Harbottle, Garman

English

Journal.fi

APPLICA TION OF THE MINI C14 COUNTER TO AN ARCHAEOLOGICAL PROBLEM: THE FROBISHER BLOOM GARMAN HARBOTTLE Chemistry Department, Brookhaven National Laboratory, Upton, New York 11973 The "Frobisher lron Bloom" at the Smithsonian Institution (Accession No . 49459) was found by the American explorer C. F. Hall on Kodlunarn Island in Frobisher Bay, Baf-fin Island, Canada, in 1861 (Hall , 1865). Since Hall also collected there relics of the Elizabethan explorer Sir Martin Frobisher, he assumed that this iron bloom (and several others, now lost) pertained to the Frobisher expeditions in the years 1576, 77 and 78: local Inuit oral history confirmed this supposition. The discovery of unmistakable Viking remains at L' Anse aux Meadows, Newfound-land, by the lngstads in 1960 reoriented peoples' thinking about the reality of Viking expeditions to the New World, and around 1967 curators at the Smithsonian Institution began to discuss the possibility that the "Frobisher bloom" might in fact be of Viking origin. Frobisher Bay lies almost directly on the presumed Iceland - Greenland -Newfoundland Viking route . lt was decided to attempt a carbon 14 dating of the bloom - actually of the iron carbides in the iron, using the technique of Van der Merwe (1969). Unfortunately, the carbon content of the bloom was only ca. 0 .05 %, and for this reason the Smithsonian Institution contracted with Brookhaven National Labora-tory (Sayre, Stoenner and Harbottle) to develop a proportional counter capable of dating 10 mg of carbon (Harbottle et al. 1979, 1983; Sayre et al. 1981). When this had been done, dates (calibrated) of 1293 ± 133 and 1262 ± 107 AD were obtained for two separate iron samples , taken from the bloom (Sayre et al. 1983). Stimulated by these findings, dates weil within the Viking period in Greenland but probably too early for Frobisher, the Smithsonian Institution sponsored an expedition to Kodlunarn Island in the summer of 1981 with William Fitzhugh as leader. Three more "Frobisher" blooms were found: these are now being conserved for museum pre-sentation in Canada. Adhering to the rough outer surface of one of the new blooms were bits of charcoal which appeared to have remained there from the time of smelting . These charcoal bits now have been dated usi ng the proportional counter. The correc-tion (calibration) procedure of Stuiver (1982) yields three possible dates, 1392, 1322 and 1337 AD, all ± 150 years: these seem consistent with the iron carbide dates from the Smithsonian bloom. Although these dates might still refer to possible smelting operations by the Frobisher expedition using driftwood as a source of charcoal, the extensive written records of those three Elizabethan expeditions contain no mention of any such metallurgy . What remains then is a mystery which has so far only partially yielded to archaeo-metric research . What does seem sure is that the Frobisher bloom and its companions are among the earliest smelted-iron artifacts to occur in the New World . 503 Acknowledgement This research was carried out at Brookhaven National Laboratory under contract DE-AC02-76CH00016 with the U. S. Department of Energy and supported by its Office of Basic Energy Sciences. REFERENCES C. F. Ha:I , 1865. Arctic Researches and Life Among the Esquimaux (New York: Haper and Brothers, 1865) . G . Harbottle, E. V. Sayre and R. W. Stoenner, 1979. Carbon 14 Dating of Small Samples by Proportional Counting, Science 206, 683. G. Harbottle, E. V. Sayre, and R. W . Stoenner, 1983. The Use of Miniature C-14 Counters in Dating and Authentication in the Museum, Proceedings of the Fifth International Seminar "Applications of Science in Examination of Works of Art", Museum of Fine Arts, Boston, Sept. 7-9, 1983, in press. N. J . Van der Merwe, 1969. The Carbon 14 Dating of lron (Chicago: Univ. of Chicago Press). E. V. Sayre, G. Harbott le, R. W. Stoenner, R. L. Otlet and G. V. Evans, 1981. The Use of the Small Gas Proportional Counters for the Carbon 14 Measurement of Very Small Samples, IAEA Proceedings on methods of Low Level Counting and Spectrometry, Yienna (1981) p. 393. E. V. Sayre, G. Harbottle, R. W. Stoenner, W. Washburn , J. S. Olin and W. Fitzhugh, 1983. The Carbon 14 Dating of an Iron Bloom Associated with the Voyages of Sir Martin Frobisher, in L. A. Currie, ed. Nuclear and Chemical Dating Techniques: Interpreting the Environmental Record, A. C. S. Symp. Series 176 p. 441. M. Stuiver, 1982. A High Precision Calibration of the AD Radiocarbon Time Scale, Radiocarbon 24: 1. 504 

Applications of the mini C-14 counter to an archaeological problem: The Frobisher Bloom

https://journal.fi/iskos/article/download/128152/77303

Applications of the mini C-14 counter to an archaeological problem: The Frobisher Bloom

Abstract

Similar works

Full text

Available Versions

Journal.fi