Fig. 4: Bulk geochemistry proxy data from Stóra Viðarvatn and Litla Viðarvatn.
From: Both redox potential and climate control molecular proxies in Icelandic Holocene lake sediments
Orange bars reflect portions of the sediment cores likely impacted by low oxygen lake conditions based on isoGDGT-0/crenarchaeol ratios (see Fig. 5a, b). a, b Magnetic susceptibility (MS, SI × 10−5), c, d percent total organic carbon (TOC), e, f carbon to nitrogen ratios (C/N), g, h organic carbon stable isotopes (δ13C, ‰), i, j biogenic silica (BSi, FTIRs absorbance units). Vertical gray dashed line reflects the onset of soil erosion in both lakes at ~1500 BP. Note that for δ13C values, the y-axis is cut off at −28‰, and that lower values are found for Stóra Viðarvatn’s basal sediment (−31.2‰) and in Litla Viðarvatn at ~8700 BP (−34.9‰). Horizontal yellow line broadly separates aquatic and terrestrial organic matter based on δ13C values.
