User:Taxelson/Late Roman gap

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Late Roman gap. There are a lot of western European oak chronologies which goes back to about the migration period. There are also a great number of Roman time chronologies from Germany, Netherlands, France and England which forms a consistent complex. But the problem is that very few links - if any - exists between those two complexes! This means that it can be argued that the whole Roman time complex is still floating!

The link seems to be based upon the work of Ernst Hollstein and Berndt Becker only. The Hollstein link, however, is proved to be built on chronologies in which erroneously dated samples have been mixed[1] and according to the Becker chronology (Southern Germany) there are no information available about the quality of the critical Late Roman/Migration period linkage.[2] It is maybe not sure that the Becker chronology did not use the Hollstein chronology as a template. We do not know.

There are also a possible link between the Northern Ireland chronology build down to first century AD and the Roman English complex, but the final, indisputable link between them has not yet been found.[3]

Another possible link is stepwise from WestDK to Netherlands AD 248-295 to Hollstein Best Roman.

List of available master chronologies and collections

Anchored in present time

Anchored in Roman time

  • Hollstein: Trier area, Germany. Data retrieved from diagrams, analyzed and made available by Lars-Åke and Petra Larsson[7] 340 BC - AD 336, but the young end may have severe problems, probably due to contamination with younger material in the mean chronologies.
  • Becker: South Germany curve 370 BC - AD 1950[8]
  • Becker: Eight curve diagrams for Roman time samples are also retrieved and avaliable.[9] 24 BC - AD 181
  • Netherlands: Collections ITRDB: neth005.rwl info, ITRDB: neth009.rwl info, ITRDB: neth010.rwl info, ITRDB: neth011.rwl info,ITRDB: neth012.rwl info, ITRDB: neth013.rwl info, ITRDB: neth019.rwl info, Ester Jansma et al., 154 BC - AD 205
  • England: A collection of chronologies from England compiled of not yet published measurement data from Sheffield University and English Heritage, compiled by Petra Ossowski Larsson.[10]
    • Southern England: 13 chronologies, 256 BC - AD 207
    • Northern England: 5 chronologies (including one from QUB - Carlisle), 372 BC - AD 103
  • Ireland (mainly): "LateBC" QUB material compiled by Petra Ossowski Larsson. 1155 BC - 69 BC[11]

The possible bridges

Becker/A100

No information about the quality of this link is available. No measurement data available. Nothing said about the number of samples and sites involved, nothing about the length of overlap or t-values found. It is therefore unwise to rely on this link if not certified by independent material.

Denmark - Netherlands - Hollstein best Romans

The chronology which can be extracted from ITRDB: neth002.rwl info and ITRDB: neth006.rwl info (Ester Jansma et al.) covers AD 248-395 if dated towards WestDK AD 200 - 1986, although with not too impressing values: corr=0.31, overlap=147, T=4.0. I.e values not strong enough to certify a dating. But the block AD 280-362, however, gives corr=0.56, overlap=82, T=6.0 - and it is not uncommon that distant chronologies as those sometimes are varying according to corr values from period to period.

The relation between the Netherlands AD 248-395 and Hollstein best Romans gives: overlap=59, corr=0.40, T=4.1. That is far from an indisputable match... Towards South Germany the overlap is the all available 147 years, but only with corr=0.34, which gives T=4.4. This means that this bridge is too weak to rely on.

Ireland - English Roman

The Hollstein pseudo(?)bridge (207 years shortcut!)

Notes

  1. Lars-Åke Larsson & Petra Ossowski Larsson: An introduction to "The validity of the European chronology".
  2. Larsson: 'Retrieving some Becker data. The "Merovingian gap" is discussed by Becker but the "Migration period" is totally left in silence.
  3. Petra Ossowski Larsson and Lars-Åke Larsson: An Irish tree ring chronology: An interpretation of some raw dendrochronology data published by the Queen's University Belfast Nov 28 2010.
  4. Lars-Åke Larsson & Petra Ossowski Larsson: Merging Hollstein curves - an interpretation of the data Download: data set WebCite-archive
  5. L-Å Larsson: Retrieving some Becker data. Download: Becker Chronology file WebCite-archive
  6. http://www.natmus.dk/sw7447.asp (WebCite-archive)
  7. Lars-Åke Larsson & Petra Ossowski Larsson: Merging Hollstein curves - an interpretation of the data Download: data set WebCite-archive
  8. L-Å Larsson: Retrieving some Becker data. Download: Becker Chronology file WebCite-archive
  9. http://www.cybis.se/forfun/dendro/hollstein/becker1/BeckerRomanSamples.rwl
  10. For details see: An Irish tree ring chronology. Downloadable file: NEngSEngRoman.zip (WebCite-archive)
  11. Consists of mean chronologies for AnnaholtyBog, Ballymacombs4, Corlea, DerraghanMore, Dorsey, GarryBog4, Navan, SwanCarr. Available in QUB20101112RWL.zip (WebCite-archive)