<html> <head> <meta http-equiv=Content-Type content="text/html; charset=unicode"> <meta name=Generator content="Microsoft Word 12 (filtered)"> <style> <!-- /* Font Definitions */ @font-face {font-family:[SO; panose-1:2 1 6 0 3 1 1 1 1 1;} @font-face {font-family:"Cambria Math"; panose-1:2 4 5 3 5 4 6 3 2 4;} @font-face {font-family:"\@[SO"; panose-1:2 1 6 0 3 1 1 1 1 1;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {margin:0cm; margin-bottom:.0001pt; font-size:12.0pt; font-family:[SO;} h3 {mso-style-link:"h 3 Char"; margin-right:0cm; margin-left:0cm; font-size:13.5pt; font-family:[SO; font-weight:bold;} h4 {mso-style-link:"h 4 Char"; margin-right:0cm; margin-left:0cm; font-size:12.0pt; font-family:[SO; font-weight:bold;} a:link, span.MsoHyperlink {color:blue; text-decoration:underline;} a:visited, span.MsoHyperlinkFollowed {color:purple; text-decoration:underline;} p {margin-right:0cm; margin-left:0cm; font-size:12.0pt; font-family:[SO;} span.3Char {mso-style-name:"h 3 Char"; mso-style-link:"h 3"; font-family:[SO; font-weight:bold;} span.4Char {mso-style-name:"h 4 Char"; mso-style-link:"h 4"; font-family:"Cambria","serif"; font-weight:bold;} .MsoChpDefault {font-size:10.0pt;} @page WordSection1 {size:595.3pt 841.9pt; margin:72.0pt 90.0pt 72.0pt 90.0pt;} div.WordSection1 {page:WordSection1;} --> </style> <!-- --> </head> <body lang=ZH-CN link=blue vlink=purple> <div class=WordSection1> <div id=mainContent> <h3><span lang=EN-US style='font-family:"Arial","sans-serif";color:blue'>GSSP for Holocene Stage</span></h3> <p class=MsoNormal><span lang=EN-US style='font-family:"Arial","sans-serif"; color:red'>&nbsp;</span></p> <h4><span lang=EN-US style='font-family:"Arial","sans-serif";color:red'>Definition:</span></h4> <p class=MsoNormal style='margin-bottom:12.0pt'><span lang=EN-US style='font-family:"Arial","sans-serif";color:red'>The base of the Holocene Series/Epoch is defined in the NGRIP ice-core record at a depth of 1492.45m at the horizon which shows the clearest signal of climatic warming, an event that marks the end of the last cold episode (Younger Dryas Stadial/Greenland Stadial 1) of the Pleistocene. </span></p> <table class=MsoNormalTable border=0 cellpadding=0> <tr> <td style='padding:.75pt .75pt .75pt .75pt'> <h4><span lang=EN-US style='font-family:"Arial","sans-serif"'>Location:</span></h4> <p class=MsoNormal><span lang=EN-US style='font-family:"Arial","sans-serif"'>The Holocene GSSP is located in the borehole NGRIP2 in the central Greenland ice sheet at a latitude of 75.10N and a longitude of 42.32W. </span></p> </td> <td valign=bottom style='padding:.75pt .75pt .75pt .75pt'></td> </tr> </table> <p class=MsoNormal style='margin-bottom:12.0pt'><span lang=EN-US style='font-family:"Arial","sans-serif"'>&nbsp;</span></p> <table class=MsoNormalTable border=0 cellpadding=0> <tr> <td style='padding:.75pt .75pt .75pt .75pt'> <h4><span lang=EN-US style='font-family:"Arial","sans-serif"'>Sedimentology:</span></h4> <p class=MsoNormal><span lang=EN-US style='font-family:"Arial","sans-serif"'>The NGRIP2 ice core consists almost entirely of glacier ice. </span></p> </td> <td valign=bottom style='padding:.75pt .75pt .75pt .75pt'></td> </tr> </table> <p class=MsoNormal style='margin-bottom:12.0pt'><span lang=EN-US style='font-family:"Arial","sans-serif"'>&nbsp;</span></p> <h4><span lang=EN-US style='font-family:"Arial","sans-serif"'>Primary Markers:</span></h4> <p class=MsoNormal style='margin-bottom:12.0pt'><span lang=EN-US style='font-family:"Arial","sans-serif"'>The base of the Holocene Series/Epoch is defined on the basis of the marked change in deuterium excess values that occurred over an interval of ca. 3 yr. </span></p> <h4><span lang=EN-US style='font-family:"Arial","sans-serif"'>Secondary Markers:</span></h4> <p class=MsoNormal style='margin-bottom:12.0pt'><span lang=EN-US style='font-family:"Arial","sans-serif"'>Over several decades, the <sup>18</sup>O changes from glacial to interglacial values (reflecting the temperature-dependent nature of the fractionation of oxygen isotopes). Dust concentrations drop an order of magnitude, reflecting a reduction in dust flux to the ice sheet from arid or poorly vegetated regions. Lower Na<sup>+</sup> values in the decades after the shift in deuterium excess suggest reduced transfer of sea-salt particles to the ice and hence less stormy conditions in the North Atlantic. Annual precipitation, as reflected in annual ice-layer thickness, increases by a factor of two during the first one or two decades immediately after the observed change in deuterium excess. This reflects the fact that climatic warming is accompanied by an increase in precipitation (and hence thicker ice layers) and is a feature seen in all polar ice cores at similar climatic transitions. </span></p> <h4><span lang=EN-US style='font-family:"Arial","sans-serif"'>Correlation Events:</span></h4> <p class=MsoNormal style='margin-bottom:12.0pt'><span lang=EN-US style='font-family:"Arial","sans-serif"'>Climatic -- End of the Younger Dryas cold spell, which is reflected in a shift in deuterium excess values </span></p> <h4><span lang=EN-US style='font-family:"Arial","sans-serif"'>Other Locations around the World:</span></h4> <p class=MsoNormal style='margin-bottom:12.0pt'><span lang=EN-US style='font-family:"Arial","sans-serif"'>Global auxiliary stratotypes have been established in the Eifelmaar Lakes in Germany, in Splan Pond, Canada, in Lake Maratoto, New Zealand, in Lake Suigetsu, Japan and in the Cariaco Basin, Venezuela. </span></p> <h4><span lang=EN-US style='font-family:"Arial","sans-serif"'>Notes on Derivation of Age:</span></h4> <p class=MsoNormal style='margin-bottom:12.0pt'><span lang=EN-US style='font-family:"Arial","sans-serif"'>Annual layer counting in ice core (&quot;ka&quot; is relative to AD2000); counting uncertainy is 69 years </span></p> <h4><span lang=EN-US style='font-family:"Arial","sans-serif"'>References:</span></h4> <p style='margin-left:36.0pt;text-indent:-36.0pt'><span lang=EN-US style='font-family:"Arial","sans-serif"'>Walker, M., Johnsen, S., Rasmussen, S.O., Steffensen, J-P., Popp, T., Gibbard, P., Hoek, W., Lowe, J., Andrews, J., Bjrck, S., Cwynar, L., Hughen, K., Kershaw, P., Kromer, B., Litt, T., Lowe, D.J., Nakagawa, T., Newnham R., and Schwande, J., 2008. The Global Stratotype Section and Point (GSSP) for the base of the Holocene Series/Epoch (Quaternary System/Period) in the NGRIP ice core. Episodes 31/2,</span></p> <p class=MsoNormal><span lang=EN-US style='font-family:"Arial","sans-serif"'>&nbsp;</span></p> <p style='margin-left:36.0pt;text-indent:-36.0pt'><span lang=EN-US style='font-family:"Arial","sans-serif"'><a href="Holocene.pdf">Walker, M., Johnsen, S., Rasmussen, S. O., Popp, T., Steffensen, J.-P., Gibbard, P., Hoek, W., Lowe, J., Andrews, J., Bjrck, S., Cwynar, L. C., Hughen, K., Kershaw, P., Kromer, B., Litt, T., Lowe, D. J., Nakagawa, T., Newnham, R., and Schwander, J. 2009. Formal definition and dating of the GSSP (Global Stratotype Section and Point) for the base of the Holocene using the Greenland NGRIP ice core, and selected auxiliary records. J. Quaternary Sci., Vol. 24 pp. 3-17.</a></span></p> <p class=MsoNormal><span lang=EN-US><br> <br> <a href="index.html">Back to GSSP Table</a></span></p> </div> </div> <!-- --> </body> </html>