Geotectonica terenurilor metarnorfice din Romania

CUPRINS

Divizarea §i etapizarea geotectonica a teritoriukii Romaniei pentni orogenezaalpina, prin prisma nomenclaturii $i conceptelor tectonicii placilor 5

1. Introducere 52. P-laci litosferice precoiizionale 63. Crusta continentala a placilor 7

a. Consideratii teoretice 7b. Descrierea cratonilor 7

4. Comentarii privind extinderea placilor 8a. Placa Preapuliana ! 8b. Placa Getica : 9c. Placa Euxinica 9

5. Orogene sau centuri mobile 9a. Criterii de divizare a orogenelor alpine din Romania 9b. Divizarea spatiala a orogenuiui carpatic 10c. Orogenul norddobrogean 10

6. Modificarea configuratiei cratonilor pe parcursul orogenezei alpine §iclasificarea temporals a unitafilor tectonice alpine 11

a. Configuratia neocimmerica • 11b. Configuratia austrica 11c. Configuratia pregosau 12d. Configuratia laramica 12e. Configuratia intraburdegaliana 12f. Configuratia intrabadeniana 12g. Configuratia sarmatiana 12

7. Relictele cratonice Bihorean §i Transilvan 128. Semnificatia notiunilor de intern §i extern 139. Problerna forlandului 13

10. Potaritate orogenica §i migrare de ax orogen 1311. Centuri mobile pericratonice, intercratonice §i intracratonice 14

Aprecierea genezei raetamorfitelor prin intermediul relatiei litologiilorcaracteristice cu contexte bazinale sau settirrgnri geotectonice prernetamorficedeterminate 15

I. Originea secventelor premetamorfice 151. Bazinele de rift continental 152. Bazinele de margine continentala pasiva 163. Bazinele intracratonice asociate cu meganfting 174. Bazine de flexare continentale sau intracratonice 175. Fosele de mare adancime de la contactele convergente 176. Bazine prearc 197. Bazine backarc 198. Bazine remanente §i de forland 20

II loan Balintoni

9. Sedimente arhaice 2110. Sedimente proterozoice 2111. Evolutia ba/inelor de la 2000 la 1500 Ma 2212. Tendinte geochimice in evolutia crustei 2213. Evolutia organica a pamantuiui 2314. Depozite metalice gazduite de sedimente 23

II. Metamorfismui si polimetamorfismui 24111. Descrierea si clasificarea metamorfitelor 25

Carpatii Oriental! 27

i. Structura , ,. 271. Considerente istorice 272. Prezentarea si descrierea Getidelor estice 29

a. Panza bucovinica 30b. Argumente in favoarea alohtoniei wildflyschului 31c. Panza subbucovinica ..•. 32d. Unitatile tectonice infrabucovinice 33

3. Unitatile tectonice varisticc 34a. Succesiunea unitatilor tectonice varistice

in soclurile celor alpine , 34b. Unitatea de Rodna 35c. Extinderea panzelor de sariaj varistice 35

II. Litostratigrafia metamorfitelor din unitatile tectonice varistice 351. Descrierea secventelor metamorftce 362. Aite secvente cristaline considerate varistice 44

III. Localizarea suturii varistice 45IV. Comentariu asupra metamorfismului varistic 46V. Problema panzelor intracutanate 46

VI. Reiatiile dintre litogrupuri in functie dc gcneza lor 47

Carpatii Meridional! 49

I. Aspecte generate 49II. Considerente istorice 49

III. Descrierea Getidelor sudice , 50l.Getidele austrice din componenta Getidei iaramice de Timis-Boia 50

a. Zona cristalino-mezozoica de la est de Olt 50b. Masivu[ Poiana Rusca , 53

2.Getidele austrice din componenta Gelidei Iaramice de Lotru-Bistra 54a. Cuvertura sedimentara a panzei getice de Lotru-Bistra 54b. Getidele supragetice din zona Oltului 55c. Getidele supragetice din nordul muntilor Sebe§ 55d. Getidele supragetice de la est de zona

sedimentara Rusca Montana 55e. Getideie supragetice de !a vest de zona

sedimentara Rusca Montana 55

Geotectonica terenurilor metamorfice din Romania III

f. Getidele supragetice din Banatul de vest •. 56g. Relatiile dintre Getideie supragetice de la vest si

est de zona sedimentara Rusca Montana 56h. Faciesurile cuverturilor sedimentare precolizionale si

forfecarile austric 57i. Panza infragetica de Borascu-Ilovita 57

3. Varsta Getidei laramice de Timij-Boia 574. Varsta Getidei laramice de Lotru-Bistra 585. Rolul tectogenezei mediteraneerie in Caipafii Meridional! 586. Constitutia soclurilor Getidelor sudice 59

a. Generality 59b. Secventele metamorfice precambriene 59c. Secventele metamorfice paleozoice "... 75

7. Sutura varistica 78a. Unitatile tectonice varistice 78b. Traseul suturii varistice 79c. Metamorfismul varistic 80

IV. Severinidele 81,V. Euxinideie daiiubicnc 83

1. Cuverturile'alpine ale Euxinidelor danubiene 862. Comentariu asupra cuverturilor alpine 883. Soclurile Euxinidelor danubiene 89

a, Compozitie 89b.Unitati tectonice varistice 90c. Complexul ofiolitic Tisovita -luti 90d. Secventele metamorfice proterozoice 91e. Secventele metamorfice varistice : 98

Muntii Apuseni , 100

I. Considerente generate 100II. Transilvanidcle 102

I. Clasificarea Transilvanidelor 102a. Transilvanidele austrice 103b. Transilvanide laramice 106

III. Apusenidele 1 1 31. Unitatea de Bihor si sistemul panzelor de Codru 113

a. Cuverturile , 113b. Soclurile 115

2. Sistemul panzelor de Biharia 127a. Cuverturile panzelor sistemului de Biharia !28b. Soclurile panzelor sistemului de Biharia 129c. Sutura varistica din muntii Apuseni 135

Orogenul norddobrogean 137

I. Structura alpina |i constitutia orogenului norddobrogean 137

IV loan Balintoni

l.Unitatile tectonice alpine principale 137a. Panza de Orliga 137b. Panza de Macin , 138c. Panza de Consul , , 142d. Panza de Niculitel 143e. Panza de Tulcea 143

2.Evoiutia orogenului norddobrogean anterior functionariifaliei Peceneaga-Camena 146

a. Riftogeneza s.i spreadingul 146b. Tectonica compresiva eocimmerica 146c. Problema strucurii panzei de Tulcea 146d. Situatia Jurasicului superior 147e. Tectonica compresionala neocimmerica 147f. Falia Peceneaga-Camena 147g. Alohtonia orogenului norddobrogean 147h. Magmatitele jurasic superioare 147i. Terenele tectono-stratigrafice din lungul -

faliei Peceneaga-Camena 147II. Structura varistica a orogenului nord dobirogean 149

III. Recapitulate privind evolutia alpina a orogenului norddobrogean 149

Metamorfitele din scuturi si platforme 151

I. Platforma Eurasiatica 151II. Scutul Dobrogei centrale 152

111. Platforma Moesica 1 53

Eclogite, metaultrabazite, granulite, migmatitc, granitoide, semiiificatiigeotectonice; aspecte petrometaiogenetke conclusive ale cursului 155

1.Eclogite 1552. Metaultrabazite , 1553. Granulite 1564. Migmatite 1565. Granitoide 156

Retrospectiva sintetica asupra metamorfitelor din Romania 158

I. Metamorfitele din orogenele carpatic si norddobrogean 1581. Metamorfitele proterozoice 1582. Metamorfitele caledoniene 1583. Metamorfitele varistice 1594. Concluzii generale asupra metamorfitelor carpatice sj nordclobrogene 159

II. Metamorfitele din scuturi §i platforme 160

Bibliografie 161

Geotectonica terenurilor metamorfice din Romania

CONTENTS

The Alpine geotectonic division and timing of Romanian territory,in the plate tectonics 5

1. Introduction , 52. Pre-coUisional Hthospheric plates 63. The plate continental crust , 7

a. Theoretical appreciation , 7b. Craton description 7

4. Comments about the plate extent 8a. The Preapulian plate 8b. The Getic plate Getic 9c. The Euxinic plate 9

5. Orogens or mobile belts 9a. Criteria for the Alpine Romanian orogen division 9b. The spatial division of the Carpathian orogen 10c. The North Dobrogea 10

6. The craton configuration modification during the Alpine orogeny andthe temporal classification 11

a. The neocimmeric configuration 11b. The austric configuration 11c. The pre-Gosau configuration 12d. The laramian configuration 12e. The intraburdigalian configuration 12f. The intrabadenian configuration 12g. The intrasarmatian configuration 12

7. The Transylvanian and Bihor craton relicts 128. The internal and external terms signification 139. The forland problem : 13

10. Orogen polarity and orogen axe migration 1311. Peri-cratonal, inter-cratonal and intra-cratonal mobile belts 14

The metamorphics origin appreciated by the relationship betweensome characteristic litologies and specific premetasnorphic basinal contexts 15

1. The premetamorpluc sequence origin 151. The continental rift basins 152. The passive continental margin basins 163. Intra-cratonal basins associated to the megarifting 174. Intra-cratona! or continental fiexurai basins 175. The deep trenches at the convergent boundaries 176. The fore-arc basins 19 /•1. The back-arc basins 19 )8. The remnant and foreland basins 20

VI loan Balintoni

9. Archaic sediments10. Proterozoic sediments11. The basinai evolution between 2000 and 1500 Ma12. Geochemica! trendsfor the crust evolution13. The Earth organic evolution14. Ore deposits in sediments

II. The metamorphisin and the polimeiamorphismIII. The mefamorphics description and classification

The East Carpathians 27

I. The structure 271. Historical appreciation 272. The presentation and description of the Eastern Getides 29

a. The bucovinic nappe 30b. Some arguments for the wildflisch allochthony 31c. The subbucovinic nappe (underbucovinic) 32d. The infrabucovinic tectonic units 33

3. The variscan tectonic units , 34a. The succession of the variscan tectonic units

in the Alpine one basements 34b. The Rodna unit 35c. The variscan nappe extent 35

II. The metamorphics lithostratigraphy in the variscan tectonic units 351. The metamorphic sequence description 362. Other variscan considered crystalline sequences 44

III. The variscan suture location 45IV. Comment about the variscan metarnorphism 46V, "The intra dermal" nappe problems 46

VI. The lithogroups relationship depending on their genesis 47

The Sooth Carpathians 49

I, General aspects , , 49II. Historical appreciation , 49

III. The South Getides description 501. The constitutive austrian Getides of the Timis-Boia laramian Getide 50

a. The Mesozoic Crystalline zone, East of the Olt river 50b. The Poiana Rusca Massif 53

2. The constitutive austrian Getides of the Lotru-Bistra laramian Getide 54a. The de Lotru-Bistra Getic nappe sedimentary cover 54b. The supragetic Getides from the Olt zone 55c. The supragetic Getides from the north of the Sebes. mountains ... 55d. The supragetic Getides from the east of the

Rusca Montana sedimentary zone 55e. The supragetic Getides from the west of

the Rusca Montana sedimentary zone 55

Geotectonica terenurilor metamorfice din Romania VII

f. The supragetic Getides from the western Banat , 56g. The relationsheep between the supragetic Getides

from the west and east of the Rusca Montana sedimentary zone .. 56h. The pre-collisional sedimentary cover facies and

the austrian shearings 57i. The Borascu-Ilovita infragetic nappe 57

3. The Timis-Boia laramian Getide age 574. The Lotru-Bistra laramian Getide age 585. The role of the pre-Gosau tectogenesis in the South Carpathians 586. The Southern Getides basement composition 59

a. Generalities 59b. Precambrian metamorphic sequences 59c. Palaeozoic metamorphic sequences 75

7. The variscan suture 78a. The variscan tectonic units 78b. The variscan suture route 79c. The variscan metamorphism 80

IV. The Severinides '. 81V. The danubian Euxinides 83

1. The danubian Euxinides Alpine covers 862. Comment about the Alpine covers 883. The danubian Euxinides basements 89

a. Composition 89• b. Variscan tectonic units 90

c. The ophiolitic Tisovita -luti complex 90d. The proterozoic metamorphic sequences 91e. The variscan metamorphic sequences 98

The Apuseni Mountains 100

I. General aspects • 100II. The Transylvanides 102

1. The Transylvanides classification 102a. The austrian Transylvanides , 103b. The laramian Transylvanides 106

III. The Apusenides 1131. The Bihor unit and the Codru Nappe System 113

a. The covers 113b. The basements 115

2. The Biharia Nappe System 127a. The covers 128b. The basements 129c. The Apuseni Mountains variscan suture 135

The North Dobrogea Orogen 137

I. The Alpine structure and the constitution of the North Dobrogea Orogen 137

VII] loan Balintoni

1. The main Alpine tectonic units 137a. The Orliga nappe 137b. The Macin nappe 138c. The Consul nappe 142d. The Niculitei nappe 143e. The Tulcea nappe 143

2. The North Dobrogea Orogen priorto the Peceneaga-Camena fault working , 146

a. The rifting and the spreading 146b. The eocimmeric compressive tectonics 146c. The Tulcea nappe structure problem 146d. The upper Jurassic situation 147e. The neocimmeric compressive tectonics 147f. The Peceneaga-Camena fault 147g. The North Dobrogea Orogen allochthony 147h. The upper Jurassic magmatlc rocks 147i. The tectono-stratigraphic terrenes along

the Peceneaga-Camena fault 147II. The North Dobrogea Orogen variscan suture 149

III. Summary of the North Dobrogea Alpine evolution 149

The metamorphics from the shields and platforms 151

I. The Eurasian platform 151II . The Central Dobrogea shield 152

I I I . The Moesian platform , 153

Eclogites, metaultrabasites, granuiites, migmatites, granitoids,geotectonic significations; conclusive petrometallogenetic aspects of the text... 155

1.Eclogites. 1552. Metaultrabasites 1553. Granuiites 1564. Migmatites 1565. Granitoids 156

Syntethic retrospect regarding the Romanian metamorphics 158

I. The metamorphics from the Carpathian and the North Dobrogea orogens.. 1581. The proterozoic metamorphics 1582. The Caledonian metamorphics 1583. The variscan metamorphics 1594. General conclusions regarding the Carpathian and

North Dobrogea metamorphicsII. The shield and platforms metamorphics

Bibliography '., - 161