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1386J. KonopaÂsek et al. / Journal of Structural Geology 23 2001) 1373±1392Fig. 9. Structural map of the studied area shows D3 and D4 monoclinal and conjugate systems of kink bands. Orientation of the kink bands is presented in thelower-hemisphere equal area projection together with the orientation of S 2 ±S 3 foliation see lower left part of the ®gure for principal fabric elements). For eachlocality numbered inside or above each projection), all measured kink bands and foliations were averaged and presented as a mean value. Estimated s 1 and s 3directions are shown at localities with developed conjugate kink bands. The equal area projection on the right hand side of the ®gure represents poles to brittleductile,late D4 shear bands in orthogneisses and micaschists. Three groups of F 4 compressional kink bands observed in the studied area are shown in the lowerpart of the ®gure. a) Kink bands showing northward normal kinematics affecting northward dipping steep foliation. b) Conjugate set of kink bands affectingsubvertical foliation. c) Kink bands showing southward normal kinematics affecting southward dipping steep foliation.symmetrically developed conjugate kink-band folds andthese are developed in a vertical foliation. Group c)consists of monoclinal kink-band folds which deform asteep, south-dipping foliations and indicates top-to-thesouthnormal kinematics.In the southern limb of the KlõÂnovec antiform, most of thekink-band folds belong to group 3, with groups 2 and 1observed less frequently. On the southern limb of theMeÏdeÏnec antiform, the three groups of kink-band folds aremore equally developed.62
J. KonopaÂsek et al. / Journal of Structural Geology 23 2001) 1373±1392 13877.2. Analysis of kink-band foldsThe geometry of symmetrical kink-band folds was usedto determine the orientation of stress axes according to themethod of Ramsay 1962a). The orientation of s 1 is perpendicularto the kink-band fold axis and lies in the plane thatbisects the obtuse angle between the conjugate kink-bandfolds. If only one set of the conjugate kink-band foldsdevelops, it implies that the maximum principal compressivestress s 1 was oblique to the foliation. The approximateorientation can be deduced but, as the angle betweens 1 and the kink-band fold is determined by the value of themechanical anisotropy Cobbold et al., 1971) and because ofthe phenomenon of stress de¯ection, it is not possible todetermine the exact orientation of s 1 .The sub-horizontal orientation of s 1 , deduced fromthegeometry and orientation of the D3 kink-band folds, isconsistent with earlier deduced N±S compression associatedwith the D3 deformation. Some of them show signsof later rotation, which probably occurred during theprogressive development of the D3 folding e.g. Locality6 in Fig. 9).The uniformorientation of the D4 fold axes and theessentially bimodal distribution of kink-band folds in thesouthern limb of the KlõÂnovec antiformFig. 9) indicatethat they probably represent a conjugate set groups a)and c), Fig. 9). This conjugate set is developed throughoutthe whole study area. Locally, only one set of the kink-bandfolds is found to have developed and, as discussed above,this can be interpreted as a result of variations of the S 2 ±S 3orientation with respect to principal compression. The stressanalysis of both the monoclinic and conjugate kink-bandfolds shows that the principal compression s 1 during theD4 deformation was subvertical.8. Discussion8.1. Kinematic interpretation of the D1±D2 structuralsuccessionÐbuilding of the nappe pileThe D1 fabric in eclogites has developed during a pressureand temperature peak in spatially different setting thanthe present-day country rocks. After their emplacement inthe crust, the eclogites were passively transported at the baseof the Lower Crystalline Nappe during the D2 thrusting andbehaved as rigid inclusions in a weak matrix of micaschists.This kind of behaviour resulted in the non-uniformorientationof the D1 structures within the isolated eclogiticboudins which were developed mainly during the largescaleD3 folding KlaÂpovaÂ et al., 1998).The D2 structures in the parautochthonous plagioclaseschists, and in the allochthonous orthogneisses, are associatedwith the main metamorphic event. They representsyn-metamorphic structures developed during thewestward thrusting of the Lower Crystalline Nappe overthe metasedimentary Saxothuringian parautochthon, asinferred from numerous kinematic indicators. KlaÂpovaÂ etal. 1998) suggested that the D2 structures in the eclogitesdeveloped in the same kinematic regime.During the ®nal stages of D2, the principal compressionthat was acting E±W caused large-scale buckling of thewhole nappe sequence and of the parautochthonous domain.These buckle folds have vertical axial planes and foldhinges perpendicular to the L 2 stretching lineation. Weinterpret these structures as a result of the buckling of thestacked nappe sequence at the end of a D2 thrusting episodecaused by the buttressing effect of a rigid autochthon. TheMeÏdeÏnec synformand the Oberwiesenthal structureoriginated in the same manner.8.2. F3 refolding and regional interference patternTwo large-scale F 3 antiforms later refolded the wholenappe system, together with the parautochthonoussequence. These antiforms have E±W striking steep axialplanes and westward plunging hinge zones. In the KlõÂnovecantiform, the D3 deformation is associated with the rotationof the omphacite L 1 lineation in the eclogites as a result ofthe active rotation of eclogitic boudins within weakerorthogneisses and metasediments.The increase in the intensity of the D3 folding in the southof the study area may be the result of the original geometryof the D2 synforms. If the late F 2 folds have a large wavelengthand small amplitude as, for example, the MeÏdeÏnecsynform), later compression parallel to their axes will resultin the development of dome and basin structures interferencepattern type I of Ramsay 1962b)). The observedstructural pattern indicates, however, that late F 2 folds areoverprinted by F 3 folds with moderate to steeply plunginghinges. The development of this kind of F 3 fold suggests thatlate F 2 folds were non-cylindrical domes and basinselongated in a N±S direction with increasing amplitude tothe south. Such periclinal basins and domes are commonlydescribed fromthe Zagros Mountains Iran) or the JuraMountains Price and Cosgrove, 1990, pp. 262±263). TheN±S compression of such a structure may produce theobserved large folds with steeply plunging hinges andE±W vertical axial plane. In this manner, an interferencepattern of type II originates Ramsay, 1962b). The D3 foldingintensity is thus controlled by D2 fold shape with basementdepth increasing towards the south and interlimb angleincreasing towards the north.8.3. Strain pattern in the F 3 fold limbs and F 3 fold mechanicsThe strain ellipsoid in the limb zones of both the KlõÂnovecand MeÏdeÏnec antiforms is characterised by oblate shapessuggesting ¯attening perpendicular to the F 3 fold axialplane Fig. 8). Moreover, the X-axis of ®nite strain inthese zones is sub-horizontal and E±W in direction as aresult of the D3 deformation. We suppose that in E±W63
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Contentsviii4.7 Schulmann, Konopás
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Dedicated to my wife Markéta, daug
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Foreword 2First topic “Quantitati
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Foreword 4source and freely availab
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1. Quantitative analysis of deforma
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Page 58 and 59: Bibliography 46Skrzypek, E., Štíp
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Table 1Statistical values of the qu
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Table 2Summary of parameters derive
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J. metamorphic Geol., 2008, 26, 273
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EXHUMATION IN LARGE HOT OROGEN 275m
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Probabi l irequencyProbabi l ireque
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EXHUMATION IN LARGE HOT OROGEN 279y
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EXHUMATION IN LARGE HOT OROGEN 281N
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EXHUMATION IN LARGE HOT OROGEN 283w
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EXHUMATION IN LARGE HOT OROGEN 285a
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EXHUMATION IN LARGE HOT OROGEN 287w
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EXHUMATION IN LARGE HOT OROGEN 289T
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EXHUMATION IN LARGE HOT OROGEN 293r
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EXHUMATION IN LARGE HOT OROGEN 295B
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EXHUMATION IN LARGE HOT OROGEN 297R
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TEXTURES OF NATURALLY DEFORMED META
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1.0--0.9__Mg~(Mg2++Fe2+)9 Core of p
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ORIGIN OF FELSIC MIGMATITES 51Cmı
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