Palaeoenvironmental significance of palustrine carbonates and calcretes in the geological record

Alonso-Zarza, Ana María

doi:10.1016/s0012-8252(02)00106-x

Cited by 505 publications

(418 citation statements)

References 150 publications

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“…Some samples of lake sediments (facies Qw) have values positioned between tufa and calcretes fields, but with more negative δ13C (Fig. 5) (Alonso-Zarza 2003). This occurred, probably, because these sediments are exposed to subsequent dry periods, which eventually could lead to calcretization processes (Wright and Tucker 1991).…”

Section: Factors Controlling the Continental Carbonates Genesis And Ementioning

confidence: 99%

Paleoenvironmental Evolution of Continental Carbonates in West-Central Brazil

Oliveira

Rossetti

Utida

2017

An. Acad. Bras. Ciênc.

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This paper presents a sedimentological and stratigraphical study of Quaternary (Middle to Late Pleistocene/ Holocene) continental carbonates outcrops inside Pantanal Basin and its surroundings, especially in Serra da Bodoquena, Pantanal do Miranda and Corumbá/Ladário plateau, in the state of Mato Grosso do Sul, as well as in Serra das Araras, in the state of Mato Grosso. The aim is to understand the depositional paleoenvironments and analyse climate and tectonic influences in their genesis and evolution. The results show that the deposition of these continental carbonates started in the Middle to Late Pleistocene and have continued, with some interruptions, until the present days. Sedimentary successions were identified in the different areas, without complete correlation. Two sedimentary successions separated by an erosional surface were described in Serra da Bodoquena and Serra das Araras. In Corumbá and Pantanal do Miranda, only one succession was described. These successions were deposited in elongated lakes parallel to fault planes; small lakes, related plains and plateaus; springs related to cliffs produced by faulting; rivers conditioned by topographic variation. The climatic interpretation, without proper temporal resolution, obtained by the stable-isotope composition and stratigraphic interpretation, indicates alternation of dry and wet periods. The Neoproterozoic faults with their neotectonics and the subsidence of the Pantanal Basin, are the major control for carbonated water flow and development of depositional areas, gradually turning plateaus into slight tilted areas, allowing the evolution of depositional systems from lakes to rivers.

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Section: Factors Controlling the Continental Carbonates Genesis And Ementioning

confidence: 99%

Paleoenvironmental Evolution of Continental Carbonates in West-Central Brazil

Oliveira

Rossetti

Utida

2017

An. Acad. Bras. Ciênc.

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“…The 328 formation of these nodular calcretes requires sufficient precipitation to translocate the carbonate, but equally 329 prerequisites high evaporation rates (Reeves, 1976). Typically they form during arid to semi-arid intervals 330 following humid periods (Wright, 1992; Alonzo-Zarza, 2003), or alternatively, calcretisation takes place in 331 the vadose zone within the floodplain during arid climates (Wright, 1992;Wright & Marriot, 1996, Alonzo-332 Zarza, 2003;Khalaf, 2007). Both processes imply rather arid climates, which is also reflected in the 333 increased destratification and related evaporation processes recognised in the host rock towards the top of the 334 sequence.…”

Section: Sedimentology Of the Essaouira Basin (Meskala Field) In Contmentioning

confidence: 99%

Sedimentology of the Essaouira Basin (Meskala Field) in context of regional sediment distribution patterns during upper Triassic pluvial events

Mader

Redfern

Ouataoui

2017

Journal of African Earth Sciences

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“…Morphological characteristics led to the interpretation that calcretes are pedogenic, because the profiles showed most of the features inherent to calcretization pedological processes (Pimentel et al 1996, Alonso-Zarza 2003, Wright 2007. Discontinuous carbonate cementation on the basis of the profiles ( Figure 5A) and the absence of a pseudogley feature also contributed to the interpretation of calcretes as having a pedogenic origin.…”

Section: Pedogenesis Of Calcretesmentioning

confidence: 99%

The mineralogy of paleosols in the Marília Formation and their importance in the environmental evolution of the Maastrichtian of the Bauru Basin in southeastern Brazil

2017

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Soils and paleosols reflect the complex interplay between sedimentation, erosion and non-deposition. An analysis of the mineralogical components of paleosols is critical for the reconstitution of the factors, processes and environments in which they were formed. The recognition of mineralogical assemblages can reveal the environmental conditions during pedogenesis and through quantitative analysis it is possible to identify a vertical variation in mineral concentration or leaching over the paleosol profiles, indirectly pointing to environmental processes that dominated during the pedogenetic evolution. The objective of this study is to discuss the significance of mineral phases and to quantify the environmental evolution and degree of development of paleosols of the Marília Formation, Maastrichtian of Bauru Basin. Three sections have been described (A1, A2, A3) in the Marília Formation. The mineralogy was determined by x-ray diffraction, and mineral quantification was obtained through the Rietveld refinement method. The calcretes of the Marília Formation are pedogenic, mostly authigenic minerals. The variation of quartz, calcite, palygorskite and smectite, the micromorphology, and the diversity of subsurface horizons (Bkm, Btkm, Bt) indicate that the studied paleosols did develop in semi-arid conditions, with episodes of higher rainfall rates, humidity, leaching and desilication. KEYWORDS:Calcrete; Paleoclimate; Palygorskite; Pedogenesis; Upper Cretaceous. RESUMO: Solos e paleossolos refletem complexa inter-relação entre sedimentação, erosão e não-deposição. A análise dos constituintes mineralógi-cos de paleossolos é fundamental para a reconstituição dos fatores, processos e ambientes no qual esses se formaram. O reconhecimento de determinadas assembléias mineralógicas podem revelar as condições ambientais durante a pedogênese e através da análise quantitativa se torna possível constatar variação vertical ao longo dos perfis de paleossolos, identificando

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Palaeoenvironmental significance of palustrine carbonates and calcretes in the geological record

Cited by 505 publications

References 150 publications

Paleoenvironmental Evolution of Continental Carbonates in West-Central Brazil

Paleoenvironmental Evolution of Continental Carbonates in West-Central Brazil

Sedimentology of the Essaouira Basin (Meskala Field) in context of regional sediment distribution patterns during upper Triassic pluvial events

The mineralogy of paleosols in the Marília Formation and their importance in the environmental evolution of the Maastrichtian of the Bauru Basin in southeastern Brazil

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