Relationship high quality syn-orogenic plutons and you will supracrustal stones when you look at the a sexy orogen – Ribeira buckle circumstances-studies
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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: singapore dating 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 D1+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 (D1+2) and was folded by the megascale F3-folds ( Fig. 4E).
In the event one among these plutons cross-cut the CFTD in its NW idea, the 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. ).
In the surrounding Oriental Terrane ( Figs. 2 and you can step 3), there are even metamorphic ages of california. 550 – 510 Ma ( Schmitt mais aussi al. 2004 Schmitt R.S., Trouw Roentgen.A.J., Van Schmus W.R., Pimentel Meters.Yards. 2004. Later amalgamation regarding the central element of Western Gondwana: the geochronological analysis and the characterization away from a great Cambrian collisional orogeny regarding the Ribeira Gear (SE Brazil). Precambrian Research , -61. , 2012a Schmitt R.S., Mendes J.C., Peternel R., Silva L.C., Dantas Elizabeth.L. 2012a. : SSAGI, Medellin, Colombia. ; Fernandes mais aussi al. 2015 Fernandes Grams.L., Schmitt R.S., Bongiolo E., Mendes J.C., Basei M. 2015. Unraveling the fresh tectonic development out-of good Neoproterozoic-Cambrian effective margin from the Ribeira Orogen (SE Brazil): U-Pb and you may Lu-Hf provenance data. Precambrian Search , -360. ). Also, a number of plutons having ages of 510 to 480 Ma intrude which terrane and so are interpreted since the post-tectonic ( Valeriano mais aussi al. 2011 Valeriano C.M., Tupinamba Yards., Simonetti Good., Heilbron Meters., Almeida J.C.H., Eirado L.G. 2011. U-Pb Los angeles-MC-ICPMS geochronology from Cambro-Ordovician post-collisional granites of your Ribeira strip, the southern area of Brazil: critical Brasiliano magmatism inside the central Gondwana supercontinent. Journal away from Southern area American Planet Sciences , -428. ). 2 and you can step 3) ( Moraes 2009 Moraes J.Yards. 2009. Geologia perform Granito Silva Jardim (RJ): Implicacoes na evolucao tectonica 2 Terrenos China elizabeth Cabo Frio. Learn Thesis UERJ. 65 p. ). Which pluton presents an established igneous foliation which will be experienced a great late-collisional magmatic muscles ( Moraes 2009 Moraes J.Meters. 2009. Geologia create Granito Silva Jardim (RJ): Implicacoes na evolucao tectonica dos Terrenos China elizabeth Cabo Frio. Grasp Thesis UERJ. 65 p. ). Brand new youngest magmatic intrusions entered from the CFTD when you look at the Paleozoic is article tectonic pegmatites and you will granites out of california. 440 Ma dated with You-Pb in the zircon ( Schmitt et al. 2004 Schmitt R.S., Trouw Roentgen.An excellent.J., Van Schmus W.Roentgen., Pimentel Meters.Meters. 2004. Late amalgamation regarding the main element of West Gondwana: this new geochronological research plus the characterization regarding a good Cambrian collisional orogeny regarding the Ribeira Gear (SE Brazil). Precambrian Search , -61. , Bongiolo mais aussi al. 2015 Bongiolo E., Renac C., D’Almeida de- Toledo P., Schmitt Roentgen.S., Faulstich F.R.L., Mexias , Silva F.P.C. 2015. Resource of pegmatites and you will drinks in the Ponta Negra (RJ, Brazil) during later- to post-collisional degrees of Gondwana System. Lithos , -275. ).