A High‐Resolution Paleosecular Variation Record for Marine Isotope Stage 6 From Southeastern Black Sea Sediments

Abstract

A full-vector paleosecular variation record (inclination, declination, relative paleointensity) from the penultimate glacial (130-180 ka) could be constructed from a total of twelve sediment cores recovered from the Arkhangelsky Ridge in the SE Black Sea. Stacking of the individual partly fragmented records was achieved by a detailed correlation using high-resolution data records from X-ray fluorescence scanning, Ca/Ti and K/Ti log-ratios, as well as magnetic susceptibility. Age constraints are provided by a detailed composite oxygen isotope stratigraphy from three of the cores, correlated to U-Th-dated speleothem oxygen isotope records from Hungary and Turkey. The temporal resolution of the stacked paleomagnetic data records is 200 years. Practically, this data set is the first high-resolution paleosecular variation record for SE Europe/SW Asia from marine isotope stage 6, comprising inclination, declination and relative paleointensity. Besides an easterly swing in declination at ~159 ka and a pronounced intensity low together with low inclinations at ~148 ka, both not reaching an excursional paleosecular variation index of > 0.5, the obtained directional variations reflect only normal paleosecular variations, with a paleosecular variation index of < 0.3. We thank S. Plewe, M. Duwe, T. Moldenhawer, and F. Brendel for their technical and logistical help during processing and sub-sampling of the cores. We also thank the captains and crews of RV Meteor, cruise M72/5 and RV Maria S. Merian, cruise MSM33, for their efforts in providing optimal scientific working conditions.

Retracted: Memory Effects in Salinity Profiles From Black Sea Sediments

“…Sediment cores from the Black Sea exhibit downward changes in sediment type (e.g., Degens & Stoffers, 1980; Wegwerth et al., 2018, 2019) and isotopic records (e.g., Badertscher et al., 2011; Zubakov, 1988) that indicate that the chemical composition of the Black Sea has oscillated over past glacial–interglacial cycles (e.g., Bahr et al., 2005, 2006; Huang et al., 2021; Kwiecien et al., 2008; Major et al., 2006; Nowaczyk et al., 2021; Schrader, 1978; Soulet, Ménot, Garreta, et al., 2011; Soulet, Ménot, Lericolais, et al., 2011; Soulet et al., 2010; Wegwerth et al., 2018, 2019). These studies indicate that during interglacial periods of the Late Pleistocene, the Black Sea was connected to the Mediterranean Sea via flow through the Bosporus and to have had brackish to marine salinity.…”

“…Holocene deepwater sedimentation rates are at most one tenth of the rates during the Weichselian (Calvert et al, 1991;Piper, 2016). Concurrently, sediment composition progressed from organic-rich sediments/sapropels in the Eemian to marine and then freshwater terrigenous sediments through most of the Weichselian to the Holocene, when marine sediments and sapropels again started to accumulate (e.g., Bahr et al, 2005Bahr et al, , 2006Huang et al, 2021;Kwiecien et al, 2008;Major et al, 2006;Nowaczyk et al, 2021;Soulet, Ménot, Garreta, et al, 2011;Soulet, Ménot, Lericolais, et al, 2011;Soulet et al, 2010;Wegwerth et al, 2018Wegwerth et al, , 2019. Down-core porewater chlorinity and derived salinity in basin sediments have been reported by Manheim and Schug (1978), Manheim and Chan (1974), Jørgensen et al (2001), Soulet et al (2010), and Ruffine et al (2021).…”

Memory Effects in Salinity Profiles From Black Sea Sediments

“…Sediment cores from the Black Sea exhibit downward changes in sediment type (e.g., Degens & Stoffers, 1980; Wegwerth et al., 2018, 2019) and isotopic records (e.g., Badertscher et al., 2011; Zubakov, 1988) that indicate that the chemical composition of the Black Sea has oscillated over past glacial‐interglacial cycles (e.g., Bahr et al., 2005, 2006; Huang et al., 2021; Kwiecien et al., 2008; Major et al., 2006; Nowaczyk et al., 2021; Schrader, 1978; Soulet et al., 2010; Soulet, Ménot, Garreta et al., 2011; Soulet, Ménot, Lericolais et al., 2011; Wegwerth et al., 2018, 2019). These studies indicate that during interglacial periods of the Late Pleistocene, the Black Sea was connected to the Mediterranean Sea via flow through the Bosporus and to have had brackish to marine salinity.…”

“…Holocene deepwater sedimentation rates are at most one tenth of the rates during the Weichselian (Calvert et al, 1991;Piper, 2016). Concurrently, sediment composition progressed from organic-rich sediments/sapropels in the Eemian to marine and then freshwater terrigenous sediments through most of the Weichselian to the Holocene, when marine sediments and sapropels again started to accumulate (e.g., Bahr et al, 2005Bahr et al, , 2006Huang et al, 2021;Kwiecien et al, 2008;Major et al, 2006;Nowaczyk et al, 2021;Soulet et al, 2010;Soulet, Ménot, Garreta, et al, 2011;Wegwerth et al, 2018Wegwerth et al, , 2019. Down-core porewater chlorinity and derived salinity in basin sediments have been reported by Manheim and Schug (1978), Manheim and Chan (1974), Jørgensen et al (2001), Soulet et al (2010), and Ruffine et al (2021).…”

Ancient Mitogenomes Reveal Stable Genetic Continuity of the Holocene Serows

“…Our BSP analysis reveals that the effective maternal population size of C. sumatraensis steadily increased from ~225 ka to ~160 ka and from ~90 ka to ~50 ka, and then remained stable for the past 50,000 years ( Figure 4 ), indicating that there had been no reduction in its genetic diversity since MIS7, despite the occurrence of multiple glacial and interglacial cycles [ 41 , 42 ]. Moreover, the population growth in C. sumatraensis occurred in two cold periods (MIS6e–MIS6d and MIS5a–MIS4) [ 43 , 44 ], which may be linked to their adaptive ability. This may be due to their adaptive ability to different altitudes [ 45 ], such as migrating to lower altitude valleys during cold periods to alleviate survival pressures and gain stronger inter-species competitive advantages.…”