Wellmann Imre szerk.: A Magyar Mezőgazdasági Múzeum Közleményei 1971-1972 (Budapest, 1973)

Lerche, Grith: Recent datings of Danish ploughing implements by the radiocarbon method

RECENT DATINGS OF DANISH PLOUGHING IMPLEMENTS BY THE RADIOCARBON METHOD GRITH LERCHE (Lyngby, Denmark) From the natural sciences several techniques have been realized that are useful in establishing the date of a period or an object important to our work; e.g. the pollen analysis and dendrochronology, the couting of tree-rings, are long established. A more recent addition is the use of measurements of Carbon

—14 in objects which have been contained in deposits. Dating by means of the C

—14 method is used by geologists, botanists, and archaeologists as well as ethnologists all over the world today

1

. The principle of this dating method can be explained as follows. The atmosphere contains — in the form of carbon dioxide gas — not onlynormal carbon, carbon 12, but also radioactive carbon 14. All living organisms absorb and thus contain the radiocarbon: animals, human beings, green plants as well as trees, etc. Since it is possible to trace this C

—14 in all organic material, and since as soon as the organism dies the absorption stops and the C

—14 quantity that was absorbed decays at a regular rate then the remaining radio-activity in ancient organic material can be measured and thus calculated. The half-life of C

—14 has been calculated to 5570 years before the present time (B. P.), and this value has been used in all C

—14 determinations. (5568 ± 30 by LIBBY.

2

) Since the first list of C

—14 datings was given from Chicago in 1951 by W. F. LIBBY, more accurate measuring-methods have been elaborated so that the original half-life of C—

14 should be 5730 ± 40, i.e. 3% older.

3 To avoid confusion it was accepted internationally by the laboratories in 1965 to continue to use the original half-life of C

—14 and to give a total rwATERBOLK, H. T. The 1959 Carbon—

14 Symposium at Groningen. Antiquity 34: 1960. 14—18. — NEUSTUPNY, EV2EN. A new Epoch in Radiocarbon Dating. Antiquity 44: 1970. 38—45. 2LIBBY, W. F. Radiocarbon Dating. Chicago 1955. — TAUBER, HENRIK. Recent Development in C

—14 Dating. In: Report of the Vlth International Congress on Quaternary, Warsaw 1961. Vol. I. Commission on the Absolute Age of Quaternary Deposits. Lodz 1965. 737. — GODWIN, HARRY. Half-life of Radio-carbon. Nature 195: 1962. 984. — TAUBER, HENRIK. Danske Kulstof—

14 dateringsresultater, II. Meddelelser fra Dansk Geologisk Forening 16 : 2 1966. 155. 3GODWIN, H. op. cit.