Late quaternary alluvial stratigraphy of a low-order tributary in central texas, USA and its response to climate and sediment supply

2004 ◽  
Vol 62 (3) ◽  
pp. 289-300 ◽  
Author(s):  
Lee Nordt
Keyword(s):  
Late Quaternary ◽  
Base Flow ◽  
Sediment Supply ◽  
Sediment Storage ◽  
Climate Conditions ◽  
Fort Hood ◽  
Stratigraphic Framework ◽  
Central Texas ◽  
High Base ◽  
Low Order

This paper presents the first comprehensive late Quaternary alluvial stratigraphic study of a low-order tributary in central Texas, using Cowhouse Creek as a case study. The late Pleistocene Jackson (JA) alluvium forms the elevated T2 terrace. The entrenched Holocene valley is filled with the buried Georgetown (GT) alluvium (approximately 11,000 to 8000 14C yr B.P.) and associated Royalty paleosol, and the surficially exposed Fort Hood (FH) alluvium (approximately 7000 to 5000 14C yr B.P.) and West Range (WR) alluvium (approximately 4200 to 600 14C yr B.P.) forming the broad T1 terrace. The Ford (FO) alluvium (<600 14C yr B.P.) forms the modern T0 floodplain entrenched into T1. Conditioned by cooler and wetter climates, Cowhouse Creek was characterized by relatively high base flow and low sediment supply during deposition of the JA and GT alluvium. Appreciable upland soil erosion ensued during the middle Holocene in response to warmer climate conditions, resulting in widespread valley filling by the FH alluvium. Deposition of the late Holocene WR and F0 alluvium was characterized by diminished sediment storage during relatively stable climate conditions. The temporal alluvial stratigraphic framework of the bedrock-confined Cowhouse Creek valley is out of phase with the alluvial sequence in the larger Brazos River valley.

Paleoenvironmental dynamics of low-order paleovalleys in the Late Quaternary – Palmas/Caçador Summit Surface – Southern Brazil

CATENA ◽  
2019 ◽  
Vol 182 ◽  
pp. 104171 ◽  
Author(s):  
Julio Cesar Paisani ◽  
Sani Daniela Lopes-Paisani ◽  
Solange Lima ◽  
Fabiano de Jesus Ribeiro ◽  
Marga Eliz Pontelli ◽  
...  
Keyword(s):  
Late Quaternary ◽  
Southern Brazil ◽  
Low Order

Stratigraphy and palaeoenvironmental interpretation of late Quaternary colluvial slope deposits in southern Africa

2021 ◽  
Author(s):  
J. Knight
Keyword(s):  
Southern Africa ◽  
Land Surface ◽  
Late Quaternary ◽  
Ecological Factors ◽  
Surface Instability ◽  
Sediment Supply ◽  
Spatial And Temporal Patterns ◽  
Catchment Scale ◽  
Accommodation Space ◽  
Slope Sediment

Abstract Slope and lowland sediment systems throughout southern Africa are dominated by the presence of colluvium with interbedded palaeosols and hardground duricrusts. These sediments correspond to phases of land surface instability and stability, respectively, during the late Quaternary. This study examines the stratigraphy and environmental interpretation of slope sediment records from specific sites in southern Africa for the period of marine isotope stages (MIS) 6 to 1 (~191 ka to present), informed by theoretical ideas of the dynamics of slope systems including sediment supply and accommodation space. Based on this analysis, phases of land surface instability and stability for the period MIS 6 to 1 are identified. The spatial and temporal patterns of land surface conditions are not a simple reflection of climate forcing, but rather reflect the workings of slope systems in response to climate in addition to the role of geologic, edaphic and ecological factors that operate within catchment-scale sediment systems. Considering these systems dynamics can yield a better understanding of the usefulness and limitations of slope sediment stratigraphies.

scholarly journals Tectonic control on the stratigraphic framework of Late Pleistocene and Holocene deposits in Marajó Island, State of Pará, eastern Amazonia

2010 ◽  
Vol 82 (2) ◽  
pp. 439-449 ◽  
Author(s):  
Dilce F. Rossetti
Keyword(s):  
Late Quaternary ◽  
Fault Reactivation ◽  
Passive Margin ◽  
Stratigraphic Correlation ◽  
Sedimentary Records ◽  
Stratigraphic Framework ◽  
Island State ◽  
Marajó Island ◽  
Northern Brazil

The traditional view that the Brazilian Amazonia is located in a tectonically stable area since the Cretaceous is changing in front of the increasing documentation of fault reactivations even during the Holocene. How the sedimentary record has responded to these events is an issue that remains to be approached with basis on field data. This work focuses on the stratigraphic correlation of late Quaternary deposits from eastern Marajó Island, with the goal of demonstrating the role of fault reactivation on the origin and preservation of these deposits. Despite the location in a stable platform of a continental passive margin, three studied stratigraphic units display significant vertical offsets that define two depocenters that are better explained through tectonic displacements. This interpretation is reinforced by several morphostructural features related to faults that occur between the studied drills. Without the influence of tectonics, sediment preservation in this characteristically low-lying terrain would have been negligible. The results of the present work motivate to look for other tectonically-influenced areas in Amazonia, which similarly might have acted as sites for sediment accommodation during the late Quaternary. These sedimentary records have great potential to be the source of valuable information for reconstructing Quaternary geological events in Northern Brazil.

scholarly journals Ground-ice stable isotopes and cryostratigraphy reflect late Quaternary palaeoclimate in the Northeast Siberian Arctic (Oyogos Yar coast, Dmitry Laptev Strait)

2017 ◽  
Author(s):  
Thomas Opel ◽  
Sebastian Wetterich ◽  
Hanno Meyer ◽  
Alexander Yu. Dereviagin ◽  
Margret C. Fuchs ◽  
...  
Keyword(s):  
Stable Isotopes ◽  
Stable Isotope ◽  
Late Quaternary ◽  
Cold Winter ◽  
Winter Climate ◽  
Climate Conditions ◽  
Winter Conditions ◽  
Winter Temperatures ◽  
Siberian Arctic ◽  
Ice Wedge

Abstract. To reconstruct palaeoclimate and palaeonvironmental conditions in the Northeast Siberian Arctic, we studied late Quaternary permafrost deposits at the Oyogos Yar coast (Dmitry Laptev Strait). New infrared stimulated luminescence ages for distinctive floodplain deposits of the Kuchchugui Suite (112.5 ± 9.6 kyr) and thermokarst lake deposits of the Krest Yuryakh Suite (102.4 ± 9.7 kyr), respectively, provide new substantial geochronological data and shed light on the landscape history of the Dmitry Laptev Strait region during the Marine Isotope Stage (MIS) 5. Ground ice stable-isotope data are presented together with cryolithological information for eight cryostratigraphic units and are complemented by data from nearby Bol'shoy Lyakhovsky Island. Our combined record of ice-wedge stable isotopes as proxy for past winter climate conditions covers the last about 200 thousand years and is supplemented by texture-ice stable isotopes which contain annual climate conditions overprinted by freezing processes. Our ice wedge stable-water isotope data indicate substantial variations in Northeast Siberian Arctic winter climate conditions during the late Quaternary, in particular between Glacial and Interglacial but also over the last millennia to decades. Stable isotope values of Ice Complex ice wedges indicate cold to very cold winter temperatures about 200 kyr ago (MIS7), very cold winter conditions about 100 kyr ago (MIS5), very cold to moderate winter conditions between about 60 and 30 kyr ago, and extremely cold winter temperatures during the Last Glacial Maximum (MIS2). Much warmer winter conditions are reflected by extensive thermokarst development during the MIS5c and by Holocene ice-wedge stable-isotopes. Modern ice-wedge stable isotopes are most enriched and testify the recent winter warming in the Arctic. Hence, ice-wedge based reconstructions of changes in winter climate conditions add substantial information to those derived from paleoecological proxies stored in permafrost and allow for distinguishing between seasonal trends of past climate dynamics. Future progress in ice-wedge dating and an improved temporal resolution of ice-wedge derived climate information may help to fully explore the palaeoclimatic potential of ice wedges.

Late Quaternary sedimentation on the southwestern Scotian Slope, eastern Canada: relationship to glaciationGeological Survey of Canada Contribution 20070176.

2008 ◽  
Vol 45 (3) ◽  
pp. 267-285 ◽  
Author(s):  
Thian Hundert ◽  
David J.W. Piper
Keyword(s):  
Late Quaternary ◽  
Sediment Cores ◽  
Sediment Supply ◽  
Scotian Shelf ◽  
Eastern Canada ◽  
Glacial Retreat ◽  
Air Gun ◽  
Continental Slopes ◽  
History Of ◽  
Seismic Reflection Profiles

The sedimentary record on continental slopes has the potential to preserve a record of glacial retreat on the adjacent continental shelf. The glacial history of the southwestern part of the Scotian Shelf is poorly known. Air-gun and high-resolution sparker profiles and numerous sediment cores up to 10 m long have been used to determine the character of sedimentation on the southwestern Scotian Slope since the last glacial maximum (LGM). Seismic-reflection profiles show that glacial till was deposited at shallow depths on the upper continental slope, and correlation to dated piston cores farther downslope show that this till dates from the LGM. Slope sedimentation at this time was dominated by local ice and deposited as plume fallout and turbidites. Progressively increasing importance of red-brown sediment derived from glacial supply to Laurentian Channel indicates retreat of ice from the shelf edge and diminishing supply of proglacial sediment from the calving embayment in the mid-Scotian Shelf. With the termination of distal proglacial sediment supply, the sedimentation rate diminished rapidly and hemipelagic sedimentation prevailed through the Holocene.

Labrador Sea bio-, tephro-, oxygen isotopic stratigraphy and Late Quaternary paleoceanographic trends

1980 ◽  
Vol 17 (7) ◽  
pp. 831-854 ◽  
Author(s):  
R. H. Fillon ◽  
J. C. Duplessy
Keyword(s):  
Deep Water ◽  
Late Quaternary ◽  
Planktonic Foraminifera ◽  
Open Water ◽  
Labrador Sea ◽  
Surface Cooling ◽  
Stratigraphic Framework ◽  
Stage 4 ◽  
Oxygen Isotopic ◽  
Stage 1

A stratigraphic framework for eastern Labrador Sea cores has been developed for the interval 0–90 000 years BP through analysis of oxygen isotopes, volcanic ash, benthonic foraminifera, and the radiolarian Diplocyclas davisiana. Benthonic and planktonic foraminiferal isotope stratigraphy and the time scale of Shackleton and Opdyke provide a basis for the approximate dating of a series of marker events which include ash zones at ca. 59 000 and ≤ 21 000 years BP; benthonic foraminiferal abundance maxima at ca. 83 000, 75 000, 60 000, 19 000, and 3000 years BP; and D. davisiana percentage maxima at ca. 90 000, 73 000, 64 000, 54 000, 45 000 – 32 000, and 10 000 years BP. Incursions of subpolar planktonic foraminifera into the area during parts of isotopic stage 2 (between about 13 000 and 25 000 years BP but probably excluding the 15 000–18 000 years BP glacial maximum interval) and during the isotopic stage 4/5a transition (around 75 000 years BP) suggest that the eastern Labrador Sea was free of sea ice, at least in summer during periods of rapid continental ice sheet growth which lead to the isotopic stage 4 and stage 2 glacial maxima. A larger than normal stage 1/stage 2 difference in the isotopic composition of benthonic foraminifera (1.8‰) implies that this open water and attendant surface cooling was a potential source for colder than modern deep water. In contrast the Norwegian Sea was a reservoir of warmer than modern deep water during the last glacial.

Neanderthal landscapes and subsistence strategies during late Quaternary glacial-interglacial periods: insights from the avian assemblages of Grotta del Cavallo (Apulia, Southern Italy)

2021 ◽  
Author(s):  
Lisa Carrera ◽  
Daniele Scarponi ◽  
Fabio Martini ◽  
Lucia Sarti ◽  
Marco Pavia
Keyword(s):  
Southern Italy ◽  
Late Quaternary ◽  
Sediment Accumulation ◽  
Sampling Effort ◽  
Paleolithic Site ◽  
Climate Conditions ◽  
Bird Assemblages ◽  
Depositional Processes ◽  
Feeding Activities ◽  
The Rich

&lt;p&gt;Grotta del Cavallo, a well-known Paleolithic site in Southern Italy (Nard&amp;#242;, Apulia), preserves one of the most important Italian Middle Paleolithic sequences. Its stratigraphic succession records the presence of Neanderthals from Marine Isotope Stage (MIS) 7 to 3, providing substantial insights on their lifeways. Here we present the taxonomic and taphonomic analysis of the bird assemblages associated to Neanderthal occupation. The rich avifaunal assemblages allowed paleoenvironmental and paleoclimatic reconstructions, noticeably improving the reconstruction of the landscape that was exploited by Neanderthals throughout the last glacial-interglacial cycles. Based on the bird taxa identified in the assemblages, Grotta del Cavallo was mainly surrounded by extensive grasslands and shrublands, with scattered open woodland and rocky outcrops, during MIS 7, 6 and 3. The coastal plain, that is currently underwater due to Holocene relative sea-level rise, hosted wetlands in the cooler periods, when it was exposed. In the cool-temperate climatic phase attributed to MIS 3, bird taxa of water and wet environments proportionally increased, as well as coverage-based rarefied richness values. This is possibly due to the expansion of wetland areas, linked to more humid conditions, or to the shorter distance of the wetland settings from the cave, compared to MIS 6 (glacial period). A consequent higher heterogeneity of the landscape is retained to drive the increased richness. The sampling effort allowed to retrieve bird taxa that provided significant paleoclimatic insights, such as Branta leucopsis, an arctic breeder, and other species currently spread at higher altitudes, that reinforce previously obtained geochemical derived inference of climate conditions cooler than the present ones. The bird assemblages also provided the first occurrence ever of Larus genei, the first Italian occurrence of Emberiza calandra, the oldest Italian occurrence of Podiceps nigricollis, and the occurrence of Sylvia communis (a species rarely retrieved in the fossil record). Ordination analyses of the bird dataset detected the drivers of taphonomic degradation and the agents responsible for the accumulation of the avian bones: modifications are mainly due to physical sin- and post-depositional processes, whereas accumulation is mainly attributed to short-range physical processes of sediment accumulation, feeding activities of nocturnal raptors and, to a lesser extent, human activities. In detail, traces found on a few bones suggest that Neanderthals introduced some of the birds in the cave with alimentary purposes, providing the earliest Italian evidence of bird exploitation ever.&lt;/p&gt;

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