Relationship high quality syn-orogenic plutons and you may supracrustal stones during the a sexy orogen – Ribeira gear instance-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: 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+2) and was folded by https://www.datingmentor.org/cs/sexsearch-recenze the megascale F3-folds ( Fig. 4E).
Even though one of those plutons get across-slice the CFTD with its NW tip, the fresh 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. ).
About adjacent Oriental Terrane ( Figs. dos and step three), there are even metamorphic chronilogical age of ca. 550 – 510 Ma ( Schmitt mais aussi al. 2004 Schmitt R.S., Trouw Roentgen.Good.J., Van Schmus W.R., Pimentel Meters.Yards. 2004. Late amalgamation from the main part of Western Gondwana: new geochronological studies therefore the characterization off a Cambrian collisional orogeny from the Ribeira Buckle (SE Brazil). Precambrian Lookup , -61. , 2012a Schmitt Roentgen.S., Mendes J.C., Peternel R., Silva L.C., Dantas E.L. 2012a. : SSAGI, Medellin, Colombia. ; Fernandes ainsi que al. 2015 Fernandes Grams.L., Schmitt Roentgen.S., Bongiolo Elizabeth., Mendes J.C., Basei Yards. 2015. Unraveling the new tectonic progression regarding an effective Neoproterozoic-Cambrian energetic margin in the Ribeira Orogen (SE Brazil): U-Pb and you may Lu-Hf provenance studies. Precambrian Search , -360. ). Furthermore, some plutons that have ages off 510 so you’re able to 480 Ma intrude which terrane and so are translated because the article-tectonic ( Valeriano ainsi que al. 2011 Valeriano C.M., Tupinamba M., Simonetti A great., Heilbron Yards., Almeida J.C.H., Eirado L.G. 2011. U-Pb La-MC-ICPMS geochronology of Cambro-Ordovician article-collisional granites of Ribeira gear, the southern area of Brazil: critical Brasiliano magmatism in the central Gondwana supercontinent. Log out-of Southern Western Planet Sciences , -428. ). dos and step three) ( Moraes 2009 Moraes J.Yards. 2009. Geologia carry out Granito Silva Jardim (RJ): Implicacoes na evolucao tectonica dos Terrenos Oriental age Cabo Frio. Master Thesis UERJ. 65 p. ). So it pluton merchandise a formulated igneous foliation in fact it is noticed a good late-collisional magmatic human body ( Moraes 2009 Moraes J.Meters. 2009. Geologia carry out 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 entered about CFTD within the Paleozoic is article tectonic pegmatites and you will granites away from ca. 440 Ma old having U-Pb during the zircon ( Schmitt ainsi que al. 2004 Schmitt Roentgen.S., Trouw Roentgen.An excellent.J., Van Schmus W.R., Pimentel M.M. 2004. Late amalgamation throughout the central section of Western Gondwana: the brand new geochronological data additionally the characterization away from a great Cambrian collisional orogeny regarding Ribeira Strip (SE Brazil). Precambrian Browse , -61. , Bongiolo et al. 2015 Bongiolo Elizabeth., Renac C., D’Almeida de- Toledo P., Schmitt R.S., Faulstich F.Roentgen.L., Mexias , Silva F.P.C. 2015. Source out-of pegmatites and you will drinks at Ponta Negra (RJ, Brazil) during the late- to post-collisional stages of your Gondwana System. Lithos , -275. ).
