Stratigraphy and sedimentology of the Orakei maar lake sediment sequence (Auckland Volcanic Field, New Zealand)

Leonie Peti, Paul C. Augustinus
2019 Scientific Drilling  
<p><strong>Abstract.</strong> Global paleo-climate reconstructions are largely based on observations from the Northern Hemisphere despite increasing recognition of the importance of the Southern Hemisphere mid-latitudes for understanding the drivers of the global climate system. Unfortunately, the required complete and high-resolution terrestrial records from the Southern Hemisphere mid-latitudes are few. However, the maar lakes in the Auckland Volcanic Field (AVF), New Zealand, are crucial in
more » ... his regard as they form outstanding depositional basins due to their small surface-to-depth ratio, restricted catchment, and absence of ice cover since their formation, hence ensuring continuous sedimentation with anoxic bottom water. Significantly, the estimated age of the AVF of ca. 250&amp;thinsp;ka may allow development of a continuous sediment record spanning the last two glacial cycles. The Orakei maar lake sediment sequence examined in this study spans the Last Glacial Cycle (ca. 126 to ca. 9.5&amp;thinsp;ka&amp;thinsp;cal&amp;thinsp;BP) from the phreatomagmatic eruption to the crater rim breach due to post-glacial sea-level rise. Two overlapping cores of <span class="inline-formula">&amp;gt;100</span>&amp;thinsp;m sediment were retrieved and combined to develop a complete composite stratigraphy that is presently undergoing a wide range of multi-proxy analyses.</p>
doi:10.5194/sd-25-47-2019 fatcat:cimmnmmhwzcwzdv443oje27qtu