Belfast Chronology

from Wikipedia, the free encyclopedia

The Belfast Chronology (also Belfast Oak Chronology) originated in Ireland in the mid-1980s . The island is an ideal place to build a tree ring chronology . Oak woods are available from almost all periods. Bog oaks were the main resource that chronology used to date back to 5474 BC. Could be built up. The only difficulty - now resolved - was the 14th century.

The first nine centuries AD could be reconstructed using the wood from Crannógs and horizontal wheel water mills . The 14th century chronology was linked to the chronology of England via Dublin timbers as it was impossible to find Irish oaks spanning the period from 750 to 1030 AD. While the chronology problems were being resolved through this association, a program based on the exploitation of the swamp oak was initiated. This oak species originally grew on the surface of the raised bogs. It was buried and preserved by the peat. In 1984 the Irish chronology was the second longest unbroken tree ring chronology in the world. The intention to combine sequences in an uninterrupted chronology was successful.

The primary purpose of Irish oak chronology was to recalibrate the radiocarbon dates. With the complete Irish tree ring chronology it was possible to form blocks of 10 or 20 growth rings with known dates. These samples were then subjected to radiocarbon testing. The resulting Belfast calibration replaced the original Bristlecone-Pines chronology and forms the basis for an international calibration curve. The radiocarbon dates of the last seven millennia can be converted into calendar dates using the curve.

The method helped to solve archaeological problems particularly effectively. Between 1159 and 1141 BC The summer growth of many swamp oaks in Ireland was severely disturbed for two decades. Similar features could already be explained with eruptions of volcanoes (e.g. Hekla ). The timing of the outbreak was controversial. As it now turned out, the Egyptian statement, which refers to simultaneous famines, was correct. Previously were z. B. also difficult to date horizontal mills. The mills rarely produced archaeological evidence of dating. Dendrochronology allowed the timbers to be dated and showed that the vast majority were made between 630 and 930. Two thirds of all mills were built between 750 and 850. It had previously been assumed that these mills had only spread to Ireland through the Normans . The timbers used in the Corlea Trackway and County Longford were between the fall of 148 and spring of 147 B.C. Has been felled. This is the only known date of the 2nd century BC. In Ireland.

See also

literature

  • MGL Baillie: The Belfast Oak Chronology to AD 1001 In: Tree-ring Bulletin Volume 37 1977
  • Michael Ryan (Ed.): Irish Archeology illustrated. Country House, Dublin 1994, ISBN 0-946172-33-1 .

Web links