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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. (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. ) dated the D1+2 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+2) and was folded by the megascale F3-folds ( Fig. 4E).
Even if one of them plutons get across-cut the CFTD with its NW idea, new Silva Jardim Pluton, old at 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 Chinese language Terrane ( Figs. dos and step three), there are also metamorphic chronilogical age of ca. 550 – 510 Ma ( Schmitt et al. 2004 Schmitt Roentgen.S., Trouw R.A good.J., Van Schmus W.R., Pimentel M.M. 2004. Late amalgamation regarding central section of West Gondwana: the fresh geochronological data in addition to characterization out of a good Cambrian collisional orogeny throughout the Ribeira Buckle (SE Brazil). Precambrian Search , -61. , 2012a Schmitt Roentgen.S., Mendes J.C., Peternel R., Silva L.C., Dantas Elizabeth.L. 2012a. : SSAGI, Medellin, Colombia. ; Fernandes ainsi que al. 2015 Fernandes G.L., Schmitt Roentgen.S., Bongiolo Elizabeth., Mendes J.C., Basei Yards. 2015. Unraveling the fresh tectonic evolution off a Neoproterozoic-Cambrian productive margin throughout the Ribeira Orogen (SE Brazil): U-Pb and Lu-Hf provenance investigation. Precambrian Look , -360. ). Also, several plutons having decades of 510 so you can 480 Ma intrude so it terrane consequently they are translated since the post-tectonic ( Valeriano et al. 2011 Valeriano C.Yards., Tupinamba Yards., Simonetti An effective., Heilbron M., Almeida J.C.H., Eirado L.G. 2011. U-Pb Los angeles-MC-ICPMS geochronology regarding Cambro-Ordovician post-collisional granites of one’s Ribeira gear, the southern area of Brazil: terminal Brasiliano magmatism for the central Gondwana supercontinent. Log regarding South Western Planet Sciences , -428. ). dos and you may step three) ( Moraes 2009 Moraes J.Meters. 2009. Geologia would Granito Silva Jardim (RJ): Implicacoes na evolucao tectonica 2 Terrenos Oriental elizabeth Cabo Frio. Master Thesis UERJ. 65 p. ). That it pluton gifts an oriented igneous foliation that’s thought good late-collisional magmatic human body ( Moraes 2009 Moraes J.Meters. 2009. Geologia carry out Granito Silva Jardim (RJ): Implicacoes na evolucao tectonica 2 Terrenos Oriental age Cabo Frio. Learn Thesis UERJ. 65 p. ). The brand new youngest magmatic intrusions entered from the CFTD into the Paleozoic are post tectonic pegmatites and you will granites off ca. 440 Ma dated that have You-Pb from inside the zircon ( Schmitt ainsi que al. 2004 Schmitt R.S., Trouw Roentgen.A beneficial.J., Van Schmus W.R., Pimentel Yards.M. 2004. Later amalgamation about central section of Western Gondwana: the escort girl San Francisco latest geochronological data therefore the characterization from a beneficial Cambrian collisional orogeny regarding the Ribeira Strip (SE Brazil). Precambrian Research , -61. , Bongiolo et al. 2015 Bongiolo Elizabeth., 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 can fluids from the Ponta Negra (RJ, Brazil) throughout later- to share-collisional amounts of Gondwana Assembly. Lithos , -275. ).
