Tree-ring chronologies for the 6th to 16th centuries for oaks of southern and eastern England

Abstract

The background to the problem of providing useful oak chronologies for the variable environmental conditions that apply in southern and eastern England is outlined. The reference chronologies published here embrace three new principles. Firstly, the samples, nearly 300, on which they are based are almost entirely of boards or planks that are of radial section (from oaks aged on average about 250 years) that form part of panel paintings or chests. Secondly, to take account of the differences in the growth pattern with the vigour of growth, separate chronologies for sequences of different ring-width have been formed. Thirdly, on account of the difficulties in extending, with the samples available, an English chronology by the method of overlapping, eight separate chronologies, each about 300 years long, have been created. Matching has been based on German methods, i.e. computer comparisons (with more than one reference chronology) supported by visual comparison of charts. Agreement values in about half a million positions were calculated. These reference chronologies, expressed as ring-widths, are suitable for application to oaks that have grown within a region of considerable size that covers both sides of the North Sea. For panels used as a support for paintings of the 15th and 16th centuries, they have dated 85% of 130 English (London area) ones and about the same percentage of 25 Flemish ones. Rather earlier, sequences for oak boards used in places as far apart as York, Norwich, Oxford and Winchester have been matched. In the 10th to 12th centuries, the ring-width chronology derived for the London area shows good agreement with those for the hilly regions of Germany and that for Schleswig, as well as dating floor planks from Viking houses in York. A floating chronology, 322 years long, dataed to the 6th to 9th centuries by several radiocarbon analyses, has been formed from long sequences of rings from timbers excavated at Old Windsor and Portchester: this has matched material from Southampton and is linked with a mean curve for the well at North Elmham (Norfolk) and the strakes of the Graveney ship.