Relationships high-grade syn-orogenic plutons and you can supracrustal stones within the a sexy orogen – Ribeira buckle instance-research

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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₊₂ 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 (D_1+dos) and was folded by the megascale F₃-folds ( Fig. 4E).

Although one of them plutons cross-slice the CFTD in NW idea, brand new Silva Jardim Pluton, dated 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 single parent match nasД±l kullanД±lД±r 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 adjoining China Terrane ( Figs. dos and step three), there are even metamorphic period of ca. 550 – 510 Ma ( Schmitt mais aussi al. 2004 Schmitt Roentgen.S., Trouw Roentgen.A.J., Van Schmus W.Roentgen., Pimentel Yards.Meters. 2004. Later amalgamation regarding main section of West Gondwana: this new geochronological analysis and characterization off an effective Cambrian collisional orogeny regarding the Ribeira Buckle (SE Brazil). Precambrian Research , -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 R.S., Bongiolo Age., Mendes J.C., Basei Meters. 2015. Unraveling the brand new tectonic development regarding a beneficial Neoproterozoic-Cambrian energetic margin about Ribeira Orogen (SE Brazil): U-Pb and you can Lu-Hf provenance studies. Precambrian Look , -360. ). In addition, a number of plutons that have decades off 510 so you can 480 Ma intrude it terrane and so are interpreted since the post-tectonic ( Valeriano mais aussi al. 2011 Valeriano C.M., Tupinamba Meters., Simonetti A great., Heilbron Yards., Almeida J.C.H., Eirado L.Grams. 2011. U-Pb Los angeles-MC-ICPMS geochronology of Cambro-Ordovician blog post-collisional granites of one’s Ribeira buckle, southeast Brazil: terminal Brasiliano magmatism when you look at the main Gondwana supercontinent. Journal out-of Southern area American Planet Sciences , -428. ). dos and you may step 3) ( Moraes 2009 Moraes J.Yards. 2009. Geologia perform Granito Silva Jardim (RJ): Implicacoes na evolucao tectonica dos Terrenos Chinese language e Cabo Frio. Learn Thesis UERJ. 65 p. ). So it pluton presents a situated igneous foliation which will be thought good late-collisional magmatic muscles ( Moraes 2009 Moraes J.Meters. 2009. Geologia manage Granito Silva Jardim (RJ): Implicacoes na evolucao tectonica dos Terrenos China e Cabo Frio. Learn Thesis UERJ. 65 p. ). The new youngest magmatic intrusions entered regarding the CFTD for the Paleozoic was article tectonic pegmatites and granites out-of california. 440 Ma dated with You-Pb when you look at the zircon ( Schmitt ainsi que al. 2004 Schmitt R.S., Trouw R.A good.J., Van Schmus W.Roentgen., Pimentel M.M. 2004. Later amalgamation on the central section of Western Gondwana: this new geochronological investigation together with characterization regarding an excellent Cambrian collisional orogeny throughout the Ribeira Belt (SE Brazil). Precambrian Look , -61. , Bongiolo mais aussi al. 2015 Bongiolo Age., Renac C., D’Almeida de Toledo P., Schmitt Roentgen.S., Faulstich F.Roentgen.L., Mexias , Silva F.P.C. 2015. Supply off pegmatites and you will drinks in the Ponta Negra (RJ, Brazil) during the later- to post-collisional grade of your own Gondwana Construction. Lithos , -275. ).