Stratigraphy, tectonics and detrital zircon U-Pb (LA-ICP-MS) geochronology of the Rio Preto Belt and northern Paramirim corridor, NE, Brazil

ABSTRACT: Two important Proterozoic metasedimentary sequences, the Rio Preto and Santo Onofre Groups, crop out along the northwestern margin of the São Francisco craton and in northern Paramirim corridor, respectively. The Rio Preto Group, involved in the eponymous fold-thrust belt along the northwestern cratonic boundary, comprises the Formosa (garnet schist, quartz-mica schist, quartzite, chlorite-sericite schist and ferriferous quartz schist) and Canabravinha (quartzite, micaceous quartzite, metarhytmite, phylite, schist and metaturbidite) formations. The Santo Onofre Group occurs exclusively in the Paramirim corridor, and is composed of quartzite and minor carbonaceous or Mn-rich phylite. These units record sedimentation in shallow to deep-water marine settings related to rift basins, and were deformed and metamorphosed under greenschist facies conditions during the Brasiliano orogeny. Here we present 427 new detrital zircon U-Pb ages, which constrain the maximum depositional ages of ca. 971 Ma for the Santo Onofre Group, ca. 912 Ma for the Canabravinha Formation, and ca. 965 Ma for the Formosa Formation of the Rio Preto Group. Our data suggests that the Santo Onofre and the Rio Preto Groups accumulated in two distinct basin settings. The latter, composed mostly of sandy rocks, would represent a relatively stable, shallow-marine shelf environment. The Rio Preto Group, with metadiamictite, quartzite, pelitic and rhythmitic rocks, represents a shallow to deep marine environment influenced by gravity flows. Both groups were probably deposited in the Late Tonian, and are potential correlatives of the lower (pre-glacial) units of the Macaúbas Group of the Araçuaí belt.

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Tracking coarse-grained gravity flows by LASS-ICP-MS depth-profiling of detrital zircon (Aveto Formation, Adriatic foredeep, Italy)

Marine and Petroleum Geology ◽

10.1016/j.marpetgeo.2016.07.014 ◽

2016 ◽

Vol 77 ◽

pp. 1163-1176 ◽

Cited By ~ 14

Author(s):

Owen A. Anfinson ◽

Marco G. Malusà ◽

Giuseppe Ottria ◽

Laura N. Dafov ◽

Daniel F. Stockli

Keyword(s):

Detrital Zircon ◽

Depth Profiling ◽

Coarse Grained ◽

Gravity Flows ◽

Icp Ms

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The early polychelidan lobster Tetrachela raiblana and its impact on the homology of carapace grooves in decapod crustaceans

Contributions to Zoology ◽

10.1163/18759866-08701004 ◽

2018 ◽

Vol 87 (1) ◽

pp. 41-57 ◽

Cited By ~ 2

Author(s):

Denis Audo ◽

Matúš Hyžný ◽

Sylvain Charbonnier

Keyword(s):

Marine Environment ◽

Deep Water ◽

Evolutionary History ◽

Sister Group ◽

Late Triassic ◽

Decapod Crustaceans ◽

Shallow Marine ◽

History Of ◽

Life Habits ◽

Groove Pattern

Polychelidan lobsters, as the sister group of Eureptantia (other lobsters and crabs), have a key-position within decapod crustaceans. Their evolutionary history is still poorly understood, although it has been proposed that their Mesozoic representatives largely inhabited shallow-marine environment and only later sought refuge in deep water. This view has recently been challenged, so the evolutionary history of polychelidans is in a need of re-appraisal. The earliest representatives, such as Tetrachela from the Late Triassic of Austria and Italy, are of great importance because of their potential in investigation of life habits of early polychelidans. Tetrachela lived in a relatively deep water, however, its well-developed eyes suggest an environment where light was still present. With its massive dorsoventrally flattened body plan, Tetrachela was probably benthic; the shape of its mandible and stocky first pereiopods suggest it was a scavenger and/or fed on slowly moving or sedentary animals. The carapace of Tetrachela has a peculiar groove pattern, which leads us to redefine some elements of the nomenclature of grooves used for polychelidans. Based on the present revision we propose that the second incision and its associated groove correspond to the hepatic groove, not the postcervical or the branchiocardiac grooves as interpreted previously. This revision allows us to review the homologies of cephalothoracic groove between polychelidans and other notable groups of decapod crustaceans.

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Benthic foraminiferal zonation in deep-water carbonate platform margin environments, northern Little Bahama Bank

Journal of Paleontology ◽

10.1017/s0022336000058819 ◽

1988 ◽

Vol 62 (01) ◽

pp. 1-8 ◽

Cited By ~ 1

Author(s):

Ronald E. Martin

Keyword(s):

Deep Water ◽

Benthic Foraminifera ◽

Carbonate Platform ◽

Sedimentary Facies ◽

Depositional Environments ◽

Near Surface ◽

Sediment Gravity Flows ◽

Gravity Flows ◽

Platform Margin ◽

Water Carbonate

The utility of benthic foraminifera in bathymetric interpretation of clastic depositional environments is well established. In contrast, bathymetric distribution of benthic foraminifera in deep-water carbonate environments has been largely neglected. Approximately 260 species and morphotypes of benthic foraminifera were identified from 12 piston core tops and grab samples collected along two traverses 25 km apart across the northern windward margin of Little Bahama Bank at depths of 275-1,135 m. Certain species and operational taxonomic groups of benthic foraminifera correspond to major near-surface sedimentary facies of the windward margin of Little Bahama Bank and serve as reliable depth indicators. Globocassidulina subglobosa, Cibicides rugosus, and Cibicides wuellerstorfi are all reliable depth indicators, being most abundant at depths >1,000 m, and are found in lower slope periplatform aprons, which are primarily comprised of sediment gravity flows. Reef-dwelling peneroplids and soritids (suborder Miliolina) and rotaliines (suborder Rotaliina) are most abundant at depths <300 m, reflecting downslope bottom transport in proximity to bank-margin reefs. Small miliolines, rosalinids, and discorbids are abundant in periplatform ooze at depths <300 m and are winnowed from the carbonate platform. Increased variation in assemblage diversity below 900 m reflects mixing of shallow- and deep-water species by sediment gravity flows.

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THE PROVENANCE OF GLACIAL TILL DEPOSITED IN ONG VALLEY, CENTRAL TRANSANTARCTIC MOUNTAINS DETERMINED BY LA-ICP-MS OF DETRITAL ZIRCON

10.1130/abs/2016am-285013 ◽

2016 ◽

Author(s):

Evan J. Miranda ◽

◽

Daniel Morgan ◽

Jaakko Putkonen ◽

Greg Balco ◽

...

Keyword(s):

Detrital Zircon ◽

Glacial Till ◽

Icp Ms ◽

Transantarctic Mountains

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U–Pb age and Lu–Hf signatures of detrital zircon from Palaeozoic sandstones in the Oslo Rift, Norway

Geological Magazine ◽

10.1017/s0016756813000885 ◽

2013 ◽

Vol 151 (5) ◽

pp. 816-829 ◽

Cited By ~ 21

Author(s):

MAGNUS KRISTOFFERSEN ◽

TOM ANDERSEN ◽

ARILD ANDRESEN

Keyword(s):

Detrital Zircon ◽

Inductively Coupled Plasma ◽

Late Carboniferous ◽

Isotopic Signatures ◽

Inductively Coupled ◽

Source To Sink ◽

Icp Ms ◽

Plasma Mass Spectrometry ◽

Isotope Analyses ◽

Multiple Episodes

AbstractU–Pb and Lu–Hf isotope analyses of detrital zircon from the latest Ordovician (Hirnantian) Langøyene Formation, the Late Silurian Ringerike Group and the Late Carboniferous Asker Group in the Oslo Rift were obtained by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Overall the U–Pb dating yielded ages within the range 2861–313 Ma. The U–Pb age and Lu–Hf isotopic signatures correspond to virtually all known events of crustal evolution in Fennoscandia, as well as synorogenic intrusions from the Norwegian Caledonides. Such temporally and geographically diverse source areas likely reflect multiple episodes of sediment recycling in Fennoscandia, and highlights the intrinsic problem of using zircon as a tracer-mineral in ‘source to sink’ sedimentary provenance studies. In addition to its mostly Fennoscandia-derived detritus, the Asker Group also have zircon grains of Late Devonian – Late Carboniferous age. Since no rocks of these ages are known in Fennoscandia, these zircons are inferred to be derived from the Variscan Orogen of central Europe.

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Research on Diffusion Effect of Sewage Marine Discharge from Different Angles

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.675-677.551 ◽

2014 ◽

Vol 675-677 ◽

pp. 551-555

Author(s):

Hang Yu

Keyword(s):

Phase Ii ◽

Marine Environment ◽

Model Test ◽

Deep Water ◽

Large Angle ◽

Premature Convergence ◽

Design Parameters ◽

Diffusion Effect ◽

Environmental Material ◽

Port Engineering

The sewage diffusion is an environmental material for protecting marine environment. It plays an important role in port engineering. Its effect under deep water was carried out between different diffuser design parameters based on the hydraulic model test, and YangKou port sewage marine disposal project phase II was taken as an example. For this project, jet angle was controlled to be 0 degree, and horizontal angle was controlled to be 0 degree. It not only can ensure that sewage fully diluted mixed, also can avoid the premature convergence and sewage lifting. It is feasible for selecting large angle nozzle under deep water and there are some technical bases have been provided for other sewage marine disposal project.

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Petrology and genesis of the Bhainskati iron ore deposit of Palpa District, western Nepal

Bulletin of the Department of Geology ◽

10.3126/bdg.v15i0.7418 ◽

2013 ◽

Vol 15 ◽

pp. 63-68

Author(s):

Sujan Devkota ◽

Lalu Prasad Paudel

Keyword(s):

Marine Environment ◽

Mineral Assemblage ◽

Iron Ore ◽

Ore Deposit ◽

Shallow Marine ◽

Shallow Marine Environment ◽

Long Time ◽

Iron Ore Deposit ◽

Petrographic Study ◽

Oolitic Ironstone

The Bhainskati Formation of the Tansen Group in the Palpa area is known for hematite iron ore deposit for long time. A prominent band of hematite of about 1-2 m thickness and extending >5 km was identified in the upper part of the Bhainskati Formation in the present study. The band is repeated three times in the area by folding and faulting. Petrographic study shows that it is oolitic ironstone of sedimentary origin. Main minerals in the band are hematite, goethite, quartz, calcite, siderite and albite. Hematite content varies considerably among samples and occurs mainly as oolite and cement. The Bhainskati ironstone with its ferrous mineral assemblage and well-rounded texture of the ooids suggests shallow marine environment (prodeltaic to estuarine) with reduced clastic input. DOI: http://dx.doi.org/10.3126/bdg.v15i0.7418 Bulletin of the Department of Geology, Vol. 15, 2012, pp. 63-68

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Caledonian terrane amalgamation of Svalbard: detrital zircon provenance of Mesoproterozoic to Carboniferous strata from Oscar II Land, western Spitsbergen

Geological Magazine ◽

10.1017/s0016756813000174 ◽

2013 ◽

Vol 150 (6) ◽

pp. 1103-1126 ◽

Cited By ~ 33

Author(s):

DETA GASSER ◽

ARILD ANDRESEN

Keyword(s):

Detrital Zircon ◽

Large Scale ◽

Strike Slip ◽

Western Coast ◽

Zircon Age ◽

The North ◽

Tectonic History ◽

Icp Ms ◽

Depositional Age ◽

Sveconorwegian Orogen

AbstractThe tectonic origin of pre-Devonian rocks of Svalbard has long been a matter of debate. In particular, the origin and assemblage of pre-Devonian rocks of western Spitsbergen, including a blueschist-eclogite complex in Oscar II Land, are enigmatic. We present detrital zircon U–Pb LA-ICP-MS data from six Mesoproterozoic to Carboniferous samples and one U–Pb TIMS zircon age from an orthogneiss from Oscar II Land in order to discuss tectonic models for this region. Variable proportions of Palaeo- to Neoproterozoic detritus dominate the metasedimentary samples. The orthogneiss has an intrusion age of 927 ± 3 Ma. Comparison with detrital zircon age spectra from other units of similar depositional age within the North Atlantic region indicates that Oscar II Land experienced the following tectonic history: (1) the latest Mesoproterozoic sequence was part of a successor basin which originated close to the Grenvillian–Sveconorwegian orogen, and which was intruded byc. 980–920 Ma plutons; (2) the Neoproterozoic sediments were deposited in a large-scale basin which stretched along the Baltoscandian margin; (3) the eclogite-blueschist complex and the overlying Ordovician–Silurian sediments probably formed to the north of the Grampian/Taconian arc; (4) strike-slip movements assembled the western coast of Spitsbergen outside of, and prior to, the main Scandian collision; and (5) the remaining parts of Svalbard were assembled by strike-slip movements during the Devonian. Our study confirms previous models of complex Caledonian terrane amalgamation with contrasting tectonic histories for the different pre-Devonian terranes of Svalbard and particularly highlights the non-Laurentian origin of Oscar II Land.

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