Use of multi-proxy approaches to determine the origin and depositional processes in modern lacustrine sediments: Carajás Plateau, Southeastern Amazon, Brazil

Sahoo, Prafulla Kumar; Souza-Filho, Pedro Walfir M.; Guimarães, José Tasso Felix; Silva, Marcio Sousa da; Costa, Francisco Ribeiro da; Manes, Carmem-Lara de Oliveira; Oti, Douglas; Júnior, Renato Oliveira Silva; Dall’Agnol, Roberto

doi:10.1016/j.apgeochem.2014.11.010

Cited by 47 publications

(46 citation statements)

References 89 publications

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“…Total sulphur (TS) and total organic carbon (TOC) were measured using a LECO CS-300 combustion analyzer. Data were statistically analyzed according Sahoo et al (2015) and Guimarães et al (2016).…”

Section: Methodsmentioning

confidence: 99%

“…SiO 2 is weakly loaded in both PC-1 and PC-2 and highly positively loaded in PC 3 along with Sc, Pb and Se (Cluster-3). Weak correlation of SiO 2 with respect to Al 2 O 3 and TOC (Table SI) (Nesbitt et al 1980, Sahoo et al 2015, Guimarães et al 2016. The CIA values vary from 91 to 99.6 in core R4, with higher values recorded between 9500 and 2000 cal yr BP associated with Mm facies (Fig.…”

Section: Elemental Geochemistrymentioning

confidence: 98%

“…The Al 2 O 3 /TiO 2 ratio in the studied sediment varies from 4.3 to 5.8, suggesting derivation from mafic rocks. However, the ratio close to the catchment laterites (6 -7.2) and soils (4.5) (Sahoo et al 2015) indicates that the sediments could be simply related to the influence of catchment rocks. Nevertheless, such small variation of the Al 2 O 3 /TiO 2 (4.3 -5.8) recorded in the deposition sequence of Lake R4 suggests that the main sources of sediments remained constant along the time.…”

Section: Massive Mud (Mm)mentioning

confidence: 99%

“…Nevertheless, such small variation of the Al 2 O 3 /TiO 2 (4.3 -5.8) recorded in the deposition sequence of Lake R4 suggests that the main sources of sediments remained constant along the time. This is further evaluated using geochemical elements such as Al, Ti, Zr, Hf, U, Th, Sc, V, Cr and REEs and their ratios since these elements are useful indicators of sediment provenance due to their relative immobile nature during weathering, transport and sedimentation (Sahoo et al 2015).…”

Section: Massive Mud (Mm)mentioning

confidence: 99%

“…Analytical precision is ± 0.1% and ±0.2‰, respectively. The interpretations about sources of organic matter were based on previous works and references therein (Deines 1980, Salomons and Mook 1981, Meyers 1994, Thornton and McManus 1994, Tyson 1995, Meyers 1994, 1997, 2003, Lamb et al 2006, Sahoo et al 2015, 2016b.…”

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confidence: 99%

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Holocene history of a lake filling and vegetation dynamics of the Serra Sul dos Carajás, southeast Amazonia

Guimarães

Sahoo

Souza‐Filho

et al. 2019

An. Acad. Bras. Ciênc.

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Down-core changes in sedimentary facies, elemental geochemistry, pollen, spore, δ 13 C, δ 15 N and radiocarbon records from a filled lake, named R4, of the Serra Sul dos Carajás were used to study the relationship between the paleomorphological and paleoecological processes and their significance for Holocene paleoclimatology of the southeast Amazonia. The sediment deposition of the R4 lake started around 9500 cal yr BP. Increase of detrital components from 9500 to 7000 cal yr BP suggests high weathering of surrounding catchment rocks and soils, and deposition into the lake basin under mudflows. At that time, montane savanna and forest formation were already established suggesting predominance of wet climate. However, from 7000 to 3000 cal yr BP, a decline of detrital input occurred. Also, forest formation and pteridophytes were declined, while palms and macrophytes were remained relatively stable, indicating that water levels of the lake is likely dropped allowing the development of plants adapted to subaerial condition under drier climate conditions. After 3000 cal yr BP, eutrophication and low accommodation space lead to high lake productivity and the final stage of the lake filling respectively, and forest formation may has acquired its current structure, which suggests return of wetter climate conditions.

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Section: Methodsmentioning

confidence: 99%

Section: Elemental Geochemistrymentioning

confidence: 98%

Section: Massive Mud (Mm)mentioning

confidence: 99%

Section: Massive Mud (Mm)mentioning

confidence: 99%

mentioning

confidence: 99%

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Holocene history of a lake filling and vegetation dynamics of the Serra Sul dos Carajás, southeast Amazonia

Guimarães

Sahoo

Souza‐Filho

et al. 2019

An. Acad. Bras. Ciênc.

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The role of fault reactivation in the development of tropical montane lakes

Souza‐Filho

Pinheiro

Costa

et al. 2020

Earth Surf Processes Landf

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This work details the role of fault reactivation in the development of tropical montane lakes by using basin morpho-structural analysis and seismostratigraphic studies. The upland lakes are severely faulted sinkholes, whose faults penetrate the Quaternary sedimentary units. Four main stages are related to the lake formation: (i) an Early Proterozoic tectonic deformation of the rocks along the southern border of the Carajás Structure, where the lake is placed; (ii) differential erosion byand building ofthe formation of the South Carajás Hill; (iii) Fe-rich crust formation by weathering and gravitational collapse faults following the E-W plateau border and the start of Violão Lake formation during the Pliocene-Pleistocene; and (iv) episodic fault-fracture reactivation by gravitational collapse causing pulses of subsidence in the lake and outlining its faulted borders. Dissolution of the lateritic crust and erosion by runoff drainage under wet climate conditions were coeval with fault activities, which allowed the deposition of relatively thick clastic deposits organized in three main seismostratigraphic units associated with major lake-level fluctuations. Initial fault reactivation under low-level water started lacustrine basin development with deposition of prograding fan deltas related to the main drainage. A second fault reactivation by gravitational collapse increased the lake accommodation space and resulted in the deposition of fine-grained sediments from dilute interflows or overflows until 36000calyear BP. At about 31000calyear BP, rapid decreases in the lake water level under redox conditions at the sediment/water interface allowed widespread siderite formation. A third gravitational collapse episode was responsible for the increase in the lake area and depth and the returning of clastic/organic deposition up to the present. This tropical montane lake can be seen as a representative example for understanding the formation of other upland lakes controlled by fault reactivation.

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Late Quaternary environmental and climate changes registered in lacustrine sediments of the Serra Sul de Carajás, south‐east Amazonia

Guimarães¹,

Sahoo²,

Souza-Filho

et al. 2016

J Quaternary Science

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Multi-proxy analyses on sediment cores from two closed basin lakes in the Serra Sul de Caraj as were used to reconstruct environmental changes in south-eastern Amazonia during the late Quaternary. The sediment record between 65 000 and 40 000 cal a BP (older dates with high level of uncertainty) is dominated by organic sediments intercalated with detritus (e.g. Al and Ti), indicating fluctuating lake levels related to changes in precipitation. A period of lower precipitation occurred from 40 000 to 35 000 cal a BP. Between $35 000 and 20 000 cal a BP, the dominance of detrital sediments suggests wetter and warmer conditions. However, iron enrichment in a siderite-rich layer associated with the end of this period coincides with the Last Glacial Maximum, suggesting diagenetic changes in the profundal portion of the lakes and indicating a transition from oxidizing to reducing conditions. Subsequently, the period between $20 000 and 15 000 cal a BP was marked by a transition from drier to wetter climate, resulting in higher energy flows (e.g. Zr) and increased erosion of the basins. Another drier period was observed between $7000 and 3000 cal a BP (low detrital input and high Ca/Ti), when the lake levels were very low and eutrophication was high.

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Use of multi-proxy approaches to determine the origin and depositional processes in modern lacustrine sediments: Carajás Plateau, Southeastern Amazon, Brazil

Cited by 47 publications

References 89 publications

Holocene history of a lake filling and vegetation dynamics of the Serra Sul dos Carajás, southeast Amazonia

Holocene history of a lake filling and vegetation dynamics of the Serra Sul dos Carajás, southeast Amazonia

The role of fault reactivation in the development of tropical montane lakes

Late Quaternary environmental and climate changes registered in lacustrine sediments of the Serra Sul de Carajás, south‐east Amazonia

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