IADO   05364
INSTITUTO ARGENTINO DE OCEANOGRAFIA
Unidad Ejecutora - UE
artículos
Título:
Holocene paleoinlet of the Bojuru region, southern Brazil.
Autor/es:
WESCHENFELDER, J; MEDEANIC, S; CORRÊA, I.C; ALIOTTA, S.
Revista:
JOURNAL OF COASTAL RESEARCH
Editorial:
The Coastal Education and Research Foundation (CERF)
Referencias:
Año: 2008 p. 99 - 109
ISSN:
0749-0208
Resumen:
The Holocene environmental evolution of the Bojuru region, Rio Grande do Sul state, southern Brazil, was inferred
from seismic, geochronologic, sedimentologic, and paleontologic data. The absolute ages of two samples, determined
by the 14C method, are 9400 140 Cal BP and 7370 150 Cal BP. On the basis of lithology and palynomorph and
diatom data, the six stages of paleoenvironmental development of this region were chosen. Layers of muddy sediments
characterized by a significant incidence of marine palynomorphs and marine and estuarine diatoms were deposited
during the Early and Middle Holocene. Seismic records (3.5 kHz) revealed a prominent buried paleochannel that can
be correlated to the present Barra Falsa channel. The main period of the channel incision was related to the last
regressive event of the Late Pleistocene. During the last Holocene transgression, this paleochannel was filled up by
fluvial, estuarine, and marine sediments. The integrated analysis of data reveals that the Barra Falsa feature resulted
from a former channel connecting the Patos lagoon and the Atlantic Ocean. The closure of this inlet channel is
attributed to shifts in the sedimentation milieu related to the transgressive maximum and subsequent regression
during the Late Holocene.
diatom data, the six stages of paleoenvironmental development of this region were chosen. Layers of muddy sediments
characterized by a significant incidence of marine palynomorphs and marine and estuarine diatoms were deposited
during the Early and Middle Holocene. Seismic records (3.5 kHz) revealed a prominent buried paleochannel that can
be correlated to the present Barra Falsa channel. The main period of the channel incision was related to the last
regressive event of the Late Pleistocene. During the last Holocene transgression, this paleochannel was filled up by
fluvial, estuarine, and marine sediments. The integrated analysis of data reveals that the Barra Falsa feature resulted
from a former channel connecting the Patos lagoon and the Atlantic Ocean. The closure of this inlet channel is
attributed to shifts in the sedimentation milieu related to the transgressive maximum and subsequent regression
during the Late Holocene.
diatom data, the six stages of paleoenvironmental development of this region were chosen. Layers of muddy sediments
characterized by a significant incidence of marine palynomorphs and marine and estuarine diatoms were deposited
during the Early and Middle Holocene. Seismic records (3.5 kHz) revealed a prominent buried paleochannel that can
be correlated to the present Barra Falsa channel. The main period of the channel incision was related to the last
regressive event of the Late Pleistocene. During the last Holocene transgression, this paleochannel was filled up by
fluvial, estuarine, and marine sediments. The integrated analysis of data reveals that the Barra Falsa feature resulted
from a former channel connecting the Patos lagoon and the Atlantic Ocean. The closure of this inlet channel is
attributed to shifts in the sedimentation milieu related to the transgressive maximum and subsequent regression
during the Late Holocene.
14C method, are 9400 140 Cal BP and 7370 150 Cal BP. On the basis of lithology and palynomorph and
diatom data, the six stages of paleoenvironmental development of this region were chosen. Layers of muddy sediments
characterized by a significant incidence of marine palynomorphs and marine and estuarine diatoms were deposited
during the Early and Middle Holocene. Seismic records (3.5 kHz) revealed a prominent buried paleochannel that can
be correlated to the present Barra Falsa channel. The main period of the channel incision was related to the last
regressive event of the Late Pleistocene. During the last Holocene transgression, this paleochannel was filled up by
fluvial, estuarine, and marine sediments. The integrated analysis of data reveals that the Barra Falsa feature resulted
from a former channel connecting the Patos lagoon and the Atlantic Ocean. The closure of this inlet channel is
attributed to shifts in the sedimentation milieu related to the transgressive maximum and subsequent regression
during the Late Holocene.