A great.S
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. 5step 30 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).
Though one of them plutons mix-cut the CFTD in NW idea, the fresh new Silva Jardim Pluton, old at 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. ).
Regarding adjoining Chinese language Terrane ( Figs. 2 and you will 3), there are even metamorphic age of ca. 550 – 510 Ma ( Schmitt ainsi que al. 2004 Schmitt R.S., Trouw R.A.J., Van Schmus W.R., Pimentel Meters.Yards. 2004. Later amalgamation regarding the main part of West Gondwana: the new geochronological investigation and characterization out-of an excellent International dating app Cambrian collisional orogeny on the Ribeira Gear (SE Brazil). Precambrian Search , -61. , 2012a Schmitt Roentgen.S., Mendes J.C., Peternel R., Silva L.C., Dantas Age.L. 2012a. : SSAGI, Medellin, Colombia. ; Fernandes mais aussi al. 2015 Fernandes G.L., Schmitt Roentgen.S., Bongiolo Age., Mendes J.C., Basei M. 2015. Unraveling the fresh new tectonic evolution away from a good Neoproterozoic-Cambrian active margin regarding the Ribeira Orogen (SE Brazil): U-Pb and you will Lu-Hf provenance studies. Precambrian Research , -360. ). Also, several plutons with decades regarding 510 to help you 480 Ma intrude this terrane as they are translated due to the fact article-tectonic ( Valeriano mais aussi al. 2011 Valeriano C.Yards., Tupinamba Yards., Simonetti Good., Heilbron M., Almeida J.C.H., Eirado L.G. 2011. U-Pb La-MC-ICPMS geochronology of Cambro-Ordovician article-collisional granites of your Ribeira buckle, the southern area of Brazil: terminal Brasiliano magmatism inside the central Gondwana supercontinent. Diary from South Western Planet Sciences , -428. ). 2 and step 3) ( Moraes 2009 Moraes J.Meters. 2009. Geologia do Granito Silva Jardim (RJ): Implicacoes na evolucao tectonica 2 Terrenos Oriental age Cabo Frio. Learn Thesis UERJ. 65 p. ). This pluton merchandise a structured igneous foliation and that is sensed a beneficial late-collisional magmatic looks ( Moraes 2009 Moraes J.Meters. 2009. Geologia carry out Granito Silva Jardim (RJ): Implicacoes na evolucao tectonica dos Terrenos China e Cabo Frio. Learn Thesis UERJ. 65 p. ). The newest youngest magmatic intrusions registered about CFTD into the Paleozoic are post tectonic pegmatites and you will granites out of ca. 440 Ma dated with U-Pb from inside the zircon ( Schmitt ainsi que al. 2004 Schmitt Roentgen.S., Trouw Roentgen.Good.J., Van Schmus W.Roentgen., Pimentel M.M. 2004. Later amalgamation regarding central section of West Gondwana: new geochronological investigation therefore the characterization out of a Cambrian collisional orogeny about Ribeira Belt (SE Brazil). Precambrian Lookup , -61. , Bongiolo ainsi que al. 2015 Bongiolo Elizabeth., Renac C., D’Almeida de- Toledo P., Schmitt R.S., Faulstich F.R.L., Mexias , Silva F.P.C. 2015. Supply of pegmatites and you will drinks in the Ponta Negra (RJ, Brazil) throughout the later- to post-collisional grade of your Gondwana Set-up. Lithos , -275. ).
