Geochemistry of Holocene and late Pleistocene soils in the Rouge River and Scarborough Bluffs areas, South-Central Ontario, Canada

1991 ◽  
Vol 148 (1) ◽  
pp. 81-92 ◽  
Author(s):  
W. C. Mahaney ◽  
R. G. V. Hancock
Keyword(s):  
Late Pleistocene ◽  
South Central ◽  
Rouge River

Late Pleistocene chronology and paleoclimate of Vancouver Island determined from cave deposits

1981 ◽  
Vol 18 (11) ◽  
pp. 1643-1652 ◽  
Author(s):  
M. Gascoyne ◽  
D. C. Ford ◽  
H. P. Schwarcz
Keyword(s):  
Late Pleistocene ◽  
Growth Period ◽  
Vancouver Island ◽  
Isotopic Equilibrium ◽  
South Central ◽  
Cave Deposits ◽  
Short Period ◽  
Thermal Buffering

Speleothems from four caves in south-central Vancouver Island have been analysed by the 230Th/234U method. Only speleothems from one cave, Cascade Cave, near Port Alberni, contained sufficient uranium for them to be dated. Twenty-seven ages determined for seven speleothems were found to cluster in two periods: 67–28 ka, corresponding to the Olympia interstadial, and <23–10 ka (or <15 ka if corrected for detrital thorium contamination), corresponding to the Fraser (late Wisconsin) deglaciation and Holocene periods. Two speleothems were found to be deposited in isotopic equilibrium with their seepage waters. Profiles of variations in δ18O of the calcite (δ18Oc) of each of the two deposits show a decrease of 1.3‰ over the growth period, 64–28 ka. At all times, δ18Oc was less than δ18O of modern calcite in the cave. Using modern cave temperature and the variation of δ18O of seawater over the dated period, the profiles of δ18Oc are interpreted in terms of a paleotemperature record for the Olympia interstadial in Vancouver Island. The results show a gradual cooling from 4 °C at 64 ka, to 0 °C between 35 and 28 ka. These results are consistent with conditions necessary for speleothem growth and with published work on surficial Wisconsin deposits in the area. No distinct, short-period warming or cooling events are seen in the record, probably due to thermal buffering by the adjacent ocean.

New excavations at the late Pleistocene site of Chinchihuapi I, Chile

2019 ◽  
Vol 92 (1) ◽  
pp. 70-80 ◽  
Author(s):  
Tom D. Dillehay ◽  
Carlos Ocampo ◽  
Jose Saavedra ◽  
Mario Pino ◽  
Linda Scott-Cummings ◽  
...  
Keyword(s):  
Late Pleistocene ◽  
Early Holocene ◽  
Occupied Site ◽  
Radiocarbon Dates ◽  
Central Chile ◽  
South Central ◽  
Cool Temperate ◽  
Human Use ◽  
Monte Verde ◽  
Point Type

AbstractThis paper presents new excavation data on the Chinchihuapi I (CH-I) locality within the Monte Verde site complex, located along Chinchihuapi Creek in the cool, temperate Valdivian rain forest of south-central Chile. The 2017 and 2018 archaeological excavations carried out in this open-air locality reveal further that CH-I is an intermittently occupied site dating from the Early Holocene (~10,000 cal yr BP) to the late Pleistocene (at least ~14,500 cal yr BP) and probably earlier. A new series of radiocarbon dates refines the chronology of human use of the site during this period. In this paper, we describe the archaeological and stratigraphic contexts of the recent excavations and analyze the recovered artifact assemblages. A fragmented Monte Verde II point type on an exotic quartz newly recovered from excavations at CH-I indicates that this biface design existed in at least two areas of the wider site complex ~14,500 cal yr BP. In addition, associated with the early Holocene component at CH-I are later Paijan-like points recovered with lithic tools and debris and other materials. We discuss the geographic distribution of diagnostic artifacts from the site and their probable relationship to other early sites in South America.

scholarly journals Soil Development as a Function of Time in the Rouge River Basin, South-Central Ontario

2007 ◽  
Vol 40 (2) ◽  
pp. 207-216 ◽  
Author(s):  
William C. Mahaney ◽  
Kalmia Sanmugadas
Keyword(s):  
River Basin ◽  
Soil Formation ◽  
Exchange Capacity ◽  
Early Holocene ◽  
Soil Thickness ◽  
South Central ◽  
Rouge River ◽  
Extractable Iron ◽  
Over Time ◽  
Changes In Soil Properties

ABSTRACT Three soils of postglacial age, representing a chronosequence in the Rouge River Basin of south-central Ontario, were studied to determine variations in morphological, physical, chemical, and mineralogical properties. These soils, forming in alluvium of mixed mineralogy represent the Late HoIocene (Entisol), Middle Holocene (lnceptisol),and Early Holocene (lnceptisol) surfaces. Horizon differentiation and soil thickness increase with greater age, while pH drops slightly in the sola of the older profiles. Cation exchange capacity (CEC) and organic matter in the surface horizons increases slightly with age, while, for the most part, CaCO3 and Ca/ Mg ratio decrease. Significant changes occur over time, especially with an increase of dithionite-extractable iron with age (from ~ 0.20 in the Late Holocene soil to ~ 0.70 in the Middle to Early Holocene profiles). Illite and illite-smectite tend to decrease with age, being replaced by small amounts of chlorite and vermiculite. In spite of some variability in parent materials due to stratification and preweathering, and minor changes in species composition, the changes in soil properties are attributed to processes of soil formation acting over time.

Late Pleistocene stratigraphy of south-central British Columbia

1978 ◽  
Vol 15 (6) ◽  
pp. 971-980 ◽  
Author(s):  
Robert J. Fulton ◽  
Geoffrey W. Smith
Keyword(s):  
British Columbia ◽  
North America ◽  
Great Lakes ◽  
Late Pleistocene ◽  
Pacific Coast ◽  
Coastal Regions ◽  
South Central ◽  
The Pacific ◽  
Valley Area ◽  
Coast Region

The late Pleistocene deposits of south-central British Columbia record two major glacial and two major nonglacial periods of deposition. The oldest recognized Pleistocene deposits, called Westwold Sediments, were deposited during a nonglacial interval more than 60 000 years ago. Little information is available on the climate of this period, but permafrost may have been present at one time during final stages of deposition of Westwold Sediments. The latter part of this nonglacial period is probably correlative with the early Wisconsin Substage of the Great Lakes – St. Lawrence Valley area. However, deposition of the Westwold Sediments may have begun during the Sangamon Interglacial.Okanagan Centre Drift is the name applied to sediments deposited during the glaciation that followed deposition of Westwold Sediments. Okanagan Centre Drift is known to be older than 43 800 years BP and probably is older than 51 000. It is considered to correlate with an early Wisconsin glacial period.Bessette Sediments were deposited during the last major nonglacial period, which in south-central British Columbia persisted from at least 43 800 years BP (possibly more than 51 000) to about 19 000 years BP. This episode corresponds to Olympia Interglaciation of the Pacific Coast region and the mid-Wisconsin Substage of the Great Lakes – St. Lawrence Valley area. During parts of Olympia Interglaciation the climate was probably as warm as the present-day climate in the interior of British Columbia. Information from coastal regions indicates that there may have been periods of cooler and moister climate.Kamloops Lake Drift was deposited during the last major glaciation of south-central British Columbia. Ice occupied lowland areas from approximately 19 000 to 10 000 years BP. This period corresponds approximately to the Fraser Glaciation of the Pacific Coast region and the late Wisconsin Substage of central and eastern parts of North America.

Late Pleistocene landscape evolution in south-central Chile constrained by luminescence and stable cosmogenic nuclide dating

2010 ◽  
Vol 122 (7-8) ◽  
pp. 1235-1247 ◽  
Author(s):  
Katrin Rehak ◽  
Samuel Niedermann ◽  
Frank Preusser ◽  
Manfred R. Strecker ◽  
Helmut P. Echtler
Keyword(s):  
Late Pleistocene ◽  
Landscape Evolution ◽  
Central Chile ◽  
Cosmogenic Nuclide ◽  
South Central ◽  
Cosmogenic Nuclide Dating

scholarly journals Yedoma Ice Complex of the Buor Khaya Peninsula (southern Laptev Sea)

2017 ◽  
Vol 14 (5) ◽  
pp. 1261-1283 ◽  
Author(s):  
Lutz Schirrmeister ◽  
Georg Schwamborn ◽  
Pier Paul Overduin ◽  
Jens Strauss ◽  
Margret C. Fuchs ◽  
...  
Keyword(s):  
Organic Matter ◽  
Late Pleistocene ◽  
Thermal State ◽  
Distribution Data ◽  
Laptev Sea ◽  
Western Coast ◽  
Radiocarbon Dates ◽  
South Central ◽  
Marine Realm ◽  
Ice Complex

Abstract. The composition of perennially frozen deposits holds information on the palaeo-environment during and following deposition. In this study, we investigate late Pleistocene permafrost at the western coast of the Buor Khaya Peninsula in the south-central Laptev Sea (Siberia), namely the prominent eastern Siberian Yedoma Ice Complex (IC). Two Yedoma IC exposures and one drill core were studied for cryolithological (i.e. ice and sediment features), geochemical, and geochronological parameters. Borehole temperatures were measured for 3 years to capture the current thermal state of permafrost. The studied sequences were composed of ice-oversaturated silts and fine-grained sands with considerable amounts of organic matter (0.2 to 24 wt %). Syngenetic ice wedges intersect the frozen deposits. The deposition of the Yedoma IC, as revealed by radiocarbon dates of sedimentary organic matter, took place between 54.1 and 30.1 kyr BP. Continued Yedoma IC deposition until about 14.7 kyr BP is shown by dates from organic matter preserved in ice-wedge ice. For the lowermost and oldest Yedoma IC part, infrared-stimulated luminescence dates on feldspar show deposition ages between 51.1 ± 4.9 and 44.2 ± 3.6 kyr BP. End-member modelling was applied to grain-size-distribution data to determined sedimentation processes during Yedoma IC formation. Three to five robust end-members were detected within Yedoma IC deposits, which we interpret as different modes of primary and reworked unconfined alluvial slope and fan deposition as well as of localized eolian and fluvial sediment, which is overprinted by in situ frost weathering. The cryolithological inventory of the Yedoma IC preserved on the Buor Khaya Peninsula is closely related to the results of other IC studies, for example, to the west on the Bykovsky Peninsula, where formation time (mainly during the late Pleistocene marine isotope stages (MIS) 3 interstadial) and formation conditions were similar. Local freezing conditions on Buor Khaya, however, differed and created solute-enriched (salty) and isotopically light pore water pointing to a small talik layer and thaw-bulb freezing after deposition. Due to intense coastal erosion, the biogeochemical signature of the studied Yedoma IC represents the terrestrial end-member, and is closely related to organic matter currently being deposited in the marine realm of the Laptev Sea shelf.

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