CIG   05423
CENTRO DE INVESTIGACIONES GEOLOGICAS
Unidad Ejecutora - UE
artículos
Título:
The Upper Jurassic (Kimmeridgian) fluvial/aeolian systems of southern Neuquén Basin, Argentina
Autor/es:
VEIGA, G.D.; SPALLETTI, L.A.
Revista:
GONDWANA RESEARCH
Editorial:
Elsevier
Referencias:
Año: 2007 vol. 11 p. 286 - 302
ISSN:
1342-937X
Resumen:
Abstract: The Kimmeridgian Quebrada del Sapo Formation in the southernmost Neuquén Basin in
Argentina represents a succession up to 40 m-thick of coarse- to fine-grained fluvial deposits overlain by
aeolian deposits. These fluvial/aeolian deposits represent a significant palaegeographic change in the basin
and are related to a major, tectonically enhanced, relative sea-level fall. The fluvial section is dominated by
braided-channel deposits, fine-grained ephemeral and sheetflood deposits. Aeolian facies are dominated by
dune deposits, with minor sandsheet and wet interdune units. Changes in the nature of both fluvial and
aeolian accumulation within the studied area suggest a regional variability of accommodation/sediment
supply conditions. The regional changes of the aeolian succession in the study area may likely reflect
different relative positions within a major erg. In the upwind margin of the erg, a relatively shallow water table
promoted waterlain accumulation in interdune areas, whereas in the central parts of the erg, dry
accumulation took place above the regional water-table level. The vertical transition observed in the
Quebrada del Sapo Fm from fluvial to aeolian deposits may be the result of a local climatic change to drier
conditions related to the development of a climatic barrier due to the vertical growth of a magmatic arc to the
west. Alternatively, the vertical transition could be related to a general water table lowering associated with
the compartmentalisation of the basin during a period of low relative sea-level.
Argentina represents a succession up to 40 m-thick of coarse- to fine-grained fluvial deposits overlain by
aeolian deposits. These fluvial/aeolian deposits represent a significant palaegeographic change in the basin
and are related to a major, tectonically enhanced, relative sea-level fall. The fluvial section is dominated by
braided-channel deposits, fine-grained ephemeral and sheetflood deposits. Aeolian facies are dominated by
dune deposits, with minor sandsheet and wet interdune units. Changes in the nature of both fluvial and
aeolian accumulation within the studied area suggest a regional variability of accommodation/sediment
supply conditions. The regional changes of the aeolian succession in the study area may likely reflect
different relative positions within a major erg. In the upwind margin of the erg, a relatively shallow water table
promoted waterlain accumulation in interdune areas, whereas in the central parts of the erg, dry
accumulation took place above the regional water-table level. The vertical transition observed in the
Quebrada del Sapo Fm from fluvial to aeolian deposits may be the result of a local climatic change to drier
conditions related to the development of a climatic barrier due to the vertical growth of a magmatic arc to the
west. Alternatively, the vertical transition could be related to a general water table lowering associated with
the compartmentalisation of the basin during a period of low relative sea-level.
Argentina represents a succession up to 40 m-thick of coarse- to fine-grained fluvial deposits overlain by
aeolian deposits. These fluvial/aeolian deposits represent a significant palaegeographic change in the basin
and are related to a major, tectonically enhanced, relative sea-level fall. The fluvial section is dominated by
braided-channel deposits, fine-grained ephemeral and sheetflood deposits. Aeolian facies are dominated by
dune deposits, with minor sandsheet and wet interdune units. Changes in the nature of both fluvial and
aeolian accumulation within the studied area suggest a regional variability of accommodation/sediment
supply conditions. The regional changes of the aeolian succession in the study area may likely reflect
different relative positions within a major erg. In the upwind margin of the erg, a relatively shallow water table
promoted waterlain accumulation in interdune areas, whereas in the central parts of the erg, dry
accumulation took place above the regional water-table level. The vertical transition observed in the
Quebrada del Sapo Fm from fluvial to aeolian deposits may be the result of a local climatic change to drier
conditions related to the development of a climatic barrier due to the vertical growth of a magmatic arc to the
west. Alternatively, the vertical transition could be related to a general water table lowering associated with
the compartmentalisation of the basin during a period of low relative sea-level.
én Basin in
Argentina represents a succession up to 40 m-thick of coarse- to fine-grained fluvial deposits overlain by
aeolian deposits. These fluvial/aeolian deposits represent a significant palaegeographic change in the basin
and are related to a major, tectonically enhanced, relative sea-level fall. The fluvial section is dominated by
braided-channel deposits, fine-grained ephemeral and sheetflood deposits. Aeolian facies are dominated by
dune deposits, with minor sandsheet and wet interdune units. Changes in the nature of both fluvial and
aeolian accumulation within the studied area suggest a regional variability of accommodation/sediment
supply conditions. The regional changes of the aeolian succession in the study area may likely reflect
different relative positions within a major erg. In the upwind margin of the erg, a relatively shallow water table
promoted waterlain accumulation in interdune areas, whereas in the central parts of the erg, dry
accumulation took place above the regional water-table level. The vertical transition observed in the
Quebrada del Sapo Fm from fluvial to aeolian deposits may be the result of a local climatic change to drier
conditions related to the development of a climatic barrier due to the vertical growth of a magmatic arc to the
west. Alternatively, the vertical transition could be related to a general water table lowering associated with
the compartmentalisation of the basin during a period of low relative sea-level.