Relationships high quality syn-orogenic plutons and you will supracrustal rocks in a hot orogen – Ribeira strip 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. (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+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+2) and was folded by the megascale F3-folds single muslim Co je to ( Fig. 4E).
Though one of them plutons get across-slice the CFTD within its NW suggestion, this new Silva Jardim Pluton, dated within 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 the adjoining Chinese language Terrane ( Figs. dos and you can step 3), there are also metamorphic ages of california. 550 – 510 Ma ( Schmitt et al. 2004 Schmitt Roentgen.S., Trouw Roentgen.A great.J., Van Schmus W.R., Pimentel Yards.Meters. 2004. Late amalgamation on the main part of Western Gondwana: the new geochronological investigation and characterization of a beneficial Cambrian collisional orogeny about Ribeira Belt (SE Brazil). Precambrian Research , -61. , 2012a Schmitt R.S., Mendes J.C., Peternel R., Silva L.C., Dantas E.L. 2012a. : SSAGI, Medellin, Colombia. ; Fernandes mais aussi al. 2015 Fernandes Grams.L., Schmitt R.S., Bongiolo Elizabeth., Mendes J.C., Basei M. 2015. Unraveling the fresh new tectonic advancement out of a good Neoproterozoic-Cambrian effective margin regarding Ribeira Orogen (SE Brazil): U-Pb and you will Lu-Hf provenance investigation. Precambrian Browse , -360. ). Additionally, several plutons having decades from 510 to 480 Ma intrude which terrane and therefore are translated as the blog post-tectonic ( Valeriano ainsi que al. 2011 Valeriano C.Yards., Tupinamba Meters., Simonetti An excellent., Heilbron Yards., Almeida J.C.H., Eirado L.G. 2011. U-Pb La-MC-ICPMS geochronology off Cambro-Ordovician article-collisional granites of one’s Ribeira gear, southeast Brazil: terminal Brasiliano magmatism when you look at the main Gondwana supercontinent. Journal out-of South American World Sciences , -428. ). 2 and you can step three) ( Moraes 2009 Moraes J.M. 2009. Geologia would Granito Silva Jardim (RJ): Implicacoes na evolucao tectonica dos Terrenos Oriental age Cabo Frio. Master Thesis UERJ. 65 p. ). So it pluton presents an oriented igneous foliation and that is considered a late-collisional magmatic muscles ( Moraes 2009 Moraes J.M. 2009. Geologia carry out Granito Silva Jardim (RJ): Implicacoes na evolucao tectonica dos Terrenos China elizabeth Cabo Frio. Grasp Thesis UERJ. 65 p. ). This new youngest magmatic intrusions inserted throughout the CFTD in the Paleozoic are article tectonic pegmatites and you will granites out of ca. 440 Ma old having You-Pb into the zircon ( Schmitt ainsi que al. 2004 Schmitt R.S., Trouw Roentgen.An excellent.J., Van Schmus W.Roentgen., Pimentel Yards.Meters. 2004. Later amalgamation on the central section of Western Gondwana: the newest geochronological study and also the characterization off a great Cambrian collisional orogeny in the Ribeira Belt (SE Brazil). Precambrian Browse , -61. , Bongiolo et al. 2015 Bongiolo Elizabeth., Renac C., D’Almeida de- Toledo P., Schmitt Roentgen.S., Faulstich F.Roentgen.L., Mexias , Silva F.P.C. 2015. Origin regarding pegmatites and you may drinks at Ponta Negra (RJ, Brazil) through the later- to create-collisional degrees of Gondwana Installation. Lithos , -275. ).
