Chronological framework for Lake Baikal and Lake Elgygytgyn drill cores and orbital forcing of continental climate in the Northern Hemisphere during the past 3.6 Ma

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We propose to develop a new understanding of (a) orbital forcing and (b) evolution of the Northern Hemisphere continental climate during the Plio-Pleistocene using two world’s longest continuous paleoclimate records obtained in ICDP-funded drilling projects: the recently obtained 3.6-Ma record from Lake Elgygytgyn, NE Siberia, and the uppermost 3.6-Ma portion of the record from Lake Baikal, SE Siberia. We will develop a common orbitally-tuned timescale for both records, establish accurate correlations of individual glacial-interglacial intervals in both records, and detail their relationship to marine oxygen isotope stages. We will then use the resultant new common timescale to address the orbital signatures in the continental proxy records of (i) the Pliocene ’41-kyr world’, (ii) the inception of the Northern Hemisphere glaciations at 2.7 Ma, and (iii) the transition to the ‘100-kyr world’. We will further address (iv) the ‘mystery’ of missing variance at precession frequencies in the marine δ18O records of the 41-kyr world, and (v) test if the high-latitude orbitally-forced continental signal is consistent with the ‘latitudinal heat gradient hypothesis’ on the origin of the Pliocene ice-ages. A systematic Baikal-Elgygytgyn comparison over the past 3.6 Ma will also shed light on (vi) the mechanisms of amplification of climate changes in the Arctic as compared to those in the upper mid-latitudes of the Northern Hemisphere on orbital time scales.