SEISMICITY, NEOTECTONICS, AND RECENT DYNAMICS with special redard to the Territory of Czech Republic 250 66 Zdiby 98, tel. 02/685 7375, fax: 02/685 7056, e-mail: odis@vugtk.cz

1. CHARACTERISTIC OF THE NEOTECTONIC STAGE

During the recent decades, a new and the youngest stage has been singled out in the evolution of the Earth, the Neotectonic Stage. In terms of time, this stage roughly includes the Neogene - Quaternary and displays a number of new features of tectonic processes, unknown in the previous stages, and justifiably considered by many authors to be an independent, post-Alpine stage in the Earth's evolution.

The principal new features of Neotectonics are: the genesis of high mountains and the growth of relief contrasts, the generation of extremely coarse-grained molasses, significant activation of platforms of various ages, change in volcanism (from acid to alkaline), increase in the rate of motions, significant predominance of upheavals over slumps, and of denudation over accumulation. Neotectonics is thus a significant orogenic stage and, so far, the largest orogenesis (understood in Gilbert's sense (1890)) in the history of the planet we are cognizant of. This is an unfinished stage - the rate of tectonic motions is still on the increase.

Neotectonics is of a global nature. It is a mobile phase of the last continuing global orogenesis, affecting all geostructural regions of the Earth. Neotectonic motions of similar magnitude and planetary nature are temporally well synchronized. For example, all the mountain masses of the planet are of the same age - Upper Pliocene - Quaternary.

No mountain masses or high mountains, as known from Neotectonics, were formed in the older periods. They also differ in a number of other characteristics, so that one is justified in assuming historical differences in the evolution of the Earth's crust. Old oceans were shallow and continents low, with no high mountains. Contrasts increased during evolution; the present epoch is an epoch of high mountains and deep oceans. As a result of neotectonic orogenesis, which has affected not only young geosynclines, but also the Earth's crust as a whole, and apparently also the upper mantle, the dry land has reached its maximum dimensions, and the relief of the Earth's surface its highest elevation and degree of contrast. Such conspicuousness and degree of contrast in the horizontal and vertical differentiation of the Earth's surface have not occurred in the whole pre-tectonic history of the Earth. This resulted in a significant enhancement of the extent of denudation in the Neogene and Quaternary.

The conception of Neotectonics as of motions of the Neogene - Quaternary, representing an independent stage in the development of the planet, is quite justified. They represent significant activation of tectonic motions which have created the foundations of the present relief, rising to high-mountain elevations and displaying considerable contrast: over 20 km (10 km the elevation of the Himalayas, 11 km the depth of the ocean). This large superelevation of the relief is responsible for the generation of coarse-grained molasses, whose fragments are as much as 10 - 15 m in diameter, and which were unknown in the pre-neotectonic stages.

The Neotectonic Stage thus covers a period of 25 - 30 mill. years. During this period the Earth's crust underwent profound restructuring in which younger tectonic structures (folds, faults) were formed. This tectonic activation moulds the present relief of the surface, the magnetic and partly also the gravity field, manifestations of volcanism, and is responsible for the high seismicity.

This stage was preceded by a stable phase of the preceding stage of the concluded Mesozoic-Palaeogene global peneplane. The present relief, the neostructure of the planet was formed in the Neogene - Quaternary as a result of the deformation of the preceding global peneplane.

A weakening (decay) of tectonic activity, emphasized by many authors, is not in evidence anywhere on the present Earth's surface. On the contrary, one can observe a pronounced activation of tectonic motions. Indeed, the combination of these processes of significant growth in tectonic activity in all types of structures determines the content of the present stage of tectonic evolution of the Earth.

The overall character of neotectonic activation of the Bohemian Massif, its timing, degree of contrast of motions and structures, its cyclic nature, increase in the rate of motions into the present, gradual increase in the coarseness of molasses, shortening of cycles, the pre-orogenic stage of peneplanation, heredity, young volcanism, the generation of a mountain relief which has now reached the highest elevations in the whole history of evolution of the Bohemian Massif, etc., fully conforms to the global pattern.

The term "younger tectonics" was first used in its present since by Šulc (1939). By younger tectonics he understood the tectonic processes which formed the principal features of the present relief of Tien-Shan.

A little later, a more complicated definition of this term was presented by Obruchev (1948). In his treatise "Fundamental features of the kinematics and plasticity of Neotectonics" he wrote: "I suggest that the structure of the Earth's crust, created during its most recent motions which took place at the end of the Tertiary and in the first half of the Quaternary, be called Neotectonics".

But the most exhausting definition of the term "Neotectonics", which essentially combined both the preceding interpretations, was presented by Nikolaev (1962) who suggested that Neotectonics can be understood as "... the theory of various tectonic processes and of the structural forms, generated in the Neogene - Quaternary period and determining the principal features of the present Earth's relief, they relate to".

Also the author of this study understands the Neotectonic Stage to the extent of the latter definition (Kopecký 1972, 1983, 1989). The author does not differentiate between the terms "Neotectonics" and "younger tectonics" as suggested by some authors; he considers these terms to be synonymous.

In this paper, the beginning of the Neotectonic Stage is considered to be the geological period in which new structures are being created, and older ones are being completely restructured, or are inheriting the style of evolution and adopting qualitatively new features. In the Bohemian Massif such a period is the Palaeogene-Neogene boundary, when the rate and differentiation of motions, and neovolcanic occurrences began to increase, and when the monotonous low peneplane began to turn into an orographically strongly divided territory with a number of midmountain relief sectors. A pronounced change in the tectonic pattern as opposed to the Mesozoic and Palaeogene occurred in this period, and that is the reason why the Neogene - Quaternary period is being considered as a more or less independent evolutionary stage, the Neotectonic Stage, of the Bohemian Massif.

In his paper (1972) the author already included the Oligocene - Quaternary period in the Neotectonics Stage of the Bohemian Massif. This is the extent to which the Neotectonic Stage is also being understood in this study. For the sake of brevity, the author uses the simplified designation Neogene - Quaternary, or Palaeogene-Neogene boundary. However, intensive young volcanism occurred during the Oligocene, and therefore it is more appropriate to include part of the Palaeogene in defining the Neotectonic Stage in the Bohemian Massif.

One of the most important theoretical bases of Neotectonics as an independent scientific discipline is the concept of existence of a stage of tectonic and geomorphological stability, which preceded the active Neotectonic stage of forming the present contrastive relief of the Earth. This is essentially the basis of the whole practice of neotectonic mapping, commencing with the definition of a supporting, regional, stratigraphic or geomorphological level, corresponding to the stage of such stabilization.

To be able to assess the magnitudes of the younger motions of the Bohemian Massif, it is necessary to depart from a regionally developed peneplane of Mesozoic-Palaeogene age, covered by a fossil weathering crust, which can be considered as the initial horizon for the further tectonic evolution of the Massif. The Mesozoic-Palaeogene stabilization and planation was of universal significance on the planet and, indeed thanks to it, the Neotectonic Stage could be assigned a concrete lower time limit. This enables neotectonic maps to be constructed, provided one assumes (to a large extent justifiably) complete planation of the Earth's relief.

The principal problems of Neotectonics can only be solved given lucid conceptions of the preceding stages of the geological evolution of the separate regions involved. Only a historical approach to the analysis of younger motion will enable one to understand their significance and the regularities of their manifestations on the Earth's surface. The principle of geotectonic heredity is now being widely applied in geology as one of the important methods of tectonic analysis.

2. THE PRINCIPAL STAGES OF FORMATION OF THE NEOSTRUCTURE OF THE BOHEMIAN MASSIF

Younger tectonic motions took place during the whole Neotectonic period, but were, of course, of different intensity and sense in time, which enables several stages of their manifestations to be distinguished. Each of these stages was reflected in the formation of lithostratigraphic units.

The younger Cenozoic sediments display several phases in the Bohemian Massif, ranging from a predominance of pelites to coarse gravels. The lower part was deposited in basins, under lacustrine and marine conditions, and their moderate motions of small amplitudes were compensated by sediments carried down from the surrounding shelves. This accumulation corresponds to the beginning of the orogenic stage, and took place under the conditions of an inconspicuous relief in the initial stage of its development.

The initial period of the Neotectonic Stage in the Bohemian Massif is characterized by the predominance of subsidences over upheavals, and by the tendency to the formation of negative structures. A considerable subsidence of part of the Bohemian Massif to the east and south occurred, i.e. the peneplane subsided to zero or even negative elevations and the sea transgressed from the Alpine-Carpathian Foredeep. The unflooded part remained a low dry land and apparently retained the original elevation of the peneplane, i.e. 100 - 150 m, and a quite levelled surface. The nature of this surface can be judged from the character of the sediments mostly consisting of pelites and psammites. The lack of coarse-grained sediments even in the immediate vicinity of contemporaneous steep slopes is evidence of the small impression young structures made in the relief, i.e. of the absence of mountains. Fine-grained lower molasses occurred at the contact of still inconspicuous units.

At the end of the Pliocene, a significant increase in the intensity of tectonic motions, nearly exclusively of the upheaval type, occurred in the Bohemian Massif. The abrupt growth of this activity (by an order of magnitude) corresponds to the orogenic phase.

The tectonic motions of the Quaternary differ from those of the preceding stages also in quality. A significant differentiation in motions and structures occurred during this period. Moderate depressions and elevations, undergoing long-term development in the Neogene, changed to orogenic structures in the Quaternary.

The predominant areal degradation changed into active erosion of rivers which was unable to compensate the growth of local structures. Brachyanticlines and brachysynclines, which create a contrastive relief, began to differentiate morphologically. Instead of the former fine-grained accumulation, coarse-grained molasses began to sediment. Consequently, the upper part of the molasses formation has quite the opposite characteristics to the Neogene; colour, grainsize, petrography, high rate of sedimentation. These are mostly coarse, polymict, gravel-sandy, gravel to boulder-like accumulations with blocks 5 m in size at the most. No pre-Quaternary formation in the Bohemian Massif displays such coarse-grained accumulation. This is a typically orogenic complex, corresponding to the main Neotectonic Stage of forming the neostructure of the Bohemian Massif.

The coarse-grained (orogenic) gravels, forming the upper part of the profile, accumulated under the conditions of a mountainous relief. It is sufficient, e.g., to compare from this point of view the coarse facies of contemporaneous rivers with the sandy clayey sediments of the Miocene streams flowing into lakes to be able to distinguish the difference between the palaeogeographic conditions prevalent in the Neogene and Quaternary.

The comparison of the overall nature of the division of the relief and of the correlating sediments is evidence of the gradual process of formation of the neostructure with the subsequent evolution of stages: the initial, transitional, and final (Kopecký 1972,1983). A certain pattern of sedimentation in the region of accumulation, type of division of the corresponding areas of denudation, the rate and spatial distribution of vertical motions of various intensity correspond to each of the stages.

3. CHARACTER AND EVOLUTION OF THE NEOSTRUCTURE OF THE BOHEMIAN MASSIF

In the present relief the peneplane only rarely retains its original, nearly horizontal and lower surface. One usually encounters it in considerably deformed condition, most frequently in the form of waves. Nevertheless, the contours of the initial peneplane can be reconstructed with a high degree of accuracy. The analysis of fragments of the peneplane is of great importance in determining the age and principal regularities of the neostructure. In concrete cases, the data on dooks and deformations of the Palaeogene surface provide evidence of the forms of failure caused by young tectonics. The shapes of the peneplane deformations, absolute heights at which its extensive areas are still located today, enable one to speculate about the morphology and morphometry of the younger structures of mountain ranges. Thus, in concrete structures the surface of the peneplane with fossil waste creates an upfold, ridge with different dips of the wings, and is well preserved in the area of the structure as a whole.

The relation between tectonics and the relief is reflected in all mountain ranges of the Bohemian Massif. The ridges correspond to anticlines, the valleys to synclines. The form of the relief and the form of the structure are nearly identical. In these cases, the ridges and valleys run parallel with the tectonic structure of the anticlinoria. The regular relation of the younger motions and of the relief is reflected not only in the large elements of the relief, but also in details. Such large dips of the denudation level of the peneplane and spatial correlations can hardly be explained otherwise than in terms of tectonics: folding and step folding. The study of mountains has proved convincingly that mountains are created by the upheaval and division of the old Mesozoic-Palaeogene peneplane.

The deformed surface of the peneplane can be followed without any fault displacements from the bottom of the valley to the tops of ridges. These dipping platforms are quite undisturbed and allow for no faults which this orography would otherwise require. However, one cannot expect the complicated structure of the foundation of fold without faults. Consequently, occasional faults, mostly of small or no, can be observed at a number of places.

One of the characteristic features of fault structures is known to be their linearity, gridplan of the river network, etc.; however, the neostructures of the Bohemian Massif completely lack these characteristic features. The amplitudes, breaking up of structures, their bifurcation and the character of sedimentary spaces will remain unexplained from the point of view of fault tectonics. Numerous shelves with waterfalls and rapid changes of long profiles of rivers should also exist here, because these are manifestations of young tectonics after the river network had been established. Young faults do not occur in the Massif everywhere and are not a necessary element of the neostructure whereas the undulating flexural elements have universal significance and are widespread in the Massif.

The fundamental structural form is the fold structure; young faults are rare and, in the author's estimate, they represent no more than 1% of the dynamic elements of the Neotectonic Stage, roughly 99% of these elements being attributable to fold deformations. Neotectonics in the Bohemian Massif as a whole are estimated to have formed a hundred thousand fold structures with amplitudes of 10 m and more, whereas the proved young faults of like amplitude do not even amount to hundreds.

Folding affects mostly crystalline complexes and is developed but weakly in sediments. However, the folding in the Bohemian Massif is not distributed randomly, but is subject to strict regularity: it is developed only in upfolds of different uplift amplitudes. The uplift amplitude also limits the intensity of folding; the intensity of uplifts increases with the intensity of folding.

The upfolds referred to above are old long-lived structures of regional extent, created as elevation forms already in the Upper Proterozoic, they functioned as inherited elevations in the Palaeozoic, and they again penetrated from the low and flat peneplane as distinct upfolds in neotectonic activation. In the Neotectonic Stage, these positive structures appeared with high accuracy within their original limits; they inherited not only the form, but also the mobility and tendency to uplift. For example, the old cores, which are characteristic of all these upfolds, again appeared in their central parts. The central parts of these upfolds display the largest long-term mobility, they are strongly granitized, affected by long-term denudation, and the highest points of the Bohemian Massif and the highest intensity of the young folding also occur in the core parts.

The bottom of neogene basins is also highly broken. They are undulated with tens of "waves" (brachystructures) mainly due to irregular sedimentary motions of unequal intensity with a predominance of brachysynclines. In this case, the bottoms of the basins were deformed during subsidence which was compensated by accumulation and, therefore, negative structures prevail over upfolds in which positive structures are distinctly more numerous.

The younger deformations (young structural forms) differ in size, morphology, relief, age, and other features. In spite of their heterogeneity, they represent a set of flexures and sags of large and small radii. In the evolution of younger deformations, the vertical component plays the principal role. That is why most structural forms are able to generate elevations and depressions on the Earth's surface.

Whereas there is now no doubt about the tectonic predetermination of relatively large orographic formations, the question of the origin of small orographic units is open to discussion. For a long time it was assumed that local differences were due exclusively to external phenomena: to the lithological character of rocks, erosion of rivers and to denudation in general. The whole set of facts now known, however, is evidence in favour of tectonics. The ridges in mountain ranges, but also in highlands and hills, built of foundation rocks, mostly represent fold structures of various orders which were formed during the period of the most recent activation of the Bohemian Massif.

Factual material indicates that all these forms represent systems of complex and simple deformations of several orders, characterized by very varied mutual relations. Most structures display irregular shapes and complex configurations in the plan; in cross-section they have the character of sectors of circles of different radii. The structures retain these basic features in all segments and on all types of rocks, granites, metamorphosed rocks and sediments, folded and not folded alike.

Typewise, however, they are very similar, differing in size and morphology; they represent typical brachystructures similar to circular structures, bifurcated to star-like shapes, being quite frequent.

It is necessary to emphasize one of the significant characteristic of this folding: this fold structure is represented only by single anticlines. The areas between the upfolds are not synclines proper, and they form residual spaces whose shape and size is determined by the adjacent anticlines which are conspicuously active.

More detailed observations indicate, however, that the separate orientations of the various folds are not detrimental to the peculiarity of each of them. Each upfold has its own peculiarity, and it is practically impossible to combine the upfolds into linear groups.

If the anticlinorium is asymmetric, the steeper wing, which displays the more contrastive folding, is the more intensive and contrastive. For example, in the asymmetric structures (upfolds) to which all boundary mountain ranges of the Bohemian Massif belong, local folds are observed to display different characters in the gradual and steep wings; the folds in the gradual wings have less contrastive parameters. The structures can be distinguished well, they are not densely accumulated in space, anticlines and synclines being developed to the same extent. In the steeper wings, the folds have more contrastive shapes, they are densely accumulated in space, anticlines prevail in area, and part of the structures display well-developed asymmetry. The steeper wings point towards the centres of mountain ranges, or into the centre of the local structure of higher order.

All the regularities mentioned are manifested to some extent in the anticlinoria of the first order, as well as in relation to partial anticlinoria and local structures.

In studying the structures of folded segments, one observes not only different range, different dips of folds, and heterogeneity of manifestation in various sectors, but as one proceeds from one sector to the next, one sees that the folding occurred in various "phases", albeit during a single cycle. This is exceptionally interesting, particularly in connection with the phase shifts in time and space being subject to certain quite concrete regularities.

All the "phases" of folding were accompanied by uplifts of the Earth's crust. Close correlation of folding with the phenomenon of upheaval of the Earth's crust is also observed. The folding is largest in central part of the range - upheaval. As the uplift gradually spread, an increasingly larger area was affected by folding. The same connection of folding with uplift can be seen in the other form: the intensity of folding is related to the intensity of the upheaval of the Earth's crust.

The most intensive deformation is synchronous with the fastest uplift, because the uplift (cymatogeny, warping) of mountain ranges is expressive of the same process of tectonic deformation of a fold natures as structures of lower orders; they are thus of the same origin and differ only in size. If the cymatogeny is not accompanied by the emergence of folds of a small radius, the process of deformation is decreasing in intensity. However, in place where the intensity of deformations is increasing, the folds change to folds of small radii (folds of the Šumava type). Their shape then depends on the intensity of tectonic forces, their location in the area of mountain ranges and segments being intensively uplifted in general. The varying tectonic conditions in the Bohemian Massif created morphologically a wide range of folds of various sizes. The separate upheavals and slumps represent practically weakly deformed sectors of the Palaeozoic and Proterozoic foundation. The deposition of the Cenozoic sedimentary cover copies the fold forms of the underlying layers.

The intensity of folding is directly proportional to the intensity of the upheaval. The most intensive folding in the Bohemian Massif occurred in the highest mountain ranges (Šumava, Krkonoše, Krušné hory, Hrubý Jeseník) which underwent the largest uplift in the Neotectonic Stage; as the uplift grows weaker, the intensity of folding also decreases. This relation holds with a high degree of accuracy between the separate upfolds, as well as within the upfolds themselves. These relations are easy to verify by comparing the intensity of folding in separate segments of the Bohemian Massif. For example, the intensity of folding of the Českomoravská vrchovina (Bohemian-Moravian Uplands) is half the intensity of folding of the Krkonoše Mts., because the neotectonic uplift of the Krkonoše is twice large. The intensity of folding of the Central Bohemian pluton is one third of the intensity of folding of the Šumava, which is also in proportion to the neotectonic uplifts of the regions mentioned.

The intensity of folding increases away from the peripheries of the upfolds towards their centres. This intensity of the regional uplift limits all the parameters of local folds, i.e. size, amplitude, dip of the wings. At the foot of the mountains the folds are small, of small amplitude and mostly of moderate wing dip. Into the mountains' interior all these values gradually increase: the dimensions, amplitudes and degree of contrast of the local folds, which reach their maximum in the centres of the upfolds, increase. This is one of the regularities of this young folding.

The conditions described completely contradict the idea of external tangential forces, because, under the action of the latter, the peripheral parts of the segment would have to be affected first, and only then its internal part, but with lesser intensity. This is the reason why the considerable intensity of folding in the centre of the segment and the gradual abatement towards its periphery is incomprehensible. The forces which deform the segment involved should be sought within the very segments, and not in their neighbourhood.

The evolution of folding in time proceeds from the axial part towards the periphery, i.e. the older phases are to be observed within the mountain range and the younger mostly at its periphery. Given these conditions of mechanics, one is unable to explain the origin of folds as due to external pressure, generated in the adjacent segments.

Argand (1922) was the first to introduce the term "deep folds" (folds of the underlying layers). Also Penck (1924) speaks of mountain upheavals as of large folds of the Earth's crust. Gerasimov (1946) suggested that large relief forms, generated mainly by tectonics, should be called morphostructural.

Large folds, evolved on crystalline complexes, are now generally acknowledged and considered to be a universal category of tectonic structures. They have been given a number of special names.

However, there is but little in the literature which concerns medium-sized and small folds. Some authors even doubt that they could have been generated at all. This is related to the outlived ideas of the small plasticity of crystalline rocks. The generation of large folds with a large radius and small amplitude does not require such a large degree of plasticity as small contrastive folds.

The period of pressure action plays a hitherto little known, but important part in the deformations of rocks. It is common knowledge that even low pressures, acting over a long period of time, decrease the ultimate elasticity, and the rock does not behave as an elastic mass. Under long-term mechanical effects, the Earth's material may deform plastically. One can claim that rocks are solid with respect to short-term effects (seismic waves), but they may deform plastically under slowly acting effects. Evidence of this is, e.g., the deformation of marble or granite tombstones in old graveyards, affected by atmospheric pressure and their own weight only. Time is thus an important deformation factor, and occurs as an unknown quantity in geological processes. Consequently, also the assessment of the forces acting within the Earth is relative, and scales of solid-state physics should not be applied to it.

Field observations in the Bohemian Massif indicate that crystalline complexes may be deformed to the utmost details, inclusive of structures a few square metres in area and tens of centimetres in amplitude, which is evidence of the considerable plasticity of these complexes. The author is of the opinion that no parameters should be applied to limit this folding in advance.

The folds in the Bohemian Massif are of several orders of magnitude: the largest folds of the 1st order are up to 100 km long, 50 km wide, and 1200 - 1400 m in amplitude (Šumava, Krušné hory, Krkonoše and some other mountain ranges). This category of folds, with exceptions, could be referred to as folds of the underlying layers or "plis de fonds" after Argand (1922). These folds are complicated structures of small size. They involve structures of several orders (6 - 7) of intermediate, small and very small sizes and amplitudes.

The amplitudes of these local folds range from 700 m (2nd order) to 10 cm (7th order), and their areas from 10 km² to 10 m². With regard to the Bohemian Massif, the author refers to these local structures as folds of the "Šumava type" (Kopecký 1983).

As a rule, all positive neotectonic structures are distinctly reflected in the relief. This does not, therefore, apply, as is frequently assumed, only to large structures, but also to the smallest forms. The small age of these forms and their present evolution and, consequently, also weak modification by denudation, enables these neotectonic structures to be studied in the greatest detail, in time as well as in space. In this respect, neotectonics are providing geology with an unusual possibility of studying the process of folding in considerable detail.

On the one hand, the Bohemian Massif is preceded by platform pre-history - a low denudation level of the peneplane type was in its place until the Neotectonic Stage (Mesozoic - Palaeogene), and on the other, there is the contrastive relief and intensive young volcanism atypical for platforms. This is where one now encounters a structure of peculiar type: its evolution includes platform pre-history and the orogenic stage, a weak Epivarisian orogenesis. This thus involves an activated Epivarisian platform with a midmountain relief, intensive folding and volcanism.

We are still not fully cognizant of the regularities of a similar revival of platforms. Belousov referred to this revival of platforms as "activation". These areas require detailed study to clarify the conditions under which they originated. One may clearly claim that the activation of platforms represents a new phenomenon having no relation to the regular change of geosyncline conditions for platform conditions, observed during known geological history.

From Nikolaev's point of view (1962) one must see in these regions new tectonic structures, differing from geosynclines and platforms. This enables one to speak of a new form of evolution of the Earth's crust.

The qualitative differences of the tectonic processes of this young orogenesis of the Bohemian Massif should also be emphasized. Apart from the high intensity, large gradient, and conspicuous differentiation of tectonic motions and structures, it is also manifested by different types of folding and multi-phase volcanism. An exceptionally large number of small, but sufficiently contrastive structures of the fold type, which characterize the Neotectonic Stage of the Bohemian Massif, was created here. Fault deformations leave the limelight here, and recede into the background, representing only a negligible fraction of neotectonic motions.

These motions have the nature of contrastive motions and structures; they are an orogenic type of motion. However, the term orogenesis has many meanings in geology. It includes not only folds, but also faults and other deformations (orogenesis). The term orogenesis, together with the term epeirogenesis, was introduced by Gilbert (1890), and became widely used, unfortunately with a number of modifications which compromised this term considerably. Literally, orogenesis means the origination of mountains, and that is why sometimes, instead of fold and fault motions, one speaks of orogenic motions.

Nevertheless, it is general knowledge that mountains do not always originate as a result of vertical upheavals of the Earth's crust. In this particular case, folds and mountains were created simultaneously, and the term orogenesis, in Gilbert's sense, is quite satisfactory and understood by the author as such.

Of course, orogenic and epeirogenic motions cannot always be separated, because orogenic motions are in fact only accelerated and more intensive epeirogenic motions. Every tectonogenesis consists of orogenic, as well as epeirogenic motions.

The appearance of the structures of mountain ranges in the Bohemian Massif, the amplitudes and gradients of motions, as well as the character of structural dislocations is close to parameters which are referred to as weak epiplatform orogenesis.

4. THE RELATION OF NEOTECTONICS TO THE OLDER STRUCTURE OF THE BOHEMIAN MASSIF

(The Principle of Geotectonic Heredity)

The area of the Bohemian Massif, whose structure is tectonically and genetically quite complicated, belongs to the very old parts of the Earth's crust. It is the result of the preceding evolutional stages which affected it in the course of geological history. It is not the purpose of this study to characterize in detail the separate stages; for this the reader is referred to the appropriate literature. The author only wishes to emphasize that it is not insignificant for studying younger tectonics. Most geological structures were created in the Neotectonic Stage, their foundations being in various older stages, and the most recent are, to a smaller or larger extent, portrayals of structures sometimes very old. Consequently, without the analysis of geological history one is unable to understand and explain correctly the multiformity of the manifestations even of the youngest motions.

The neotectonic structure of the Bohemian Massif evolved on a heterogeneous substratum (Cadomian, Hercynian). In this connection, there emerges the important question of the relation of younger deformations to the older structures of the fundamental complex.

In the problems being studied, as stated by Shatskii (1951), Pejre (1956,1965) and Petrushevskii (1964), three aspects have to be distinguished: 1. the heredity of tectonic plains; 2. the heredity of tectonic forms; 3. the heredity of tectonic motions.

The first thing that draws attention in analysing neotectonic maps is the complete dependence of younger motions on the principal structural features of the Bohemian Massif. In comparing any geological map with a topographic map, one sees considerable agreement between structural and orographic elements: plains correspond to sedimentary formations, mountain ranges to outcrops of the most metamorphosed rocks of the Precambrian and Palaeozoic. Moreover, the individual elements of the mountain ranges mostly agree with orographic elements of the second order, the appropriate upfolds. That is why, e.g., the arching of the structural elements in the northern part of the Massif and the isometric shape of the southern half of the MoldanuODISum can be distinguished in topographic, as well as geological maps.

The younger structural plain of the Bohemian Massif is fully determined by old tectonics. It is reflected particularly in the orientation of the Cadomian and Hercynian structure. This is, in turn, reflected in the configuration of regions, in the location of areas with different tectonic patterns.

Some parts of the Bohemian Massif underwent early stabilization, and are characterized in the Neotectonic Stage by a stable platform pattern, e.g., a wider region of the Barrandien in Central Bohemia. In this area neither intensive Cadomian, nor Hercynian regional metamorphosis took place, and neotectonics here are least intensive in all the Bohemian Massif. Other segments have continued in orogenic evolution to the present (which intermissions). This, e.g., applies to the long-term mobile zone at the border of the Massif (Šumava, Bohemian Forest, Krušné hory, Krkonoše, Hrubý Jeseník). Intensive Cadomian and Hercynian tectonogenesis came to bear in this zone, and neotectonics also display the highest intensity there of the whole Bohemian Massif (weak elpiplatform orogenesis). Many more similar examples could be given. Therefore, neotectonics, which are a continuation of the whole preceding geological history, and which continue to develop its fundamental long-term tendency, has had different effects in the separate parts of the Massif, depending on previous geological history. And it is indeed in these differences that distinct regularities can be observed.

All peculiarities of the neotectonics of the Bohemian Massif may thus be explained within the Massif itself, without considering the substantial influence of adjacent structures (e.g., The Alpine zone) as assumed by most authors, by the long-term controlled evolution of the Bohemian Massif.

As reported by Zeman (1970), in the mobile zones of the Bohemian Massif Hercynian evolution is related to older tectonic metamorphic manifestations, and one can claim that it represents their continuation. According to the same author, Hercynian tectonogenesis is not an independent tectonogenic cycle. It is the last and most intensive stage of Palaeozoic tectonogenesis, related in mobile zones to the older evolution.

Also Máška (1961) claims that the Hercynian structural plain has adopted in altered form many of the features of the Cadomian structural plain (including the arc in the northern half of the Bohemian Massif). In spite of the changes introduced into the structural pattern of the Bohemian Massif by Hercynian tectonogenesis, it is quite evident that this is the original Cadomian structural plain.

"The peculiarities of Cadomian, Caledonian and Hercynian formational characteristics in Central Europe", claims Bogdanov (1976), "lead one to think that all these three systems represent but stages of a single cycle in the evolution of the Proterozoic-Palaeozoic geosynclinal region."

In the Bohemian Massif, therefore, neotectonic activation took place according to the predetermined Cadomian and Hercynian plains from which it differs in its smaller intensity. Neotectonics adopted the structural plains of these tectonogenic stages, together with the intensity of motions (mainly from the Hercynides) and with a number of concrete tectonic structural forms - anticlinoria, synclinoria.

One can claim that the last three reconstructible tectonogeneses, the Cadomian, Hercynian and Neotectonic, represent three links of a single chain. They are closely related in space, structure and mobility which control the evolution of the uniform structural plain of the Bohemian Massif.

In the Bohemian Massif, the conformity of the fundamental structural Cadomian-Hercynian and neotectonic elements is evident and appears continuously. In neotectonics, structures of all directions, Cadomian as well as Hercynian, evolve simultaneously; the Cadomian directions dominate. In this case, one is able to agree with Pejre's conclusions (1956) that the predominating orientation of tectonic structures is exceptionally stable and that it is inherited from one structural level to the next.

The further evolution of orogenic neostructures was determined, on the one hand, by constant heredity of their spatial distribution and features of motions, and, on the other, by a no less distinct tendency towards further restructuring of old structural plains.

In the Bohemian Massif, the relation between the inherited and newly created fold and fault structure is defined sufficiently clearly. Both processes are taking place simultaneously and conditionally, however, the tendency to heredity prevails.

The actual role of neotectonic motions is reflected here in a further differentiation of the inherited structures, by creating structures of lower orders but retaining tectonic style. In the Neotectonic Stage, a large number of structures, again of the fold brachystructural type, are being created on the old inherited upfolds, antiforms. The degree of differentiation depends on the intensity of neotectonic motions and is responsible for the difference in the degree to which the structure and relief are broken. The larger intensity of neotectonic motions is reflected in the higher degree of restructuring of inherited structures. Older structures affected by younger restructuring are replaced by younger structures which are characterized by being considerably conservative, retaining their old plain, location and character of tectonics.

Thus, in the Neotectonic Stage, the type of deformation is inherited to a considerable extent, young upfolds of smaller size, repetitive of the nature of old tectonics, are created. These young folds do not differ in morphology and type from the folds developed in the rocks of the basement. As regards the old formations (crystalline complex) of the Bohemian Massif, anticlinoria and synclinoria of various orders with a pronounced predominance of antiforms are typical. Also granitoids form mostly isometric vault-like structures. Identical structural elements, elements of the neostructure and palaeostructure, can be observed therein.

Neotectonic structures are created by differentiation, by the disintegration of large structural formations (upfolds) related to preceding geological stages. The younger structural forms thus represent the sum of elements of old and new deformations.

The young folding, which is the essence of the Neotectonic Stage in the Bohemian Massif, is not, therefore, distributed randomly or chaotically in the area of the Massif, but is subject to strict regularity; it is bound to the vault-like structures of higher orders (regional upheavals), i.e. to the segments which are intensively lifted in the Neotectonic Stage. These are all old long-lived structures inherited from the Cadomian and Hercynian stages which have outlived several tectonic stages and have preserved their tendency to uplift. In neotectonics this then involves inherited (renewed) structures with mobility inherited from the preceding tectonogenic stages. The evolving process of neotectonic tectonogenesis is responsible for the complexity of the large structures created earlier.

The maximum concentration of granite massifs, Palaeozoic as well as older, is also observed in the areas of upfolds. This regularity is distinct to such a degree that authors are subscribing to the opinion of a geotectonic relation existing between the processes of upfold generation and the forming of granitoid masses.

In the Neotectonic Stage, the uniform peneplane is disintegrating into a large number of structures of various orders and geneses, and structural and geomorphological differentiation occurs. However, these new structures are not distributed randomly, but assume most of the elements of the old basement. The orientation of most neotectonic structures agrees with the orientation of the principal tectonic structures of the basement.

In neotectonic structures of the second and lower orders, an analogous correlation can be observed clearly in places, less so in others, and is non-existent in yet others. The contours of larger, more deeply founded structures inherit very similar contours, and the contours of lower order structures undergo differentiation.

The heredity of tectonic forms of lower orders is also observed, the character (style) of old tectonics being inherited. Together with the inherited, there also appear new features which complicate or alter the old structures. Folds of lower orders themselves are autogenous.

5. THE FOLDING MECHANISM

One of the important problems of the methodology of regional research into neotectonic motions is their division into basic types, and the "independent" study of these deformations, caused by each type of these tectonic motions. In the Bohemian Massif, two types of motions can be distinguished in the course of the Neotectonic Stage: regional and local (tectonogenic). The former appeared simultaneously on extensive surfaces. They are characterized by frequent change of sense and considerable summary amplitude. They are related to Miocene marine transgressions and regressions, and to the emergence of mountain ranges as a whole.

Local motions, creating structures of lower orders, mostly in the form of folds, can be observed on the background of motions of a regional nature. The tectonogenic motions were more stable in time and were inherited, to a larger extent, from old motions. A number of transitions can be observed between both types of motions.

Quite widespread in the geological literature is the division of tectonic motions into vertical and horizontal, i.e. into motions taking place essentially in the vertical oirection, and motions essentially horizontal. This classification, however, schematizes phenomena excessively.

First of all, it is incorrect to assume that the vertical and horizontal directions are the basis for the displacement of material of the Earth's crust. These displacements occur in any direction, and the vertical and horizontal directions are only assumed to be leading because it has become customary to illustrate the structure of the Earth's crust either in vertical sections, or on horizontal maps.

Secondly, tectonic motions are never observed in pristine form. They always represent an essentially complicated combination of motions of various orders. Vertical motions always generate, in the quality of similar phenomena, horizontal and diagonal (oblique) motions, connected with the vertical by a single mechanism.

This indicates that the task of dividing motions into vertical and horizontal is not as simple as might be expected, because it is very difficult to determine accurately what order of motion is involved.

Difficulties with classifying tectonic motions also arise, because the individual types of structural forms and, consequently, also the tectonic motions generating them, are non-uniform. For example, faults are not independent, but always represent the consequence of and uplift or downthrow of the Earth's crust, or of folding. One can claim that even folding itself represents a secondary phenomenon which evolves under certain conditions as the mechanical consequence of vertical motions of the Earth's crust.

From this point of view, it would be possible to divide tectonic motions into primary or original, and secondary or derived. Folding of the Earth's crust upwards (cymatogeny) and downwards (step-folding) should be assigned to the primary motions, and folding and faultage to the secondary.

As regards the basic mechanism of folding, the author is of the opinion that this young folding of the Bohemian Massif is caused by processes of diapirism. Evidence of this is the distinct predominance of the vertical component and also the form of the fold structures, which is close to circular.

Isostasy cannot be considered a basic cause of tectonic motions. The orientation of tectonic motions frequently does not conform to the sign of the isostatic anomaly. In places where the Earth's crust should rise to achieve equilibrium, but slumps instead, the mechanism of uplifting motions has its source in the deep structure, mostly down in the mantle.

The main cause of folding is the regional uplift of upfolds of higher orders. It should be emphasized that this young folding in the Bohemian Massif is not distributed randomly, but that it is subject to certain regularities; it is developed only in the upfolds of regional nature. In this case, structures inherited from the Cadomian are involved, which functioned as upfolds during the Hercynian, and in the Neotectonic Stage they once again penetrated as significant elevations. These upfolds re-appeared with a high degree of accuracy within their old limits. For example, the old cores of these uplifts are now located in their central parts. Together with the structure, these uplifts also inherited increased mobility and tendency to upheaval from the preceding stages. It is indeed this increased mobility with the tendency to upheaval which is the main cause of neotectonic folding. The folding involved thus reflects, to a considerable extent, the pre-neotectonic evolution of the Bohemian Massif. They are vaultlike long-lived structures which have survived several tectonic stages, and which have retained, on a long-term basis, their basic characteristics: form, increased mobility and tendency to upheaval. And it is on these rising uplifts that neotectonic folding evolves.

This regional upheaval causes an increase of the volume of the segments involved, which then leads to mass expansion. The generation of local folds is then only a secondary phenomenon, derived from the regional upheaval, and is its consequence. The regional uplift of a mountain range thus provides for the overall uplift of the upfold, as well as for its detailed division into neotectonic structures of lower orders.

The problem of the principal role of vertical motions, uplifts, may in this case be considered solved with sufficient certainty, and the subsequent task is in solving the problem of the manner in which vertical forces cause folding.

The upfold increases as a result of the local action of the vertical forces of the uplift. It is indeed here that the most poignant problem of contemporary geotectonics arises: the problem of the forms of the relation between vertical forces and folding, of the ways in which vertical stress is transformed into horizontal, into horizontal displacements of the material of the Earth's crust.

To discover the essence of the mechanism of transformation of regional motion (in this particular case of uplift) into local structures is among the cardinal problems of tectonics. The essence of this mechanism can apparently only be discovered with the aid of structures of small and medium dimensions, i.e. the details of the structure involved.

Detailed study of the morphological properties of even the smallest structures with regard to spatial relations enables the process of folding and the mechanism to be reconstructed in the widest sense of the word. To determine the correct form and correct scale of the folds is an absolutely necessary condition for understanding their genesis and mechanism of formation. Namely the medium-sized and small structures enable one to understand more precisely the mechanism and history of the origination of structural forms, because they allow tectonic motions taking place in nature to be investigated in detail.

A characteristic feature of this young folding is the emergence in the wings of folds of all orders (apart from ministructures) of similar structures of smaller dimensions which complicated these structures. All these forms represent anticline upswelling (upfolding) caused by the expansion of the mass of the particular structure. The essence of this transformation is in the transfer of part of the mass into the wings and into the upfold flexure, into the free space of the particular structure, which results in the creation of similar folds of smaller size. In the diminishing mass, i.e. in the structures of lower orders, the stress leading to expansion and to the generation of smaller and smaller folds decreases.

As a result of expansion, the regional structure grows upwards and expands in width. This basic trend is characteristic for structures of all orders. Besides this basic process of mass expansion, smaller folds are created in the wings of the upfolds.

Structures of the 2nd order are created immediately on structures of the 1st order (regional), the former being one order smaller than the latter. Their dimensions are proportional to the intensity of the expanding mass, i.e. to the size of the first-order structure. Third-order folds do not always originate immediately on first-order structures, but appear in the wings of second-order folds. Similarly, fourth-order folds, also an order smaller, originated in the wings of third-order folds, and fifth-order folds, which are complicated by sixth-order folds, appear on fourth-order folds. Structures of decimetre amplitudes may originate on the smallest, sixth-order structures (ministructures) with amplitudes of 1 m.

As a result of the expansion process, structures of several orders, ranging in amplitude from 700 m to 10 cm, which have their specific role in a particular structure, are created in mountain ranges.

The dimensions of the emerging structures are proportional to the stress of the expanding mass: Second-order structures with dimensions of 10 km and maximum amplitudes of 700 m, i.e. one order smaller, are created on structures of the 1st order as a result of mass expansion; the largest regional upfolds in the Bohemian Massif, with dimensions of around 100 km and amplitudes of 1200 - 1500 m belong to the first-order structures. The structures of smaller orders are in a similar ratio to the immediately larger structures.

The process of transformation is thus subject to strict regularity; it proceeds from larger mass to smaller, and from larger stress to smaller, being subject to the laws of mechanics. No feedback is possible. In this case one cannot speak of structures affecting each other, because this process is unidirectional, the larger mass controlling the smaller, but not vice versa.

The effect of mass expansion is directly proportional to this mass; folds, corresponding to the mass and its stress, are generated on a large mass. As the mass decreases, i.e. in structures of lower orders, the expansion stress decreases together with the tendency to generate ever smaller folds in the wings.

The expanding mass causes this mass to be displaced in all directions, vertically, horizontally and diagonally. Most of the mass, roughly 85 - 90%, is displaced radially, the balance in various directions (see Fig. 1 and 2).

Mass expansion is thus the main cause of generation of local folds. As a result of the expansion process, structures of several orders, of similar genesis and with amplitudes and dimensions corresponding to the expansion effect, are generated. Folds of lower order represent the details of the same structure and reflect the same process.

The scale on which the vertical and horizontal motions take place in the Earth's crust is not, in principle, inconsistent with the transformation and with the horizontal and diagonal motions being subject to the vertical.

Structures of all orders evolve in mutual union. Large structures, which are complicated by structures of the second and lower orders, down to ministructures, take the longest to evolve. Consequently, the evolution of rapidly evolving and alternating small local structures can only be understood on the background of the larger structures.

The mechanism of neotectonic folding in the Bohemian Massif, discussed above, represents a natural and, on the whole, simple process. It proves that the causes of folding are in natural factors rather than in artificially constructed deformation fields.

6. CONCLUSION

The overall character of neotectonic activation of the Bohemian Massif, its definition in time, degree of contrast of motions, its cyclic nature, increase in the rate of motions towards the present, shortening of cycles, the pre-Neogene stage of peneplanation with chemical products of weathering, heredity, young multi-act alkaline volcanism, emergence of the mountainous relief, folding, etc., is being fully impressed on the global pattern.

The non-uniformity of neotectonic motions enables this stage to be divided into three phases, differing in the intensity and sense of motion. The first corresponds roughly to the Oligocene - Lower and Middle Miocene, the second to the Upper Miocene and Lower Pliocene, and the third phase to the Upper Pliocene - Quaternary.

The first phase is characterized by a predominance of slumps over upheavals in most of the Massif's area, by a tendency to form basins and, essentially, by a balance between the intensity of motions and denudation and/or accumulation in most of the massif, so that it preserved its plane character and low elevations. The phase ends with the decay of Oligocene-Miocene basins which become regions of denudation.

The second phase is characterized by a relatively quiet tectonic pattern and negligible occurrence of sediments. A moderate, weakly differentiated upheaval occurred.

The third phase, which is still continuing, is characterized by a significant increase in the intensity of tectonic motions as compared with the two preceding phase, by a predominance of uplifts over slumps, by a significant predominance of neotectonic motions over denudation. The Upper Pliocene and Quaternary represent a conspicuous relief period, during which the present relief was formed, in the youngest geological history of the Bohemian Massif. The most characteristic feature of this phase is the emergence of a number of mountain ranges, of roughly one hundred thousand local folds and coarse-grained molasses, which have no analogy in the preceding stages.

Folding, which is the essence of the Neotectonic Stage, is primarily affecting crystalline complexes, but is weakly developed in sediments. This folding, however, is not distributed randomly in the Bohemian Massif, but is subject to concrete regularities; it is developed only on regional upfolds of various uplift amplitudes, which also limits the intensity of the folding. The intensity of folding increases with the intensity of uplift.

The upfolds mentioned are old, long-lived structures of regional extent which were formed as elevation already in the Upper Proterozoic, functioned as elevation structures on the basis of heredity in the Palaeozoic and were renewed again during neotectonic activation as conspicuous upfolds. The Neotectonic Stage continues to develop the structures of these upfolds.

The largest mobility has been taking place in the central parts of these upfolds for a long time. They are strongly granitized, affected by long-term denudation, and the highest points of the Bohemian Massif and the highest intensity of the young folding now occur in their core parts. Neotectonics did not inherit only the forms of these upfolds, but also the mobility and tendency to upheaval.

An important problem of younger tectonics in the Bohemian Massif is establishing the relation between structures and relief, and between young structures and older evolution. Heredity is of dominant importance for neotectonics; neotectonics inherit all fundamental features from preceding stages. Without appraising the whole of the preceding evolution of the Bohemian Massif, one cannot understand even the most recent of the motions. Consequently, the features of the past are more or less distinctly reflected next to the new features in the phenomena observed. This not only clearly emphasizes the direct overall heredity of young tectonics with respect to the preceding stages, but also the high degree of stability of the structures of the Bohemian Massif.

The Neotectonic Stage is the period of folding and, from this point of view, neotectonics have inherited the tectonic style of the preceding stages; the Cadomian and Hercynian stages were also stages of folding. In many instances, the younger tectonics develop the same tendencies, which were founded during these tectonogeneses, and are their continuation.

The type of neo- and palaeo-structural relations is characterized by significant neotectonic trituration of the basement. The younger tectonic structures thus represent old tectonic structures, modified by younger motions. The younger structures thus represent the sum of elements of old and new deformations.

All the peculiarities of neotectonics of the Bohemian Massif can thus be explained within the Massif, without referring substantially to adjacent structures (e.g. the Alpine zones), by long-term controlled evolution of the Massif. The same energy source which provided for the Cadomian tectonogenesis also provided for the Hercynian stage, and is also providing energy for neo-tectonic processes, this energy being weaker in a number of cases.

Neotectonics have inherited their mobility mostly from the hercynides; in the segments in which the Hercynian tectonogenesis was most intensive in the Bohemian Massif, also neotectonics are the most intensive.

The main cause of neotectonic folding is the regional uplift of upfolds, apparently due to processes of diapirism. This uplift increases the volume of the segments involved, and leads to mass expansion. The generation of local folds is only a secondary phenomenon, derived from regional uplift, and represents its consequence. The regional uplift of a mountain range, in this case, is responsible for its overall uplift, as well as for its division into local structures.

The problem of the principal role of vertical motions, upheavals, may in this case be considered solved with sufficient certainty, and the subsequent task is in solving the problem of the manner in which vertical forces generate local folds.

The essence of the mechanism of transformation of regional motion into local structure can only be discovered with the aid of structures of small and intermediate dimensions, i.e. of the details of the structure in question. The detailed study of the morphological peculiarities of even the smallest structures in spatial relations enables the process of folding and the mechanism, in the broadest sense of the word, to be reconstructed.

The detailed study particularly of the small and medium-sized structures enabled the author to draw the conclusion that the main cause of generation of local folds is mass expansion. Folds of all sizes are generated by local upswelling of part of the mass into free space, into the wings and into the hinge of the fold. At the circumference of the fold, this expansion creates a similar anticline upswelling of smaller dimensions, down to ministructures (see Fig.1 and 2).

Expansion causes the transfer of mass in all directions: vertically, horizontally and diagonally. Most of the mass, roughly 85 - 90%, is displaced radially, the remainder then in various directions.

The effect of mass expansion is directly proportional to the volume of this mass; folds, corresponding in dimension to the mass and to its stress, are created on a large mass. On smaller masses, i.e. on structures of lower orders, the stress which leads to the generation of folds of decreasing dimensions in the wings, diminishes.

The process of transformation corresponds with the laws of mechanics. It proceeds from the larger mass to the smaller, and from larger stress to the smaller. No feedback is possible. In this case one cannot speak of the structures affecting each other in space, because the process is unidirectional: the larger mass controls the smaller, but never vice versa.

In view of the character of the neotectonic pattern, the Bohemian Massif can be assigned to the category of activated platforms. The neotectonic structures of the Bohemian Massif display typically neither geosyncline, nor platform parameters; they are structures of a transitional type.

7. REFERENCES

ARGANDE, (1924): La tectonique de l'Asie. Congres geol. Intern. Bruxelles.

BELOUSOV, V.V. (1954): Osnovnye voprosy geotektoniki. Moskva.

BELOUSOV, V.V. (1962): Osnovnye voprosy geotektoniki. Moskva.

BOGDANOV, A.A. (1976): Tektonika platform i skladčatych oblastej. Izdat. Nauka. Moskva.

GERASIMOV, I.P. (1946): Opyt geomorfologičeskoj interpretacii obščej schemy geologičeskogo strojenija SSSR. Probl. fiz. geogr., 12, Moskva, Leningrad.

GILBERT, (1890): Lake Bonevile, United States Geological Survey Monographs, 1, Washington D.C.

KOPECKÝ, A. (1970): Úloha kvartérní tektoniky při dotváření současné struktury a geomorfologie Českého masivu. Čas. Mineral. Geol., 15, 4, Praha, 347-357.

KOPECKÝ, A. (1972a): Hlavní rysy neotektoniky Československa. Sbor. geol. věd, Antropozoikum, 6, Praha, 77-155.

KOPECKÝ, A. (1972b): Drobné vrásové deformace v nezpevněných neogén-kvartérních sedimentech Českého masivu. Sbor. geol. věd, Geologie, 27, Praha, 117-151.

KOPECKÝ, A. (1973): Neotektonická mapa Československa měřítka 1:1 000 000. Praha.

KOPECKÝ, A. (1982): Zpráva o výzkumu neotektoniky Českého masivu v letech 1971-1981.

Výzkumná práce ÚÚG, 29d, Praha, 60-62.

KOPECKÝ, A. (1983): Neotektonický vývoj a stavba šumavské horské soustavy. Sbor. geol. věd, Antropozoikum, 15, Praha, 71-159.

KOPECKÝ, A. (1986a): Neotektonika Hrubého Jeseníku a východní části Orlických hor. Čas. Slez. Muz., Serie, Opava, 35-117.

KOPECKÝ, A. (1986b):Neotektonika severočeské hnědouhelné pánve a Krušných hor. Sbor. geol. věd, Geologie, 44, Praha, 155-170.

KOPECKÝ, A. (1989): Mapa mladších tektonických struktur Českého masivu 1:500 000. Praha.

MÁŠKA, M. (1961): Základní rysy struktury a vývoje Českého masivu. In: T. Buday et al.: Tektonický vývoj Československa. ÚÚG Praha, 15-27.

NIKOLAJEV, N.I. (1962): Neotektonika i jejö vyraženije v strukture i rel'jefe territorii SSSR. Gosgeoltechizdat. Moskva.

NIKOLAJEV, N.I., ŠULC, S.S. (1961): Obzornaja karta novejšej tektoniki SSSR i principy jejo sostavlenija. Neotektonika SSSR, Riga, 47-63.

OBRUČEV, B.A. (1948): Osnovnyje čerty kinetiki i plastiki neotektoniki. Izv. Akad. Nauk SSSR, Serija Geologia, 5, Moskva.

PEJVE, A.V. (1956): Princip unasledovannosti v tektonike. Izv. Akad. Nauk SSSR, Serija Geologija, 6, Moskva.

PEJVE, A.V. (1965): Gorizontalnyje dviženija zemnoj kory i principy unasledovannosti. Geotektonika, 1, Moskva.

PENCK, W. (1924): Die morpholoGISchen Analyse. Ein Kapitel der physikalischen Geologie. Geographische Abhandlungen, 2-te Reihe, 4.2, Stuttgart.

PETRUŠEVSKIJ, B.A. (1964): O principe unasledovannosti razvitija vertikalnych dviženij i problemy krupnych gorizontalnych peremeščenij. Bjull. Obšč. Ispyt., Otd. Geol., 19, 1, Moskva.

ŠULC, S.S. (1939): O novejšej tektonike Ťjaň-Šanja. Tr. XVII. sessija MGK, 1937, GONGJ.

ŠULC, S.S. (1948): Analiz novejšej tektoniki i rel'jev Ťjaň-Šana. Zap. Vsesojuz. geol. Obšč., Nov. Se., 3, Moskva.

ZEMAN, J.( 1970): Variská tektogeneze Českého masivu a její vztah k hlubinným zlomům. Geol. průzkum, 12, 10, Praha, 289-292.