contains some of the most impure native copper that has been analysed to date. Arsenic and silver values of these impure samples overlap with those of European coppers, but consideration of several elements can still distinguish native copper from European copper.     

CHEMICAL CHARACTERIZATION OF ANCIENT MESOAMERICAN ‘COPAL’ RESINS: PRELIMINARY RESULTS*

So‐called ‘copal’ resins from nine Aztec/Mixtec turquoise mosaics have been subject to analysis by gas chromatography – mass spectrometry to examine their higher terpenoid composition with a view to botanical identification. Botanical specimens and modern commercial ‘copal’ resins were analysed for reference. A range of botanical sources for the resins was identified, including pine, Protium and possibly Bursera. The data reinforce the ambiguity in the use of the term ‘copal’ and demonstrate the need for further work on characterization of ancient Bursera resins.     

1H‐NMR AND 31P‐NMR CHARACTERIZATION OF THE LIPID FRACTION IN ARCHAEOLOGICAL OINTMENTS

Lipids are a broad group of naturally occurring molecules, which includes fats, oils, waxes, sterols, terpenes, fat‐soluble vitamins, monoglycerides, diglycerides, phospholipids and others. Lipids have been widely used in human history and they are often present in archaeological finds. In particular, in the field of medicine and cosmetics, lipids have been employed as base in the preparation of unguents, salves and balms. The characterization of these products and their degradation products induced by ageing is important for an understanding of the ancient pharmaceutical techniques and to assess the state of conservation. ¹H‐NMR and, for the first time, ³¹P‐NMR spectroscopy have been applied to the characterization of such compounds. By derivatization of the samples with 2‐chloro‐4,4,5,5‐tetramethyl‐1,3,2‐dioxaphospholane, it is possible to recognize, quantify and evaluate the degradation degree of lipids in archaeological unguent samples. With this new approach, lipids have been recognized in 17th‐century archaeological ointments from the Aboca Museum. Moreover, severe hydrolysis and oxidation markers have been detected.