Tectonics of the Upper Nysa Kłodzka Graben, the Sudetes

Tec ton ics of the Up per Nysa K³odzka Graben, the Sudetes

Janusz Badura

& Marta Rauch

1 Lower Silesian Branch, Pol ish Geo log i cal In sti tute – Re search Na tional In sti tute,, al. Jaworowa 19, 50-122 Wroc³aw, Po land;

e-mail: janusz.badura@pgi.gov.pl

2 In sti tute of Geo log i cal Sci ences PAS, Re search Cen tre in Wroc³aw, ul. Podwale 75, 50-449 Wroc³aw, Poland

Key words: ba sin in ver sion, post-Al pine tec ton ics, sub-Cre ta ceous base ment, neotectonics.

Ab stract

Manu script re ceived 3 Feb ru ary, ac cepted 5 March 2014

IN TRO DUC TION

The Up per Nysa K³odzka Graben (= Nysa Graben, NG) oc curs to the SE of the Intra-Sudetic Synclinorium (¯elaŸ- niewicz et al., 2011). It was filled with ma rine sed i ments in early Cenomanian through Coniacian to Santonian times (Teisseyre, 1975; Radwañska, 1960 a, b; Kêdzierski, 2002).

In the Turonian, only two is lands emerged from the then shal - low sea, the East ern and West ern-Sudetic Is lands (Fig. 1).

Vari able ver ti cal dis place ments along base ment faults ini ti - ated lo cal sub si dence in the Coniacian, among oth ers in the NG area (Don & Don, 1960; Jerzykiewicz, 1971). This tec - toni cally con trolled sub si dence led to ac cu mu la tion of over

three times thicker suc ces sion of Coniacian de pos its in the graben than in the ad ja cent ar eas and the ver ti cal dis place - ment along the bor der nor mal faults was as sessed at 600 m (Rode, 1936; Pachucki, 1959; Don & Don, 1960). The sub- sidence in the graben ceased al ready in the Coniacian. In the NG, the ter mi na tion of the sub si dence is in di cated by a shal- low ing- and coars en ing-up ward suc ces sion of marls over lain by sand stones and then by con glom er ates (Jerzykiewicz, 1971;

Wojewoda, 1997). Since that time, the Late Cre ta ceous Ba sin was sub jected to in ver sion. This study pres ents the main events in the ba sin in ver sion and in the struc tural evo lu tion of the NG.

PHYS I OG RA PHY

The NG is a dis tinc tive top o graphic sub unit in the Ko- tlina K³odzkaValley. It trends NNW–SSE, and Boboszów in the south. The NG de pres sion is the broad est in the north, be ing ~12 km wide and it nar rows down to ~2 km at the south ern ter mi na tion. El e va tion dif fer ence of mod ern topo- graphic sur face is ~ 250 m over a dis tance of ~50 km. The de pres sion sep a rates the Bystrzyca Mts. and Orlica Mts.

ranges in the west from the Œnie¿nik Range in the east (Fig. 2).

The Krowiarki Mts. Range ter mi nates the de pres sion to the north, whereas to the south, it wedges out near the town of Štíty (Czech Re pub lic). An over all top o graphic sur face of the de pres sion is in clined to wards the north and south re - spec tive the Miêdzylesie Pass.

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GE OL OGY

The NG is lo cated in the cen tral part of the Orlica–

Œnie¿nik Dome (Don et al. 1990). It is a nar row, wedge- shape in ge om e try unit that stretches over ~50 km be tween the vil lage of Krosnowice in the north and the town of Krá- líky (Fig. 2). Its width di min ishes from about 12 km in the north to ~1.3 km at the south ern ter mi na tion near the town of Štíty (Radwañski, 1975). The max i mum ob served thick - ness of Up per Cre ta ceous rocks (Turonian–Santonian) in the graben is about 720 m (Radwañski, 1975; Valeèka, 1988). Neo gene flu vial de pos its oc cur at the Miêdzylesie Pass and in the area of Králíky (Žateèka, 1996; Sroka &

Kowalska, 1998). The youn gest infill in the NG is rep re - sented by re cent flu vial and col lu vial de pos its.

Some au thors cor re late the north ern bound ary of the graben with the Kamienna Góra Horst (Don, 1996) or Ka- mienny Grzbiet–Babilon Fault Zone (Don & Gotowa³a, 2008). This fault zone, pos si bly the east ern pro lon ga tion of the Hronov–Poøíèí Fault Zone, is ac tu ally a horst bounded by the Duszniki–Gorzanów Fault on the south ern side and the Pstr¹¿na–Gorzanów Fault on the north ern side (Figs 1–4). The north ern part of the NG bor ders on Perm ian bed - rock of the Intra-Sudetic Synclinorium (Fig. 3), which out - crops in the vi cin ity of Krosnowice on the south ern slope of the Góra Czerwoniak Hill (Wojewoda & Burliga, 2008).

The south ern part of the graben bor ders on crys tal line rocks from which it is sep a rated by steep faults with an es ti mated throw of ~600 m (Rode, 1936; Pachucki, 1959; Don & Don, 1960). A step-like fault ing is also ev i denced in side the sou- Fig. 2. Out crops of Up per Cre ta ceous rocks (green) in the Up per Nysa K³odzka Graben against the DEM model of the area. 5 times ver ti cal ex ag ger a tion.

thern part of the graben, where two fault-bounded blocks are dis tin guished: the Bystrzyca Mts. block (the most up - lifted part of the graben) and the £omnica High block. The south ern most tip of the NG is sit u ated on the Czech Re pub - lic ter ri tory and re ferred to as the Králíky Graben.

Infill of the graben

The sed i men tary infill of the NG rep re sents the east ern - most frag ment of the for merly con tin u ous Up per Cretace-

ous sed i men tary cover (Fig. 1). In the area of study, the co- ver is dis mem bered into four do mains lo cated across the Pol ish-Czech bor der.

In the Cenomanian, a trans gress ing sea en tered the area of the Kotlina K³odzka Val ley from the north west and in un - dated the rel a tively flat sub-Cenomanian sur face (Pachucki, 1959; Don & Don, 1960). The Up per Cre ta ceous rocks are rep re sented by sand-clay-marl fa cies de pos ited in a shal low epicontinental sea. The sea was deep en ing un til the Early Turonian and the sed i men tary fa cies pat terns changed in the Mid dle Turonian. The abun dance of coarser clastic de pos its Fig. 3. Geo log i cal sketch of the Nysa Graben to show lines of geoelectrical pro files and lo ca tions of bore holes that reached the sub-Cre ta - ceous bed rock. 1 – Ce no zoic; 2 – Coniacian; 3 – Cenomanian and Turonian; 4 – Tri as sic; 5 – Perm ian; 6 – Car bon if er ous; 7 – meta mor phic and plutonic rocks; 8 – basaltoids; 9 – faults in sub-Cre ta ceous base ment; 10 – bore holes; 11 – elec tri cal re sis tiv ity pro files with num bers.

Ab bre vi a tions: SMF – Sudetic Mar ginal Fault.

sug gests that the source ar eas were up lifted on ei ther side of the graben and that troughs de vel oped in the graben, in areas where thick clastic sed i ments were ac cu mu lated. The stron gest sub si dence oc curred in the east ern part of the graben which abut ted against the con cur rently el e vat ing Œnie¿nik Range that was the main source of clastic sed i - ments. In the NW part of the graben, the Cre ta ceous sed i - ments ac cu mu lated in a broad and realtively shal lower sub-ba sin re ferred to as the Batorów trough. The me dium grained sand stones and con glom er ates of the Idzików Beds are re garded as the youn gest Cre ta ceous de pos its in the NG (Don & Gotowa³a, 2008).

The thick ness of the Cre ta ceous strata in the NG ranges be tween 400 and 900 m (Radwañski, 1957, 1961; Pachucki, 1959; Don & Don, 1960). Jerzykiewicz (1971) es ti mated the to tal thick ness at ~900 m. The Up per Cenomanian to Mid dle Turonian sed i men tary fa cies and the thick nesses of

de pos its are sim i lar in the Nysa Graben and in the Intra- Sudetic Synclinorium (Don & Gotowa³a, 2008). Ac cord ing to Don & Don (1960) the dif fer ences in sed i men tary pat - terns of youn ger Cre ta ceous de pos its be tween the graben and synclinorium in di cate that since the Mid dle Turonian the sed i men ta tion in the area south of K³odzko went on un - der tec tonic con trol. Since the Coniacian, the sed i men tary fa cies in the two depocentres sig nif i cantly dif fer en ti ated as ev i denced by the 900–1000 m thick Idzików beds in the Nysa Graben whereas their equiv a lents in the Intra-Sudetic ba sin did not ex ceed 370 m (Don & Wojewoda, 2003).

The thick ness of Coniacian de pos its in teh NG was over - es ti mated in older anal y ses (Jerzykiewicz, 1971). Later bore - holes pro vided more cor rect in for ma tion. In two bore holes, Pisary IG1 and 7R in Stary Waliszów, the thick ness of Co- niacian suc ces sion was 398.3 m and 355 m, re spec tively (Radwañski, 1975). In the nar row est part of the graben near Fig. 4. Dig i tal el e va tion model of the sub-Cre ta ceous base ment. Dense grid: pre-Up per Cre ta ceous bed rock; thin dashed lines – faults. Ab - bre vi a tions: BH – Babilon Horst; H-PT – Hronov-Poøíèí Thrust; SMF – Sudetic Mar ginal Fault. 5 times ver ti cal ex ag ger a tion.

Králíky, the thick ness of Coniacian de pos its was 468.3 m in the KP-1 bore hole and the ap par ent thick ness of 553.5 m was ev i denced in the KP-2 bore hole (Valeèka, 1988). In case of the Batorów and Po lice troughs, Coniacian sed i - ments were thin ner since their bed rock was el e vated as ev i - denced in the Batorów IG-1 borehole and, thus they were en tirely eroded. There is a NNE–SSW trending fault zone near Polanica Zdrój which pres ently sep a rates the Krosno- wice Syncline from the Bato- rów Syncline (Don & Goto- wa³a, 2008), the lat ter be ing up lifted by ~350 m with re spect to the for mer (Radwañski, 1975).

Open syn clines and anticlines in bed ding of Up per Cre - ta ceous rocks in the Nysa Graben were rec og nized and mapped by Don & Gotowa³a (2008). These tec tonic struc - tures were brought about by the NNE-SSW ori ented short - en ing in a compressional re gime. Our ob ser va tions show that the pres ent day syn clines found in the out crop pat tern ac tu ally de vel oped over for mer sedimentary troughs.

There are also Neo gene flu vial de pos its ev i denced at the Miêdzylesie Pass and in the area of Králíky (Žateèka, 1996; Sroka & Kowalska, 1998). The youn gest infill in the NG is rep re sented by re cent flu vial and col lu vial de pos its.

Tec ton ics

The NG de vel oped in the Late Cre ta ceous–Ter tiary (Pachucki, 1959; Don & Don, 1960; Jerzykiewicz, 1971) and was sep a rated from sur round ing meta mor phic rocks by steep bor der faults. The ver ti cal dis place ments along the in - di vid ual bor der faults vary be tween 600 m (Rode, 1936; Pa- chucki, 1959; Don & Don, 1960) and 1600 m (Don & Goto- wa³a, 2008).

Sev eral in ter pre ta tions of tec tonic evo lu tion of the gra- ben were pro posed. The ear li est con cept by Cloos (1922, 1936) as sumed that an extensional trough was formed in the ax ial part of the ris ing up Orlica–Œnie¿nik Dome. Other au - thors (Don & Don, 1960; Don 1996; Don & Wojewoda, 2005; Don & Gotowa³a, 2008) dis tin guished two ma jor sta- ges in the evo lu tion of the graben: (1) a synorogenic, grav i - ta tional sub si dence in duced by the ex ten sion of the meta - mor phic base ment dur ing its up lift; (2) a compressional phase at the turn of the Cre ta ceous and Paleogene (‘Lara- mian’ phase). Wojewoda (1997) also pro posed a multiphase evo lu tion of the NG in the Late Cre ta ceous with de vel op - ment of nor mal listric faults at its bor ders. The nor mal faults were then re ju ve nated as dextral strike-slip faults and the ex ten sion of the base ment con tin ued in the Coniacian–San- tonian through Neo gene.

Tec tonic ac tiv ity along the east ern bor der nor mal fault en hanced sub si dence in the ad ja cent ar eas of the Cre ta ceous ba sin and led to de vel op ment of an asym met ric graben, deeper in the east ern part of the ba sin and shal lower in the west ern one (Jerzykiewicz, 1971). An es ti mated throw along the east ern bor der fault in the vi cin ity of the Czarna Góra Hill was ~1600 m (Don & Don, 1960). The ver ti cal dis place ment along the west ern bor der fault dif fered along

the fault strike: hun dreds of me ters in its south ern sec tion and a few me ters in the north ern sec tion, i.e. near the bound - ary be tween the NG and the Intra-Sudetic Synclinorium (Don & Gotowa³a, 2008). The dif fer ence in thick ness of the Cre ta ceous de pos its through out the NG is due to both the asym me try of the graben and de vel op ment of sub sid iary faults in the graben af ter the Mid dle Turonian.

Ac cord ing to Don & Gotowa³a (2008), the most sig nif i - cant event in the next stage of the NG evo lu tion was the ac - tiv ity of the NW–SE trending Krowiarki Mar ginal Fault (KMF) which bounded the graben to the north be tween the vil lages of Nowy Waliszów and Gorzanów (Fig. 4). The Cre ta ceous graben infill is in con tact with meta mor phic ba- sement rocks along this fault. It is a nor mal com po nent fault, how ever, lo cally it ap pears as a re verse one with sinistral strike-slip com po nent. The KMF con sti tutes a part of a re gional fault zone which con tin ues to wards the south - east, across the Œnie¿nik Range and the Staré Mìsto Belt to the Keprnik Dome. To ward the north west, the KMF ex tends as the Duszniki–Gorzanów Fault Zone (Fig. 4). The south - ern tip of the NG bor ders on the Štíty Fault (Don et al., 2003). This is a re verse fault which trends par al lel to the KMF.

Don & Gotowa³a (2008) in di cate the im por tance of lat - eral com pres sion in the tec tonic evo lu tion of the NG, which took place at the turn of the Cre ta ceous and Paleogene. The com pres sion in duced in ver sion of the nor mal faults and led to de vel op ment of re verse, NW–SE trending faults in the north ern and south ern parts of the graben. It also re sulted in large-scale, open fold ing of the ba sin infill, with the fold axes trending NW–SE, obliquely to the ex tent of the graben.

Sev eral folds are dis tin guished: Miêdzylesie– Roztoki Syn- cline, D³ugopole Zdrój Anticline, Wilkanów Syncline, Bys- trzyca Anticline, Idzików–Krosnowice Syncline and the Domaszków–D³ugopole Zdrój–Bystrzyca K³odzka Anti- cline. The lat ter ex tends in the cen tral part of the graben.

A bunch of faults trending WNW–ESE/NW–SE also for- med dur ing the very stage of de for ma tion (Fig. 2).

The Krosnowice–Miêdzygórze Fault de picts vari able dis place ment and ge om e try (Don & Don, 1960). It in duced drag fold ing of Cre ta ceous beds in the vi cin ity of Gorzanów (Grocholska & Grocholski, 1958). The dis place ment on the fault sig nif i cantly in creases near the vil lage of Mielnik, where the beds are down-thrown on the fault to wards the south east. West wards, the fault plane steep ens up to ver ti cal and in the vi cin ity of Nowy Waliszów the fault at tains a re - verse ge om e try.

Dumicz (1964) and Fr¹ckiewicz (1965) de scribed ev i - dence of thrust ing of meta mor phic rocks over Cre ta ceous de pos its in sev eral lo ca tions in the NG area. Also Dzie- wañski (1984) re ported thrust ing of gneiss es over Cre ta - ceous rocks near the vil lage of M³oty in the Bystrzyca Mts.

The above ev i dence points to lat eral com pres sion and re - verse fault de vel op ment at the late stage of the NG evo lu - tion. These as pects are more thor oughly dis cussed by W.

Kozdrój (2014) who pres ents the re sults of shal low drillings both in the graben and in the ad ja cent ar eas.

TO POG RA PHY OF SUB-CRE TA CEOUS SUR FACE IN THE GRABEN AND AD JA CENT UNITS

The stud ies on the con tem po rary tec ton ics in the NG and ad ja cent re gions were car ried out with use of the dig i tal el e va tion mod els (DEM, Fig. 4) as well as the anal y sis of changes in river tracts (Fig. 2), anal y sis of to pog ra phy of de - pres sions which are not re lated to the mod ern river sys tem and anal y sis of tri an gu lar fac ets (Fig. 5). These anal y ses were cor re lated with the re sults of geo phys i cal stud ies (elec tri cal re sis tiv ity pro fil ing) by Grzegorczyk et al. (1993) and Farbisz (1993) and with the data from a few bore holes which pen e trated the base ment rocks un der ly ing the Cre ta - ceous de pos its in the NG. Farbisz (1993) also re in ter preted the ear lier ac quired re sis tiv ity pro fil ing data.

There are nu mer ous geo phys i cal in di ca tions of ro ta tion and flex ural bend ing of Cre ta ceous beds in the vi cin ity of faults in the NG (Fig. 6). The re sis tiv ity im ages show an in - creased re sis tance of rocks in the vi cin ity of the flex ural folds, for ex am ple in Pasterskie Ska³y (Shep herds’ Rocks).

Orig i nally, this phe nom e non was in ter preted as a change in li thol ogy or lo cal up lift of the base ment. How ever, our stud - ies showed that the ob served in crease in the re sis tiv ity re - sults from in tense frac tur ing of the bent and dragged beds in the open flex ures, as well as from steep en ing of beds and, thus, ap par ent in crease of thick ness of rocks with high elec - tri cal re sis tiv ity (Farbisz, 1993).

Scat tered data on the depth of the sub-Cre ta ceous sur - face ob tained from a few bore holes were cor re lated with the height at which the base ment rocks out crop on the sur face at pres ent. The 3D model of the sub-Cre ta ceous sur face was con structed uti liz ing dif fer ent type of soft ware: Ex cel (data

bases), Surfer (com pi la tion of data bases, griding), Global Map per (im ag ing, 3D pro jec tion, con tour maps).

The re in ter pre ta tion of the elec tric re sis tiv ity pro files on a re gional scale (Farbisz, 1993; Grzegorczyk, 1993) and the data ob tained from bore holes in the Intra-Sudetic Syn- clinorium showed that the Cre ta ceous de pos its over lay Perm ian de pos its in the north ern part of the Intra-Sudetic Synclinorium, and Car bon if er ous and Perm ian de pos its in its SW part. In the area of Batorów, Duszniki Zdrój, Pola- nica Zdrój and Krosnowice, the Cre ta ceous de pos its are un - der lain by meta mor phic rocks. Sev eral sub or di nate syn - clines and anticlines are dis tin guished over the area cov ered by Cre ta ceous de pos its: Krzeszów, Po lice, Batorów, Kros- nowice, Nysa Graben, and Králíky.

In the NG, a sharp scarp de lin eates its north ern bound - ary and sep a rates the graben from meta mor phic rocks of the K³odzko Meta mor phic Mas sif and the Krowiarki Meta mor - phic Belt ( Don & Gotowa³a, 2008). Also the east ern edge along the con tact with the Œnie¿nik Meta mor phic Mas sif is very dis tinc tive. Only the SW bound ary of the graben is less clearly ex pressed due to the oc cur rence of ex ten sive mor- photectonic flat step-like blocks, trending NW–SE, which sep a rate the Nysa Graben from the Orlica Mts. and Bys- trzyca Mts. Two broad mor pho log i cal steps with steep east - ern slopes and gen tler west ern ones are dis tin guished in the NE part of the Orlica Mts. They are re ferred to as the Bys- trzyca and £omnica High steps (Fig. 4). The morphotec - tonic step of Gorzanów is sit u ated in the pro lon ga tion of the

£omnica step. The asym met ric morphotectonic Bystrzyca

Fig. 5. Tri an gu lar fac ets along the Wilkanów Fault.

step trends obliquely to the graben, be ing partly cov ered by Cre ta ceous de pos its (Fig. 4). Turonian de pos its are cov ered by Coniacian de pos its in its east ern part. The SE part of that step oc curs at deeper depths and cor re lates with the Wilka- nów Syncline dis tin guished by Don & Gotowa³a (2008).

The el e va tion dif fer ence be tween sum mits in the Orlica Mts. (1000–1100 m a.s.l.) and the Divoká Orlice river bed is

~350–400 m. The dif fer ence in the north ern and cen tral sec - tions of the Bystrzycka Mts. flat step is ~150 m and over 400 m in its south ern sec tion. The £omnica High Step is

~3 km wide and it rises ~220 m above the River Bystrzyca val ley. The east ern slope of this step dips steeply to wards the River Nysa K³odzka val ley, mak ing up a 350 m high scarp. Cre ta ceous de pos its are pre served only fragmentarily on the top of the step.

All four steps cut-off on their north ern side on a tec - tonic zone of the Duszniki–Gorzanów Fault Zone (Rad- wañski, 1975; Fistek, 1977; Kie³czawa & Teisseyre, 2000;

Don & Gotowa³a, 2008). Turonian de pos its are up lifted

along this zone and con sti tute a horst which is 11 km long and 1 km high. The zone is ev i denced as a scarp in a nu mer - i cal model of the sub-Cre ta ceous base ment (Fig. 6) and it ex tends north of the vil lage of Gorzanów (Farbisz, 1993).

The up lifted base ment blocks formed ridges on the sur face which shifted lo cal stream val leys. For ex am ple, one of the streams orig i nally flow ing northeastwards changed the di - rec tion of flow to the SEE, i.e. par al lel to the up lifted horst.

A pass in the Kamienny Grzbiet ridge is the rem nant of the for mer NE-trending stream valley.

A num ber of sec ond-or der tec tonic struc tures can be distinguished in re cent to pog ra phy of the sub-Cre ta ceous base ment (Fig. 7). These are tec tonic troughs and horsts which de pict high dif fer ence in el e va tion in places. Lon gi - tu di nal scarps of the troughs, trending N–S, NNE–SSW and NE–SW, ter mi nate on the lat i tu di nal scarps which trend W–E, NWW–SEE and NW–SE. There fore, the for mer group of scarps ap pear to be sec ond ary mor pho log i cal fea- tures in respect to the latter.

Fig. 6. Geo log i cal in ter pre ta tion of the elec tri cal re sis tiv ity pro fil ing (thin lines and num bers at the back ground). For lo ca tions see Fig. 3.

Pink – base ment; green – Up per Cre ta ceous infill of the Nysa Graben; ver ti cal dashed lines – faults; thick dashed lines – at ti tude of bed ding planes in volved in open folds, note bend ing of beds in the prox im ity of faults which re corded mul ti ple move ments with chang ing ki ne mat ics.

The sub-Cre ta ceous base ment in the NG is asym met ri - cally el e vated (Fig. 7). A dis tinct trough (~ Idzików Syn- cline) oc curs in the north ern part of the graben along the Krowiarki Mar ginal Fault and the other be tween the Nysa Fault and Szalejów–Krosnowice Fault (Krosnowice Syn- cline). In the Krosnowice Syncline, the base ment grad u ally rises southwestwards, then, it is abruptly up lifted along the Kamienny Grzbiet–Babilon Horst which makes up a remar- kable ramp at the SE mar gin of the Krosnowice Syncline.

The edges of this de pres sion out line a tra pe zium in a plan view. Also in the Idzików Syncline, a tra pe zium-shape bed - rock trough is no tice able and the base ment top sur face grad - u ally rises to wards the Kamienny Grzbiet–Babilon Horst which is very nar row near the vil lage of Idzików. In the cen - tral part of the NG, be tween the vil lages of P³awnica and Goworów, the base ment of the graben is up lifted and bor - dered by WNW–ESE trending edges. The north ern edge of this up lifted block is sit u ated in the vi cin ity of the Zab³ocie–

Idzików Fault and the south ern one in the vi cin ity of Go- worów (see Tec tonic Map of the Nysa K³odzka Graben in Don & Gotowa³a, 2008).

There are two deep troughs or grabens in the bed rock of the south ern part of the NG. These are the Králíky–Pisary trough and the Gaworów trough, both more than 700 m deep. The lat ter oc curs be low the Miêdzylesie Syncline. The two de pres sions are sep a rated by the Miêdzylesie Step which rises ~200 m above the base ment of the troughs and stretches along the Kamieñczyk and Králíky Fault. The el e - va tion dif fer ence be tween the bot toms of both troughs and the crests of neigh bour ing hills is over 800–900 m.

To wards the south west from the vil lage of Roztoki, a tri an gu lar in shape part of the NG base ment rises by ~250 m. This part of the NG is a SE pro lon ga tion of the £omnica High Step, which was more deeply bur ied. Its was named the Roztoki Syncline by Don & Gotowa³a (2008).

An other up lifted horst ex tends be tween D³ugopole Zdrój and Nowa Wieœ. It is a south east ward con tin u a tion of the £omnica High Step. There are ~75 m el e va tion dif fer - ences in the mor pho log i cal sur face of this bur ied horst. The highs and de pres sions may in di cate that this sur face ev i - dences bur ied etchplain where regoliths occur.

Less vari able mor phol ogy is ev i denced on top of the bur ied ex ten sion of the Bystrzyca flat step (Bystrzyca Anti- cline). This step de lin eates the north ern bound ary of an other deep trough re ferred to as the Idzików Brachysyncline (Don, 1996; Don & Gotowa³a, 2008). The re search bore - hole 7R drilled to a depth of 625 m showed that Mid dle Turonian de pos its oc cur at the bot tom of the bore hole, thus, the meta mor phic base ment has to oc cur some 20–40 m deeper (Radwañski, 1975). The el e va tion dif fer ences be - tween the crest of Krowiarki Mts. Range and the bot tom of the crys tal line base ment of the trough is over 620 m and over 400 m in re spect to the buried Bystrzyca step.

The re sis tiv ity pro fil ing along lines cross-cut ting the NG re vealed vari a tion in re sis tiv ity of the graben infill. Low re sis tiv ity (20–50 Wm) rocks oc cur in the west ern part of the graben and in the prox im ity of tec tonic bor ders of the Krowiarki Mts. Range and Œnie¿nik mas sif. The re sis tiv ity of rocks sharply in creases from 75 to 410 Wm in the vi cin ity of the east ern bor der of the graben (Farbisz, 1993). Low re - sis tiv ity rocks also oc cur at depths be low 100 m. The band of high re sis tiv ity rocks is ~1300 m wide and has sharp bound aries. There fore, it is rather un likely to as sume this fea ture as rep re sent ing sand and gravel deltaic de pos its, which interfinger with clay and sand ones. The anal y sis of the geo phys i cal data is hin dered due to the oc cur rence of sev eral hun dred me ter wide tec tonic steps which ob scure the dis tri bu tion of re sis tiv ity of rocks in the graben.

The Krosnowice trough sit u ated in the north ern part of the graben has tra pe zium-shape bound aries in a plan view.

It nar rows eastwards, where it bor ders on the Krowiarki Mts.

Range. Along this tec tonic bound ary, the east ern most oc - cur rence of Perm ian de pos its is ev i denced in the River Bia³a L¹decka val ley (Grocholska & Grocholski, 1958). The NW bor der of the trough is de lin eated by the Czerwoniak Thrust, whereas the west ern bound ary cor re sponds to NNE–SSW trending faults, which sep a rate the trough from the up lifted by ~300 m Batorów Ba sin (Radwañski, 1975; Don & Goto- wa³a, 2008). The south ern bound ary is out lined by the Ka- mienny Grzbiet–Babilon Horst. The deep est bore hole drilled in that area re vealed that the to tal thick ness of Cre ta ceous de - pos its is 518 m (Grzegorczyk et al., 1993). The el e va tion dif - fer ence in re spect to the Góra Czerwoniak hill is over 420 m.

CON CLU SIONS

The anal y sis of the sub-Cre ta ceous base ment mor phol - ogy in the NG, based on data from a few bore holes and from rel a tively dense net work of re sis tiv ity pro fil ing, ev i denced block dis place ments. The most sig nif i cant sub si dence took place in the south ern part of the graben, where the great est thick ness (~720 m) of Cre ta ceous de pos its is doc u mented (Fig. 4). In the north ern part of the Nysa Graben, in the Idzików Trough (~Syncline), these de pos its are only up to 640 m thick.

The NG is dis tinctly bounded by steep faults along the north ern and east ern bor ders. The west ern bound ary is de - lin eated by a sys tem of en ech e lon faults (Jagodna and D³ugopole Faults) which el e vated the base ment in step-like

blocks up to the sur face. These tec tonic steps are asym met - ric, be ing gently in clined to wards SW and steeply to wards NE. The steps con tinue fur ther to the east where they are still rec og niz able in the mor phol ogy of the graben bot tom which is con cealed un der Cre ta ceous strata. These tec tonic steps are also asym met ric, be ing more gently in clined on their SW sides and more steeply on the NE sides.

The to pog ra phy of the NG base ment and con tin u a tion of the step-like ar range ment of the fault blocks out side the west ern bound ary of the graben in di cate that the tec tonic struc ture of the graben was mod i fied af ter the Late Cre ta - ceous–Paleogene in ver sion, ow ing to the NE–SW ori ented ex ten sion. The pres ent out line of the graben was shaped

Fig. 7. A – blockdiagram show ing the struc ture of the Nysa Graben. Grey net: pre-Up per Cre ta ceous bed rock, ver ti cal ex ag ger a tion 10 times; B – tec tonic sketch of the Nysa Graben. Ab bre vi a tions: BH – Babilon Horst; BS – Batorów Step; DGF – Duszniki–Gorzanów Fault.

effectively in the Mio cene. Then, at the turn of the Late Mio cene and Plio cene, the in ver sion along WNW–ESE to NW– SE trending faults el e vated the graben shoul ders by 70 m rel a tive to the orig i nally deep est ar eas of the graben.

The re sul tant highs lo cally changed the drain age sys tem, which is re flected by the shift of river val leys. Fur ther sub si - dence con tin ued only in the Krosnowice Syncline area.

The Nysa Graben is one of a few ar eas in Po land, which was ver ti cally dis placed by sev eral hun dreds metres af ter the ba sin in ver sion at the Cre ta ceous–Palaeogene turn. The es ti mated dis place ments in the Nysa Graben are likely com -

pat i ble with those ob served at the con tact be tween the Eger Graben and Erzgebirge and Lausitz Mas sif. Strik ingly, Ce - no zoic strata are al most miss ing from the Nysa Graben.

Ac knowl edge ments

We would like to ex press our grat i tude to Andrzej ¯e- laŸniewicz for his help, fruit ful dis cus sions and deep en - gage ment in var i ous stages of prep a ra tion of this pa per. We are also greatly in debted to Stanis³aw Burliga for help in trans la tion the Pol ish orig i nal into English.

REFRENCES

ADAMOVIÈ, J. & COUBAL, M., 1999. In tru sive ge om e tries and Ce no zoic stress his tory of the north ern part of the Bo he mian Mas sif. GeoLines 9: 5–14.

ALEXANDROWICZ, S. W. & BIRKENMAJER, K,. 1973.

Lower Senonian Age of Clays Surronding Ter tiary Ba saltic Plugs, at Gracze, Lower Silesia. Biull. Acad. Pol. Sc. Sér. Sc.

Terre, 21: 45–49.

BADURA, J., PRZYBYLSKI, B. & ZUCHIEWICZ, W., 2004.

Caino zo ic evo lu tion of Lower Silesia, SW Po land: a new in - ter pre ta tion in the light of sub-Caino zo ic and sub-Qua ter nary to pog ra phy. Acta Geodynamica et Geomaterialia, 1, 3(135):

7–29.

BA TIK, P., DOKTÓR, S., GRANICZNY, M. & ŠEBESTA, J., 1996. Rola tektoniki nieci¹g³ej w kszta³towaniu rzeŸby Ma- sywu Œnie¿nika. In: A. Jahn, S. Koz³owski, M. Pulina (Eds.), Masyw Œnie¿nika – zmiany w œrodowisku przyrodniczym.

Polska Agencja Ekologiczna S.A.: 27–33. {in Pol ish only}.

BIRKENMAJER, K., PÉCSKAY, Z., GRABOWSKI, J., LO- RENC, M. W. & ZAGO¯D¯ON, P. P., 2002, Ra dio met ric dat ing of the Ter tiary volcanics in Lower Silesia, Po land. II.

K-Ar ages and palaeomagnetic data from Neo gene basanites near L¹dek Zdrój, Sudetes Mts. Annales Societatis Geologo- rum Poloniae, 72: 119–129.

CHLUPÁÈ, I., BRZOBOHATÝ, R., KOVANDA, J. & STRÁ- NÍK, Z., 2002. Geologická minulost Èeské republiky [Geo - log i cal his tory of the Czech Re pub lic]. Akademie vìd Èeské republiky, Praha: 436 pp.

CICHA, I., BRZOBOHATÝ, R., ÈTYROKÁ, J., GABRIELOVÁ, N., KREJÈÍ, O., KRYSTEK, I., MÁTL, V., MOLÈÍOVÁ, V., NOVOTNÁ, E., ØEHÁKOVÁ, Z., SOTÁK, J., STAÒ- KOVÁ, J., KNOBLOCH, E. & VÁCA, F., 1985. Neogén v opìrných vrtech OS-1 Kravaøe a OS-2 Ha• v opavské pánvi.

Sbornik Geologických Vìd, Geologie, 40: 183–229.

CLOOS, H., 1922. Der Gebirgsbau Schlesiens und die Stellungs- einer Bodenschätze. Gebrüder Borntraeger, 8: 1–107. Berlin.

DON, J., 1996. The Late Cre ta ceous Nysa Graben: im pli ca tions for Me so zoic–Ce no zoic fault-block tec ton ics of the Sudetes.

Zeitschrift für geologische Wissenschaften, 24: 317–324.

DON, B. & DON, J., 1960. Geneza rowu Nysy na tle badañ wyko- nanych w okolicach Idzikowa. [Notes on the or i gin of the Nysa graben]. Acta Geologica Polonica, 10: 71–106.

DON, J. & GOTOWA£A, R., 2008. Tec tonic evo lu tion of the late Cre ta ceous Nysa K³odzka Graben, Sudetes, SW Po land. Geo- logia Sudetica, 40: 51–63.

DON, J., SKÁCEL, J. & GOTOWA£A, R., 2003. The bound ary zone of the East and West Sudetes on the geo log i cal map of the Velké Vrbno, Staré Mésto and Œnie¿nik Meta mor phic Units. Geologia Sudetica, 35: 25–59.

DON J. & WOJEWODA J. 2004. Tec ton ics of the Up per Nysa

K³odzka Graben: Con ten tious Is sues. Acta Geodyn. Geoma - ter., 1, 3(135): 173–178.

DON, J. & WOJEWODA, J., 2005. Tektonika rowu górnej Nysy K³odzkiej – sporne problemy – dyskusja [Tec ton ics of up per Nysa K³odzka Graben – con tro ver sial is sues – dis cus sion].

Przegl¹d Geologiczny, 53: 212–221.

FARBISZ, E., 1993. Dokumentacja badañ geoelekrycznych temat:

Rów Nysy K³odzkiej, woj. wa³brzyskie. NAG Warszawa. {in Pol ish only}.

FR¥CKIEWICZ, W., 1965. Obserwacje nad bezpoœrednim kon- taktem gnejsów œnie¿nickich i górnej kredy w Nowej Wsi i Wilkanowie ko³o Bystrzycy K³odzkiej (Sudety – grupa Œnie¿- nika). [Ob ser va tions of the di rect con tact of the Œnie¿nik gnei- sses and the up per cre ta ceous sed i ments at Nowa Wieœ and Wilkanów, near Bystrzyca K³odzka (Sudetes – the Œnie¿nik K³odzki mas sif)]. Biuletyn Instytutu Geologicznego, 181: 5–22.

FISTEK, J., 1977. Szczawy Kotliny K³odzkiej i Gór Bystrzyckich.

[Acid u lous springs of the K³odzko Ba sin and Bystrzyckie Mts.]. Biul. Geol. Uniwersytetu Warszawskigo, 22: 61–115.

GROCHOLSKA, J. & GROCHOLSKI, A., 1958. Tektonika pó³- nocno-wschodniej czêœci rowu Nysy. [Tec ton ics of the NW part of the Nysa graben]. Przegl¹d Geologiczny, 8–9: 351–353.

GRZEGORCZYK, K., KRAWCZYK, J., NOWAK, A., D¥B- ROWSKI, S., WIJURA, A. & FISTEK, J., 1993. Dokumen- tacja hydrogeologiczna dyspozycyjnych zasobów wód pod- ziemnych w utworach kredy górnej rejonu rowu Nysy K³odzkiej i Niecki Batorowa. NAG Warszawa. {in Pol ish only}.

IVAN, A., 1996. Mor pho tec tonics of SE (mar gin of the Bo he mian Cre ta ceous Ba sin, two half-grabens and their sur round ings north of Brno (Moravia). Moravian Geo graph ical Re ports, 4, 1: 2–28.

JAHN, A., £AÑCUCKA-ŒRODONIOWA, M. & SADOWSKA, A., 1984. Stanowisko utworów plioceñskich w Kotlinie K³odzkiej [The site of Plio cene de pos its in the K³odzko Ba - sin, Cen tral Sudetes]. Geologia Sudetica, 18, 2: 7–43.

JAMROZ, O., BADURA, J. & ZUCHIEWICZ, W., 2011. Mor - pho tec tonics of the Œnie¿nik Mas sif west ern edge. 12^th Czech–

Pol ish Work shop: On Re cent geodynamics of the Sudety Mts.

and ad ja cent ar eas. Jugowice, Oc to ber 20-22, 2011: 28–29.

JERZYKIEWICZ, T., 1971. A flysch/lithoral suc ces sion in the Sudetic Up per Cre ta ceous. Acta Geologia Polonica, 21:

165–199.

JOD£OWSKI, S., 1999. Utwory kredy i jej pod³o¿e w Kotlinie K³odzkiej w œwietle badañ geofizycznych. I. Rów górnej Nysy K³odzkiej. [The Cre ta ceous and un der ly ing beds of K³odzko val ley – geo phys i cal in ves ti ga tions. I. Trough of the Up per Nysa K³odzka]. Szczeliniec, 3: 21–40.

KÊDZIERSKI, M., 2008. Cal car e ous nannofossil and inoceramid biostratigraphies of a Mid dle Turonian to Mid dle Coniacian

sec tion from the Opole Trough of SW Po land. Cre ta ceous Re - search 29: 451–467.

KIE£CZAWA, B. & TEISSEYRE, B., 2000. Nowe dane do tekto- niki okolic Gorzanowa w Sudetach Œrodkowych. [New data on the tec tonic of Gorzanów en vi rons in the mid dle Sudetes].

Prace Naukowe Instytutu Górnictwa Politechniki Wroc³aw- skiej, 87, Studia i Materia³y, 28: 19–27.

KOZDRÓJ, W., 2014. Re sults of shal low sci en tific drillings in the Up per Nysa K³odzka Graben and the Zieleniec area, Sudetes.

Geologia Sudetica, 42: 149–159.

MLÈOCH, B. & KONOPÁSEK, J., 2010. Pre-Late Car bon if er ous ge ol ogy along the con tact of the Saxothuringian and Teplá–

Barrandian zones in the area cov ered by youn ger sed i ments and volcanics (west ern Bo he mian Mas sif, Czech Re pub lic).

Jour nal of Geosciences, 55: 81–94

KOTAÑSKI, Z. & RADWAÑSKI, S., 1977. Geologia wg³êbna Opolszczyzny. [Subsurface ge ol ogy of the Opole Ba sin]. Biu- letyn Instytutu Geologicznego, 303: 91–165.

LEPPLA, A., 1900. Geologisch-hydrographische Beschreibung des Niederschlagsgebietes der Glatzer Neisse (oberhalb der Steine mündung) mit geologischer Übersichtskarte 1:50000. Abhand- lungen des Preußischen Geologischen Landes-Amt, N,F., 32, X.

MITCH ELL, A.J., ULIÈNÝ, D., HAMPSON, G.J., ALLISON, P.A., GORMAN, G.J., PIGGOTT, M. D., WELLS, M. R. &

PAIN, C. C., 2010. Mod el ling tidal cur rent-in duced bed shear stress and palaeocirculation in an epicontinental sea way: the Bo he mian Cre ta ceous Ba sin, Cen tral Eu rope. Sedimentology, 57: 359–388.

PACHUCKI, C., 1959. O stratygrafii i litologii kredy w rowie Nysy K³odzkiej [Über die Stratigraphie und Litologie der Kreide im Neissegraben]. Annales Universitatis Mariae Cu - rie-Sk³odowska, Sectio B, 12: 1–66.

RADWAÑSKA, Z. 1960a. Prob lem górnego turonu w kredzie dolno- œl¹skiej. [The prob lem of the Up per Turonian in the Lower Sile- sian Cre ta ceous]. Kwartalnik Geologiczny, 4: 113–121.

RADWAÑSKA, Z., 1960b. O wieku tzw. “i³ów idzikowskich”.

[On the age of the so-called “Idzików Clays”]. Z badañ geolo- gicznych na Dolnym Œl¹sku, 8, Biuletyn Instytutu Geologicz- nego, 151: 5–24.

RADWAÑSKI, S., 1961. Deltowe osady koniaku w okolicy Idzi- kowa [Delta de pos its of the Coniacian in the re gion of Idzi- ków (Lower Silesia)]. Kwartalnik Geologiczny, 5: 108–121.

RADWAÑSKI, S., 1975. Kreda Sudetów Œrodkowych w œwietle wyników nowych otworów wiertniczych [Up per Cre ta ceous of the cen tral part of the Sudetes in the light of new bore hole ma te ri als]. Biuletyn Instytutu Geologicznego, 187: 5–59.

RANOSZEK, W., 1998. Morfologia progów tektonicznych obra- mowuj¹cych Rów Górnej Nysy. Acta Universitatis Wratisla- viensis 2061, Prace Instytutu Geograficznego, ser. A, 9: 23– 35.

RANOSZEK, W., 1999. Zastosowanie ró¿nych metod morfome- trycznych w analizie morfologii progu tektonicznego na przy- k³adzie zachodniej krawêdzi Masywu Œnie¿nika. Przegl¹d Geologiczny, 47: 1027–1031.

RANOSZEK, W., 2001. Tec toni cally-con trolled mor pho log i cal es carp ments in the Sudetes in the light of nu mer i cal pa ram e - ters (in Pol ish), Un pub lished Ph.D. the sis, Fac ulty of Nat u ral Sci ences, Uni ver sity of Wroc³aw, Wroc³aw, 200 ms. pp.

RODE, K., 1934. Mesozoische Krustenbewegungen in Schlesien.

Zeitschrift der Deutscher Geologischen Gesellschaft, 86:

483–490.

RODE, K., 1936. Die Schichtenfolge der Kreide im Neißegraben.

Zentralblatt für Mineralogie (B): 109–118.

SKÁCEL, J., 1961. Rozšireni køidowego útvaru na Osoblazsku.

Pøir. Èas. Slezký, 22 : 367–375.

SKÁCEL, J., 1966. Neogen a køida ve vrtu OS-5 severnì od Oso- blahy. Zprávy o geologických výzkumech v roce 1964, 310–

311. Praha.

SROKA, W., 1997. Ewolucja morfotektoniczna Sudetów w rejo- nie Kotliny K³odzkiej w œwietle analizy morfomeryczno-sta- tystycznej. [Morphotectonic evo lu tion of the Sudetes in the K³odzko Ba sin in the light of the morphometric-sta tis tic anal - y sis]. Prace Geologiczno-Mineralogiczne, 68: 1–97.

SROKA, W. & KOWALSKA, A., 1998. The preglacial flu vial de - pos its in the south ern part of the Up per Nysa De pres sion, cen tral Sudetes Mts., south west ern Po land. Geologia Sude- tica, 31: 157–170.

TEISSEYRE, B., 1975. Stratygrafia mikrofaunistyczna górnej kredy rowu Nysy (Sudety Œrodkowe) [Stra tig ra phy based upon Foraminifera of Up per Cre ta ceous de pos its, Nysa Graben, Central Sudetes]. Rocznik Polskiego Towarzystwa Geologicz- nego, 45: 81–134.

ULRYCH, J., DOSTAL, J., ADAMOVIÈ, J., JELÍNEK, E., ŠPAÈEK, P., HEGNER, E. & BALOGH, K., 2011. Re cur rent Ce no zoic vol ca nic ac tiv ity in the Bo he mian Mas sif (Czech Re pub lic Re cur rent Ce no zoic vol ca nic ac tiv ity in the Bo he - mian Mas sif (Czech Re pub lic). Lithos 123: 133–144.

WOJEWODA, J., 1997. Up per Cre ta ceous lit to ral-to-shelf suc ces - sion in the Intrasudetic Ba sin and Nysa Trough, Sudety Mts.

In: Wojewoda , J. (Ed.), Obszary •ród³owe: Zapis w osadach, tom I: 81–96. Wroc³aw WIND.

WOJEWODA, J., 2004. Skamienia³oœci œladowe w p³ytkowod- nych osadach santonu na obszarze rowu Górnej Nysy K³odz- kiej. In: Muszer, J. (Ed.), Zapis paleontologiczny jako wskaŸ- nik paleoœrodowisk, XIX Konferencja Naukowa Paleobio- logów i Biostratygrafów PTG: 95–96. {in Pol ish only}

WOJEWODA, J., ROTNICKA, J. & RACZYÑSKI, P. 1997.

Obszar Sudetów w póŸnej kredzie. In: J. Wojewoda (Ed.), Obszary •ród³owe: Zapis w osadach, VI Krajowe Spotkanie Sedymentologów, Materia³y: 98–129.

WOJEWODA, J. & BURLIGA, S., 2008. Osady permskie basenu œródsudeckiego, Stanowisko 1 Krosnowice (Czerwoniak). In:

Wojewoda, J. (Ed.), Baseny Œródgórskie: Kontekst Regionalny Œrodowisk i Procesów Sedymentacji, Kudowa Zdrój, 15- 21.09.2008, Materia³y Konferencyjne, wycieczka B: 67–70.

VALEÈKA, J., 1984. Storm-surge ver sus turbidite or i gin of the Coniacian-to-Santonian sed i ments in the east ern part of the Bo he mian Cre ta ceous Ba sin. Geologische Rundschau, 113:

651–682.

VALEÈKA, J., 1988. Sedimentology of the Up per Cre ta ceous in the Králíky Graben (NE Bo he mia), (in Czech with Eng lish sum.). Sbornik Geologických Vìd, Geologie, 43: 147–191.

VALEÈKA, J. & SKOÈEK, V., 1991. Late Cre ta ceous lithoevents in the Bo he mian Cre ta ceous Ba sin, Czecho slo va kia. Cre ta - ceous Re search, 12: 561–577.

ZIEGLER, P.A. & DêZES P., 2007. Ce no zoic up lift of Variscan Mas sifs in the Al pine fore land: Tim ing and con trol ling mech - a nisms. Global Planet. Change, 58: 237–269.

ŽATEÈKA, P., 1996. Vývoj øíèního systému v povodí nejhoøejší Tiché Orlice. Orlické hory a Podorlicko, Sborník vlastivìd- ných prací, Brož 8: 17–24.

¯ELAZNIEWICZ, A., ALEKSANDROWSKI, P., BU£A, Z., KARNKOWSKI, P. H., KONON, A., OSZCZYPKO, N., ŒL¥CZKA, A., ¯ABA, J. & ¯YTKO, K., 2011. Regionaliza- cja tektoniczna Polski. Komitet Nauk Geologicznych PAN, Wroc³aw, pp. 60