Estudo Dos Parâmetros Hidrodinâmicos Obtidos Em Ensaios  De Campo Em Itabiritos Brandos Da Porção Sudoeste Do  Quadrilátero Ferrífero, Mg

Mesquita, Daniele Costa de; Dantas, Júlia Cotta Maciel; Paula, Rodrigo Sérgio de; Guerra, Kênia Janete

doi:10.18285/geonomos.v25i2.1077

Cited by 4 publications

(7 citation statements)

References 3 publications

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“…The climate regime in the SE area is highly seasonal, with over 80% of the ∼1,400 mm/year rainfall concentrated in November-March. Canga is a highly porous rock, with values between 24 and 29% (Costa and Sá, 2018), while the friable ore underneath the canga is highly impermeable with values as low as 10 −8 m/s (Mesquita et al, 2017). Thus, rainfall infiltrates quickly through the canga towards the caves and then drains rapidly toward the surface, with very little retention of water, except in a few shallow internal ponds.…”

Section: Fe(iii) Reduction In Column Incubationsmentioning

confidence: 99%

“…Given the inhibition of Fe-reduction by oxygen, we wondered whether this material was involved in promoting Fe-reduction and increased porosity, leading to formation of the IFCs. Canga is a rather porous media, and active vertical percolation of water occurs during rainfall, the patterns of which can be irregular, depending on season (Mesquita et al, 2017;Parker et al, 2018). As such, intermittent periods of extensive water circulation around and within caves and their hosting rocks can occur, followed by water stagnation or dry periods.…”

Section: Introductionmentioning

confidence: 99%

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Hydrologic Alteration and Enhanced Microbial Reductive Dissolution of Fe(III) (hydr)oxides Under Flow Conditions in Fe(III)-Rich Rocks: Contribution to Cave-Forming Processes

et al. 2021

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Previous work demonstrated that microbial Fe(III)-reduction contributes to void formation, and potentially cave formation within Fe(III)-rich rocks, such as banded iron formation (BIF), iron ore and canga (a surficial duricrust), based on field observations and static batch cultures. Microbiological Fe(III) reduction is often limited when biogenic Fe(II) passivates further Fe(III) reduction, although subsurface groundwater flow and the export of biogenic Fe(II) could alleviate this passivation process, and thus accelerate cave formation. Given that static batch cultures are unlikely to reflect the dynamics of groundwater flow conditions in situ, we carried out comparative batch and column experiments to extend our understanding of the mass transport of iron and other solutes under flow conditions, and its effect on community structure dynamics and Fe(III)-reduction. A solution with chemistry approximating cave-associated porewater was amended with 5.0 mM lactate as a carbon source and added to columns packed with canga and inoculated with an assemblage of microorganisms associated with the interior of cave walls. Under anaerobic conditions, microbial Fe(III) reduction was enhanced in flow-through column incubations, compared to static batch incubations. During incubation, the microbial community profile in both batch culture and columns shifted from a Proteobacterial dominance to the Firmicutes, including Clostridiaceae, Peptococcaceae, and Veillonellaceae, the latter of which has not previously been shown to reduce Fe(III). The bacterial Fe(III) reduction altered the advective properties of canga-packed columns and enhanced permeability. Our results demonstrate that removing inhibitory Fe(II) via mimicking hydrologic flow of groundwater increases reduction rates and overall Fe-oxide dissolution, which in turn alters the hydrology of the Fe(III)-rich rocks. Our results also suggest that reductive weathering of Fe(III)-rich rocks such as canga, BIF, and iron ores may be more substantial than previously understood.

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Section: Fe(iii) Reduction In Column Incubationsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Hydrologic Alteration and Enhanced Microbial Reductive Dissolution of Fe(III) (hydr)oxides Under Flow Conditions in Fe(III)-Rich Rocks: Contribution to Cave-Forming Processes

et al. 2021

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“…According to Mourão (2007) and Mesquita et al (2017), the hydraulic conductivity in the soft itabirite shows continuity across the entire Moeda Syncline, which is corroborated by Guerra (2010) and Bertachini (2020). The variation in transmissivity values presented indicates the variation in thickness of the Cauê Formation, in addition to the presence of regions of confinement and structural control associated with secondary permeability.…”

Section: Hydrogeologymentioning

confidence: 73%

“…To characterize the aquifer units, hydrodynamic parameters such as hydraulic conductivity (K), transmissivity (T), and storage (S) are compared. Among the parameters calculated for the Cauê Aquifer in previous works (Table 2), we highlight the works of Mourão (2007), carried out in the central-northern portion of the Moeda Syncline; Mesquita et al (2017), who presented parameters referring to the southwestern region of this structure; Guerra (2010), who performed tests in the municipality of Nova Lima, in the Serra do Curral Homocline; and Schlumberger Water Services (2017) and Bertachini (2020) in the western edge of the Syncline.…”

Section: Hydrogeologymentioning

confidence: 76%

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The Cauê Aquifer on the eastern limb of the Moeda Syncline: characterization, impacts, and flow in the western Iron Quadrangle (Quadrilátero Ferrífero), MG, Brazil

Magalhães

Melo

Guiguer³

et al. 2022

Braz. J. Geol.

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The Cauê Aquifer is an important water supplier to the third largest urban agglomeration in Brazil. The Metropolitan Region of Belo Horizonte is in the Iron Quadrangle, site of intense iron ore mining, requiring large volumes of water and mine dewatering. In this context, we evaluate the regional impact on groundwater level between 2000 and 2019 based on a conceptual hydrogeological flow model on the eastern limb of the Moeda Syncline. This study includes the definition of boundary conditions and aquifer units, the calculation of hydrodynamic parameters, water balance, renewable reserve, and flow analysis. The Cauê, Gandarela, and Moeda aquifers are considered aquifer units, among which the Cauê Aquifer showed the highest hydraulic conductivity (9.45×10 -7 m/s on average) as well as the highest recharge rate, with 38.67% rainfall. The average volume pumped was estimated at 41 million m³/year, equivalent to about 150% of the renewable reserve of the Cauê Aquifer, calculated at 27 million m³/year. Underground flow in the area tends southward, and the Cauê Aquifer acts as a water divide, which is less evident in the center of the area, where the greatest impact on groundwater level lowering occurs.

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Estimating transmissivity and storativity in a karst aquifer by direct and indirect methods

Pena,

de Paula,

Velasquez

et al. 2024

Hydrological Processes

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The karst aquifer located in the Environmental Protection Area of Lagoa Santa, Minas Gerais, Brazil, exhibits the characteristic morphological features of an evolved karst environment, including large caves, sinkholes, and copious springs. Understanding the hydrogeological characteristics of karst aquifers is crucial for effective management of public resources and prevention of contamination, as these aquifers are highly vulnerable, making it essential to identify and mitigate potential risks. Given the ongoing economic and population growth in this region, the assessment of the hydrogeological parameters that control the dynamics of local flow becomes relevant for the proper evaluation of hydrogeological models and the management of water resources. Four classical pumping test analysis methods were compared to quantify the flow and storativity of the aquifer: Theis (1935), Neuman (1972), Moench (1984), and Agarwal (1980). In addition, indirect estimation methods based on the identification of capture zones and the analysis of recession curves of water courses were employed, since these approaches are cheaper and easier to apply in areas with low information. The statistical analysis of the results suggests that classical solutions can be applied to the karst aquifer to estimate hydrogeological parameters, apart from the Storage Coefficient obtained using the Neuman method. In general, the indirect estimation methods tend to produce values that are consistent with those obtained through direct methods, albeit with some reservations. The transmissivity values obtained from the pumping tests were approximately 3.0 × 10−4 m2/s, while the storage coefficient is estimated to be around 3.7 × 10−3. The indirect estimation methods yield transmissivity values of about 1.8 × 10−4 m2/s using the capture zone method, and storage coefficient values of 4.0 × 10−3 and 3.9 × 10−2 using recession curve analysis.

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Estudo Dos Parâmetros Hidrodinâmicos Obtidos Em Ensaios De Campo Em Itabiritos Brandos Da Porção Sudoeste Do Quadrilátero Ferrífero, Mg

Cited by 4 publications

References 3 publications

Hydrologic Alteration and Enhanced Microbial Reductive Dissolution of Fe(III) (hydr)oxides Under Flow Conditions in Fe(III)-Rich Rocks: Contribution to Cave-Forming Processes

Hydrologic Alteration and Enhanced Microbial Reductive Dissolution of Fe(III) (hydr)oxides Under Flow Conditions in Fe(III)-Rich Rocks: Contribution to Cave-Forming Processes

The Cauê Aquifer on the eastern limb of the Moeda Syncline: characterization, impacts, and flow in the western Iron Quadrangle (Quadrilátero Ferrífero), MG, Brazil

Estimating transmissivity and storativity in a karst aquifer by direct and indirect methods

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