The Integrated Schizophrenia of Quaternary Geochronology II
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Railsback's Fundamentals of Quaternary Science The integrated schizophrenia of Quaternary geochronology II Pleistocene has four named “stages” and 103 isotope The named geochronology of Quaternary ages stratigraphy of climate (in fact technically called “stages”. The “Mid-Pleistocene Transition” of isotope (Early-Middle-Late Pleistocene or Gelasian-Calabrian- “climatostratigraphy'). That makes the of system of stratigraphy is in the named “Early Pleistocene”, rather Berger, W.H., Wefer, G., 2003. On the Dynamics of the Ice Ages: Ionian-Tarantian) is well integrated with magnetic marine isotope stages ideal for contextualizing than the Middle Pleistocene. The beginning of the last Stage-11 Paradox, Mid-Brunhes Climate Shift, and 100-ky chronostratigraphy. The result is strong definition with changes in climate. However, it is has been difficult to interglacial in isotope stages (the beginning of MIS 5) Cycle. In: A.W. Droxler, R.Z. Poore and L.H. Burckle (eds.) respect to time, in that timing of the age boundaries can assign absolute ages to the marine isotope record, has been shown to be a little earlier than the beginning Earthʼs Climate and Orbital Eccentricity: The Marine Isotope be well established in stratigraphic sections where mag- which has largely been dated by orbital tuning (fitting of the last interglacial in named stages (the beginning Stage 11 Question. AGU Geophysical Monograph 137, netic results are available. However, the geochronologic of the record to Earth's orbital parameters). Thus the of the Eemian) (Shackleton et al., 2002). Finally, the 41-59. boundaries have little to do with changes in climate, strength of one side of Quaternary geochronology is beginning of the present interglacial in isotope stages Emiliani, C., 1955. Pleistocene temperatures. Journal of Geology which is the main topic of interest in Quaternary science. the weakness of the other, and vice versa. is a little earlier than the beginning of the Holocene in 63, 538–578. In contrast, the isotopic chronostratigraphy of the Quater- The contrast between the two (or three) systems Lisiecki, L.E., Raymo, M.E., 2005. A Pliocene-Pleistocene stack of named geochronology, as discussed in another of these 18 nary (i.e., marine isotope stages) is explicitly a chrono- can also be seen in the confusions between it. The pages. Thus the two (or three systems) go somewhat 57 globally distributed benthic d O records. Paleoceanography 20, doi:10.1029/2004PA001071. their separate ways – caveat geochronologator. Railsback, L.B., Gibbard, P.L., Head, M.J., Voarintsoa, N.R.G., and Magnetic chronostratigraphy: Toucanne, S., 2015. An optimized scheme of lettered marine isotope substages for the last 1.0 million years, and Chron the climatostratigraphic nature of isotope stages and Brunhes Matuyama Gauss substages. Quaternary Science Reviews, in press. Railsback, L.B., Brook, G.A., Ellwood, B.B., Liang, F., Cheng, H., Subchron Jaramillo Olduvai Edwards, R.L., in prep, A record of wet glacial stages and dry interglacial stages over the last 560 kyr from a Holocene Conventional chronostratigraphy: 1.806 Ma 2.588 Ma massive stalagmite in Carlsbad Cavern, New Mexico, USA. Age/ Tarantian 0.781 Ma Shackleton, N.J., 1969. The last interglacial in the marine and Stage Ionian Calabrian Gelasian Pliocene terrestrial record. Proceedings of the Royal Society of London, B. 174, 135–154. Age/ Late/ Stage Upper Middle Pleistocene Early/Lower Pleistocene Pliocene Epoch/ Series Pleistocene Pliocene Period/ System Quaternary Neogene Isotopic chronostratigraphy: Thousand of years before present 0 Marine isotope stages (MIS) G3 11 103 5 9 47 81 25 37 63 1 7 13 15 17 19 G10 3 96 100 Even-numbered O (‰ vs VPDB) O 52 14 stages are glacials, 18 4 8 Mid-Pleistocene δ and odd-numbered 10 Transition stages are interglacials. 2 6 12 16 (40-kyr to 100-kyr cycles) Marine isotope stages (MIS) Sources: Cohen & Gibbard 2011; Lisiecki & Raymo 2005; Pillans & Gibbard 2012.