Avanavero mafic magmatism, a late Paleoproterozoic LIP in the Guiana Shield, Amazonian Craton: U–Pb ID-TIMS baddeleyite, geochemical and paleomagnetic evidence

Reis, Nelson Joaquim; Teixeira, Wilson; Hamilton, M. A.; Bispo-Santos, Franklin; Almeida, Marcelo Esteves; D’Agrella-Filho, Manoel S.

doi:10.1016/j.lithos.2012.10.014

Cited by 80 publications

(45 citation statements)

References 74 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…13b; Table 7), which are all within error of ca. 1.79-1.78 Ga Avanavero magmatism (Reis et al, 2013) and probably represent the widespread resetting of the K-Ar system in WM1 during the major intrusive event. Four samples give younger plateau and pseudo-plateau apparent ages between 1756 ± 2 Ma and 1723 ± 10 Ma that were interpreted from undisturbed to slightly disturbed age spectra ( Fig.…”

Section: Ar/ 39 Ar Geochronologymentioning

confidence: 99%

“…The Bamara-Mazaruni Supergroup, Burro-Burro Group, and Roraima Supergroup were intruded by voluminous mafic dikes and sills of the Avanavero Suite, which consist of diabase with tholeiitc affinity (Gibbs, 1987;Choudhuri et al, 1990;Gibbs and Barron, 1993;Reis et al, 2013). Much of the Avanavero Suite was emplaced within the Roraima Supergroup as sills that are up to 500 meters thick (Reis et al, 2013), with a volume estimated at 30,000 km 3 by Gibbs (1987).…”

Section: Geological Settingmentioning

confidence: 99%

“…Much of the Avanavero Suite was emplaced within the Roraima Supergroup as sills that are up to 500 meters thick (Reis et al, 2013), with a volume estimated at 30,000 km 3 by Gibbs (1987). Zircon and baddeleyite in Avanavero sills give U-Pb dates between 1787 Ma and 1780 Ma in Brazil (Santos et al, 2002(Santos et al, , 2003, and dates between 1795 Ma and 1793 Ma in Brazil and Guyana (Norcross et al, 2000;Reis et al, 2013), possibly suggesting two pulses of magmatism during the Avanavero event (Reis et al, 2013).…”

Section: Geological Settingmentioning

confidence: 99%

“…10b). The first has low, primitive 87 Sr/ 86 Sr ratios and low Sr concentrations that occur predominantly in Ca1 cement in the Roraima Supergroup, probably representing magmatic fluids associated with the mantle-derived Avanavero Suite (Reis et al, 2013). The second has intermediate 87 Sr/ 86 Sr ratios and high Sr + Mn concentrations ( Table 4) that occur in Ca1 veins in the Roraima Supergroup, possibly representing a basinal fluid having higher Rb/Sr ratios (thus giving higher 87 Sr/ 86 Sr ratios) due to interaction with Rbbearing detrital K-feldspar in the Roraima Supergroup.…”

Section: Sr In Calcitementioning

confidence: 99%

“…The sedimentology, stratigraphy, and diagenetic history of the Roraima Supergroup are also poorly documented and known only at a general level due to difficulty accessing exposures and correlating widely spaced sections. Additionally, despite increasing knowledge of the geochronology of the Roraima Basin and related rocks (Norcross et al, 2000;Reis et al, 2000;Santos et al, 2002Santos et al, , 2003Reis et al, 2013), the timing of key events in the diagenetic history of the Roraima Supergroup and how they relate to the tectonic evolution of the Amazon Craton remain unknown. Partially as a result of this limited knowledge, only limited U exploration has occurred over the last 50 years in the Roraima Basin.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Stratigraphy, diagenesis and geological evolution of the Paleoproterozoic Roraima Basin, Guyana: Links to tectonic events on the Amazon Craton and assessment for uranium mineralization potential

Beyer

Hiatt

Kyser

et al. 2015

Precambrian Research

View full text Add to dashboard Cite

Section: Ar/ 39 Ar Geochronologymentioning

confidence: 99%

Section: Geological Settingmentioning

confidence: 99%

Section: Geological Settingmentioning

confidence: 99%

Section: Sr In Calcitementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Stratigraphy, diagenesis and geological evolution of the Paleoproterozoic Roraima Basin, Guyana: Links to tectonic events on the Amazon Craton and assessment for uranium mineralization potential

Beyer

Hiatt

Kyser

et al. 2015

Precambrian Research

View full text Add to dashboard Cite

Paleoproterozoic Geomagnetic Field Strength From the Avanavero Mafic Sills, Amazonian Craton, Brazil

Chiara

Muxworthy

Trindade³

et al. 2017

Geochem Geophys Geosyst

View full text Add to dashboard Cite

A recent hypothesis has suggested that Earth's inner core nucleated during the Mesoproterozoic, as evidenced by a rapid increase in the paleointensity (ancient geomagnetic field intensity) record; however, paleointensity data during the Paleoproterozoic and Mesoproterozoic period are limited. To address this problem, we have determined paleointensity from samples from three Paleoproterozoic Avanavero mafic sills (Amazonian Craton, Brazil): Cotingo, 1,782 Ma, Puiuà, 1,788 Ma, and Pedra Preta, 1,795 Ma. We adopted a multiprotocol approach for paleointensity estimates combining Thellier‐type IZZI and LTD‐IZZI methods, and the nonheating Preisach protocol. We obtained an average VDM value of 1.3 ± 0.7 × 1022Am2 (Cotingo) of 2.0 ± 0.4 × 1022Am2 (Puiuà) and 6 ± 4 × 1022Am2 (Pedra Preta); it is argued that the Cotingo estimate is the most robust. Our results are the first data from the upper Paleoproterozoic for South America and are comparable to data available from other regions and similar periods. The new data do not invalidate the hypothesis of that Earth's inner core nucleated during the Mesoproterozoic.

show abstract

Large Igneous Provinces (LIPs) and Anoxia Events in “The Boring Billion”

Zhang

Ernst

Pei

et al. 2021

Geophysical Monograph Series

View full text Add to dashboard Cite

Recent results on ca. 1,380 Ma LIPs and black shales indicate a temporal link between LIPs and black shales and suggest a potential way for using coeval LIPs and black shales as natural markers for boundaries in the Mesoproterozoic timescale. In this chapter, we provide a brief review of LIPs and black shales during "the Boring Billion" in different cratons. The results show that in addition to the ca. 1,380 Ma LIP activity that is coeval with black shales, other major LIPs during this period can preliminarily be divided into several stages and are likely/possibly contemporaneous with black shales, especially the 1,650-1,620 Ma and ca. 1,100 Ma LIPs. Our results demonstrate that the global-scale LIPs and black shales in the Boring Billion can potentially be used as natural markers for subdivisions of the Proterozoic timescale. The results also suggest that, while the Boring Billion was characterized by suboxic or mildly oxygenated marine basins, it was interrupted by several OAEs that are partly caused by the environmental impact of LIPs. Preliminarily proposed correlation of LIPs and black shales provide a new way to explain the fluctuating evolution of atmosphere, life, and marine basins during the Boring Billion as identified by many recent studies.

show abstract

Avanavero mafic magmatism, a late Paleoproterozoic LIP in the Guiana Shield, Amazonian Craton: U–Pb ID-TIMS baddeleyite, geochemical and paleomagnetic evidence

Cited by 80 publications

References 74 publications

Stratigraphy, diagenesis and geological evolution of the Paleoproterozoic Roraima Basin, Guyana: Links to tectonic events on the Amazon Craton and assessment for uranium mineralization potential

Stratigraphy, diagenesis and geological evolution of the Paleoproterozoic Roraima Basin, Guyana: Links to tectonic events on the Amazon Craton and assessment for uranium mineralization potential

Paleoproterozoic Geomagnetic Field Strength From the Avanavero Mafic Sills, Amazonian Craton, Brazil

Large Igneous Provinces (LIPs) and Anoxia Events in “The Boring Billion”

Contact Info

Product

Resources

About