Paleoclimatic evidence in duricrust, paleosoils and siliciclastic deposit of the Cenozonic of Uruguay

The continental deposits found in southern and western Uruguay show important climatic changes along the Cenozoic. The sequence begins with Paleocene palustrine carbonates known as the Queguay Formation, associated with calcretes of phreatic origin which developed mainly on fluvial sediments of Merc...

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Detalles Bibliográficos
Autor principal: Tofalo, Ofelia Rita de las Mercedes
Publicado: 2009
Materias:
Duricrusts
Paleoclimates
Paleosols
Siliciclastic sedimentites
climate variation
duricrust
fluvial deposit
loess
Miocene
Paleocene
paleoclimate
paleosol
pedogenesis
Pleistocene
siliciclastic deposit
Uruguay
Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00044822_v65_n4_p674_Tofalo
http://hdl.handle.net/20.500.12110/paper_00044822_v65_n4_p674_Tofalo
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
id paper:paper_00044822_v65_n4_p674_Tofalo
record_format dspace
spelling paper:paper_00044822_v65_n4_p674_Tofalo2023-06-08T14:26:22Z Paleoclimatic evidence in duricrust, paleosoils and siliciclastic deposit of the Cenozonic of Uruguay Tofalo, Ofelia Rita de las Mercedes Duricrusts Paleoclimates Paleosols Siliciclastic sedimentites climate variation duricrust fluvial deposit loess Miocene Paleocene paleoclimate paleosol pedogenesis Pleistocene siliciclastic deposit Uruguay The continental deposits found in southern and western Uruguay show important climatic changes along the Cenozoic. The sequence begins with Paleocene palustrine carbonates known as the Queguay Formation, associated with calcretes of phreatic origin which developed mainly on fluvial sediments of Mercedes Formation (Late Cretaceous), and indicates a semiarid climate, seasonally contrasted. The Asencio Formation (Early Eocene) is separated from Mercedes Formation by the Yapeyu paleosurface, limiting two sedimentary cycles. Fluvial deposits lies above this surface, on which Ultisols developed under a warm and humid climate; periods of intense dryness would provoked their induration and formation of ferricretes, which under subsequent increased precipitation were dismantled. Above, Fray Bentos Formation (Oligocene-Early Miocene) lies unconformably. It is composed by loessic sediments deposited in a semiarid climate, paleosols and diverse pedogenic calcretes developed on these sediments, among which a new type named tubular calcrete, are here described; in the latter the tubular units are related to a coarse prismatic structure derived from shrink-swell processes and the surface morphology of this calcrete refers to a gilgai microrelief, typical for Vertisols. The pedogenic calcretes point to a seasonal semiarid climate. The Raigón Formation (Late Pliocene- Middle Pleistocene) of fluvial origin was formed in a humid period, and shows a paleosol at the top developed in a seasonally contrasted climate. Lying unconformably, the Libertad Formation (Early to Middle Pleistocene) is composed by loesses deposited during glacial periods that were subsequently modified by pedogenesis during interglacial periods. Fil:Tófalo, O.R. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2009 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00044822_v65_n4_p674_Tofalo http://hdl.handle.net/20.500.12110/paper_00044822_v65_n4_p674_Tofalo
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Duricrusts
Paleoclimates
Paleosols
Siliciclastic sedimentites
climate variation
duricrust
fluvial deposit
loess
Miocene
Paleocene
paleoclimate
paleosol
pedogenesis
Pleistocene
siliciclastic deposit
Uruguay
spellingShingle Duricrusts
Paleoclimates
Paleosols
Siliciclastic sedimentites
climate variation
duricrust
fluvial deposit
loess
Miocene
Paleocene
paleoclimate
paleosol
pedogenesis
Pleistocene
siliciclastic deposit
Uruguay
Tofalo, Ofelia Rita de las Mercedes
Paleoclimatic evidence in duricrust, paleosoils and siliciclastic deposit of the Cenozonic of Uruguay
topic_facet Duricrusts
Paleoclimates
Paleosols
Siliciclastic sedimentites
climate variation
duricrust
fluvial deposit
loess
Miocene
Paleocene
paleoclimate
paleosol
pedogenesis
Pleistocene
siliciclastic deposit
Uruguay
description The continental deposits found in southern and western Uruguay show important climatic changes along the Cenozoic. The sequence begins with Paleocene palustrine carbonates known as the Queguay Formation, associated with calcretes of phreatic origin which developed mainly on fluvial sediments of Mercedes Formation (Late Cretaceous), and indicates a semiarid climate, seasonally contrasted. The Asencio Formation (Early Eocene) is separated from Mercedes Formation by the Yapeyu paleosurface, limiting two sedimentary cycles. Fluvial deposits lies above this surface, on which Ultisols developed under a warm and humid climate; periods of intense dryness would provoked their induration and formation of ferricretes, which under subsequent increased precipitation were dismantled. Above, Fray Bentos Formation (Oligocene-Early Miocene) lies unconformably. It is composed by loessic sediments deposited in a semiarid climate, paleosols and diverse pedogenic calcretes developed on these sediments, among which a new type named tubular calcrete, are here described; in the latter the tubular units are related to a coarse prismatic structure derived from shrink-swell processes and the surface morphology of this calcrete refers to a gilgai microrelief, typical for Vertisols. The pedogenic calcretes point to a seasonal semiarid climate. The Raigón Formation (Late Pliocene- Middle Pleistocene) of fluvial origin was formed in a humid period, and shows a paleosol at the top developed in a seasonally contrasted climate. Lying unconformably, the Libertad Formation (Early to Middle Pleistocene) is composed by loesses deposited during glacial periods that were subsequently modified by pedogenesis during interglacial periods.
author Tofalo, Ofelia Rita de las Mercedes
author_facet Tofalo, Ofelia Rita de las Mercedes
author_sort Tofalo, Ofelia Rita de las Mercedes
title Paleoclimatic evidence in duricrust, paleosoils and siliciclastic deposit of the Cenozonic of Uruguay
title_short Paleoclimatic evidence in duricrust, paleosoils and siliciclastic deposit of the Cenozonic of Uruguay
title_full Paleoclimatic evidence in duricrust, paleosoils and siliciclastic deposit of the Cenozonic of Uruguay
title_fullStr Paleoclimatic evidence in duricrust, paleosoils and siliciclastic deposit of the Cenozonic of Uruguay
title_full_unstemmed Paleoclimatic evidence in duricrust, paleosoils and siliciclastic deposit of the Cenozonic of Uruguay
title_sort paleoclimatic evidence in duricrust, paleosoils and siliciclastic deposit of the cenozonic of uruguay
publishDate 2009
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00044822_v65_n4_p674_Tofalo
http://hdl.handle.net/20.500.12110/paper_00044822_v65_n4_p674_Tofalo
work_keys_str_mv AT tofaloofeliaritadelasmercedes paleoclimaticevidenceinduricrustpaleosoilsandsiliciclasticdepositofthecenozonicofuruguay
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