Early Mesozoic Wind Patterns as Suggested by Dune Bedding in the Botucatú Sandstone of Brazil and Uruguay

Bigarella, João José; Salamuni, Riad

doi:10.1130/0016-7606(1961)72[1089:emwpas]2.0.co;2

Cited by 57 publications

(24 citation statements)

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“…Further details about the GAS are given by Bigarella and Salamuni (1961), Gilboa et al (1976), Zálan et al (1990), Araújo et al (1999), Campos (1998Campos ( , 2000, and Rosello et al (2006), among others. All technical reports resulting from the PSAG can be found at http://pag-ar00.…”

Section: Location Geology and Hydrogeologymentioning

confidence: 99%

Conceptual and numerical modeling approach of the Guarani Aquifer System

Rodríguez

Vives

Gómez

2013

Hydrol. Earth Syst. Sci.

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Abstract. In large aquifers, relevant for their considerable size, regional groundwater modeling remains challenging given geologic complexity and data scarcity in space and time. Yet, it may be conjectured that regional scale groundwater flow models can help in understanding the flow system functioning and the relative magnitude of water budget components, which are important for aquifer management. The Guaraní Aquifer System is the largest transboundary aquifer in South America. It contains an enormous volume of water; however, it is not well known, being difficult to assess the impact of exploitation currently used to supply over 25 million inhabitants. This is a sensitive issue because the aquifer is shared by four countries. Moreover, an integrated groundwater model, and therefore a global water balance, were not available. In this work, a transient regional scale model for the entire aquifer based upon five simplified, equally plausible conceptual models represented by different hydraulic conductivity parametrizations is used to analyze the flow system and water balance components. Combining an increasing number of hydraulic conductivity zones and an appropriate set of boundary conditions, the hypothesis of a continuous sedimentary unit yielded errors within the calibration target in a regional sense. The magnitude of the water budget terms resulted very similar for all parametrizations. Recharge and stream/aquifer fluxes were the dominant components representing, on average, 84.2 % of total inflows and 61.4 % of total outflows, respectively. However, leakage was small compared to stream discharges of main rivers. For instance, the simulated average leakage for the Uruguay River was 8 m 3 s −1 while the observed absolute minimum discharge was 382 m 3 s −1 . Streams located in heavily pumped regions switched from a gaining condition in early years to a losing condition over time. Water is discharged through the aquifer boundaries, except at the eastern boundary. On average, pumping represented 16.2 % of inflows while aquifer storage experienced a small overall increment. The model water balance indicates that the current rate of groundwater withdrawals does not exceed the rate of recharge in a regional sense.

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Section: Location Geology and Hydrogeologymentioning

confidence: 99%

Conceptual and numerical modeling approach of the Guarani Aquifer System

Rodríguez

Vives

Gómez

2013

Hydrol. Earth Syst. Sci.

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“…It is composed of dominantly aeolian deposits, represented by large scale sets of cross strata (1e30 m) interpreted as aeolian dune deposits (Almeida, 1954;Bigarella and Salamuni, 1961). The lowermost deposits immediately above the basal contact locally contain conglomerates and gravelly sandstones deposited by ephemeral streams, as well as coarse-grained sandstones interpreted as aeolian sand sheets deposits (Bigarella and Salamuni, 1961;Soares, 1975;Almeida and Melo, 1981;Scherer, 2002). The thickness of Botucatu Formation varies from 0 to 800 m, the greatest thickness occurring in the northwestern portion of Paraná Basin (Milani, 1997).…”

Section: Palaeogeographic and Geological Settingmentioning

confidence: 99%

Early Cretaceous coniferous woods from a paleoerg (Paraná Basin, Brazil)

Pires

Guerra-Sommer

Scherer

et al. 2011

Journal of South American Earth Sciences

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“…These indicated palaeowind directions and allowed the reconstruction of regional wind patterns in Midwestern Gondwana (Scherer and Goldberg 2007). Due to the reduced thickness of the Botucatu Formation in the outcrop area, in this work, cross-strata dip directions were compiled from data available in the literature, such as the work of Bigarella and Salamuni (1961), Scherer and Goldberg (2007), and predicted wind patterns (1992). Mean vectors were plotted on the map with the "tadpole" symbol and the large arrows show the predicted wind patterns close to the studied area (Fig.…”

Section: Discussionmentioning

confidence: 99%

Zircon ages delimit the provenance of a sand extrudite from the Botucatu Formation in the Paraná volcanic province, Iraí, Brazil

Pinto

Hartmann

Santos

et al. 2015

An. Acad. Bras. Ciênc.

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Ion microprobe age determinations of 102 detrital zircon crystals from a sand extrudite, Cretaceous Paraná volcanic province, set limits on the origin of the numerous sand layers present in this major flood basalt province. The zircon U-Pb ages reflect four main orogenic cycles: Mesoproterozoic (1155-962 Ma), latest Proterozoic-early Cambrian (808-500 Ma) and two Palaeozoic (Ordovician-480 to 450 Ma, and Permian to Lower Triassic-296 to 250 Ma). Two additional small concentrations are present in the Neoarchean (2.8 to 2.6 Ga) and Paleoproterozoic (2.0 to 1.7 Ga). Zircon age peaks closely match the several pulses of igneous activity in the Precambrian Brazilian Shield and active orogeny in Argentina. A main delimitation of the origin of the sand is the absence of zircon ages from the underlying Cretaceous basalts, thus supporting an injectite origin of the sand as an extrudite that emanated from the paleoerg that constitutes the Botucatu Formation.

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Early Mesozoic Wind Patterns as Suggested by Dune Bedding in the Botucatú Sandstone of Brazil and Uruguay

Cited by 57 publications

References 0 publications

Conceptual and numerical modeling approach of the Guarani Aquifer System

Conceptual and numerical modeling approach of the Guarani Aquifer System

Early Cretaceous coniferous woods from a paleoerg (Paraná Basin, Brazil)

Zircon ages delimit the provenance of a sand extrudite from the Botucatu Formation in the Paraná volcanic province, Iraí, Brazil

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