On the origin of strata-bound Zn-Pb ores in the Upper Silesia, Poland

Annales Societatis Geologorum Poloniae (1998), vol. 68: 267-278.

ON THE ORIGIN OF STRATA-BOUND Zn-Pb ORES IN THE UPPER SILESIA, POLAND

Maria SASS-GUSTKIEWICZ1 & Stanisław DŻUŁYŃSKI2

1 Faculty o f Geology, Geophysics and Environment Protection, University o f Mining and Metallurgy, al. Mickiewicza 30, 30-059 Kraków, Poland

2Institute o f Geological Sciences, Jagiellonian University, ul. Oleandry 2a, 30-063 Kraków, Poland

Sass-Gustkiewicz, M ., & Dżułyński, S., 1998. On the origin o f strata-bound Zn-Pb ores in the U pper Silesia, Poland.

Ann. Soc. Geol. Polon., 6 8 : 267-278.

A b stract: In view o f the renew ed discussion on the origin o f U pper Silesian Zn-Pb ores w e give som e comm ents on this subject. In our opinion the recurrently invoked post-Jurassic age o f these deposits is at variance w ith geological facts w hich point to pre-Jurassic age. The source o f m etal-bearing solutions could be looked in deeper parts o f the E arth’s crust, presum ably in Paleozoic rocks, or in older accum ulations o f ore deposits regenerated during Triassic reorganization o f crustal plates.

A b stra k t: W naw iązaniu do wznowionej dyskusji nad pochodzeniem i w iekiem górnośląskich złóż rud Zn-Pb autorzy uzasadniają pogląd, że przypisyw anie im po-jurajskiego w ieku je st sprzeczne z faktami geologicznym i, które w skazują na ich przed-jurajski wiek. Źródeł roztw orów metalonośnych m ożna się dopatryw ać w głębszych częściach skorupy ziemskiej praw dopodobnie w paleozoicznych skałach, bądź w starszych złożach kruszców, zregenerowanych podczas przem ieszczania się kier globalnych w triasie.

K ey w ords: M V T deposits, age o f m ineralization, derivation o f ore fluids.

Manuscript received 7 January 1999, accepted 18 January 1999

INTRODUCTION GEOLOGIC SETTING

The strata-bound Zn-Pb sulfide ores in the Triassic of Upper Silesia belong to the category o f Mississippi Valley- type deposits (abbreviated to M VT deposits). These depos­

its were once designated as “Upper Silesia - Mississippi Valley type deposits” (Dunham, 1950). Recently, however, they are described as “Silesia-C racow ” ores. As in our ear­

lier publications, in this paper we return to the name “Upper Silesian ores”, unless the designation “Silesia-Cracow ” is quoted in excerpts from other publications.

The origin o f Upper Silesian deposits is still open to dis­

cussion. Time and again contradictory ideas on this subject have been advanced, largely because some investigators as­

cribe negligible importance to certain geological data that are at variance with their preconceived ideas or because o f insufficient understanding o f geological setting o f these ores. The dispute is centered on the following subjects: 1 - relationship o f ores to their karst receptacles; 2 - relation­

ship o f ore bodies to tectonic features o f the district; 3 - age o f ore emplacement; 4 - derivation o f ore fluids, their driv­

ing mechanism and routes o f migration; 5 - source o f base metals.

The Triassic sequence o f Upper Silesia is separated from overlying Jurassic and underlying Paleozoic rocks by major unconformities o f regional extent. The sequence be­

gins with non-marine sandstones, conglomerates and claystones (Bunter). In the ore district, the thickness o f non­

marine sediments varies from zero to 20 m, but to the south­

east, it may amount up to 1500 m (Moryc, 1971). The non­

m arine sediments are followed by 300 to 400 m thick se­

quence o f M uschelkalk limestones and early diagenetic dolostones deposited, to a considerable extent, under oxidiz­

ing and high energy conditions. These shallow-water car­

bonates, in turn, are covered, with a slight unconformity, by red non-marine Keuper claystones. The claystones contain, locally, pure lacustrine limestones, the so called “Woźniki limestones” (Roemer, 1870), which are interpreted in terms o f hot spring deposits (Bogacz et al., 1970).

In most o f Upper Silesia, the Triassic overlies almost flat-lying Upper Carboniferous Coal Measures. However, along the north-eastern margin o f the Upper Silesian basin, the Triassic covers with a transgressive overlap the irregular paleorelief (change o f elevation up to 300 m) o f folded Lower Carboniferous and Devonian carbonates (e.g. Ale- xandrowicz, 1971; W yczółkowski, 1971, 1974), whose basement consists o f Lower Paleozoic sedimentary, meta- morphic and igneous rocks (e.g. Wieser, 1957; Ekiert, 1971;

268

Fig. 1. Distribution o f U pper Silesian Zn-Pb strata-bound ores in relation to m ajor Paleozoic fracture zones and faults presented on a background o f schem atic geological map w ithout m inor tec­

tonic features and Cainozoic strata. Paleozoic tectonics simplified after Herbich (1981) and M oraw ska (1997). 1 - Cretaceous; 2 - Jurassic; 3 - Triassic; 4 - Permian; 5 - Carboniferous; 6 - D e­

vonian; 7 - Carpathians C retaceous-T ertiary; 8 - Zn-Pb ore de­

posits; 9 - fracture zones and m ajor faults; 1 0 - Carpathian nappes.

KLFZ - the K raków -Lubliniec Fracture Zone; TGFZ - the Tar­

nowskie Góry Fault Zone; U SF - the U pper Silesian Fault

R y k a, 1978, B u k o w y , 1994). T h e se ro c k s m a k e u p the W N W -E S E tre n d in g lin e a m e n t (R u lsk i, 1973), a lo n g th e so ca lle d K ra k ó w - M y s z k ó w s tru c tu ra l e le v a tio n (K o ta s , 1982,

1985). T o th e w e st o f M y s z k ó w th is e le v a tio n tu rn s w e s t­

w a rd s a n d jo in s th e W - E tr e n d in g K r a k ó w - L u b lin ie c F ra c ­ tu re Z o n e F ig. 1 (M o ra w s k a , 1997). T h is fra c tu re zo n e sep erats th e M a ło p o lsk a M a s s if fro m th e U p p e r S ile sia n M a s s if (e.g ., B e lk a & S ie w n ia k -M a d e j, 1996). It is re a s o n ­ ab le to in te g ra te th e a b o v e m e n tio n e d fra c tu re z o n e s into on e K ra k ó w - L u b lin ie c lin e a m e n t (B u ła & J a c h o w ic z , 1996;

M o ra w sk a , 1997). In its p re s e n t fo rm , th e K r a k ó w - L u b ­ lin iec lin e a m e n t (a b b re v ia te d to K L lin e a m e n t) is a V a ris c a n stru ctu re. It in c lu d e s, h o w e v e r, th e re lic s o f C a le d o n ia n s tru c tu re s a n d is c h a ra c te riz e d b y th e p re s e n c e o f late P a le o ­ zoic in tru siv e an d e x tru s iv e ro ck s. T h is lin e a m e n t o r fr a c ­ tu re z o n e d e lin e a te s th e n o rth e rn a n d n o rth -e a s te rn b o rd e r o f th e U p p e r S ile sia n b a s in a n d re p re s e n ts a se g m e n t o f th e tra n sc o n tin e n ta l “ H a m b u r g - C r a c o w ” fa u lt z o n e (O b erc, 1993; Ż a b a , 1997). T h e lin e a m e n t is th o u g h t to c o in c id e w ith H e rc y n ia n sin istra l ro ta tio n re s u ltin g fro m d ex tral strik e -slip fa u lt (B o g a c z & K ro k o w s k i, 1981). It sh o u ld be b o rn e in m in d , h o w e v e r, th a t th e fra c tu re zo n e in q u e stio n ex te n d s b e y o n d K ra k ó w in so u th -e a s te rn d ire c tio n . Its p ro ­ lo n g atio n h as b e e n re c o g n iz e d u n d e r th e C a rp a th ia n n a p p e s so u th o f B o c h n ia in R a jb ro t (J a c h o w ic z & M o ry c , 1995).

S ta rtin g w ith the U p p e r P a le o z o ic , th e K r a k ó w - M y s z ­ k ó w stru c tu ra l e le v a tio n h a s b e e n a ffe c te d b y th re e se p a ra te e p o c h s o f m in e ra liz a tio n . T h e first, late C a rb o n if e ro u s - P e r-

m ia n p o ly m e ta llic v e in -ty p e m in e ra liz a tio n , w a s d ire c tly r e ­ la te d to in te n siv e te c to n ic s a n d ig n e o u s a c tiv ity (e.g.

G ó re c k a , 1972; H a ra ń c z y k , 1979, 1984; G ó re c k a & N o w a k ­ o w sk i, 1979). T h e s e c o n d , s tra ta -b o u n d m in e ra liz a tio n , c o m p o s e d c h ie fly o f sp h a le rite , g a le n a a n d iro n su lfid e s , is c o n fin e d to M id d le T ria s sic c a rb o n a te s (M u sc h e lk a lk ). T h e last, e c o n o m ic a lly u n im p o rta n t m in e ra liz a tio n , o c c u rs in J u ­ ra s sic lim e s to n e s a n d c o n sists m a in ly o f iro n su lfid e s, g a ­ le n a a n d , lo c a lly , o f in s ig n ific a n t a m o u n ts o f sp h alerite.

T h is m in e ra liz a tio n is g e n e tic a lly r e la te d to E a rly T e rtia ry fa u lts w h ic h b e c a m e tru n c a te d d u rin g th e P a le o g e n e p la n a - tio n . T h e N e o g e n e fa u lts w h ic h are c le a rly m a r k e d as h o rsts a n d g ra b e n s in th e p re s e n t to p o g r a p h y o f th e C ra c o w U p ­ lan d (D ż u ły ń s k i, 1953) are b a rre n o f o re m in e ra ls.

A lth o u g h th e fo llo w in g d is c u s s io n is c h ie fly c o n c e rn e d w ith o res in th e M u s c h e lk a lk , th e e x is te n c e o f e a rly T e rtia ry fa u lt-h o s te d m in e ra liz a tio n s s h o u ld b e k e p t in m in d , b e ­ c a u se o f its b e a rin g o n th e c o n tro v e rs ie s c o n c e rn in g th e o ri­

gin a n d ag e o f s tra ta -b o u n d o re s in T ria s sic c a rb o n a te s.

THE HOST ROCK OF TRIASSIC ORES

T h e h o s t-ro c k p ro p e r o f su lid e o re s in th e T ria s sic is th e o re -b e a rin g d o lo m it (a b b re v ia te d to O B D ). T h is n e o s o m e or m e ta s o m e o c c u rs in th e fo rm o f la te ra lly e x te n s iv e , irre g u la r o r ro u g h ly ta b u la r b o d ie s w ith in u n a lte re d T ria s sic c a rb o n ­ ates (p a le o so m e ). T h e se b o d ie s are lo c a liz e d a lo n g the so u th w e s te rn m a rg in o f th e K L fra c tu re z o n e a n d a re a b se n t fu rth e r to th e so u th w e s t, as w e ll as o n th e e a ste rn sid e o f th is stru c tu ra l e le v a tio n .

T h e c ro s s -c u ttin g m e ta s o m a tic c o n ta c ts o f th e O B D w ith u n a lte re d T ria s sic c a rb o n a te s a n d th e p re s e n c e o f is o ­ la te d re m n a n ts o f th e s e c a rb o n a te s w ith in th e O B D , leav e no d o u b ts as to its s e c o n d a ry , m e ta s o m a tic n a tu re (e.g ., B o g a c z et cii, 1972 ).

T h e O B D re s u lte d fro m s u c c e s iv e stag es, th ro u g h d olo- m itiz a tio n o f lim e s to n e s an d re c ry s ta lliz a tio n o f e a rly -d ia g e - n etic d o lo s to n e s (B o g a c z et al., 1975). T h e re are at least th re e g e n e ra tio n s o f th e O B D : 1 - fin e -c ry s ta llin e , d a rk d o ­ lo m ite w ith d is p e rse d iro n s u lfid e s , 2 - c o a rs e -c ry s ta llin e ru s ty d o lo m ite an d , 3 - g a n g u e d o lo m ite in v ein s.

T h e se g e n e ra tio n s (see: K rz y c z k o w s k a -E v e re s t, 1990) w e re th e re s u lts o f th e sa m e fo rm a tiv e p ro c e s s. T h e y w ere d ire c tly re la te d to th e tr a n s fe r o f h o t m in e ra liz in g so lu tio n s a n d m o b iliz e d c o n n a te o r g ro u n d w a te rs th ro u g h th e p o re s p a c e o f T ria s sic p a le o a q u ife r.

T h e ag e o f th e O B D is p re -J u ra s s ic , b e c a u se th e C al- lo v ia n m a rin e s e d im e n ts re s t d ire c tly u p o n th e e ro d e d su r­

fa c e o f th is d o lo m ite , th e p h e n o m e n o n a lre a d y o b s e rv e d by e a rly g e o lo g ists (e.g . P e tra sc h e c k , 1918).

A s is th e c ase w ith m a n y o th e r M V T d e p o sits, m o s t stu ­ d e n ts re g a rd th e O B D as a h y d ro th e rm a l a lte ra tio n a n d th ere is re lia b le e v id e n c e su p p o rtin g th is c o n c lu s io n (fo r re f e r­

e n c e s a n d d e ta ils , see: B o g a c z e t a l. , 1972, 1975). A c c o rd ­ in g to so m e a u th o rs, h o w e v e r, th e O B D o rig in a te d in d e ­ p e n d e n tly o f ore m in e ra liz a tio n (e.g . Ś liw iń sk i, 1969).

R e c e n tly , L e a c h e t al. (1 9 9 6 a ) c la im th a t o n ly a lim ited p a rt o f th is d o lo m ite is g e n e tic a lly re la te d to th e e m p la c e ­ m e n t o f s tra ta -b o u n d su lfid e o res. T h e s tra ta -b o u n d o res are

O RIGIN OF Zn-Pb ORES IN THE UPPER SILESIA

269

in d e e d re s tric te d e n tire ly a n d e x c lu s iv e ly to th e O B D (e.g.

M ic h a e l, 1904; S a s s -G u s tk ie w ic z , 1975b, 1985; S o b c z y ń sk i et al., 1978). O u tsid e th e m in e ra liz e d zo n e, th e T ria ssic is d ev o id o f th e O B D . It sh o u ld b e b o rn e in m in d , h o w e v e r, th a t d o lo m itiz in g so lu tio n s w e re fo re ru n n in g th e m e ta l-b e a r- ing ones. T h e se latter m ig h t h a v e c o v e re d o n ly p a rt o f th e h o st stra ta a lre a d y tr a n s fo r m e d in to th e o re -b e a rin g d o lo ­ m ite. B e c a u se o f th e ir g re a te r s p e c ific d e n s ity su ch m in e ra l­

izin g so lu tio n s e m p la c e d o re s c h ie fly in th e lo w e r p o rtio n s o f th e O B D .

A d m itte d ly , th ere a re e a rly d ia g e n e tic , p re -o re d o lo s- to n es b u t th e y in v a ria b ly o c c u r as “ s tra tifo rm ” b o d ie s i.e., no rm al s e d im e n ta ry b ed s c o n ta in in g w e ll p re s e rv e d m ic ro ­ fo ssils an d o th e r o rg an ic re m n a n ts w h ic h in th e O B D are o b lite ra te d o r b lu rre d b y re c ry s ta lliz a tio n . T h e O B D is su ­ p e rim p o se d u p o n such d o lo s to n e s a n d sh o w s c ro ss-c u ttin g m e ta so m a tic c o n ta c ts, s im ila r to th o s e o b s e rv e d w ith lim e ­ stones.

T h e a p p e a ra n c e o f th e O B D h e ra ld e d th e o n se t o f ore m in e ra liz a tio n a n d b o th p h e n o m e n a w e re p a rts o f th e sam e fo rm ativ e p ro c e sse s. T h e O B D re p re s e n ts th e first lin k in th e ch ain o f a lte ra tio n s b ro u g h t a b o u t b y th e p a ss a g e o f h o t a s ­ c e n d in g a n d m in e ra liz in g so lu tio n s (e.g. B o g a c z e ta l., 1970;

P rzen io sło , 1974; M o c h n a c k a & S a ss -G u s tk ie w ic z , 1981).

T h e re fo re , th e o rig in o f O B D h a s b e e n tra d itio n a lly lin k ed w ith th e g e n e sis o f ores.

TEMPERATURE OF ORE EMPLACEMENT

T h e s tra ta -b o u n d o re s in th e U p p e r S ilesia, like m a n y o th e r M V T d e p o sits, are “ s h a llo w ” i.e., e m p la c e d c lo se to the c o n te m p o ra ry E a rth ’s su rfa c e . C o n s e q u e n tly , th e s e d e ­ p o sits are “te le th e rm a l” a n d te m p e ra tu re s o f th e ir e m p la c e ­ m en t ran g e fro m 80° to 1 5 8 °C (K o z ło w sk i, 1995) o r fro m

120° to 2 2 0 °C (P rz e n io sło , 1974). It is re a liz e d , h o w e v e r, th a t at g re a te r d ep th , w h e re th e m in e ra liz in g flu id s w e re d e ­ riv ed , th e ir te m p e ra tu re m u s t h a v e b e e n h ig h e r (K o z ło w sk i, 1995) an d p re s u m a b ly in h ib ito ry to p re c ip ita tio n o f su lfid es.

ORE-BODIES

A lth o u g h th e o re -b o d ie s m a y a ss u m e d iffe re n t p o sitio n s in th e O B D , th e y are th o u g h t to o c c u r in th re e so c a lle d “h o ­ riz o n s” (e.g ., D u w e n se e , 1928; S o b c z y n sk i & S zu w arzy ri- ski, 1974; S z u w a rz y n sk i, 1 9 9 6 ), th e lo w e s t o f w h ic h is lo ­ ca te d n e a rb y a n d a lo n g th e lo w e rm o s t m e ta so m a tic b o u n d ­ ary o f th e O B D . T h e o re s c o n ta in e d in th e s e “ h o riz o n s ” o c ­ cu r in th e fo rm o f re p la c e m e n t (m e ta so m a tic ), c a v ity -fillin g an d a m m o b la s tic o res (se e later).

T h e p ro b le m o f r e p la c e m e n t o re s h a s b e e n tre a te d in m an y p u b lic a tio n s (fo r re f e re n c e s a n d d e ta ils see: e.g. B o - g a c z et al., 1973a; M o c h n a c k a & S a ss -G u stk ie w ic z , 1981) an d d o es n o t c a u se c o n tro v e rs ie s . C o n s e q u e n tly , th e re is n o n e e d to d w e ll on th is s u b je c t. C o m m e n ts, h o w e v e r, are n e e d e d on th e q u e stio n o f c a v ity fillin g ores.

CAVITY-FILLING ORES

M in e ra liz e d p a rts o f th e O B D a re rid d le d w ith c o u n tle ss d is so lu tio n v o id s, w h ic h ta k e th e fo rm o f sh e e t-lik e , low - c e ilin g e d , ta b u la r a n d s p o n g e w o rk c a v itie s . T h e v o id s also in c lu d e o p e n in g s p ro d u c e d b y “ k a rs t te c to n ic s ” (B a lw ie rz &

D zu fy n sk i, 1976) i.e., th e ro c k d is tu rb a n c e s , s u c h as c o l­

la p se b re c c ia s o r m in o r g ra v ity fa u lts, p ro d u c e d b y d is s o lu ­ tio n in d u c e d stre ss re d istrib u tio n . T h e a b o v e m e n tio n e d v o id s are lin e d o r fille d w ith su lfid e o re s.

I n c ip ie n t s h e e t-lik e c a v itie s m a y h a v e fo rm e d d u rin g r e ­ p la c e m e n t o f th e O B D b y su lfid e m in e ra ls , w h e n d is so lu tio n ru n a h e a d o f d e p o sitio n (L in d g re n , 19 1 8 ). S u ch c a v itie s te n d to o c c u r a lo n g b e d d in g s u rfa c e s, fra c tu re s o r s e c o n d a ry d if­

fu s io n b a n d s (M o c h n a c k a & S a s s -G u s tk ie w ic z , 1981; D z u ­ fy n sk i & S a ss -G u s tk ie w ic z , 1985; D z u fy n sk i & R u d n ic k i,

1986; S a s s -G u s tk ie w ic z & M o c h n a c k a , 19 9 3 a).

T h e m in e ra liz e d c a v itie s in th e U p p e r S ile sia n d is tric t, as w e ll as in o th e r M V T d e p o sits, a re b e s t e x p la in e d in te rm s o f h y d ro th e rm a l k a rs t p h e n o m e n a as a n o re -fo rm in g p ro c e s s (B o g a c z e ta l., 1970; D z u fy n sk i, 1976; D z u fy n sk i &

S a ss -G u s tk ie w ic z , 1980, 1985; S a s s -G u s tk ie w ic z et al., 1982; S a ss -G u s tk ie w ic z , 1985). T h is c o n c e p t is b a se d on th re e p re m iss e s: 1. th e o re s in fillin g o r lin in g th e v o id s are p re c ip ita te d fro m h y d ro th e rm a l s o lu tio n s, 2 . th e v o id s s e rv ­ in g as o re re c e p ta c le s are o f d is s o lu tio n o rig in an d , 3. th e v o id s a n d o re s re s id e n t in th e m a re fo rm e d c o n te m p o ra n e ­ o u sly o r p e n e c o n te m p o ra n e o u s ly b y th e sa m e fo rm a tiv e p ro c e ss.

T h e te rm “ h y d ro th e rm a l k a rs t” is n o w w e ll e sta b lis h e d in k a rs t sc ie n c e s (e.g . K u n sk y , 1957; O z o ra y , 1961; M a k s i­

m o v ic h , 1969, D z u fy n sk i 1976; Ja k u c s , 1977; R u d n ic k i, 1979; D u b ly a n sk i, 1995). C a v ity m a k in g b y m e ta l-b e a rin g h y d ro th e rm a l so lu tio n s h as a lso b e e n su g g e s te d b y se v e ra l o re -g e o lg ists, e ith e r as an a lte rn a tiv e (e .g ., P a rk & C a n n o n , 1943) o r e x p lic it e x p la n a tio n o f c a v ity -f illin g o re s (e.g.

P o se p n y , 1894; M c C le lla n d & W h ite b re a d , 1965). T o th is c a te g o ry o f p h e n o m e n a b e lo n g th e c a v ity -f illin g su lfid e ores in th e U p p e r S ilesian d is tric t (B o g a c z et a l , 1970; Sass- G u stk ie w ic z , 1974, 1975b). T h e in te rp re ta tio n th a t m in e ra l­

ized c a v itie s w e re p ro d u c e d b y o re b e a rin g so lu tio n s fin d s its s tro n g e st su p p o rt in th e so lu tio n c o lla p s e b re c c ia s w h ic h a re a m o n g im p o rta n t o re re c e p ta c le s . T h e k a rs tic o rig in o f th e se b re c c ia s is te s tifie d b y th e fo llo w in g fe a tu re s:

1. T h e lo w e rm o st b o u n d a rie s o f b re c c ia s are d is so lu tio n s u rfa c e s c o v e re d w ith m in e ra liz e d c a v e s e d im e n ts m a d e up o f g ra in s o f d is in te g ra te d d o lo m ite a n d sp h a le rite , in s o lu b le re sid u a ls, c la s tic fra g m e n ts o f o re s a n d h o st ro c k , an d id io - m o rp h ic su lfid e c ry s ta ls (B o g a c z e t al., 1973b; S a ss-G u st­

k ie w ic z , 1975a, 1996).

2. T h e u p p e r a n d lateral b o u n d a rie s o f b re c c ia s are g ra ­ d a tio n a l, w h e re b y th e ru b b le o f a n g u la r d o lo m ite b lo c k s in th e c e n te r o f b re c c ia b o d ie s p a s s e s th ro u g h c ra c k le b re c c ia s in to a n e tw o rk o f m in e ra liz e d fra c tu re s . A b o v e th e h ig h -d o - m a l b re c c ia b o d ie s th e m in e ra liz e d fissu re s are c o m m o n ly a rra n g e d in p re s s u re a rc h e s (S a s s -G u s tk ie w ic z , 1974).

3. In p la n v ie w , th e b re c c ia s a re h ig h ly irre g u la r (S a s s- G u stk ie w ic z , 1975b).

4. T h e ro c k fra g m e n ts m a k in g u p th e b re c c ia b o d ie s are d e v o id o f slic k e n s id e d s u rfa c e s o r te c to g ly p h s .

270

T h e m in e ra liz e d b re c c ia s w e re fo rm e d s y n c h ro n e o u s ly an d /o r p e n e c o n te m p o ra n e o u s ly w ith th e e m p la c e m e n t o f o re s fro m a n a lte rn a tin g su c c e s s io n o f b re c c ia tio n a n d m in ­ e ra liz a tio n e p is o d e s in w h ic h th e s u c c e s s iv e ly y o u n g e r o re m in e ra ls e n v e lo p e d th e c la s tic p ro d u c ts o f e a rlie r b re c c ia ­ tio n a n d m in e ra liz a tio n e p is o d e s (S a s s-G u stk ie w ic z ,

1975b). A s se e n in p la n v ie w , th e b re c c ia b o d ie s re v e a l c o n ­ c e n tric a n d zo n a l a rra n g e m e n t, w ith s u c c e s iv e ly y o u n g e r sta g e s o f m in e ra liz a tio n c o v e rin g p ro g re s s iv e ly m o re e x ­ te n d e d a reas. S u ch a re la tio n s h ip im p lie s th a t b o th th e k a rs t re c e p ta c le s a n d th e o re s re s id e n t in th e m a re p ro d u c ts o f th e sam e fo rm a tiv e p ro c e s se s a n d th a t th e ir c o e x is te n c e in sp a c e is n o t d u e to a n a c c id e n ta l s u p e rp o s itio n o f u n re la te d ev e n ts.

T h is c o n c lu s io n can b e e x te n d e d to c o v e r th e u n c o lla p s e d m in e ra liz e d k a rs t c a v itie s . T h e b a n d e d o re c ru s tific a tio n s p ass fro m in te rfra g m e n ta l v o id s o f th e b re c c ia s in to su ch c a v itie s w ith o u t in te rru p tio n .

S ig n ific a n tly , th e m in e ra liz e d k a rs t c a v itie s se ld o m , i f ev er, o c c u r in lim e sto n e s. T h is b e h a v io u r m a y b e e x p la in e d b y th e in c re a se d p e rm e a b ility o f c o a rs e -c ry s ta llin e O B D a n d b y th e fa c t th a t a t te m p e ra tu re s a b o v e 4 0 °C , th e d o lo ­ m ite is m o re so lu b le th a n lim e s to n e (M a n d y , 1945, fid e J a k u c s, 1977).

T h e d is so lu tio n m o tiv a te d o rig in o f m in e ra liz e d b re c ­ cias in th e T ria s sic s tra ta -b o u n d d e p o sits is ig n o re d , m in i­

m iz e d o r re je c te d b y a u th o rs w h o in s ist on th e ir tru e te c to n ic d e riv a tio n (e.g ., K ib itle w s k i, 1993; S z u w a rz y n sk i, 1983, 1993). T h e p re v io u sly in d ic a te d c h a ra c te ris tic fe a tu re s o f th e b re c c ia s in q u e stio n , h o w e v e r, are in c o m p a tib le w ith th e ir a lle g e d tru e te c to n ic o rig in .

O u r in te rp re ta tio n is a ls o p a rtly q u e stio n e d b y A m e ri­

c an in v e s tig a to rs . T h e m o o t p o in t in th e d is p u te is th e p re s ­ en ce o r th e a lle g e d p re s e n c e o f “p r e - o re ” b re c c ia s in th e O B D , p ro d u c e d by d is s o lu tio n m o tiv a te d c o lla p se , in d e ­ p e n d e n tly o f th e tr a n s fe r o f m in e ra liz in g so lu tio n s. L e a c h et al. (1 9 9 6 a) use th e te rm “p re -o re b re c c ia ” to d e scrib e “ d is­

so lu tio n c o lla p se b re c c ia s w h ic h la c k d ia g n o s tic e v id e n c e o f in v o lv e m e n t o f e ith e r m e te o ric o r h y d ro th e rm a l flu id s a n d w h o se fo rm a tio n p re d a te s th e e m p la c e m e n t o f o re m in e ra ls ” (I.e. p. 4 5 ) T h e a b o v e m e n tio n e d a u th o rs c o n c lu d e th a t

“ m a n y o re -b e a rin g b re c c ia s in th e S ile s ia n -C ra c o w re g io n are R E P L A C E M E N T B R E C C IA S (c a p ita l le tte rs b y th e p re s e n t au th o rs) th a t a re th e re s u lt o f su p e rp o sitio n o f ore stage d is so lu tio n an d h y d ro th e rm a l b re c c ia tio n on a p re -o re b re c c ia an d th e se le c tiv e re p la c e m e n t o f p re -o re k a rs t b r e c ­ cias by s u lfid e s ” (I.e. p. 4 6 ). In m a trix -s u p p o rte d b re c c ia s, th e m a trix is p re fe re n tia lly s u b je c te d to d is so lu tio n a n d r e ­ p la c e m e n t, b u t fro m th is it d o e s n o t fo llo w th a t th e m e ta so - m a tic p ro c e s s is s u p e rim p o s e d u p o n th e p re -o re b re c c ia u n ­ re la te d to th e tra n sfe r o f m in e ra liz in g so lu tio n s (se e b e lo w ).

L each e t al. (1 9 9 6 a) su g g e s t th re e p o ss ib ilitie s fo r th e d e v e lo p m e n t o f m in e ra liz e d b re c c ia s in th e O B D : 1 - m e te ­ oric k arst sy s te m d e v e lo p e d p rio r to th e in tro d u c tio n o f o re- fo rm in g flu id s w h ich a lte re d a n d e n la rg e d th e o rig in a l, m e ­ te o ric c o lla p se b re c c ia s, 2 - th e p re -o re b re c c ia s d e v e lo p e d fro m an e a rlie r h y d ro th e rm a l e v e n t, w h ic h w a s u n re la te d to o re e m p la c e m e n t an d , 3 - h y d ro th e rm a l k a rs t m ig h t h a v e fo rm ed d u rin g th e in itial in tro d u c tio n o f o re -fo rm in g flu id s b u t p rio r to th e d e p o sitio n o f su lfid e s (I.e. p .4 6 ). T h e p o s s i­

b ilitie s su g g e s te d h a v e a lr e a d y b e e n d isc u sse d , in a so m e ­

w h a t s im ila r w a y , b y D z u ly n s k i & S a s s -G u s tk ie w ic z (1 9 8 5 , p . 4 0 0 ).

T h e a b o v e liste d p o s s ib ilitie s re q u ire th e fo llo w in g c o m m e n ts:

a d 1. In d e e d b o th , th e u n a lte re d T ria s s ic h o s t stra ta a n d th e O B D re v e a l m e te o ric k a rs t fe a tu re s b e lo n g in g to th e th re e p e rio d s o f m e te o ric k a rs tific a tio n : p re -J u ra s s ic , L o w e r T e rtia ry , a n d P le is to c e n e -R e c e n t. T h e s e m e te o ric k a rs t fe a ­ tu re s d e v e lo p e d u n d e r o x id iz in g c o n d itio n s . O n th e o th e r h a n d , th e m in e ra liz e d k a rs t fe a tu re s in th e O B D d o n o t sh o w a n y e v id e n c e o f h a v in g b e e n d e v e lo p e d u n d e r o x id iz in g c o n d itio n s a n d n o c o e v a l k a rs t b re c c ia s o f th is ty p e h a v e e v e r b e e n o b s e rv e d in th e h o s t s tra ta o u ts id e th e O B D . T h e s h e e t c a v itie s w h ic h are c h a ra c te ris tic o f h y d ro th e rm a l k arst o re s (rib b o n o re s) are a lso a b s e n t in n o n -m in e ra liz e d c a r­

b o n a te s . T h e rib b o n o res, in te rp re te d as p ro to -k a rs t fe a tu re s, are re p re s e n ta tiv e s o f th e first s ta g e in d e v e lo p m e n t o f h y ­ d ro th e rm a l k a rs t p h e n o m e n a (S a s s -G u s tk ie w ic z , 1993;

D z u ly n sk i & S a ss -G u s tk ie w ic z , 1993). T h e m in e ra liz e d c o l­

la p s e b re c c ia s re p re s e n t th e m a tu re sta g e o f su c h d e v e lo p ­ m e n t. S u m m in g u p , th e m in e ra liz e d b re c c ia s re s u lte d p e n e ­ c o n te m p o ra n e o u s ly o r s y n c h ro n o u s ly w ith d e p o s itio n o f o res a n d h a v e n e v e r b e e n p re -o re m e te o ric k a rs t fe a tu re s.

In th e O B D , th e re are L o w e r T e rtia ry sin k h o le s c o n ta in ­ in g c la s tic fra g m e n ts o f o re s d e riv e d fro m e a rlie r m in e ra li­

z a tio n s. S u ch sin k h o le s w e re p r o d u c e d d u rin g su b a e ria l e ro ­ sio n fo llo w in g th e re tre a t o f th e C re ta c e o u s sea. S o m e o f th e m b e c a m e in n u d a te d b y th e M io c e n e tra n s g re s s io n an d p a rtly fille d w ith m a rin e se d im e n ts (P a n e k & S z u w a rz y n sk i, 1975). I f th is is th e c ase, th e s in k h o le s m a y c o n ta in re m o ­ b iliz e d g a le n a c ry s ta ls in sh e lls o f M io c e n e m o llu s c s a t­

ta c h e d to th e w a lls o f sin k h o le s (B o g a c z e t a l , 1973b).

ad. 2 T h e re is n o e v id e n c e th a t m in e ra liz e d k a rs t c a v i­

tie s in th e O B D d e v e lo p e d fro m an e a rlie r h y d ro th e rm a l flu id e v e n t, u n re la te d to th e o re s in th em .

ad. 3 T h e th ird p o s s ib ility is n o t a t v a ria n c e w ith the c o n c e p t o f h y d ro th e rm a l o re -fo rm in g k a rs t p ro c e s se s. T he fo rm a tio n o f v o id s p re c e d e d s h o r tly th e e m p la c e m e n t o f ores, b u t b o th p ro c e s se s w e re p e n e c o n te m p o ra n e o u s s an d p a rts o f th e sa m e fo rm a tiv e e v e n t.

B r ie f c o m m e n ts are n e e d e d o n b re c c ia s w h ic h a p p e a r to b e o n ly p a rtly m in e ra liz e d . S u c h b re c c ia s m a y g iv e th e im ­ p re s sio n th a t m in e ra liz in g s o lu tio n s in v a d e d th e p re -o re m e ­ te o ric k a rs t stru c tu re s. M in e ra liz in g so lu tio n s, h o w e v e r, m a y d e p o sit su lfid e s in m o re p e rm e a b le p a rts o f b re c c ia s, le a v in g o th e r p a rts o f th e b re c c ia s a p p a re n tly b a rre n o f ore m in e ra ls. N e v e rth e le s s , su ch se e m in g ly b a rre n p o rtio n s in ­ v a ria b ly c o n ta in sm a ll a m o u n ts o f d is p e rs e d su lfid es.

L a rg e c o lla p se b re c c ia b o d ie s in th e U p p e r S ile sia n re ­ g io n are p re fe re n tia lly lo c a te d a lo n g th e lo w e rm o s t m e ta so - m a tic b o u n d a ry o f th e O B D . T h is b o u n d a ry a p p ro x im a te s th e to p lim it o f th e G o g o lin b e d s w h ic h c o n sist o f fin e -c ry s ­ ta llin e , th in - to m e d iu m -b e d d e d lim e s to n e s in te rc a la te d w ith m arls. T h e G o g o lin b e d s p ro v id e d a n im p e rm e a b le flo o r for h o riz o n ta lly s p re a d in g d o lo m itiz in g so lu tio n s. T h e fo llo w ­ ing, h e a v y a n d a g g re s iv e m in e ra liz in g s o lu tio n s also m o v e d a lo n g su c h a n in te rfa c e , ta k in g a d v a n ta g e o f a n in c re a se d p o ro s ity o f th e c o a rs e -c ry s ta llin e O B D .

C o n v e rg in g in m o re p a s s a b le c o n d u its, th e s e so lu tio n s c o u ld d isso lv e siz a b le c a v e rn s w h ic h w e re s u b je c t to ro o f

O RIGIN OF Zn-Pb ORES IN THE U PPER SILESIA

271

failu re s in b e d d e d an d c ra c k e d d o lo m ite s. In a s m u c h as th e r o o f fa ilu re s p ro p a g a te d u p w a rd s , in v o lv in g s u c c e s siv e ly th e o v e rly in g d o lo m itic b e d s, th e ro c k fra g m e n ts m a k in g up th e b re c c ia b o d y c o n s is t e x c lu s iv e ly o f th e O B D .

BRECCIAS NOT RELATED TO ROOF FAILURES OF CAVERNS

N o t all o f m in e ra liz e d b re c c ia s in th e O B D m a y b e a t­

trib u te d to r o o f fa ilu re s o f c a v e rn s . W ith h y d ro th e rm a l k a rs t p h e n o m e n a , n e w b re c c ia tin g fa c to rs c o m e in to a c tio n su c h as “h y d ra u lic fra c tu rin g ” a n d “ h y d ra u lic e x p lo s io n s ” (M u f­

fler et al., 1971; P h illip s, 1972). T h e h y d ro th e rm a l e x p lo ­ sio n s re s u lt fro m ra p id tr a n s fo r m a tio n o f w a te r in to steam an d m a y d is ru p t th e c o n fin in g ro c k . A lso a s u d d e n d ro p in p re s su re m a y b u rs t it a p a rt w ith th e o n s e t o f d ila ta n c y (e.g.

B rid g em an , 1952; K e n ts, 1964). T h e a b o v e m e n tio n e d p ro c ­ e sses h a v e p la y e d a d o m in a n t ro le in th e fo rm a tio n o f b rec- ciated , v e rtic a l ore v e in s w h ic h s e rv e d as c h a n n e lw a y s fo r a sc e n d in g o re flu id s (D z u fy n sk i, 1976; D z u fy n sk i & S ass- G u s tk ie w ic z 1978; 1985). T h e y a lso m ig h t h a v e o p e ra te d as c o n trib u to ry a g e n t in b re c c ia tio n o f th e h o s t d o lo m ite . T h e p re s e n t w rite rs, h o w e v e r, d o n o t c o n s id e r th e h y d ro te c to n ic s as th e k ey fa c to r in th e fo rm a tio n o f larg e b re c c ia b o d ie s in the O B D , as su g g e s te d b y Ja ro s z e w s k i (1 9 9 3 ).

B re c c ia tio n is also p ro m o te d b y th e d is ru p tin g a c tio n o f m in erals c ry s ta lliz in g in fr a c tu re s (e.g . “ b re c h e d ’ec la te - m e n t” - G ig n o u x & A v n im e le c h , 1937 o r “ c h e m ic a l b re c ­ c ia tio n ” - S a w k in s, 1969). T h is p ro c e s s is p a rtic u la rly c o m ­ m o n in th e O B D w h ic h is p a rtly a ffe c te d b y so lu tio n a l d is ­ a g g re g a tio n . T h e so lu tio n a l d is a g g re g a tio n m a y b e p a rt o f h y d ro th e rm a l k a rs t p h e n o m e n a . It is e ffe c te d b y d is so lu tio n o f cry sta l e d g es, w h e re b y th e so lid ro c k is d e lith ifie d an d tra n sfo rm e d in to a soft, stru c tu re le s s m ass o f in c o h e re n t or se m i-c o h e re n t g ra in s in w h ic h a ll tra c e s o f p rim a ry stru c ­ tu res are o b lite ra te d .

T h e d isa g g re g a te d g ra in s a n d c la y e y re s id u a ls w h ic h te n d to a c c u m u la te at th e b o tto m o f c a v e rn s m a y b e re d e p o ­ sited b y th e flo w o f m in e ra liz in g s o lu tio n s (B o g a c z e t al., 1973b). M a s siv e o r p ie c e m e a l r o o f fa ilu re s a lso stir th e u n ­ c o n so lid a te d b o tto m m a te ria ls g iv in g rise to c lo u d s o f su s­

p e n sio n s w h ic h m a y s p re a d la te ra lly in th e fo rm o f su b te rra ­ n ean tu rb id ity c u rre n ts (D z u fy n sk i & S a ss -G u s tk ie w ic z ,

1980).

D isa g g re g a te d d o lo m ite s, re f e rre d to as “ s a n d e d ” (L o w ­ e rin g et al., 1949) o r “p u lv e ru le n t” (Jak u c s, 1977) p ro v id e fav o ra b le c o n d itio n s fo r a n u n h in d e r e d g ro w th o f su lfid e m in erals. S u ch m in e ra ls te n d to lin e th e b o u n d a rie s o f d is a g ­ g reg ated c a rb o n a te s in th e fo rm o f d ru sy in c ru sta tio n s p ro ­ je c tin g w ith th e ir free c ry s ta l fa c e s in to th e d is a g g re g a te d m ass o f g rain s. T h is ty p e o f o re m in e ra liz a tio n , first d e ­ scrib ed fro m th e U p p e r S ile sia n o re s (B o g a c z e t a l., 197 3 b ), h as b e e n in d ic a te d as “a m m o b la s te s is ” (D z u fy n sk i & S ass- G u stk ie w ic z , 1985).

S o lu tio n a l d is a g g re g a tio n m a y p ro c e e d c o n c u rre n tly w ith the a m m o b la s te sis a n d m a y c o n tin u e a fte r th e e m p la c e ­ m e n t o f o re m in e ra ls. In s u c h situ a tio n s , th e su lfid e in c ru sta ­ tio n s b e c o m e su s p e n d e d in a m a s s o f in c o h e re n t g ra in s and, d e v o id o f so lid s u p p o rt m a y b re a k in to still sm a lle r fra g ­

m e n ts. A lso th e p re e x is tin g b e d d in g - c o n tr o lle d o re v e in s are a ffe c te d by su c h b re c c ia tio n . W ith p ro g re s s in g d is a g g re g a ­ tio n th e y b e c o m e fra g m e n te d a n d d is p la c e d , th o u g h so m e o f th e m are still a lig n e d in strin g s, m a r k in g th e o rig in a l p o s i­

tio n s o f v e in s (D ż u ły ń s k i & S a s s -G u s tk ie w ic z , 1978 - Fig.

2, 1 9 8 5 - F i g . 26).

F ra g m e n ts o f d o lo m ite d e ta c h e d fro m s id e -w a lls o f c o l­

lap se b re c c ia s o r c a v itie s , w h ic h are e n tire ly e n c lo s e d in so ft m a trix o f in c o h e re n t g ra in s, are s u b je c t to sp e c ific ty p e o f

“ s e lf-b re c c ia tio n ” . S u ch fra g m e n ts, w e a k e n e d b y in c ip ie n t d isa g g re g a tio n , y ie ld to w e a k s tra in s a n d b re a k in to sm a lle r p ie c e s a lo n g th e p re -e x is tin g c ra c k s . T h e se d is c o n tin u itie s are w id e n e d b y in je c te d d is a g g re g a te d g ra in s a n d d isru p tin g g ro w th o f a u tig e n ic su lfid e c ry s ta ls a n d fo rm a k in d o f “ m i­

c ro -c ra c k le b re c c ia s (D ż u ły ń s k i & S a s s -G u s tk ie w ic z , 1985;

S a s s -G u s tk ie w ic z e t al., 1982 - F ig . 23).

RELATIONSHIP OF ORE BODIES IN TRIASSIC CARBONATES TO

TECTONIC FAULTS

A k e y te n e t o f m a n y in te rp re ta tio n s o f s tra ta -b o u n d ores in th e T ria s sic o f U p p e r S ile sia is th a t th e te c to n ic fau lts w h ic h a ffe c t th e h o s t stra ta h a v e p la y e d an im p o rta n t ro le in th e fo rm a tio n a n d d is trib u tio n o f o re b o d ie s (e.g . G a łk ie - w ic z , 1983; S z u w a rz y ń sk i, 1993; K ib itle w s k i & G ó re c k a , 1988; K ib itle w sk i, 1993). T h e p o s s ib ility th a t so m e o f th e s e fau lts h a v e b e e n a s s o c ia te d w ith e a rly C im m e ria n m o v e ­ m e n ts h a s a lso b e e n in v o k e d (e.g . P ie k a rs k i, 1965; S z u w a r­

z y ń sk i, 1983). T h e d ire c t re la tio n s h ip o f th e s tra ta -b o u n d o re to p re - o r sy n -o re te c to n ic s is n o t c le a rly re c o r d e d in m in e w o rk in g s b u t a p p e a rs fro m sta tis tic a l a n a ly s e s o f d is ­ trib u tio n s o f th e o re b o d ie s (B la jd a , 1993; S a s s -G u s tk ie w ic z e t a l , 1997).

T h e U p p e r S ile sia n re g io n w a s a ffe c te d b y e a rly C im ­ m e ria n m o v e m e n ts w h ic h a p p e a r to b e re c o rd e d b y so m e s e d im e n ta ry s tru c tu re s (S z u lc , 1993). T h e e a rly C im m e ria n fau lts m ig h t h a v e a n d p re s u m a b ly d id fo llo w th e p a tte rn o f e a rlie r te c to n ic fra c tu re s a lth o u g h th e ir a m p litu d e w a s m u c h s m a lle r th a n th a t o f th e V a ris c a n fa u lts (H e rb ic h , 1981;

G ó re c k a , 1993). H o w e v e r, th e m a jo rity o f fau lts w h ic h tr a n ­ s e c t a n d d is p la c e th e s tra ta -b o u n d o re b o d ie s in th e T ria ssic are p o s t-o re p h e n o m e n a re la te d to E a rly T e rtia ry a n d N e o ­ g en e te c to n ic s . A s n o te d , th e e a rly T e rtia ry fa u lts w e re a s s o ­ c ia te d w ith lo c a l re g e n e ra tio n a n d re m o b iliz a tio n o f p re e x ­ istin g su lfid e o res a n d w e re re s p o n s ib le fo r in s ig n ific a n t fa u lt-h o s te d m in e ra liz a tio n o f J u r a s s ic lim e sto n e s.

AGE OF STRATA-BOUND MINERALIZA­

TION IN TRIASSIC CARBONATES

A g e o f th e su lfid e m in e ra liz a tio n in T ria s sic c a rb o n a te s h a s lo n g b e e n a b o n e o f c o n te n tio n b e tw e e n p ro p o n e n ts o f

“ s y n g e n e tic ” a n d “ e p ig e n e tic ” in te rp re ta tio n s . In sp ite o f p ro lo n g e d d is c u ssio n s n o c o n c e n s u s o f o p in io n h a s b e e n r e a c h e d o n th is su b je c t.

T h e s y n s e d im e n ta ry n o n -h y d r o th e rm a l in te rp re ta tio n , o n c e p o p u la r (e .g .,G u e ric h , 1903; S ta p p e n b e c k , 1928; K eil,

272

1956; G ru sz c z y k , 1967; S m o la rsk a , 1968) is n o w g e n e ra lly a b a n d o n e d . S o m e p ro p o n e n ts o f e p ig e n e tic in te rp re ta tio n s su g g est p o st-U p p e r J u r a s s ic a n d /o r T e rtia ry a g e o f th e stra ta -b o u n d su lfid e o re s in T ria s sic c a rb o n a te s, re la tin g th is m in e ra liz a tio n to th e “ A lp in e te c to n ic s ” in th e C a rp a th ia n s (e.g. A lth a n s, 1891; S a c h s, 1930; H a ra ń c z y k , 1979; K o z ­ ło w sk i, 1995; G ó re c k a e t a l , 1 9 9 6 ;) . A s an a rg u m e n t in fa ­ v o r o f su c h in te rp re ta tio n , th e y p o in t to th e m in e ra liz a tio n in U p p e r J u ra ssic lim e s to n e s lo c a te d a lo n g th e e a rly T e rtia ry faults. T h is c o n c e p t h a s b e e n re c e n tly a c c e p te d by A m e ric a n in v e s tig a to rs (L e a c h & V ie ts , 1993; L each et al., 1996a, 1996b; C h u rc h et al., 1 9 9 6 ) a n d su p p o rte d b y S y m o n s e t al.

(1 9 9 6 ) on th e b asis o f p a le o m a g n e tic in v e s tig a tio n s o f ore sam p les. It sh o u ld be b o rn in m in d , h o w e v e r, th a t L o w e r T e rtia ry fa u lt-h o s te d o re s m a y be su p e rim p o s e d u p o n th e s tra ta -b o u n d d ep o sits, w h e re th e s e d e p o sits are c u t by L o w e r T e rtia ry faults. S u c h s itu a tio n re q u ire s p re c is e lo c a l­

iz a tio n o f sa m p le s a n d th e ir p re s e n ta tio n a g a in s t th e b a c k ­ g ro u n d o f o re stru c tu re s in th e s a m p lin g site. T h e sa m p le s in v e stig a te d , h o w e v e r, d o n o t s a tisfy th is re q u ire m e n t.

M o reo v er, a n y g e n e tic h y p o th e s is e x p la in in g th e o rig in o f M V T -d e p o sits m u s t b e in a c c o rd w ith a ll a sp e c ts o f g e o lo g ic settin g th a t e x is te d a t th e tim e th e d e p o s it w e re fo rm e d (O h le, 1980). T h e T e rtia ry in te rp re ta tio n o f th e stra ta -b o u n d o res d is c u sse d is d iffic u lt to re c o n c ile w ith fie ld e v id e n c e .

A s n o te d , th e stra ta -b o u n d su lfid e o re s are p re -J u ra s s ic b e c a u se C a llo v ia n se d im e n ts re s t w ith tra n sg re s siv e o v e rla p up o n th e e ro d e d su rfa c e o f th e O B D w h ic h w a s fo rm e d p e n e c o n te m p o ra n e o u s ly w ith th e e m p la c e m e n t o f su lfid e o res. T h e lo w e rm o st n o n -m a rin e J u ra s s ic se d im e n ts h av e b een re p o rte d to rest o n a k a rs tifie d su rfa c e o f th e O B D , w h e re b y th e o re s th e m s e lv e s h a v e a lre a d y b e e n s u b je c te d to w e a th e rin g a n d o x id a tio n (e.g . P e tra sc h e c k , 1918; P ie k a r­

ski, 1965).

T h e p re s e n c e o f su lfid e s in J u ra ssic lim e s to n e s g a v e rise to th e c o n c e p t o f m u lti-s ta g e m in e ra liz a tio n e x te n d e d o v e r a lo n g tim e in te rv a l fro m U p p e r T ria s sic to L o w e r T e rtia ry (e.g., R ó ż k o w s k i et al., 1979; S z u w a rz y ń sk i, 1983). T h e e a rly T e rtia ry m in e ra liz a tio n , h o w e v e r, as c o m p a re d w ith th e T ria s sic m in e ra liz a tio n , to o k p la c e u n d e r e n tire ly d iffe r­

en t te c to n ic , stru c tu ra l a n d e n v iro n m e n ta l settin g s. T h is m in e ra liz a tio n is fa u lt-h o s te d im p o v e ris h e d (S z u w a rz y ń sk i, 1983) a n d d o e s n o t o c c u r in th e fo rm o f s tra ta -b o u n d b o d ies.

T h e e m p la c e m e n t o f s tra ta - b o u n d o res w a s an e a rlie r an d se p a ra te e v e n t an d n o t a ste p in a lo n g -la stin g m in e ra liz a tio n p ro c e ss, e m b ra c in g J u r a s s ic a n d C re ta c e o u s c a rb o n a te s (see later).

T h e c o n c e p t th a t th e s tra ta -b o u n d su lfid e o re s w e re em - p la c e d in p o st-U p p e r J u r a s s ic o r p o st C re ta c e o u s tim e ra ise s a n u m b e r o f q u e stio n s w h ic h , u n d e r su c h a ss u m p tio n , r e ­ m ain u n a n sv e ra b le :

1 - W h y a s c e n d in g h y d ro th e rm a l so lu tio n s d id n o t sp re a d la te ra lly th ro u g h p e rm e a b le , sa n d y B a th o n ia n -C a l- lo v ian se d im e n ts ?

2 - W h y d id th e y d e p o s it th e b u lk o f th e ir b a se m e ta ls in the M u s c h e lk a lk an d n o t in b e d d e d U p p e r J u ra ssic o r C re ta ­ c eo u s c a rb o n a te s?

3 - W h y , in J u ra ssic o r C re ta c e o u s c a rb o n a te s is th e re n o th in g c o m p a ra b le to th e O B D ?

O n th e o th e r h an d , th e p re - J u ra s s ic ag e o f stra ta -b o u n d

d e p o sits e x p la in s th e b e d d in g - p a ra lle l d e p o s itio n o f o re- b o d ie s. T h e d o lo m itiz in g so lu tio n s fo re ru n n in g th e e m ­ p la c e m e n t o f su lfid e s , c o u ld s p r e a d la te ra lly , ta k in g a d v a n ­ ta g e o f h ig h p rim a ry p o ro s ity , w ith o u t b e in g in h ib ite d o r d e ­ v ia te d b y fau lts. T h e fo llo w in g m in e ra liz in g a n d a g g re siv e so lu tio n s u tiliz e d th e s e c o n d a ry p o ro s ity o f c o a rs e c ry s ta l­

line te x tu re o f th e d o lo m itic n e o s o m e . F in a lly , th e p re - J u ra s ­ sic a g e o f m in e ra liz a tio n is c o n s is te n t w ith w h a t is k n o w n o f m a n y o th e r M V T d e p o sits, n a m e ly th e p ro x im ity o f su ch d e p o sits to a re g io n a l u n c o n fo r m ity a b o v e th e h o st strata.

T h e M V T d e p o sits or, a t le a s t m o s t o f th e m , w e re e m p la c e d c lo s e to th e c o n te m p o ra ry E a rth su rfa c e .

W e do n o t k n o w e x a c tly w h e n m in e ra liz in g so lu tio n s sta rte d to in v a d e th e T ria s sic p a le o a q u ife r a n d h o w lo n g th e in flo w o f su c h so lu tio n s lasted . T h e tim e in te rv a l in w h ic h th e p a ss a g e o f m in e ra liz in g so lu tio n s p e rs is te d , e s tim a te d by R e p e tsk i & N a rk ie w ic z (1 9 9 6 ) as o f th e o rd e r 1,000 to 5 ,0 0 0 y e a rs , is p re s u m a b ly to o sh o rt. E s tim a tio n s b y L e w c h u k &

S y m o n s (1 9 9 6 ) fo r th e M V T D fr o m 1 to 8 M y a p e a r to be m o re re a listic .

T h e b e g in n in g o f in flo w o f m in e ra liz in g so lu tio n s b e ­ g an a fte r m u c h , i f n o t all, o f th e M u s c h e lk a lk su c c e s s io n h a d b e e n d e p o site d . It is p o s s ib le th a t a c e rta in a m o u n t o f m e ta l- b e a rin g so lu tio n s m ig h t h a v e le a k e d in to th e s e a w a te r. P e r­

h ap s, th e sm a ll q u a n titie s o f d is p e rs e d su lfid e s re p o rte d fro m th e u p p e rm o s t la g u n a l T ria s s ic s e d im e n ts b e a r e v i­

d e n c e to th is e v e n t (“ d ip lo g e n e tic o re s ” - L o w e rin g , 1963).

In d eed , s u b m a rin e e x h a la tio n s o f o re flu id s h a v e b e e n su g ­ g e ste d (E k ie rt, 1957; P rz e n io sło , 1974; H a ra ń c z y k , 1993).

H o w e v e r, th e o x id iz in g a n d h ig h e n e rg y se d im e n ta ry e n v i­

ro n m e n t o f th e M u s c h e lk a lk w a s n o t c o n d u c iv e to a n y sig ­ n if ic a n t a c c u m u la tio n o f su lfid e d e p o s its o n th e se a flo o r (S ie d le c k i, 1955; K ra je w sk i, 1957). C o n se q u e n tly , th e s tra ta -b o u n d d e p o sits in th e T ria s sic are e p ig e n e tic w ith re ­ s p e c t to th e h o st stra ta , n o t b e c a u s e th e o re flu id s c o u ld n o t re a c h th e b o tto m su rfa c e , b u t b e c a u s e m o s t o f th e m e ta ls h a d p re c ip ita te d b e fo re r e a c h in g th e b o tto m a n d b e c a u s e o f the la c k o f su ita b le re c e p ta c le s o n th e s e a flo o r (D ż u ły ń s k i &

S a ss -G u s tk ie w ic z , 1980).

T h e a b o v e in te rp re ta tio n d o e s n o t d e b a r th e p o ss ib ilty th a t th e in flo w o f as c e n d in g h y d ro th e rm a l s o lu tio n s c o n tin ­ u ed a fte r th e r e tre a t o f th e T ria s s ic sea. T h e p re v io u s ly m e n ­ tio n e d la c u s trin e W o ź n ik i lim e s to n e s (K e u p e r) re p re s e n t h o t sp rin g d e p o sits, as fin al p ro d u c ts o f h y d ro th e rm a l a c tiv ity th a t e a rlie r re s u lte d in d is s o lu tio n o f k a rs t c a v itie s a n d e m ­ p la c e m e n t o f o re s (B o g a c z e t al., 1970). T h e h o t w aters, w h ic h p re c ip ita te d c a lc iu m c a rb o n a te , h o w e v e r, w e re d e ­ p le te d o f b a se m e ta ls. S m a ll a m o u n ts o f d is p e rs e d su lfid e s h a v e a lso b e e n re p o r te d fro m b o th th e K e u p e r a n d R a e th ia n se d im e n ts (A ssm a n , 1948; E k ie rt, 1957, 1971; B e d n a re k et al., 1983; S zu w a rz y ń sk i, 1996). T h e K e u p e r c lay s, h o w ­ e v er, d id n o t a c t as a d iv e rs io n a ry b a rrie r fo r m in e ra liz in g s o lu tio n s b e c a u se th e re is n o c o n c e n tra tio n o f o res b e n e a th th e s e clay s.

F ro m th e fo re g o in g c o n s id e ra tio n s , it a p p e a rs th a t the ag e o f th e s tra ta -b o u n d su lfid e o re s is late T ria s sic (co m p , a lso E k ie rt, 1957; P rz e n io sło , 1 9 7 4 ). S u c h o re s are “ e p ig e ­ n e tic ” w ith re s p e c t to th e e n c lo s in g M u s c h e lk a lk c a rb o n a te s b u t are “ s y n g e n e tic ” on th e s c a le o f T ria s sic s e q u e n c e as a w h o le . T h e re is y e t a n o th e r lin e o f s u p p o r t in th is re s p e c t.

O RIGIN OF Zn-Pb ORES IN THE U PPER SILESIA

273

A c c o rd in g to re c e n t p re lim in a ry in v e s tig a tio n b y B a n a ś et al. (1 9 9 6 ) o n illitiz a tio n o f sm e c tite , th e re w as a d istin c t th e rm a l e v e n t b y th e e n d o f T ria s s ic tim e w h ic h re s u lte d in sig n ific a n t rise o f te m p e ra tu re o f th e T ria s sic stra ta o v e rly ­ ing th e U p p e r C a rb o n ife ro u s (s e e la te r). In th is c o n n e c tio n it is to be re c a lle d th a t e a rly is o to p ic a g e d e te rm in a tio n s o f o res fro m U p p e r S ile sia b y B o ru c k i (1 9 7 8 ) h a v e led h im to c o n c lu d e th a t th e ra n g e o f “ a n a ly tic a l e rro rs ” , 4 0 a n d 2 20 M y “ im p a irs th e re lia b ility ” o f th e s e d e te rm in a tio n s. H o w ­ ever, th e first ag e (4 0 M y ) c o rre s p o n d s to P a le o g e n e a n d th e se c o n d (2 2 0 M y ) to th e late T ria s sic . T h is is in a g re e m e n t w ith th e tw o se p a ra te e p o c h s o f o re m in e ra liz a tio n p o s tu ­ lated b y th e p re s e n t a u th o rs.

DERIVATION AND TRANSFER OF MINERALIZING SOLUTIONS

T h e o rig in o f o re flu id s w h ic h e m p la c e d th e su lfid e o res in T ria s sic c a rb o n a te s is a m a tte r o f c o n je c tu re . H y p o th e se s c o n c e rn in g th e ir d e riv a tio n are b a s e d o n p re c o n c e p tio n s ra th e r th an o n d ire c t o b s e rv a tio n s , b e c a u s e su ch o b s e r v a ­ tio n s are lacking.

T h e m in e ra liz a tio n “ p e r d e s c e n d u m ” fro m o v e rly in g ro ck s (e.g. A lth a n s, 1891; S a c h s, 1930; A ssm a n n , 1948) is n ow a b a n d o n e d , b e c a u se th e s e ro c k s are e ith e r b a rre n o r c o n ta in to o little b a se m e ta ls to a c c o u n t fo r larg e strata- b o u n d d e p o sits. F o r s im ila r re a s o n s , it is u n lik e ly th a t th e m etals h a v e b e e n d e riv e d fr o m c o m p a c tio n b rin e s re s id e n t in T ria ssic h o st stra ta o r fro m re c o n c e n tra tio n o f d is p e rse d s e d im e n ta ry o re m in e ra ls b y c ir c u la tin g g ro u n d w a te rs (e.g . S ta p p e n b e c k , 1928). T h e T ria s s ic h o s t stra ta d o n o t sh o w an y e v id e n c e s o f su ch c irc u la tio n .

O n on e p o in t a g re e m e n t h a s b e e n re a c h e d , n a m e ly , th a t the ores w e re e m p la c e d b y a s c e n d in g h y d ro th e rm a l s o lu ­ tio n s. T h is is a lso in d ic a te d b y o re -flu id in c lu sio n s w h ic h re ­ veal th e p re s e n c e o f v e rtic a l th e rm a l flu id g ra d ie n t p o in tin g to th e c o o lin g o f th e s e flu id s to w a rd s th e E a r th ’s su rface (K o z ło w sk i, 1995). P re s e n tly , th e d is c u ssio n is c e n te re d on m ig ratio n ro u te s o f o re flu id s , th e ir d riv in g fo rc e an d th e so u rc e o f b a se m etals.

T h e m in e ra liz in g so lu tio n s h a v e g a in e d a c c e ss to th e M u s c h e lk a lk th ro u g h fo ld e d a n d fra c tu re d L o w e r P a le o z o ic ro ck s o f the p re v io u sly m e n tio n e d K r a k ó w - L u b lin ie c F ra c ­ tu re Z one. E v id e n c e fo r th is is se e n in v e ric a l o r su b v e rtic a l ore v ein s lo c a te d in fa u lts a n d fra c tu re s th a t tra n s e c t th e s e ro ck s. In p la c e s o f in te rs e c tio n o f su c h te c to n ic d is c o n tin u i­

ties, th e o re b o d ies m a y a s s u m e c h im n e y -, o r p ip e -lik e sh ap es (K w a ś n ie w ic z , 1 9 3 2 ). It s h o u ld b e n o te d th a t large ac c u m u la tio n s o f Z n -P b o re s in T ria s s ic c a rb o n a te s o c c u r p re fe re n tia lly w h e re th e u n d e rly in g P a le o z o ic ro c k s are stro n g ly te c to n iz e d (M ic h a e l, 1904).

T h e fa u lts an d fra c tu re s m e n tio n e d a re m a n ife sta tio n s o f late V a ris c a n o ro g e n y a s s o c ia te d w ith an e le v a te d h e a t flow (B e lk a & S ie w n ia k -M a d e j, 1996). A s n o te d , in v a n in g stag es o f th is o ro g e n y , th e m o v e m e n t a lo n g th e s e d is c o n ti­

n u itie s m ig h t h a v e c o n tin u e d , d u rin g th e o n s e t o f T ria s sic cy c le o f s e d im e n ta tio n (H e rb ic h , 1981), as is th e c a se w ith re c e n t p o st-A lp in e n e o te c to n ic s . S o m e o f th e fau lts m ig h t h av e b e e n re a c tiv a te d d u rin g E a rly C im m e ria n o ro g e n y

(S z u w a rz y ń sk i, 1983).

M in e ra lo g ic a l c o m p o s itio n o f th e s e fa u lt-h o s te d ore v e in s in P a le o z o ic ro c k s m a y b e s im ila r to th a t o f th e strata- b o u n d d e p o sits (G ó re c k a , 1973). T h e o re v e in s re v e a l also sim ila r b re c c ia tio n w h ic h is e x p la in e d in te rm s o f h y d ra u lic fra c tu rin g (D ż u ły ń s k i & S a s s -G u s tk ie w ic z 1985). S u ch b re c c ia tio n m ig h t h a v e b e e n a s s o c ia te d w ith “ s e ism ic p u m p ­ in g ” (S ib so n e t al., 1975; S ib so n , 1987), as is th e c a se w ith re c e n t, e a rth q u a k e g e n e ra te d v io le n t e x p u ls io n s o f h o t m in ­ e ra liz in g s o lu tio n s (L e b e d e v , 1974).

T h e ore v e in s are p a rtic u la rly w e ll d e v e lo p e d in fo ld e d L o w e r C a rb o n ife ro u s a n d D e v o n ia n c a rb o n a te s. T h e se c a r­

b o n a te ro c k s s to o d h ig h in p re -T ria s s ic to p o g ra p h y in th e fo rm o f “ k n o b s ” w h ic h a re c o n s id e re d c h a ra c te ris tic o f th e M V T d e p o sits ( “ o re -k n o b re la tio n s h ip ” - O h le , 1996). F ro m su c h k n o b s, th e a s c e n d in g s o lu tio n s c o u ld e a sily c ro ss th e P a le o z o ic /T ria s s ic u n c o n fo rm ity a n d e n te r d ire c tly into h o riz o n ta lly d is p o s e d M u s c h e lk a lk c a rb o n a te s (A le x a n d ro - w icz, 1971).

T h e fo rm a tio n o f e x te n s iv e stra ta -b o u n d d e p o s its r e ­ q u ire s a v ig o ro u s flo w o f larg e v o lu m e s o f m e ta l-b e a rin g s o ­ lu tio n s. T o sa tisfy th is re q u ire m e n t s u c h so lu tio n s m u s t h a v e a lre a d y b e e n m a d e a v a ila b le a n d it is re a s o n a b le to a c c e p t th e id e a o f d e e p -s e a te d “fo s s il re s e rv o irs ” as a p o ssib le so u rc e s (F y fe e t al., 1978). T h e d ra in in g o f su ch reserv o irs m u s t h a v e b e e n v ery ra p id a n d w ith th e a p p e a ra n c e o f th e p re v io u s ly m e n tio n e d a c tiv e te c to n ic fra c tu re s th e o re flu id s w e re a b ru p tly re le a s e d (D ż u ły ń s k i & S a ss -G u s tk ie w ic z ,

1985).

D e riv a tio n o f o re -flu id s, d riv in g fo rces, th e ro u te s o f th e ir m ig ra tio n a n d th e u ltim a te s o u rc e o f b a se m e ta ls are o p e n to d is c u ssio n . S in c e th e stra ta -b o u n d o re s are p re -Ju - ra s sic (se e a b o v e ), b o th th e u p lift a n d th ru s t o f th e C a rp a ­ th ia n n a p p e s c o u ld n o t h a v e b e e n th e d riv in g m e c h a n is m for o re flu id s, as e n v is io n e d b y so m e in v e s tig a to rs (e.g . S y m o n s e ta l., 1995; L each e t al., 1 9 9 6 b - F i g . 37). T h e C a rp a th ia n s as a n o ro g e n ic b e lt d id n o t e x is t in T ria s s ic tim e . T h e d e v e l­

o p m e n t o f th e C a rp a th ia n g e o s y n c lin e h a d o n ly ju s t b e g a n an d th e a c c u m u la tio n o f th ic k ( 7 - 8 k m ) fly sc h se q u e n c e s ta rte d b y th e e n d o f th e J u ra ssic (T ith o n ia n ) a n d h a s c o n tin ­ u e d till th e M id d le M io c e n e . A t th a t tim e , th e s e d im e n ta ry fly sc h b a sin s w e re situ a te d fa r a w a y to th e so u th . T h e re fo re th e fo rm a tio n m o d e l d e p ic te d in F ig. 37 in th e p u b lic a tio n b y L each et al., (1 9 9 6 b ), is m isle a d in g . A d m itte d ly , to the so u th o f th e p re s e n t o c c u rre n c e s o f C e n tra l E u ro p e a n M u sc h e lk a lk , th e re e x is te d a la n d a re a w h ic h m ig h t h av e g iv e n rise to to p o g ra p h y d riv e n flo w o f o re flu id s (co m p . P e lisso n ie r, 1965, R ó ż k o w s k i e t al., 1979; C h u rc h &

V a u g h n , 1993), b u t e v id e n c e in th is re s p e c t is in c o n c lu siv e . A n a lte rn a tiv e to th e lo n g -d is ta n c e la te ra l flo w o f h y ­ d ro th e rm a l flu id s, is th e s h o rt-d is ta n c e flo w fro m so u rc e s lo ­ ca te d n e a rb y b e n e a th th e p re s e n t o c c u rre n c e s o f strata- b o u n d d e p o sits. W o d z ic k i (1 9 8 7 ) su g g e s te d a re a s o n a b le h y p o th e s is th a t th e o re s u n d e r c o n s id e ra tio n re s u lte d from e p is o d ic e x p u ls io n o f o re flu id s fro m C a rb o n ife ro u s stra ta d u rin g E a rly C im m e ria n o ro g e n y . T h e C o a l M e a s u re s are o c c a s io n a lly c u t b y o re v e in s , b u t th e s e v e in s m a y a lso be in te rp re te d as c h a n n e lw a y s o f o re flu id s d e riv e d fro m p re- C a rb o n ife ro u s ro c k s (e.g . K o s m a n n , 1883; R ru s c h , 1929).

A s is th e c a se w ith m a n y o th e r M V T d e p o sits, the

274

stra ta -b o u n d o res u n d e r c o n s id e ra tio n d o n o t re v e a l a n y d i­

re c t re la tio n sh ip to ig n e o u s ro c k s . M a n y a u th o rs, h o w e v e r, su g g e st a m a g m a tic o rig in o f th e s e o re s (e.g . K ru sc h , 1929;

H a ra ń c z y k , 1963, 1984; P a ły s , 1967; G a lk ie w ic z , 1971; K u ­ c h arsk i, 1996). T h ere is, in d e e d , a s trik in g sp a tia l c o e x is ­ te n c e b e tw e e n th e lo c a liz a tio n o f s tra ta -b o u n d o res in T ria s - sic c a rb o n a te s a n d th e a p p e a ra n c e o f ig n e o u s ro c k s in th e u n d e rly in g P a le o z o ic s tra ta (B e lk a & S ie w n ia k -M a d e j,

1996). It sh o u ld also b e b o m in m in d th a t th e K L lin e a m e n t (K L fra c tu re zo n e) w a s a s s o c ia te d w ith ig n e o u s in tru sio n s w h ic h m a te ria liz e d in th e fo rm a tio n o f a larg e b a th o lith (R u lsk i, 1973, K u c h a rsk i, 1996). W e d o n o t k n o w h o w lo n g it tak es fo r a large, d e e p -s e a te d b a th o lite to lo o se its last m a n ife sta tio n s o f th e th e r m a l a c tiv ity . P e rh a p s , th e tim e in ­ terv al b e tw e e n th e la s t m a n ife s ta tio n s o f ig n e o u s a c tiv ity in the P a le o z o ic a n d th e e m p la c e m e n t o f Z n -P b o re s in th e T ri- assic (c.a. 4 0 M y ) w as n o t lo n g e n o u g h to p re c lu d e a g e n e tic re la tio n sh ip b e tw e e n th e s e tw o ev en ts.

P rz e n io sło (1 9 7 4 ) is re a d y to a c c e p t su ch a p o ss ib ility . H e su g g e sts th a t th e V a ris c a n m a g m a tis m a n d th e e m p la c e ­ m e n t o f s tra ta -b o u n d o re s in th e T ria s sic h a v e a c o m m o n so u rce. A s a n a rg u m e n t in fa v o r o f th is c o n c lu s io n h e calls atten tio n to th e o p in io n o f F re n c h a u th o rs (S a rc ia et al., 1958) th a t in th e C e n tra l M a s s if, th e o re -fo rm in g h y d ro th e r­

m al a c tiv ity re la te d to la te P a le o z o ic in tru sio n s o f g ra n itic m a g m a m a y be tra c e d in T ria s s ic a n d L o w e r J u ra ssic strata.

A s k n o w n , th e h y d ro th e rm a l o re fo rm in g so lu tio n s m a y r e ­ m ain fo r a lo n g tim e in th e so c a lle d “ fo ssil w a te r re s e r­

v o irs” .

A s a c o lo ra ry o f m a g m a tic o rig in o f o re flu id s o r as an alte rn a tiv e e x p la n a tio n is th e g e n e ra tio n o f h e a t a n d th e s u b ­ se q u e n t re g e n e ra tio n o f L a te P a le o z o ic o re s as a c o n s e ­ q u e n c e o f g e o lo g ic e v o lu tio n o f th e E a r th ’s crust. T h e M V T d ep o sits te n d to o c c u r a t sp e c ific sta g e s o f su ch ev o lu tio n . T h e se stag es c o rre sp o n d to th e g lo b a l b re a k -u p o f p la te s a n d th e b e g in n in g o f n ew g e o s y n c lin e s in th e E a r th ’s h isto ry . Such tu rn in g p o in ts in th e e v o lu tio n o f th e E a r th ’s c ru s t are in v a ria b ly a ss o c ia te d w ith sig n ific a n t h e a t flo w . T h e e m ­ p la c e m e n t o f th e U p p e r S ile sia n s tra ta -b o u n d su lfid e ores o c c u re d in th e T ria s sic w h ic h re fle c ts th e P a n g e a n b re a k -u p fo llo w in g th e E a rly P e rm ia n a ss e m b ly o f P a n g e a (e.g.

T ra m p y , 1982; V e e v e rs, 19 8 9 ). It is th u s te m p tin g to in te r­

p re t th e o rig in o f th e U p p e r S ile sia n s tra ta -b o u n d su lfid e o re s in te rm s o f g lo b a l p la te re o rg a n iz a tio n (P rz e n io sło ,

1974; P a ły s , 1967; D ż u ły ń s k i & S a ss -G u s tk ie w ic z , 1985).

S u m m in g up, w ith th e p re s e n t state o f k n o w le d g e it is d iffic u lt to p ro v id e re lia b le e v id e n c e c o n c e rn in g th e so u rc e o f b ase m etals. T h e p o s s ib ility o f a lo n g d is ta n c e flu id flo w fro m u n k n o w n o r h y p o th e tic a l so u rc e b e d s c a n n o t b e d is ­ card ed . H o w e v e r, th e s o u rc e o f m e ta l-b e a rin g flu id s m ay w ell b e se a rc h e d in d e e p e r p a rts o f th e c ru st, b e lo w th e p r e ­ sen t T ria s sic d ep o sits. In a s p e c u la tiv e re c o n s tru c tio n o f the p ro c e s se s w h ic h re s u lte d in th e e m p la c e m e n t o f strata- b o u n d su lfid e o res w e a rriv e a t th e fo llo w in g te n ta tiv e fo r­

m a tio n m o d el. T h e p rim a ry m e ta l-b e a rin g flu id s w e re o rig i­

n ally r e la te d to th e L a te P a le o z o ic ig n e o u s a c tiv ity w h ic h g av e rise to th e p o ly m e ta llic o res. T h e se o re flu id s o r ores b ec a m e re m o b iliz e d b y h e a t flo w d u rin g th e late T ria s sic p la te -te c to n ic re o rg a n iz a tio n a n d re d e p o s ite d as stra ta - b o u n d d e p o sits in th e M u s c h e lk a lk h o st strata. D u rin g th e

L o w e r T e rtia ry , th e flo w o f h y d ro th e rm a l so lu tio n s w as r e ­ a c tiv a te d a n d re s u lte d in d e p o s itio n o f e c o n o m ic a lly u n im ­ p o rta n t, fa u lt-h o s te d s u lp h id e o re v e in s . T h is tim e , in d e e d , th e fa u ltin g w a s re la te d to fin a l th ru s tin g o f th e C a rp a th ia n n a p p e s. T h e h e a t g e n e ra te d b y fric tio n o f ro c k m a s se s a lo n g th e fa u lt su rfa c e s ris e d th e te m p e ra tu re o f g ro u n d w a te rs an d e n a b le d th e re m o b iliz a tio n o f e a rlie r su lfid e d e p o sits.

REFERENCES

A lexandrow icz, S., 1971. Relationship between Triassic formation and the Paleozoic basem ent betw een Klucze and Bydlin.

Rudy i Met. Nieżel., (In Polish), 16: 468-470.

A lthans, R., 1891. Die Erzform ation des M uschelkalk in Oberschlesien. Preuss. Ceol. Landesanst. Jahrb., 12: 37-98.

A ssmann, P., 1948. Zur Frage der Entstehung der oberschlesis- chen-polnisch Blei-Zink Erz Lagerstatten. Deutsch. Geol.

Ges. Z , 98: 30-69.

Balwierz, J. & Dżułyński, S., 1976. Experim ents on rock deform a­

tions produced by underground karst processes. Ann. Soc.

Geol. Polon., 46: 419—434.

Banaś, M., Clauer, N. & Środoń, J., 1996. Reconstruction o f the therm al history o f the U pper Silesian Coal Basin on the basis o f the illite/sm ectite dating from the pyroclastic layers. Pro­

ceedings o f Scientific Session on “Mineral and rock dating", University o f Maria Skiodowska-Curie, Lublin, Poland, (In Polish), p. 6-12.

Bednarek, J., Górecka, E. & Zapaśnik, T., 1983. Tectonically controlled developm ent o f ore mineralization in Jurassic se­

quence o f the Silesian-C racovian M onocline. (In Polish, Eng­

lish summary). Ann. Soc. Geol. Polon., 53: 43-62.

Belka, Z. & Siewniak-M adej, A., 1996. Therm al maturation o f the Low er Paleozoic strata in the southwestern margin o f the M ałopolska M assif, southern Poland: no evidence for Caledo­

nian regional m etamorphism . Geol. Rundsch., 85: 775-781.

Blajda, R., 1993. The geom etric-m athem atical model o f the zinc and lead ore deposits from the O lkusz region. Geol. Quart., 37: 175-188.

Bogacz, W. & Krokowski, J., 1981. Rotation o f the basem ent of the U pper Silesian Coal Basin. Ann. Soc. Geol. Polon., 51:

361-382.

Bogacz, K., Dżułyński, S. & H arańczyk, C., 1970. Ore-filled hydrotherm al karst features in the Triassic o f the U pper Sile­

sian region. Acta Geol. Polon., 20: 247-267.

Bogacz, K., Dżułyński, S., Harańczyk, C. & Sobczyński, P., 1972.

C ontact relations o f the ore-bearing dolom ite in the Triassic o f the C racow -Silesian region. Ann. Soc. Geol. Polon., 42:

347-372.

Bogacz, K , Dżułyński, S., H arańczyk, C. & Sobczyński, P., 1973a. Sphalerite ores reflecting the pattern o f prim ary strati­

fication in the C racow -Silesian region. Ann. Soc. Geol.

Polon. 43: 285-300.

Bogacz, K , Dżułyński, S, & Harańczyk, C. & Sobczyński, P., 1973b: Caves filled w ith clastic dolom ite and galena m inerali­

zation in disaggregated dolom ites. Ann. Soc. Geol. Polon., 43:

59-72.

Bogacz, K., Dżułyński, S. & Harańczyk, C. & Sobczyński, P., 1975. Origin o f the ore-bearing dolom ite in the Triassic o f the C racow -Silesian region. Ann. Soc. Geol. Polon., 45: 139—

155.

Borucki, J., 1978. Isotopic com position and absolute age. Prace Inst. Geol., 83: 229-235.

Bridgeman, P. W., 1952. Studies in Large Plastic Flow and Frac­

tures. M cGraw-Hill, N ew Y ork, pp. 362.