This is also a lack of CM depth though. (sbnation.com)
With less than 3,500 glass shards per gram of sediment found within 1 cm depth of core, we estimate that the ash would not have formed a visible layer over the Malawi catchment. (pnas.org)
The Holocene assemblage is consistently recorded in the upper 5 to 20 cm of sediment on the Lomonosov Ridge and down to 15 cm depth in the Makarov Basin. (pubs.geoscienceworld.org)