Middle Holocene dry climate caused by change in atmospheric circulation patterns: Evidence from lake levels and stable isotopes

Research Article| March 01, 1997 Middle Holocene dry climate caused by change in atmospheric circulation patterns: Evidence from lake levels and stable isotopes Zicheng Yu; Zicheng Yu 1Department of Botany, University of Toronto, Toronto, Ontario M5S 3B2, Canada2CBCB, Royal Ontario Museum, Toronto, Ontario M5S 2C6, Canada Search for other works by this author on: GSW Google Scholar John H. McAndrews; John H. McAndrews 2CBCB, Royal Ontario Museum, Toronto, Ontario M5S 2C6, Canada3Departments of Botany and Geology, University of Toronto, Toronto, Ontario M5S 3B2, Canada Search for other works by this author on: GSW Google Scholar Ueli Eicher Ueli Eicher 4Institute of Physics, University of Bern, CH-3012 Bern, Switzerland Search for other works by this author on: GSW Google Scholar Geology (1997) 25 (3): 251–254. https://doi.org/10.1130/0091-7613(1997)025<0251:MHDCCB>2.3.CO;2 Article history first online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Zicheng Yu, John H. McAndrews, Ueli Eicher; Middle Holocene dry climate caused by change in atmospheric circulation patterns: Evidence from lake levels and stable isotopes. Geology 1997;; 25 (3): 251–254. doi: https://doi.org/10.1130/0091-7613(1997)025<0251:MHDCCB>2.3.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract Sediment hiatuses, detritus layers, and inwashed terrestrial moss layers in five cores at Crawford Lake, Ontario, Canada, show that the lake level was low between ca. 4.8 and 2 ka (1 ka = 1000 14C yr B.P.). This low level is attributed to a dry and warm climate, which has also been documented at other sites in southern Ontario, southern Michigan, and southern Wisconsin. Oxygen isotope (δ18O) values from authigenic marl show a negative shift of 2.4‰ from −9‰ to −11.4‰ (Vienna Peedee belemnite) between ca. 5 and 2 ka. Enhanced evaporation under dry and likely closed-basin conditions would lead to more enrichment in 18O, so we suggest that the trend to depleted 18O indicates a significant change in the δ18O value of the source meteoric water. The major moisture source for the Great Lakes region is the Gulf of Mexico, from which the amount and seasonality of precipitation are affected by the interplay of air masses from the Gulf of Mexico and North Pacific, probably controlled by jet stream positions and storm tracks. In the late middle Holocene, the isotopically heavy moisture from the gulf might have contributed less precipitation and/or a higher proportion in winter months, probably caused by more frequent eastward extension of dry Pacific air depleted in 18O. This hypothesis implies that the δ18O values of paleoprecipitation in the middle Holocene reflected moisture-source history more strongly than paleotemperature. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.