Radiocarbon Wiggle-Match Dating of Bulk Sediments-How Accurate Can it Be?

We used the radiocarbon wiggle-match dating technique to date the varved sediments of Lake Gyltigesjon in southern Sweden with the main aim to construct an accurate chronology covering the period between about 3000 and 2000 cal BP. Wiggle-match dating was applied to bulk sediments to evaluate the possibility of constructing accurate chronologies in the absence of terrestrial plant macrofossils and when the amount of old carbon in the sediments is unknown. Facilitated by a floating varve chronology and relatively stable C-14 reservoir ages, the results show the possibility to assess the contribution of old carbon solely based on the C-14 wiggle-matching of bulk sediments. We confirm the wiggle-matched chronology and the C-14 reservoir age of approximately 260 yr by cross-checking the results with C-14 dating of macrofossils. The obtained calibrated ages based on bulk sediments have an uncertainty range of about 60-65 yr (95.4% confidence interval). This study confirms that C-14 wiggle-match dating of bulk sediments is a viable tool when constructing high-resolution chronologies. The method is especially useful in Sun-climate studies since the timing between solar activity variations (expressed as C-14 variations) and climate changes can be accurately determined. (Less)