01961nas a2200181 4500008004100000245011300041210006900154260001200223300001200235490000700247520135900254100002001613700002701633700002401660700002601684700001901710856005001729 2006 eng d00aA multiproxy environmental investigation of Holocene wood from a submerged conifer forest in Lake Huron, USA0 amultiproxy environmental investigation of Holocene wood from a s c07/2006 a67–770 v663 a

Remains of a Holocene drowned forest in southern Lake Huron discovered in 12.5 m of water (164 m above sea level), 4.5 km east of Lexington, Michigan USA (Sanilac site), provided wood to investigate environment and lake history using several proxies. Macrofossil evidence indicates a forest comprised primarily of conifers equivalent to the modern “rich conifer swamp” community, despite generally low regional abundance of these species in pollen records. Ages range from 7095 ± 50 to 6420 ± 70 14C yr BP, but the clustering of stump dates and the development of 2 floating tree-ring chronologies suggest a briefer forest interval of no more than c. 400 years. Dendrochronological analysis indicates an environment with high inter-annual climate variability. Stable-carbon isotope composition falls within the range of modern trees from this region, but the stable-oxygen composition is consistent with warmer conditions than today. Both our tree-ring and isotope data provide support for a warmer environment in this region, consistent with a mid-Holocene thermal maximum. This drowned forest also provides a dated elevation in the Nipissing transgression at about 6420 14C yr BP (7350 cal yr BP) in the southern Lake Huron basin, a few hundred years before reopening of the St. Clair River drainage.

1 aHunter, Douglas1 aPanyushkina, Irina, P.1 aLeavitt, Steven, W.1 aWiedenhoeft, Alex, C.1 aZawiskie, John uhttps://greatlakes.ltrr.arizona.edu/node/5229