Bulk element composition versus trace element composition in the reconstruction of an obsidian source system

It has become possible, through compositional analysis, to differentiate among discrete obsidian quarry and collecting localities within a single source area. The analytical potential of such information is considerable yet studies are seldom undertaken owing to the difficulties associated with trace element analysis.This study is intended to explore the feasibility of using bulk element data instead of trace element data in such compositional analyses. Techniques of bulk element analysis are far more accessible to archaeologists. The results of an experiment utilizing carefully controlled samples from the El Chayal obsidian source, Guatemala, are reported and discussed.     

Age and exploitation of obsidian from the Medicine Lake Highland,California

The relationship between major and minor elements, trace element composition, and age of obsidian sources within a volcanic field, is of considerable interest for obsidian source and artifact research in the New and Old World. The present study investigates this relationship in the Medicine Lake Highland of western North America. Geological evidence had indicated a very young age for all obsidian sources in the Highland, yet archaeological evidence suggested that obsidian was utilized for several thousand years. X-ray fluorescence analysis distinguished the latest flow (Glass Mountain) from the Cougar Butte, Grasshopper Flat, and Lost Iron Wells sources. Data obtained from two nearby archaeological sites showed that obsidian from the latter two sources was used by c. 7500 bc, while Glass Mountain material was not used (or available) until after 1360± 240 bp. These findings indicate that inferences of an extremely recent age for all obsidian sources in the volcanic field were unwarranted. Further analysis of major and minor elements indicated different hydration rates for these sources. The results argue that significant geochemical variability, as well as age differences, can exist between obsidian sources within the same volcanic field.     

First Obsidian in the Northern French Alps during the Early Neolithic

An exceptional discovery was made in 2013 in the northern French Alps, at the Grande Rivoire site in Sassenage (Isère department): an obsidian bladelet from Sardinia was found in a cultural horizon dated to about 5360–5210 cal b.c. The abundant arrowheads found with it are characteristic of the Early Neolithic in the South of France (Cardial/Epicardial). Yet there was no pottery or domestic fauna, and only discrete markers of farming. The typological, technological and micro-wear analysis of this bladelet, as well as the determination of the origin of the raw material, open new avenues of reflection for the neolithization of the northern Alps, in particular concerning the role played by the Early Neolithic cultures of northern Italy.     

The distribution and provenance of archaeological obsidian in central and eastern Europe

The sources of archaeological obsidian in central and eastern Europe are briefly described and analyses of 48 samples from 10 of these sources in northeast Hungary and southeast Slovakia are reported. Instrumental Neutron Activation Analysis was used to determine 16 trace elements and two major elements. Principal Components Analysis supported by Discriminant Analysis showed seven analytical groups in these data. A total of 270 pieces of archaeological obsidian were assigned by Discriminant Analysis to three of the Carpathian source groups defined, the remaining four source groups not being represented in the archaeological record. The three source groups used are: (1) Szöllöske and Málá Toron?a in Slovakia (designated group Carpathian 1); (2) Csepegö Forrás, Tolcsva area, Olaszliszka and Erdöbénye in Hungary (Carpathian 2a); and (3) Erdöbénye (Carpathian 2b). Carpathian 2a and 2b type obsidians are both found at the re-deposited source of Erdöbénye. Carpathian obsidian was used most widely in Hungary, Slovakia and Romania, and also reached south to the Danube in Yugoslavia, west to Moravia, Austria and to the Adriatic near Trieste, and north to Poland. Carpathian 2a obsidian was used in the Aurignacian period, Carpathian 1 in the Gravettian and Mesolithic, and Carpathian 1, 2a and 2b in the Neolithic, when Carpathian 1 predominated and obsidian use was at its most intensive. Only Carpathian I type has been identified in the Copper and Bronze Ages. There is no evidence at present for any overlap between the Carpathian obsidian distribution and the distributions of the Near Eastern or Aegean sources, but there is an overlap with Mediterranean obsidian at the Neolithic site of Grotta Tartaruga in northeast Italy where Liparian and Carpathian 1 material were identified. The distribution of obsidian from the Carpathian sources is considered in terms of linear supply routes. Based on limited available evidence the supply zone is significantly smaller and the rate of fall-off with distance slightly lower than that reported for Near Eastern obsidians.     

The distribution and sources of archaeological obsidian from southern France

One-hundred-and-sixty-two pieces of obsidian have been found at 50 archaeological localities in southern France. The distribution is concentrated in the Rhône Valley, but includes sites in Drôme and in southwest France. The obsidian is mainly from sites of the Chassey culture (4th and 3rd millennium Neolithic), but there is one Impressed Ware site (Early Neolithic) and four Copper Age sites with obsidian. Only a small proportion of the obsidian (31 pieces) consists of waste pieces, providing little evidence for on-site working. 10 pieces of obsidian were analysed by instrumental neutron activation analysis to determine their geological provenance. Seven pieces proved to be from the Sardinian SA source, one from Lipari, and two from Pantelleria. Chronologically there is some division between sources used: all three pieces of Liparian obsidian so far identified from southern France, in this work and by earlier researchers, belong to Early Chassey contexts, and the two Pantellerian pieces are from a Copper Age dolmen. Sardinian and Liparian obsidian probably reached France by way of northern Italy. where both types were in use in contemporary cultures. The two Pantellerian pieces are evidence of some type of contact between France and the southern Mediterranean in the Copper Age, despite earlier suggestions of a very restricted distribution for the Pantellerian source. Obsidian was probably imported to southern France with other goods since the small amounts used would not warrant a separate trading network for obsidian alone.