Relationship high grade syn-orogenic plutons and you may supracrustal stones when you look at the a sexy orogen – Ribeira gear instance-investigation

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The deformation and high grade metamorphism responsible for the tectonic inversion of the sedimentary basin is attributed to an orogenic event of Cambrian age. Schmitt et al. (200cuatro Schmitt R.S., Trouw R.A.J., Van Schmus W.R., Pimentel M.M. 2004. Late amalgamation in the central part of West Gondwana: new geochronological data and the characterization of a Cambrian collisional orogeny in the Ribeira Belt (SE Brazil). Precambrian Research , -61. , 2008b Schmitt R.S., Trouw R.A.J., Van Schmus W.R., Passchier C.W. 2008b. Cambrian orogeny in the Ribeira Belt (SE Brazil) and correlations within West Gondwana: ties that bind underwater. : Pankhurst R.J., Trouw R.A.J., Brioto Neves B.B., De Wit M.J. (eds.) West Gondwana: Pre-Cenozoic Correlations across the South Atlantic Region . Geological Society, London , Special Publications, -296. ) dated the D_1+dos syntectonic leucosome from both basement and supracrustals, and defined a ca. 5step three0 Ma tectonometamorphic event related to a convergent margin that culminated with a continental collision (Buzios Orogeny). This partial melt product was generated during the metamorphic peak (D_1+dos) and was folded by the megascale F₃-folds ( Fig. 4E).

Regardless of if one among these plutons get across-cut the CFTD in its NW tip, the fresh new Silva Jardim Pluton, old within 505 Ma ( Figs

In the basement, the lower intercepts of the U-Pb discordia lines are in the interval between 600 and 450 Ma, consistent with this event ( Schmitt et al. 2004 Schmitt R.S., Trouw R.A.J., Van Schmus W.R., Pimentel M.M. 2004. Late amalgamation in the central part of West Gondwana: new geochronological data and the characterization of a Cambrian collisional orogeny in the Ribeira Belt (SE Brazil). Precambrian Research , -61. , 2008b Schmitt R.S., Trouw R.A.J., Van Schmus W.R., Passchier C.W. 2008b. Cambrian orogeny in the Ribeira Belt (SE Brazil) and correlations within West Gondwana: ties that bind underwater. : Pankhurst R.J., Trouw R.A.J., Brioto Neves B.B., De Wit M.J. (eds.) West Gondwana: Pre-Cenozoic Correlations across the South Atlantic Region . Geological Society, London , Special Publications, -296. ). The metamorphic rims of the Paleoproterozoic zircon grains in the shear zones are dated at ca. 505 Ma ( Schmitt et al. 2008b Schmitt R.S., Trouw R.A.J., Van Schmus W.R., Passchier C.W. 2008b. Cambrian orogeny in the Ribeira Belt (SE Brazil) and correlations within West Gondwana: ties that bind underwater. : Pankhurst R.J., Trouw R.A.J., Brioto Neves B.B., De Wit M.J. (eds.) West Gondwana: Pre-Cenozoic Correlations across the South Atlantic Region . Geological Society, London , Special Publications, -296. ). In the supracrustals, all metamorphic minerals are formed during the Cambrian (ca. 530 Ma). Zircon, monazite, sphene and rutile were dated and yielded a metamorphic time interval between 525 and 510 Ma for the eastern CFTD and 505 – 490 Ma for the western CFTD ( Schmitt et al. 2004 Schmitt R.S., Trouw R.A.J., Van Schmus W.R., Pimentel M.M. 2004. Late amalgamation in the central part of West Gondwana: new geochronological data and the characterization of a Cambrian collisional orogeny in the Ribeira Belt (SE Brazil). Precambrian Research , -61. ). The occurrence of a late F₄-reclined megascale fold in the western region could partially explain this ( Fig. 3). These younger ages could indicate that units in this region stayed deeper in the crust and the D₄ deformational phase would bring them up later. The cooling rate calculated for the eastern part of CFTD is rapid until ca. 510 Ma (more than 20 o C/Ma), and after this diminishes to 5 – 10 o C/Ma ( Schmitt et al., 2004 Schmitt R.S., Trouw R.A.J., Van Schmus W.R., Pimentel M.M. 2004. Late amalgamation in the central part of West Gondwana: new geochronological data and the characterization of a Cambrian collisional orogeny in the Ribeira Belt (SE Brazil). Precambrian Research , -61. ).

Regarding the surrounding China Terrane ( Figs. dos and step three), there are even metamorphic chronilogical age of california. 550 – 510 Ma ( Schmitt mais aussi al. 2004 Schmitt R.S., Trouw R.An effective.J., Van Schmus W.R., Pimentel Yards.M. 2004. Later amalgamation throughout the main section of Western Gondwana: the fresh geochronological studies therefore the characterization regarding a beneficial Cambrian collisional orogeny in the Ribeira Gear (SE Brazil). Precambrian Lookup , -61. , 2012a Schmitt Roentgen.S., Mendes J.C., Peternel R., Silva L.C., Dantas Elizabeth.L. 2012a. : SSAGI, Medellin, Colombia. ; Fernandes mais aussi al. 2015 Fernandes G.L., Schmitt R.S., Bongiolo E., Mendes J.C., Basei Meters. 2015. Unraveling new tectonic progression out-of a beneficial Neoproterozoic-Cambrian active margin regarding the Ribeira Orogen (SE Brazil): U-Pb and you may Lu-Hf provenance investigation. Precambrian Search , -360. ). Also, some plutons with age of 510 to 480 Ma intrude which terrane consequently they are interpreted because the blog post-tectonic ( Valeriano et al. 2011 Valeriano C.M., Tupinamba Meters., Simonetti A great., Heilbron M., Almeida J.C.H., Eirado L.Grams. 2011. U-Pb La-MC-ICPMS geochronology away from Cambro-Ordovician blog post-collisional granites of one’s Ribeira gear, the southern area of Brazil: critical Brasiliano magmatism inside main Gondwana supercontinent. Journal regarding Southern area Western Environment Sciences , -428. ). dos and you will step three) ( Moraes 2009 Moraes J.Yards. 2009. Geologia carry out Granito Silva Jardim (RJ): Implicacoes na evolucao tectonica dos Terrenos Oriental e Cabo Frio. Master Thesis UERJ. 65 p. ). Which pluton gift suggestions a formulated igneous foliation which is thought a beneficial late-collisional magmatic system ( Moraes 2009 Moraes J.Yards. 2009. Geologia manage Granito Silva Jardim (RJ): Implicacoes na evolucao tectonica dos Terrenos Chinese language age Cabo Frio. Master Thesis UERJ. 65 p. ). The fresh youngest magmatic intrusions inserted regarding the CFTD inside Paleozoic was article tectonic pegmatites and granites out of ca. 440 Ma old having U-Pb into the zircon ( Schmitt ainsi que al. 2004 Schmitt R.S., Trouw R.A.J., Van Schmus W.Roentgen., Pimentel Meters.Meters. 2004. Late amalgamation in the main section of West Gondwana: the newest geochronological study while the characterization of a great Cambrian collisional orogeny on Ribeira Belt (SE Brazil). Precambrian Browse , -61. , Bongiolo ainsi que al. 2015 Bongiolo E., Renac C., D’Almeida de Toledo P., Schmitt R.S., Faulstich F.R.L., Mexias , Silva F.P.C. 2015. Source out of pegmatites and you will liquids within Ponta Negra (RJ, Brazil) during the late- to share-collisional values of one’s Gondwana Set up. Lithos , -275. ).