Illinoian (stage)

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The Illinoian Stage is the name used by Quaternary geologists in North America to designate the period c.191,000 to c.130,000 years ago, during the Chibanian stage of the Pleistocene, when sediments comprising the Illinoian Glacial Lobe were deposited. It precedes the Sangamonian Stage and follows the Pre-Illinoian Stage in North America. The Illinoian Stage is defined as the period of geologic time during which the glacial tills and outwash, which comprise the bulk of the Glasford Formation, accumulated to create the Illinoian Glacial Lobe. [1] It occurs at about the same time as the penultimate glacial period.

Contents

Definition

At its type exposure in Peoria County, Illinois, the Illinoian deposits consist of three till members of the Glasford Formation. They overlay Pre-Illinoian tills of the Banner Formation, in which the Yarmouth Soil (paleosol) has developed. In this exposure, the Illinoian Glasford Formation, in which the interglacial Sangamon Soil (palesosol) has developed, is overlain by early Wisconsinan stage loess, called the Roxana Silt. A paleosol, called the Pike Soil, separates two of the till members within the Glasford Formation. [1]

Substages

The Illinoian Stage is further subdivided into:

Correlation

Since 1986, the Illinoian Stage has been interpreted as consisting of two glaciations, the early Illinoian (Marine Isotope Stage 8) and late Illinoian glaciations (Marine Isotope Stage 6) and the intervening interglacial period (Marine Isotope stage 7). In this interpretation, the Pike Soil is proposed to an interglacial (Marine Isotope Stage 7) paleosol. [4] [5] According to this interpretation, the Illinoian Stage started about 300,000 years ago and ended about 130,000 years ago. [6] [7]

However, later studies of the fluvial deposits of the Pearl Formation and Illinoian glacial tills of the Glasford Formation, which fill an ancient and buried Mississippi River valley in north-central Illinois, demonstrated that the Illinoian Stage in its type area consists of glaciations that occurred only during Marine Isotope Stage 6. The age of proglacial fluvial sediments underlying the oldest known glacial till (Kellerville Member) of the Glasford Formation yield optically stimulated luminescence (OSL) dates that averaged 160,000 BP. The oldest fluvial sediments, which overlay bedrock in the deepest part of the valley, were dated by OSL dating to around 190,000 BP. [8] [9] These OSL dates demonstrate that the Illinoian Stage is temporarily equivalent only to Marine Isotope Stage 6, which ended at 130,000 BP and started at 191,000 BP. [6] If the Illinoian Stage is limited in duration to Marine Isotope Stage 6, the Yarmouth Soil (paleosol) spans a period of geologic time equivalent to Marine Isotope stages 7, 8, 9, 10, and 11. [4]

The Illinoian Stage in North America is not exactly equivalent to the Wolstonian Stage of the British Isles. The Wolstonian stage is equivalent to Marine Isotope stages 6, 7, 8, 9, and 10. [10] [11] and, thus, started about 352,000 years ago and ended 130,000 years ago. [6] [7] As a result, the Illinoian Stage is only temporally equivalent to either middle and late Wolstonian stage or late Wolstonian stage in the British Isles. In North America, the term "Wolstonian stage" is not used by geomorphologists and Quaternary geologists [1] [5] [12] to designate glacial deposits and paleosols lying between the Sangamon and Yarmouth soils (paleosols).

Extent

During the Illinoian Stage, the Laurentide Ice Sheet covered about 85 percent of Illinois. At its maximum extent during this stage, this ice sheet reached its southernmost extent in North America near Carbondale, Illinois. At their maximum extent, the edge of Illinoian ice sheet(s) lay further south than the southernmost extent, i.e. Douglas County, Kansas, of any of the Pre-Illinoian ice sheets. [12]

See also

Related Research Articles

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The Pleistocene is the geological epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was finally confirmed in 2009 by the International Union of Geological Sciences, the cutoff of the Pleistocene and the preceding Pliocene was regarded as being 1.806 million years Before Present (BP). Publications from earlier years may use either definition of the period. The end of the Pleistocene corresponds with the end of the last glacial period and also with the end of the Paleolithic age used in archaeology. The name is a combination of Ancient Greek πλεῖστος, pleīstos, 'most' and καινός, kainós, 'new'.

<span class="mw-page-title-main">Last Glacial Period</span> Period of major glaciations of the northern hemisphere (115,000–12,000 years ago)

The Last Glacial Period (LGP), also known colloquially as the last ice age or simply ice age, occurred from the end of the Eemian to the end of the Younger Dryas, encompassing the period c. 115,000 – c. 11,700 years ago. The LGP is part of a larger sequence of glacial and interglacial periods known as the Quaternary glaciation which started around 2,588,000 years ago and is ongoing. The definition of the Quaternary as beginning 2.58 million years ago (Mya) is based on the formation of the Arctic ice cap. The Antarctic ice sheet began to form earlier, at about 34 Mya, in the mid-Cenozoic. The term Late Cenozoic Ice Age is used to include this early phase. The previous ice age, the Saalian glaciation, which ended about 128,000 years ago, was more severe than the Last Glacial Period in some areas such as Britain, but less severe in others.

<span class="mw-page-title-main">Timeline of glaciation</span> Chronology of the major ice ages of the Earth

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<span class="mw-page-title-main">Anglian stage</span> Period of the Pleistocene epoch

The Anglian Stage is the name used in the British Isles for a middle Pleistocene glaciation. It precedes the Hoxnian Stage and follows the Cromerian Stage in the British Isles. The Anglian Stage is correlated to Marine Isotope Stage 12, which started about 478,000 years ago and ended about 424,000 years ago.

The Cromerian Stage or Cromerian Complex, also called the Cromerian, is a stage in the Pleistocene glacial history of north-western Europe, mostly occurring more than half a million years ago. It is named after the East Anglian town of Cromer in Great Britain where interglacial deposits that accumulated during part of this stage were first discovered. The stratotype for this interglacial is the Cromer Forest Bed situated at the bottom of the coastal cliff near West Runton. The Cromerian stage preceded the Anglian and Elsterian glacials and show an absence of glacial deposits in western Europe, which led to the historical terms Cromerian interglacial and the Cromerian warm period. It is now known that the Cromerian consisted of multiple glacial and interglacial periods.

The Hoxnian Stage was a middle Pleistocene stage of the geological history of the British Isles. It was an interglacial which preceded the Wolstonian Stage and followed the Anglian Stage. It is equivalent to Marine Isotope Stage 11. Marine Isotope Stage 11 started 424,000 years ago and ended 374,000 years ago. The Hoxnian is divided into sub-stages Ho I to Ho IV.

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<span class="mw-page-title-main">Elster glaciation</span>

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The Beestonian Stage is an early Pleistocene stage used in the British Isles. It is named after Beeston Cliffs near West Runton in Norfolk where deposits from this stage are preserved.

The Pastonian interglacial, now called the Pastonian Stage, is the name for an early or middle Pleistocene stage used in the British Isles. It precedes the Beestonian Stage and follows the Pre-Pastonian Stage. Unfortunately the precise age of this stage cannot yet be defined in terms of absolute dating or MIS stages. The Pre-Pastonian Stage is equivalent to the Tiglian C5-6 Stage of Europe and the Pre-Illinoian I glaciation of the early Pre-Illinoian Stage of North America.

The Pre-Pastonian Stage or Baventian Stage, is the name for an early Pleistocene stage used in the British Isles. It precedes the Pastonian Stage and follows the Bramertonian Stage. This stage ended 1.806 Ma at the end of Marine Isotope Stage 65. It is not currently known when this stage started. The Pre-Pastonian Stage is equivalent to the Tiglian C4c Stage of Europe and the Pre-Illinoian J glaciation of the early Pre-Illinoian Stage of North America.

The Bramertonian Stage is the name for an early Pleistocene biostratigraphic stage in the British Isles. It precedes the Pre-Pastonian Stage. It derives its name from Bramerton Pits in Norfolk, where the deposits can be found on the surface. The exact timing of the beginning and end of the Bramertonian Stage is currently unknown. It is only known that it is equivalent to the Tiglian C1-4b Stage of Europe and early Pre-Illinoian Stage of North America. It lies somewhere in time between Marine Oxygen Isotope stages 65 to 95 and somewhere between 1.816 and 2.427 Ma. The Bramertonian is correlated with the Antian stage identified from pollen assemblages in the Ludham borehole.

<span class="mw-page-title-main">Marine isotope stages</span> Alternating warm and cool periods in the Earths paleoclimate, deduced from oxygen isotope data

Marine isotope stages (MIS), marine oxygen-isotope stages, or oxygen isotope stages (OIS), are alternating warm and cool periods in the Earth's paleoclimate, deduced from oxygen isotope data reflecting changes in temperature derived from data from deep sea core samples. Working backwards from the present, which is MIS 1 in the scale, stages with even numbers have high levels of oxygen-18 and represent cold glacial periods, while the odd-numbered stages are lows in the oxygen-18 figures, representing warm interglacial intervals. The data are derived from pollen and foraminifera (plankton) remains in drilled marine sediment cores, sapropels, and other data that reflect historic climate; these are called proxies.

<span class="mw-page-title-main">Late Pleistocene</span> Third division (unofficial) of the Pleistocene Epoch

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<span class="mw-page-title-main">Cromer Forest Bed</span> Geological formation in Norfolk, England

The Cromer Forest Bed is a geological formation in Norfolk, England. It consists of river gravels, estuary and floodplain sediments predominantly clays and muds as well as sands along the coast of northern Norfolk. It is the type locality for the Cromerian Stage of the Pleistocene between 0.8 and 0.5 million years ago. The deposit itself range varies in age from about 2 to 0.5 million years ago. It is about 6 metres thick and is exposed in cliff section near the town of West Runton. For over a century the bed, named after the local town of Cromer, has been famous for its assemblage of fossil mammal remains, containing the diverse remains of numerous taxa, including deer, carnivorans and birds. Although most of the forest bed is now obscured by coastal defence, the Cromer Forest Bed continues to be eroded and is rich in fossils including the skeletal remains of the West Runton Mammoth which was discovered in 1990. The oldest human footprints outside Africa, the Happisburgh footprints as well as handaxes and bison bones with cut marks were also found in layers considered to belong to this deposit near the town of Happisburgh.

The Pre-Illinoian Stage is used by Quaternary geologists for the early and middle Pleistocene glacial and interglacial periods of geologic time in North America from ~2.5–0.2 Ma.

The Sangamonian Stage is the term used in North America to designate the last interglacial period. In its most common usage, it is used for the period of time between 75,000 and 125,000 BP. This period of time is equivalent to all of Marine Isotope Stage 5 and the combined Eemian period and early part of the Weichselian glaciation in Europe. Less commonly, the Sangamonian Stage is restricted to the period between 122,000 and 132,000 BP, which is equivalent to Marine Oxygen Isotope Substage 5e and the Eemian period of Europe. It preceded the Wisconsinan (Wisconsin) Stage and followed the Illinoian Stage in North America.

<span class="mw-page-title-main">Don Glaciation</span> Major glaciation of eastern Europe

The Don Glaciation, also known as the Donian Glaciation and the Donian Stage, was the major glaciation of the East European Plain, 0.5–0.8 million years ago, during the Cromerian Stage of the Middle Pleistocene. It is correlated to Marine Isotope Stage 16, approximately 650,000 years ago, which globally contained one of the largest glacial volumes of the Quaternary.

References

  1. 1 2 3 Willman, H.B., and J.C. Frye, 1970, Pleistocene Stratigraphy of Illinois. Bulletin no. 94, Illinois State Geological Survey, Champaign, Illinois.
  2. In Illinois, there is accepted evidence for 3 glacial episodes (Liman, Monican, and Jubileean) separated by warmer non-glacial intervals, although recent work suggests that there were more glacial events. Mickelson, D. M. (2005) "Status of the Wisconsin and Illinoian Glaciations in their type area" Resúmenes del XVI Geológico Argentino, 20 al 23 de septiembre de 2005, La Plata
  3. Ehlers, Jürgen and Gibbard, Philip Leonard (2004) Quaternary glaciations: extent and chronology, Part 2: North America Elsevier, Amsterdam, page 77, ISBN   978-0-444-51592-6
  4. 1 2 Johnson, W.H. (1986). "Stratigraphy and correlation of the glacial deposits of the Lake Michigan lobe prior to 14 ka BP". Quaternary Science Reviews. 5: 17–22. Bibcode:1986QSRv....5...17J. doi:10.1016/0277-3791(86)90170-8.
  5. 1 2 Richmond, G.M. & D.S. Fullerton (1986). "Summation of Quaternary glaciations in the United States of America". Quaternary Science Reviews. 5: 183–196. Bibcode:1986QSRv....5..183R. doi:10.1016/0277-3791(86)90184-8.
  6. 1 2 3 Lisiecki, L.E., 2005, Ages of MIS boundaries. LR04 Benthic Stack Boston University, Boston, MA
  7. 1 2 Lisiecki, L. E.; Raymo, M. E. (January 2005). "A Pliocene-Pleistocene stack of 57 globally distributed benthic δ18O records" (PDF). Paleoceanography. 20 (1): PA1003. Bibcode:2005PalOc..20.1003L. doi:10.1029/2004PA001071. hdl: 2027.42/149224 .
    Lisiecki, L. E.; Raymo, M. E. (May 2005). "Correction to "A Pliocene-Pleistocene stack of 57 globally distributed benthic δ18O records"". Paleoceanography. 20 (2): PA2007. Bibcode:2005PalOc..20.2007L. doi: 10.1029/2005PA001164 .
    data: doi : 10.1594/PANGAEA.704257.
  8. McKay, E.D., 2007, Six Rivers, Five Glaciers, and an Outburst Flood: the Considerable Legacy of the Illinois River. Proceedings of the 2007 Governor's Conference on the Management of the Illinois River System: Our continuing Commitment, 11th Biennial Conference, Oct. 2-4, 2007, 11 p.
  9. McKay, E.D., and R.C. Berg, 2008, Optical ages spanning two glacial-interglacial cycles from deposits of the ancient Mississippi River, north-central Illinois. Geological Society of America Abstracts with Programs, Vol. 40, No. 5, p. 78 with Powerpoint presentation
  10. McMillan, A.A. (2005). "A provisional Quaternary and Neogene lithostratigraphic framework Great Britain". Netherland Journal of Geosciences. 84 (2): 87–107. doi: 10.1017/S0016774600022988 .
  11. Gibbard, P.L., S. Boreham, K.M. Cohen and A. Moscariello, 2007, Global chronostratigraphical correlation table for the last 2.7 million years v. 2007b, jpg version 844 KB. Subcommission on Quaternary Stratigraphy, Department of Geography, University of Cambridge, Cambridge, England
  12. 1 2 Stiff, B. J., and A.K. Hansel, 2004, Quaternary glaciations in Illinois. in Ehlers, J., and P.L. Gibbard, eds., pp. 71-82, Quaternary Glaciations: Extent and Chronology 2: Part II North America, Elsevier, Amsterdam. ISBN   0-444-51462-7

Further reading