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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 D1+dos syntectonic leucosome from both basement and supracrustals, and defined a ca. 530 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+dos) and was folded by the megascale F3-folds ( Fig. 4E).
Even though one of those plutons get across-cut the CFTD in NW idea, the Silva Jardim Pluton, dated during the 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. ).
On adjoining Oriental Terrane ( Figs. 2 and step 3), there are even metamorphic age california. 550 – 510 Ma ( Schmitt mais aussi al. 2004 Schmitt R.S., Trouw R.Good.J., Van Schmus W.R., Pimentel Yards.Yards. 2004. Late amalgamation in the central section of West Gondwana: new geochronological analysis additionally the characterization out of an excellent Cambrian collisional orogeny regarding the Ribeira Gear (SE Brazil). Precambrian Browse , -61. , 2012a Schmitt R.S., Mendes J.C., Peternel Roentgen., Silva L.C., Dantas Age.L. 2012a. : SSAGI, Medellin, Colombia. ; Fernandes ainsi que al. 2015 Fernandes Grams.L., Schmitt Roentgen.S., Bongiolo Age., Mendes J.C., Basei Meters. 2015. Unraveling brand new tectonic progression off an effective Neoproterozoic-Cambrian productive margin throughout the Ribeira Orogen (SE Brazil): U-Pb and you may Lu-Hf provenance analysis. Precambrian Search , -360. ). Furthermore, some plutons having many years of 510 to help you 480 Ma intrude so it terrane and so are interpreted just like the post-tectonic ( Valeriano mais aussi al. 2011 Valeriano C.M., Tupinamba M., Simonetti An effective., Heilbron M., Almeida J.C.H., Eirado L.Grams. 2011. U-Pb La-MC-ICPMS geochronology regarding Cambro-Ordovician article-collisional granites of one’s Ribeira gear, southeast Brazil: critical Brasiliano magmatism from inside the central Gondwana supercontinent. Log regarding South Western Environment Sciences , -428. ). 2 and you can step 3) ( Moraes 2009 Moraes J.M. 2009. Geologia do Granito Silva Jardim (RJ): Implicacoes na evolucao tectonica 2 Terrenos Oriental elizabeth Cabo Frio. Master Thesis UERJ. 65 p. ). So it pluton gift ideas a situated igneous foliation and that’s believed an excellent late-collisional magmatic human body ( Moraes 2009 Moraes J.Meters. 2009. Geologia would Granito Silva Jardim (RJ): Implicacoes na evolucao tectonica dos Terrenos China elizabeth Cabo Frio. Learn Thesis UERJ. 65 p. ). The new youngest magmatic intrusions registered on the CFTD into the Paleozoic was article tectonic pegmatites and you will granites out of ca. 440 Ma dated having You-Pb inside the zircon ( Schmitt mais aussi al. 2004 Schmitt Roentgen.S., Trouw Roentgen.An effective.J., Van Schmus W.Roentgen., Pimentel Meters.M. 2004. Later amalgamation throughout the main section of West Gondwana: the newest geochronological analysis in addition to characterization from a beneficial Cambrian collisional orogeny throughout the Ribeira Buckle (SE Brazil). Precambrian Lookup , -61. , Bongiolo et al. 2015 Bongiolo E., Renac C., D’Almeida de- Toledo P., Schmitt Roentgen.S., Faulstich F.R.L., Mexias , Silva F.P.C. 2015. Provider away from pegmatites and you will liquids on Ponta Negra (RJ, Brazil) while in the later- to create-collisional stages of Gondwana Installation. Lithos , -275. ).