Earth:Waalian interglacial
The Waalian interglacial (German: Waal-Warmzeit or Waal-Interglazial) [1] or Waalian Stage was an interglacial period of the Early Pleistocene in north-west Europe. It was preceded by the Eburonian Stage and succeeded by the Menapian Stage. It coincides with part of the much longer Beestonian stage in Britain.[2] It is variously dated by different authorities. Oxford Reference gives 1.3 to 0.9 million years ago[3] and the British Geological Survey 1.6 to 1.36 million years ago.[2] However, the 2020 chart of the international authority on stratigraphic dating, the International Commission on Stratigraphy shows it as c. 1.6 to 1.4 million years ago.[4] It is distinct from other Pleistocene periods in its complexity, vegetational composition, and vegetational succession. Its name is derived from a major branch of the Rhine delta, the Waal.
Distinguishing features
Unlike later interglacial periods, the Waalian Interglacial had at least one period of permafrost conditions, making it a "complex stage".[5] It has been proposed that the Waalian Interglacial was composed of three phases: a temperate phase, a cool phase, and another temperate phase.[6][7] The Waalian Interglacial is also distinct from later interglacial periods in that the migration of tree species during this period did not follow a clear pattern of succession (i.e., most of the species that were present at the end of the Waalian were there at the beginning).[5] In addition, though earlier research indicated that the forest species assemblage of the Waalian period mirrored that of the Tiglian,[6] more recent research into pollen records show that there was a marked decrease in the number of arboreal taxa from earlier Pleistocene periods.[8] Common arboreal taxa from the Waalian period included Tsuga, Eucommia, Celtis, and Pterocarya.[8]
References
- ↑ Zagwijn, W.H., 1960. Aspects of the Pliocene and Early Pleistocene vegetation in the Netherlands. Mededelingen Geologische Stichting, Serie C-III-l, 5: 178 pp.
- ↑ 2.0 2.1 "Waalian Stage". British Geological Survey. https://data.bgs.ac.uk/id/Geochronology/Division/BW. Retrieved 28 November 2021.
- ↑ "Waalian". Oxford Reference. https://www.oxfordreference.com/view/10.1093/oi/authority.20110803120307676. Retrieved 28 November 2021.
- ↑ "Global chronostratigraphical correlation table for the last 2.7 million years v. 2020b". International Commission on Stratigraphy. https://stratigraphy.org/ICSchart/QuaternaryChart1.jpg. Retrieved 28 November 2021.
- ↑ 5.0 5.1 Zagwijn, Waldo H. (1992-01-01). "The beginning of the Ice Age in Europe and its major subdivisions" (in en). Quaternary Science Reviews 11 (5): 583–591. doi:10.1016/0277-3791(92)90015-Z. ISSN 0277-3791. Bibcode: 1992QSRv...11..583Z. https://dx.doi.org/10.1016/0277-3791%2892%2990015-Z.
- ↑ 6.0 6.1 West, R. G. (1962-01-09). "Vegetational history of the Early Pleistocene of the Royal Society Borehole at Ludham, Norfolk" (in en). Proceedings of the Royal Society of London. Series B. Biological Sciences 155 (960): 437–453. doi:10.1098/rspb.1962.0011. ISSN 0080-4649. Bibcode: 1962RSPSB.155..437W. https://royalsocietypublishing.org/doi/10.1098/rspb.1962.0011.
- ↑ Zagwijn, W.H (1957). "Vegetation, climate and time-correlations in the Early Pleistocene of Europe". Oeol. En Mijnb N.S. (19): 233–244.
- ↑ 8.0 8.1 Hahne, Jürgen; Ellwanger, Dietrich; Stritzke, Rüdiger (2009-04-01). "Evidence for a Waalian thermomer pollen record from the research borehole Heidelberg UniNord, Upper Rhine Graben, Baden-Württemberg" (in en). E&G Quaternary Science Journal 57 (3/4): 403–410. doi:10.3285/eg.57.3-4.7. ISSN 2199-9090. https://egqsj.copernicus.org/articles/57/403/2009/.
 |  |
