CARACTERIZAÇÃO LITOLÓGICA E EVOLUÇÃO METAMÓRFICA DA PORÇÃO LESTE DO COMPLEXO METAMÓRFICO BRUSQUE, SANTA CATARINA

RUY PAULO PHILIPP, GUILHERME MALLMANN, MARIA DE FÁTIMA BITENCOURT, EDUARDO RECKZIEGEL DE SOUZA, MARCOS M.A. DE SOUZA, JOAQUIM DANIEL DE LIZ, FELIPE WILD, SILVANA ARENDT, ALESSANDRO S. DE OLIVEIRA, LAUREN DUARTE, CRISTIANE B. RIVIERA, MAURÍCIO PRADO
2004 Revista Brasileira de Geociências  
Re vista Brasileira de Gcociencias Ruy Paulo Philipp et al. 34( I ):2 1-34 . marco de 2()()4 The eastern portion of the Brusque Metamorphic Complex comprises dominantly mctasscdimcntary rocks. with subordinate metavolcanics.Sheets ofpcraluminous lcucc granitcs arc concordantly intrusive in this sequence. as well as larger granitic bodies. as the Compra Tude. Valsungana and Serra dos Macacos granitoids. Regional deformation and orogenic metamorphism are here interpreted as polyphase events of
more » ... yphase events of Neoproterozoic age associated to continental collision. A younger metamorphic event is related to heat transfer from granitic magmas and to the development of ductile shear zones. Protoliths arc dominantly marine sediments probably deposited in rift systems evolving towards continental margin enviroments. No evidence of ancient oceaniccrust is found.Turbidites are characterized by systematically alternate petites. fcldspathic sandstones and quartz sanstoncs. with minor amounts of limestone and marble. Massive metavolcanic rocks of tholeiitic affinity are interpreted as form er subaqueo us basa lt flo ws. Minor occurrences of chemical exhalative intcrflow s are found as handed iron formations. Metamorphic evolution is complex and intimately related to deformation events. M, e M! metamorphic events arc related to low-pressure, regional orogenic metamorphism synchronous to the development of foliations Sl and 51' Both were formed during continentalcollision, which caused import ant tectonic interleaving of the volcano-sedimentarysequence. Temperature conditions range from those of the greenschist facies to lower amphibolite, marked by chlorite. biotite. garnet. andaluzitc and conl icritc zones. Metamorphic zoning pattern is complex. with repetition and incompatibility of zones due to tectonic interleaving. M, metamorphic event is related to the intrusion of syn-transcurrcncc (D,). Neoproterozoic Valsungana and Serra dos Macacos granites, which develop contact metamorphic aureoles containing pelitic and calc-silicate rocks formed under albite-epidote hornfels to pyroxene hornfels facies conditions. Mylonitic rocks formed under grcenshist facies conditions arc found along the Major Gercino and Itajai-Perimbo shear zones. Resume A Ixm;ao leste do Complexo Metam6rlico Brusque econstituida por lima sequencia de rochas prcdominantcmcntc rnct asscdimcrnarcs. com ocorrencia subordinada de ruchas mctavulcflni rus. Esta sequencia e intrudida por granitoidcs. representados por corpos tabulurcs e inJcc;oes de lcucogranitos pcraluminosos. c pclos granitos Compra Tudo. Valsunguna e Serra des Macacos. A dcto rmucno c 0 metamorfismo regional orogcnico sao intcrprctados ncstc trahalho como polifasicos e ocorrcmm no Ncopmtcrozoico. associados a urn proccsso de colisno continental. Urn novo cvcnto metamorfico esta rclucionado a transferencia de calor JX-)r magmas graniticos c ao dcscnvol vimcnt o de zonas de cisalhamento du ctcis. A scdimc ntaciic e domin untemcn te marinha e rclacionada provavelmcnte a urnsistema de rifts que evolucm para uma margent continental. scm registro de crusta oceanica. Ocorrem turbidites. caracterizados pcla altcmfincia sistematica de pclnos. arenites fcldspaticos e quartzo-arcniros. e de modo subordinado calcareos e margas. As roches vulcanicas currespondcm a dcrram es basicos subaquososde afinidadc toleftica. com estruturas macicus. lntcrfluxos cxalanvos quunicos. tais como fcnnacocs feniferas bandadas. ocorrem de forma rcstrita. A cvotucao metamorfica e rcmplexa e cncomra-sc intimamcntc rclacionada nos cvcnros dcformacionais. Os cventos M I e M. s50 rclacionados a metamorfismo regional orogemco de haixu pressao. ocorrendo concomitantes com 0 dcscnvclvimcruo das foliac;oes metamorficas 51 e S!. amhas csuu turas gcradas durante 0 cvcruo colisional. Esta csuu turacao c rcsponsavcl pcla intcrcalacuo tcctonica de fatius da sequencia vulc a noscdimcntar prcrcrtta. As condicocs de temperatura evoluem da facies xistos verdes a anfibolito inferior, e possuem um padrao de 1.0na<;5.0 complcxo. com rcpcticdes c incougrucncias de zonas mcramorficas. que varium dcsdc a zona da clorita. passnndo para biotita. granada. andaluzita c cordicrita. 0 evcnto M) cs ui ussociudo ;:10 postctonamcmo UOS granit6ides Brusiliunos sintrunscorrcncia ( 0.\) Valsungunac Scn udos Macaccs.e desenvolve aureola de metamorfismo de contato. com cornubianitos pcliticos c calci-silicaticos. sob ccndicocs mctumorficas da faciesalbita-cpidoto comubianito a piroxenio comubianito. Pala vms -cha ve: Escudo Cutariucusc. Complexo Mctamorfico Brusque. Estratigrafia. Petrologia Mctamorfica
doi:10.25249/0375-7536.20043412134 fatcat:xncc3lhdw5cfzhzure4mnixdre