Paleomagnetism and Paleoenvironmental Magnetism Studied on BDP-98 Sedimentary Cores from Lake Baikal

10Be record and magnetostratigraphy of a Miocene section from Lake Baikal: Re‐examination of the age model and its implication for climatic changes in continental Asia

“…Age scale‐reference polarity chrons from Table 1. Depth scale‐magnetic inclination for this core [ Sakai et al , 2003]. New MS ages are close to the 10 Be ages.…”

“…Figure 3 shows a comparison of the 10 Be dating, our new age model, based on the revised magnetostratigraphy (the 10 Be‐supported MS age model, Be‐MS), and the previous two MS age models: Suggested by Kashiwaya et al [2001] and Sakai et al [2003] (KSHWY) and the other model by Antipin et al [2001] (ANTPN). The major difference between Be‐MS and the other MS models partly originates from differences in the MS correlation at the top part of the core, which is dated here as between 4.4–5.0 My BP (191–248 m.b.l.f.…”

“…Recently, the ages of certain polarity chrons of late Miocene time as found in the standard reference by Cande and Kent [1995] have been challenged by precise astronomical dating [ Krijgsman et al , 1999]. However, we have used the conventional ages because they were the ones used in the previous studies with this core [ Kashiwaya et al , 2001; Antipin et al , 2001; Sakai et al , 2003].…”

“…There is still considerable uncertainty in the chronosequence of Lake Baikal sediments, which provide the longest archive of paleoclimatic change and ecological evolution in mid continents [e.g., Baikal Drilling Project Group ( BDPG ), 1998, 2000; Kashiwaya et al , 2001; Antipin et al , 2001]. Although four sedimentary records on the million‐year scale [ BDPG , 1998, 2000] have been obtained from cores taken on the Akademichesky Ridge of the lake, their age assignments have been made entirely using the magneto‐stratigraphic (MS) technique, [ BDPG , 1998, 2000; Kashiwaya et al , 2001; Antipin et al , 2001; Sakai et al , 2003], and the standard magnetic stratigraphy [ Cande and Kent , 1995]. The validity of the MS assignments for the 5 My core BDP96‐hole1(96‐1) [ Sakai et al , 2000] is supported by the decay of 10 Be in this core [ Horiuchi et al , 2003].…”

“…Until now, the MS age assignments for the longest core recovered so far from Lake Baikal, BDP98‐hole2(98‐2) core, which was recovered from 191–600 meters below the lake floor (m.b.l.f.) and is believed to extend to the Miocene period (10 to 12 My BP) [ Kashiwaya et al , 2001; Antipin et al , 2001; Sakai et al , 2003], have not been confirmed by an independent method.…”