Migration of glacial centers across Gondwana during Paleozoic Era

Caputo, Mário V.; Crowell, John C.

doi:10.1130/0016-7606(1985)96<1020:mogcag>2.0.co;2

Cited by 400 publications

(160 citation statements)

References 10 publications

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“…2900 Ma; Young et al, 1998), Paleoproterozoic (2400-2200 Ma; Crowell, 1999;Bekker et al, 2001;Kopp et al, 2005;Melezhik et al, 2013), Neoproterozoic (750-550 Ma;Hoffman and Li, 2009), Paleozoic (a short glacial event at 450 Ma and a longer one at 330-300 Ma; Crowell, 1978;Visser, 1982;Caputo and Crowell, 1985;Hambrey, 1985) and Cenozoic (2.58-0.01 Ma; Pillans and Gibbard, 2012). The glacial diamictites investigated here come from all five of these periods, over five geographic regions: southern Africa, North America, southern China, South America and Greenland.…”

Section: Samplesmentioning

confidence: 97%

Influence of chemical weathering on the composition of the continental crust: Insights from Li and Nd isotopes in bauxite profiles developed on Columbia River Basalts

Liu

Rudnick

McDonough

et al. 2013

Geochimica et Cosmochimica Acta

100

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Glacial diamictites, with ages ranging from $2900 to 0.01 Ma, record the changing composition of the upper continental crust through time (Gaschnig et al., 2014). Li concentrations and isotopic compositions, combined with Pb isotopic compositions, chemical index of alteration (CIA) values and relative Sr concentrations are used here to assess the degree of chemical weathering recorded in these deposits and the origin of this signature. The d Li values of most of the diamictites (ranging from À3.9 to +3.5) are lower than those of mantle-derived basalts (+3.7 ± 2, 2r), and the low d7 Li values are generally accompanied by high CIA and low Sr/Sr * values (or Sr depletion factor, Sr/Sr * = Sr/(Ce * Nd) 0.5 ), reflecting a weathering signature that may have derived from pre-depositional, syn-depositional, and/or post-depositional weathering processes. Profiles through three glacial diamictites with relatively high CIA (a fresh road cut of the Neoproterozoic Nantuo Formation (CIA = 62-69), and drill cores through the Paleoproterozoic Timeball Hill (CIA = 66-75) and Duitschland Formations (CIA = 84-91)) do not show evidence of significant post-depositional weathering. High Th/U, reflecting loss of uranium during oxidative weathering, is seen in all Paleozoic and Neoproterozoic diamictites and a few Paleoproterozoic deposits. Pb isotopic systematics suggest that this signature was largely inherited from preexisting crust, although a subset of samples (the Neoproterozoic Konnarock, Paleozoic Dwyka, and several of the Paleoproterozoic Duitschland samples) appears to have experienced postdepositional U loss. Modern glaciomarine sediments record little weathering (CIA = 47, Sr/Sr * = 0.7, d7 Li = +1.8), consistent with the cold temperatures accompanying glacial periods, and suggesting that limited syn-depositional weathering has occurred. Thus, the chemical weathering signature observed in ancient glacial diamictites appears to be largely inherited from the upper continental crust (UCC) over which the glaciers traversed. The strength of this weathering signature, based on the CIA, is greatest in the Mesoarchean and some of the Paleoproterozoic diamictites and is weaker in the Neoproterozoic and Phanerozoic glacial diamictites. Combining these data with data for Archean shales and other types of post-Paleoproterozoic sedimentary rocks (i.e., shales, mudstones, etc.), it appears that post-Paleoproterozoic upper continental crust experienced less intense chemical weathering, on average, than Archean and Paleoproterozoic upper continental crust.

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Section: Samplesmentioning

confidence: 97%

Influence of chemical weathering on the composition of the continental crust: Insights from Li and Nd isotopes in bauxite profiles developed on Columbia River Basalts

Liu

Rudnick

McDonough

et al. 2013

Geochimica et Cosmochimica Acta

100

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“…Furthermore, glacial and periglacial conditions have been inferred for the upper Cabeças Formation by Carozzi et al (1975), Caputo (1985, Caputo and Crowell (1985), Loboziak et al (2000), Streel et al (2000), Caputo et al (2008) and Isaacson et al (2008). Caputo (1985) proposed that during the late Frasnianearly Famennian the glaciers were restricted to upland regions and that during subsequent Famennian time they advanced over the Parnaíba, Amazonas and Solimões basins.…”

Section: A New Depositional Model For the Cabeças Formationmentioning

confidence: 99%

Flood-dominated fluvio-deltaic system: a new depositional model for the Devonian Cabeças Formation, Parnaíba Basin, Piauí, Brazil

Ponciano

Fávera²

2009

An. Acad. Bras. Ciênc.

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The depositional model of the Cabeças Formation is re-evaluated in the context of the Devonian paleogeography of the Parnaíba Basin, and with particular reference to similarities between the formation's facies associations on the eastern border of the basin and the flood-dominated fluvio-deltaic system facies that have been discussed in recent literature. The widespread occurrence and nature of sigmoidal clinoforms (with asymptotic cross-stratification and climbing ripples) of the Cabeças Formation are here considered as strong evidence of flood-influenced depositional settings. Sandy strata of the Passagem Member, in the vicinity of Pimenteiras and Picos (Piauí State), are interpreted as the distal part of fine-grained mouth-bar deposits interbedded with delta-front sandstone lobes showing hummocky cross-stratification. Richly fossiliferous levels, with diverse megainvertebrates and plant cuticles, occur within the delta-front lobes and the distal mouth-bar deposits, reflecting continuation of shallow marine conditions.

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“…This climate change is reflected in a decrease in coal seams and a change in paleosol type from gley soils to redder soils with Fe rich concretions and Ca rich concretions (e.g., Barren Red Beds of late WD age; Besly & Fielding, 1989). The Late Carboniferous is characterized by icehouse conditions (Caputo & Crowell, 1985;Maynard & Leeder, 1992). As a consequence, it is thought that eustatic sea-level changes triggered by the waxing and waning of the Gondwanan icesheet occurred during this interval (Wanless & Shepard, 1936).…”

Section: Paleoclimate and Sea Levelmentioning

confidence: 99%

The alluvial architecture of the Coevorden Field (Upper Carboniferous), the Netherlands

Kombrink

Bridge

Stouthamer

2007

Netherlands Journal of Geosciences

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A detailed reconstruction of the alluvial architecture of the Coevorden gas Field (Tubbergen Formation, Upper Carboniferous), which is located in the northeastern part of the Netherlands, is presented. This reconstruction is based on well logs, cross-sections and paleogeographic maps. Sedimentological analysis of a 93 m long core allowed to refine the interpretation of the depositional environment. Accurate width determinations are necessary to correctly correlate fluvial sandbodies and reconstruct alluvial architecture. Without using sedimentological information, sandbody width is likely to be overestimated. A method developed by Bridge and Tye (2000) was used to calculate the width of one sandstone body from cross-set thicknesses. On the basis of this calculation and the paleogeographic reconstructions, it may be stated that on average the width of the channel belts we studied in the Coevorden field does not exceed 4 km. Moreover, our paleogeographic reconstructions, which point to a northwestern direction of paleoflow, are in accordance with earlier observations from the study area. The Tubbergen Formation and time-equivalent sediments in Germany are reviewed briefly to put the Coevorden Field in a regional context. The thickness of the Tubbergen Formation is ∼450 m in our study area. In the adjacent German area, time-equivalent sedimentary sequences reach higher thicknesses. This may be attributed to tectonic movements along the Gronau Fault zone and the coming into existence of the Ems Low, of which the Coevorden Field is the westernmost part.

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Migration of glacial centers across Gondwana during Paleozoic Era

Cited by 400 publications

References 10 publications

Influence of chemical weathering on the composition of the continental crust: Insights from Li and Nd isotopes in bauxite profiles developed on Columbia River Basalts

Influence of chemical weathering on the composition of the continental crust: Insights from Li and Nd isotopes in bauxite profiles developed on Columbia River Basalts

Flood-dominated fluvio-deltaic system: a new depositional model for the Devonian Cabeças Formation, Parnaíba Basin, Piauí, Brazil

The alluvial architecture of the Coevorden Field (Upper Carboniferous), the Netherlands

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