Palaeomagnetic Studies of Polish Rocks. II. The Upper Carboniferous and Lower Permian of the Sudetes

T o m ( V o l u m e ) X X X V I I I — 1968 Z e s z y t ( F a s c i c u l e ) 4 K r a k ó w 1968

K RZYSZTOF BIRK ENM AJER ł, ANDRZEJ G R O C H O L SK I2, JERZY M IL E W IC Z 3, A L A N E. M. N A IR N 4

STUDIA PALEOMAGNETYCZNE SKAŁ POLSKICH II. GÓRNY KARBON I DOLNY PER M SUDETÓW

(16 fig., 6 tab.)

Palaeomagnetic Studies of Polish Rocks

II. T he Upper Carboniferous and L o w er Perm ian of the Sudetes

(16 Figs., 6 tabs.)

STRESZCZENIE

O pracow anie zaw iera w yniki pom iarów k ie ru n k u n atu raln eg o m agne­

tyzm u szczątkowego w górnokarbońskich i dolnoperm skich skałach m ag­

m ow ych in tru z y jn y c h i w ylew nych oraz w przeobrażonych osadach tego w ieku, w y stępujących w depresjach śródsudeckiej i północnosudeckiej.

Stw ierdzono ponadto, że niektóre skały opisyw ane dotychczas pod nazw ą

„m elafirów ” są najpraw dopodobniej zm etasom atyzow anym i skałam i osa­

dowymi, n a co w sk azu ją re lik ty s tr u k tu r sedym entacyjnych.

*

* *

A b s t r a c t . The m ean directions of m agn etization d eterm ined from th e e x a ­ m ination of L ow er P erm ian volcan ics and U pper C arboniferous v o lca n ics and in tru sives from th e S u detic region of Poland (Lower Silesiia) w e r e 196 — 4 (virtu al pole p osition 175E43N) and 196 — 12 (174E 43N) resp ectively. D etailed descriptions- of th e sam plin g sites are g iv en and reasons adduced for considering the alteration of the C arboniferous ign eou s rocks to be of C arboniferous rath er th an of P erm ian age.

It w a s found that certain of th e rocks p revio u sly id en tified as „m elap h yres”

w ere m etasom atised sed im en ts on th e basis of retained sed im en ta ry structures. This h o w ev er w as not observed in som e cases w h ere th eir origin rem ain doubtful.

INTRODUCTION

The p rese n t p ap e r is a continuation of the palaeom agnetic stu d y o f Polish rocks begun in 1961, and extends th e su rv ey of P e rm ia n rocks from th e K raków area ( B i r k e n m a j e r a nd N a i r n , 1964) to th e

1 L aboratory of G eology, P olish A ca d em y of Sciences, K raków , ul. S en ack a 3»

2>3 G eological S u rvey of Poland, L ow er S ilesia n Branch, W rocław , ul. J a w o ­ row a 19— 21.

4 Case W estern R eserv e U niversity, D epartm ent of G eology, C leveland, Ohio.

— 436 ^—

S u d etic basin (Figure 1). In all, some 32 sites w ere visited (see F igures 2 and 3), and if this n u m b e r is sm all, th e m ajo r outcrops are nevertheless represented. The w ork com plem ents the p u re ly palaeom agnetic stu d y on th e P e rm ia n rocks in the Czech p a r t of th e S udetic basin (B u c h a et

Fig. 1. G łów n e elem en ty stru k tu raln e S u detów (budow ę geologiczn ą bloku p rzed - su d eck iego pom inięto). 1 — sk a ły archaiczne; 2 — sk a ły p rek a m b ry jsk ie i staro- paleozoiczne; 3 — s k a ły paleozoiczne; 4 — gran itoidy w aryscyjsikie; 5 — sk a ły m łod op aleozoiczn e ii m ezozoiczne; 6 — obszary pobrania prób; 7 — g łó w n e d y slo ­

k acje; I — blok g n ejso w y Gór Sowiich; II — blok K arkonoszy— Gór Izerskich;

III — kom pleks m eta m o rficzn y L ą d k a-Ś n ieżn ik a; IV — kom p lek s m etam orficzn y G ór B ystrzyck ich i Gór O rlickich; V — k om p lek s m etam orficzn y w sch o d n ich K ar­

konoszy; VI — kom p lek s m etam orficzn y kłodzki; VII — k a led on id y Gór K aczaw skich;

V III — struktura w schod n iosu d eck a; IX — struktura Barda; X — depresja Ś w ie ­ bodzic; X I — gra n ito id y K udow ej; X II — granitoidy K arkonoszy; X III — lintruzja k łod zk o-złotostock a; X IV — granitoidy Z ulovej; X V — depresja północnosudecka;

X V I —■ depresja śródsudecka

Fig. 1. M ain structural elem en ts o f th e Sudetes m ou n tain s (ex clu siv e of the geological stru ctu re in th e Fore-Sudetdc Block, NE o f th e S u detic B order Fault). 1 — A rchaean rocks; 2 — P re-C am b rian and older P alaeozoic rocks; 3 — P alaeozoic rocks; 4 — V ariscan granitoids; 5 — L ate P alaeozoic and M esozoic rocks; 6 — Sam pled areas;

7 — M ain d islocations; I — G neiss block of th e Góry S o w ie m ts.; II — K arkon o­

sze—G óry Izersk ie block; III — M etam orphic com p lex of L ądek—-Snieżnik; IV — M etam orphic co m p lex o f Góry B y strzyck ie and Góry O rlickie; V — M etam orphic co m p lex of E K arkonosze m ts.; VI — M etam orphic co m p lex of Kłodzko; V II — C aledonides o f th e Góry Kaczawskiie; VIII — E a st S u d etic region; IX — Bardo region; X — Ś w ieb o d zice depression; X I — G ranitoids of K udow a; X II — G ranitoids of K arkonosze; X III — K łodzko-Z łoty Stok intrusion; X IV — Z ulova granitoids;

X V — N orth S u detic D epression; X V I — In ner S u detic D ep ression

al., 1964). C ertain C arboniferous rocks are included, and a com parison of these m easurem ents to g e th er w ith resu lts from th e Czech p a r t of th e basin have been com pared w ith th e re su lts from rocks of th e sam e age on the Bohem ian M assif ( B i r k e n m a j e r , K r s , N a i r n , 1968).

The a u th o rs are deeply indebted to th e D irector of th e L ow er Silesian b ran ch of th e Geological Survey, D r L. S a w i c k i , for facilities read ily m ade available.

OUTLINE O F GEOLOGY

a) U p p e r C a r b o n i f e r o u s a n d L o w e r P e r m i a n o f t h e I n n e r S u d e t i c D e p r e s s i o n

The In n e r S udetic Depression (or Basin) has an elongated synclinal form. It is b o rd ered b y crystalline m assifs save o n ly in th e sou th -w est w h ere th e re is tectonic contact w ith the P e rm ia n to Mesozoic fill of the H ronov G raben. The so u th -ea st and n o rth -w e st m argins of th e D epres­

sion are form ed b y th e crystalline rocks of the G óry Orlickie, G óry B y­

strzyckie and Kłodzko massifs, and th e K arkonosze-G óry Izerskie m assifs respectively. The n o rth -e a st flank is form ed by the Caledonides of th e G óry Kacza wskie and th e gneiss of th e Góry Sowie m o u n tain s (Figs. 1, 2).

The In n e r S udetic Depression is a V ariscan stru c tu re , accentuated b y bordering fau lts w hich generally p arallel th e Elbe line and w hich w ere re ac tiv a ted in y o u n g er geological tim es. T e rtia ry orogenic m ove­

m ents resu lted in a d o m in an tly Saxonian type tectonic stru c tu re .

Since th e Visean, an d possibly even w ith in th e T ournaisian, th e De­

pression w as an area of deposition in w hich accum ulated locally derived, p red o m in a n tly fre sh -w a te r sedim ents, th ro u g h o u t th e U p p er C arbonifero­

us to P e rm ia n in to L ow er Triassic (Bunter) times. The youngest sedim ents found, excluding Q u a te rn a ry and some problem atic (?T ertiary) deposits, a re m arine U pper C retaceous beds. The In n er S udetic Basin w as in itiated as a re su lt of la te B retonie m ovem ents, and according to th e conclusions of recent studies (cf. D z i e d z i c , 1966; A u g u s t y n i a k a nd G r o ­ c h o l s k i , 1967), was not influenced b y m ovem ents of th e S udetic Phase.

The Erzgebirge and A stu ric phases w ere im p o rta n t and re p ea ted e a rth m ovem ents assigned to th e la tte r occurred a t in terv als fro m W estphalian B tim es th ro u g h th e S tephanian. F u r th e r distinctive m ovem ents d uring th e L ow er P e rm ia n (Rotliegende) are assigned to th e S aalic Phase.

The m ore im p o rta n t stages in th e tectonic h isto ry of th e basin w ere accom panied by volcanic activity, th e earliest b u t n o t v e ry m ark ed a c tiv ity occurred in L ow er C arboniferous: T ournaisian-V isean (A. K.

T e i s s e y r e , 1966). Im p o rta n t volcanism accom panied th e A stu ric mo­

vem ents, b u t th e g reatest volcanic activ ity occurred in th e Middle R ot­

liegende. i

The tectonic in stab ility of th e area is reflected in th e ch a ra cte r of the deposits, m ost form ations begin w ith a coarse often conglom eratic u n it and th e re is m a rk ed lithological v a ria tio n b o th la te ra lly and vertically.

T here are in consequence m any difficulties in stra tig ra p h ic correlation.

Table 1 p resen ts th e c u rre n tly accepted correlation for th e P olish and Czech p a rts of th e basin ( A u g u s t y n i a k , G r o c h o l s k i , 1967; H o- l u b , 1961; T a s l e r , 1966) com pared against th e older established suc­

cessions found in B r i n k m a n n (1954) and D o r n (1966).

— 4 3 8 —

T a b l e 1 S tratigraphic colum n of the U pper C arboniferous and L o w er P erm ian deposits in th e Inner S u detic D epression after A u g u s t y n i a k and G r o c h o l s k i (1967) and T a s l e r (1966). The older colum ns of B r i n k m a n n (1954) and D o r n

(1966) are g iv en for com parison 1966 Brinktnann I95*< P O L I S H ( N E ) PART

A u g u s t y n i a k , G r o c h o ls k i l%7

CZECH f JW) PART

Tatler 1^66 Saxonian

( F a n q lo c n C r a t e s

iii^r. .la i of Radkrfw

!lCHcle I and Mieroszów Trutnov rm. U.

-- 4)

TJ_c

01O'

!! Cycle

Autunian L.Rolliegende L. Rotlipgende

I

V o lc a n ic comp

" B u i l d i n g " Ss.

Broumov Fm.

I Cycle

r

C o n g lo m e r a t e s

/■u i ' f BetWov Mb.

Chvalec J - ---- . Fra. ) Vernerovice

\ Mb.

Ho C division

given

Stephanian ft Radowenz Beds

Radowenz beds Wexenstein Beds Hexenstein

ArUose

’L. Anłhracosia Sh Ludwi-7--- Wowice i 5andstone Fm s

Conglomerate

hiatos

Odolov Fm. ⁾

Jfvka

^Mb.

Radvanice Coals Zaltman ArUose

Idastall Beds Idastall Beds I SvatoKovice

M b.

Z. Nejedly Coals

Schadowitz Beds GliniW Fm.

■Schadowtz Reds ^{2 hiatus}

W estphalian

Zdiarek Beds Schatzlar Beds

Schatz I ar Beds Z a c i e r

Fm

( V o l c a n i c

-{activity

U p p e r M b .

Zacier } Middle Mb.

Fm. Lowe* Mb Weisstein Beds

Namunan B Waldenburg Beds

Weisstem Beds

h ia t u s

Biat'y

k a m i e ń Fm .

h i a t u s

Waldenburg Beds

W a t b r t y c h Fm

N o w a R u d a

Fm

BiaVy Kamień Fm.

hiatus

The U pper Carboniferous stratig rap h ic schemes are based on m acro­

floras, supplem ented by inform ation from the m icroflora. The low est u n it the W ałbrzych Form ation, up to 325 m thick, is developed in tw o local basins (the W ałbrzych and Wolibórz basins). The basal p art, m ainly silt- stones and claystones, represents a g rad u al tran sitio n from th e u n d e r­

lying Visean beds. H igher in the sequence a q u artz conglom erate horizon occurs w hich pass upw ards into siltstones and claystones w ith num erous coal seams. The conglom erate is th e base of a new sedim en tary cycle which, according to D z i e d z i c (1966), is rela ted to clim atic change.

The age of th e W ałbrzych F orm ation is N am u rian A.

The Biały K am ień Form ation, rep resen ted b y coarse clastics, is tra n s ­ gressive, and separated from th e W ałbrzych F orm ation b y a local uncon­

form ity. The fo rm ation is best developed in th e n o rth e rn p a rt of the Inner Sudetic Depression, w here it reaches a m ax im u m thickness of 350 m. In the so u th -eastern p a rt of the Depression, th e Biały K am ień

\WAŁBRZyci]\^_iQ

Lubawka

\S,WięrJ(,

V b ^ \\V\/2\

Ś cinaw ka

y ✓ ✓ /■"’V

F ig . 2. S z k ic g e o lo g ic z n y p o ls k ie j częśai d e p r e s j i ś r ó d s u d e c k ie j . 1 — g n e j s y G ó r S o w ic h , p r e k a m b r ; l a — m y l o n it y i k a t a k l a z y t y ; 2 — k o m p l e k s m e ta m o r f i c z n y w s c h o d n ic h K a r k o n o s z y ; 3 — k o m p l e k s m e t a m o r f i c z n y k ło d z k i; 4 — g a b r a i d i a b a z y w a ł u k ło d z k ie g o ; 5 — o s a d y p a le o z o ic z n e s t r u k t u r y b a r d z k i e j ; 6 — o s a d y g ó r n o d e w o ń s k i e i d o ln o k a r b o ń s k i e d e p r e s j i Ś w ie b o d z ic ; 7 — g r a n i to i d y K a r k o n o s z y i K u d o w y ; 8 — o s a d y d o ln o k a r b o ń s k i e ; 9 — o s a d y g ó r n o k a r b o ń s k i e , 10 — m ło d o p a le o z o ic z n e s k a ł y w u l k a n i c z n e n i e o k r e ś lo n e g o b liż e j w i e k u ( k a r b o n lu b d o ln y p e r m ) ; 11 —• s k a ł y w u l k a ­ n ic z n e g ó r n o k a r b o ń s k i e (g łó w n ie p o rf iry ) ; 12 — o sa d y d o ln o p e r m s k ie (c z e r w o n y sp ąg o w iec); 13 — s k a ł y w u l k a n i c z n e d o ln o p e r m s k ie ( m e la f ir y , p o r f ir y , tu f y it d .) ; 14 — o sa d y g ó r n o p e r m s k i e (cech szty n ): 15 —• o sa d y m e z o z o ic z n e (tria s i k r e d a ) ; 16 — u s k o k i s t w i e r d z o n e i p r z y p u s z c z a ln e ; 18 — m i e j s c a p o b r a n i a p r ó b (liczby j a k w ta b . 5). S k a ł y k e n o z o ic z n e

p o m i n ię t o

Fig. 2. G e o lo g ic a l s k e t c h m a p of t h e P o li s h p a r t of t h e I n n e r S u d e ti c D e p re ssio n . 1 — G n e is s e s of t h e G ó r y Sow ie, P r e - C a m b r i a n ; l a — M y lo n ite s a n d c a t a c la s i te s ; 2 — M e t a m o r p h i c c o m p le x of t h e e a s t e r n K a r k o n o s z e m ts .; 3 — M e t a ­ m o r p h ic c o m p le x of K ło d zk o ; 4 — G a b b r o s a n d d ia b a s e s of t h e K ło d z k o R id g e ; 5 — P a la e o z o ic s e d i m e n t s of t h e B a r d o r e g io n ; 6 — U p p e r D e v o n ia n a n d L o w e r C a r b o n i f e r o u s s e d i m e n t s of t h e Ś w ie b o d z ic e D e p re s s io n ; 7 — G r a n i t o i d s of K a r k o n o s z e a n d K u d o w a ; 8 — L o w e r C a r b o n i f e r o u s s e d i m e n t s ; 9 — U p p e r C a r b o n i f e r o u s s e d i m e n t s ; 10 — L a t e P a la e o z o ic v o lc a n it e s of u n k n o w n ag e ( C a r b o n i f e r o u s or L o w e r P e r m i a n ) ; 11 — U p p e r C a r b o n i f e r o u s v o lc a n it e s ( m a in l y p o r p h y r ie s ) ; 12 — L o w e r P e r m i a n (R o tlie g e n d e ) s e d i m e n t s ; 13 L o w e r P e r m i a n v o lc a n it e s (m e la p h y r e s , p o r p h y r i e s , t u f f s etc.); 14 — U p p e r P e r m i a n (Z e c h s te in ) s e d i m e n t s ; 15 — M esozoic (T ria s s ic a n d C re ta c e o u s ) s e d i m e n t s ; 16 — F a u l t s r e c o g n i z e d a n d s u p p o s e d ; 17 — G e o lo g ic a l b o u a n d a r i e s re c o g n iz e d a n d su p p o s e d ; 18 — S a m p l i n g lo c a li tie s (s ite n u m b e r s r e f e r

to Tab. 5). Post-Mesozoic rocks not m arked

— 439 —

F o rm atio n in its type developm ent is lacking, b u t some a u th o rs reg a rd as its equivalent the N ow a R uda F orm ation, a sequence of sed im en tary breccias and regoliths, passing u pw ards into kaolinitic shales and siderite- -bearin g siltstones. According to D z i e d z i c (1966), deposition of th e N ow a R uda F orm ation beg an in th e Low er C arboniferous. A N am u ria n C to low er W estphalian A age is generally accepted for th e B iały K am ień Form ation.

The B iały K am ień F o rm a tio n g ra d u a lly passes u p w ard s to th e Zacier Form ation. In n o rth -e a ste rn p a rt of th e Depression the age of th e Żacler F orm ation (up to 900 m thick) is reg ard ed as W estphalian A and B, w hile in the so u th -w estern p a r t of th e D epression it also includes W estphalian C.

The low er p a r t of th e form ation consists m ainly of sandstones and silt­

stones w ith coal seams. In the u pper p a r t of th e form ation sandstones and conglom erates dom inate.

On th e n o rth -e a ste rn flank of th e In n e r S udetic D epression th e Glinik F orm ation, 100— 600 m thick, fo rm e rly know n as th e „O ttw eiler Schich- te n ” , is transgressive over th e Żacler, and locally over th e W ałbrzych F orm ation. It has a W estphalian C — Low er S tep h an ian age ( G r o c h o l ­ s k i , 1965) and w ith a succession of conglom erates and sandstones alte rn a tin g w ith red siltstones is lithologically distinct from th e u n d e r­

lying Żacler F orm ation.

T hree sed im en tary cycles can be recognized in th e W estphalian beds corresponding ro u g h ly to th e W estphalian A, B, and C. The m iddle (W estphalian B) and u p p e r (W estphalian C) cycles begin w ith conglo­

m erates, th e la tte r being p a rtic u la rly w ell developed over th e w hole of th e In n er S udetic Depression. Volcanic m a terial is p rese n t in the m iddle and u p p er cycles in th e so u th -w estern (Czech) p a r t of th e basin, b u t only in th e u p p er cycle (Glinik Form ation) in th e P olish p a r t of the Depression. The m ax im u m volcanic activ ity occurred in W estphalian C ( H o l u b , 1961).

The Glinik F o rm a tio n is overlain by conglom erates passing u pw ards into sandstones, w hich in tu r n give w ay to siltstones and claystones, fo rm e rly know n as th e „ first se d im en tary cycle of th e R otliegende” . The argillaceous horizon, k now n as th e „1st A nthracosia shale horizon” , contains spore assem blages typical for th e S tephanian, as w ell fre sh - -w a te r pelecypod Anthraconaia prolifera (Wat.) of th e sam e age (T. G ó- r e c k a and K. A u g u s t y n i a k , pers. comm.). This form ation, younger th a n th e G linik F o rm atio n and older th a n the Rotliegende proper, has been ren am ed th e Ludw ikow ice F orm ation ( A u g u s t y n i a k , G r o ­ c h o l s k i , 1967).

In th e so u th e rn p a r t of th e In n er S udetic Depression a b re a k in deposition is recognized a t th e b o u n d ary of W estphalian C and D. The S tep h a n ian is rep rese n ted by th e Odolov F orm ation, w hich is subdivided into the low er Svatohovice M em ber, an d th e u p p er Jiv k a M em ber. B oth m em bers begin w ith coarse sandstones, occasionally even conglom erates, a n d differ from th e u n d erly in g Żacler Form ation. These differences have been a ttrib u te d to clim atic change and to th e appearance of new sources of clastic m a terial as th e re su lt of A sturic m ovem ents, alth o u g h tectonic in stab ility alone seems an. adequate cause.

The Svatonovice M em ber rep rese n ts th e W estphalian D and Low er S tephanian, on th e basis of palaeobotanic studies of th e coals from Z. N ejedly pit. The R advanice coals of th e Jiv k a M em ber are com pared

on floral grounds w ith the K ounov coals of C entral Bohemia, and re p re s­

e n t th e S te p h a n ia n B and p a r t of S tep h a n ian C. A sed im en tary b re a k w ith erosion of th e top p a r t of th e Jiv k a M em ber has been recognized in th e u pperm ost p a r t of th e S tep h a n ian (T a s l e r , 1966).

The Rotliegende of th e P olish p a r t of the I n tra S udetic Depression is up to 1,800 m thick and shows th e characteristics of cyclic molasse sedim entation ( D z i e d z i c , 1961). It is sep arated b y an u nconform ity from th e u n d erly in g C arboniferous. The se d im en tary cycles u su a lly s ta r t w ith conglom erates (fanglom erates) and grade u p w ard s into sandstones and shales. T h ree cycles have been recognized, and assigned to th e Lower, Middle, and U pper Rotliegende respectively. A complex of effusive acid and basic volcanics ap p ear a t th e close of th e second cycle ( D z i e d z i c , 1961; K o z ł o w s k i , 1963). P rio r to th e recognition of the Ludw iko wice F orm ation, this w as reg ard ed as th e th ir d cycle.

Two stra tig ra p h ic m em bers, both startin g w ith conglom erates an d grading upw ard s into fin er deposits w ith lim estone horizons are recogniz­

ed in th e Czech p a r t of th e In n er Sudetic Depression. The low er V erne- rovice M em ber contains a th in coal seam w ith „Walchia”. The u pper Beckov M em ber contains a lim estone horizon n ea r th e top. B oth m em bers belong to th e L ow er Rotliegende. The M iddle Rotliegende is rep resen ted b y th e B roum ov Forma|tion w hich contains tu ffs a n d lav a sheets of p o rp h y ry and m elaphyre. The T ru tn o v F orm ation rep rese n ts th e U pper Rotliegendes. In th e Polish p a r t of the Depression its equivalents are th e fanglom erates of Radków and Mieroszów.

b) U p p e r C a r b o n i f e r o u s a n d L o w e r P e r m i a n o f t h e N o r t h S u d e t i c D e p r e s s i o n

The sedim ents in th e N o rth S udetic Depression rest on a su b stra tu m of epim etam orphic schists of th e G óry K aczaw skie m ountains, W est S udetes (Figures 1, 3). The borders of th e D epression are m ain ly tectonic, and its prolongation to the n o rth w est is concealed u n d er Cenozoic sedim ents. The old er form ations of th e D epression are U pper C arboni­

ferous (S part) and Rotliegende (N part), th e y o unger form ations being rep rese n ted b y th e Zechstein, th e B unter, th e M uschelkalk and U pper C retaceous deposits.

The U pper C arboniferous deposits are poorly k now n from scanty outcrops and fro m boreholes. The W estphalian B, m ore th a n 100 m thick, recognized only in boreholes in an area close to th e P olish-G erm an fro n ­ tiers (Nysa Ł użycka river), is rep rese n ted by siltstones w ith sandstone and conglom erate intercalations and b y p o rp h y ry lavas and tuffs ( H i r s c h m a n n , 1959). The lack of th e W estphalian C deposits is a p p a re n tly th e re s u lt of A sturic uplift. The W estphalian D and S tep h an ian sequence, up to 300 m thick ( M i l e w i c z , G ó r e c k a , 1965), sta rts w ith regolithic breccias overlain by alte rn a tin g conglom erates, arkosic sandstones, and generally b ro w n -red and g rey siltstones and claystones ( M i l e w i c z , 1967). F our sed im en tary cycles have been recognized here, and these can be correlated w ith th e cycles found in th e C en tral Bohe­

m ian U pper Carboniferous. P o rp h y ry sills pro b ab ly S te p h a n ia n in age occur in the deposits of th e u p p er cycle.

The P e rm ia n is rep resen ted by continental deposits of th e R otlie­

gende and b y th e p red o m in a n tly m arine Zechstein. The Rotliegende deposits are especially well know n in th e e a ste rn p a r t of th e Depression.

— 4411 —

H ere th re e sed im en tary cycles m ay be recognized ( M i l e w i c z , 1966) in a succession 500— 1000 m thick. The firs t cycle, of 170— 340 m, consists m a in ly of fine sandstones and siltstones, coarser beds being in fre q u e n t and thin. The second cycle, 200— 400 m thick, is lithologically m ore variable: w ith sandstones dom inating over siltstones, and w ith conglo­

m e ra tes in fre q u en t in th e low er p a r t of th e cycle, b u t m ore com m on in its u p p er p art. The e ru p tiv e com plex a ttrib u te d to th e second cycle is re p rese n ted by porphyries and p o rp h y ry tu ffs in th e ea ste rn p a r t of th e D epression and b y m elaphyres and m elap h y re tu ffs in th e central p a r t of the Depression. A b re a k in sedim entation and erosion of th e u n d erly in g deposits is recognized a t th e base of th e th ird cycle, th e re su lt of th e S aalic uplift. The th ird cycle, 200— 500 m thick, consists alm ost en tirely of fine conglom erates (fanglom erates), grading upw ard s into coarse san d ­ stones.

LOWER PE R M IA N VOLCANIC A N D SEDIM ENTARY ROCKS OF THE NORTH SUDETIC D EPR ESSIO N

D e s c r i p t i o n o f L o c a l i t i e s P ł ó c z k i G ó r n e

(Fig. 4a, Tab. 5: S ites 1— 3)

T hree m elap h y re la v a flows are exposed a t Płóczki G órne in th e W leń G raben. The low er p a r t of th e la v a flows consists of basal breccia 1— 3 m in thickness. I t is m ade up of frag m en ts and blocks of vesicular and am yg- daloidal red m elaphyre, and of re d sandstone blocks u p to 1 m in diam eter.

The m ain lava flow above th e breccia is 15— 18 m th ic k and consists of red-brow n, massive, tra n s v e rs a lly jointed m elaphyre in th e low er p a rt, and vesicular and am ygdaloidal m elap h y re in th e u p p er 3— 5 m.

Below th e firs t flow th e re occur re d sandstones and q u a rtz conglo­

m e ra tes of th e Rotliegende, dipping 95° NNE 30°. The dip of th e la v a flow s is conform able w ith th e dip of th e underly in g sedim ents.

The oriented sam ples w ere collected from th e m assive m elap h y re of the firs t and second flows and from th e vesicular region in th e u pper p a r t of the th ird flow.

P ł a w n a G ó r n a

(Fig. 4b, Tab. ,5: S ites 4, 5)

The exposures a t P ła w n a Górna also belong to th e W leń G raben. In a railro ad cu ttin g th re e m elap h y re flows dipping ENE are displaced by a fault. The first flow is poorly exposed w ith only its u p p e r p a r t access­

ible. In appearance i t is a violet-red m assive m elap h y re passing u pw ards in to am ygdaloidal m elaphyre. The second flow, about 27 m thick, dips a b o u t 45° to w ard s the ENE. I t has a basal breccia about 10 m th ick in w hich are blocks of vio let-red vesicular and am ygdaloidal m elaphyre, 0.1— 1.5 m in diam eter, as w ell as frag m en ts of b rick -re d sandstones and q u a rtz pebbles, 2—5 cm in diam eter. Upon this rests m assive vio let-red m elaphyre. It is trav e rse d b y joints, b o th p arallel and tra n sv e rse to th e basal plane, as well as b y calcite veins. The top p a r t of the flow, 4 m thick, to th e NE of th e fault, dips 170° ENE 30°. It has a sim ilar colour a n d is vesicular and am ygdaloidal. The th ird la v a flow m ore th a n 26 m th ick , again h as a basal breccia, 0.5— 2 m thick, consisting of frag m en ts of violet-red am ygdaloidal m elaphyre blocks, 0.3— 1 m in diam eter, above

— 4 4 3 —

w hich th e re is some 17 m of massive m elaphyre, sim ilar in colour to the b o tto m breccia, w ith th e rm a l joints parallel and tran sv e rse to th e flow bottom . The top 7 m of th e flow is vesicular and am ygdaloidal m elaphyre.

O riented sam ples w ere collected from the massive zone in the second a n d th ird flows.

P ł a w n a Ś r e d n i a

(Fig. 4c, Tab. 5: S ite 6)

The exposures at P ła w n a Średnia lie in th e Lwówek G raben. Two m e lap h y re lava flows are recognized in an outcrop at the rig h t b an k of th e S re b rn a riv er, NE of th e church. The firs t flow is rep rese n ted by th e u p p er 2 m of a green m elaphyre. The second flow has a basal breccia 4— 5 m thick, consisting of blocks 0.1— 1 m in d iam eter of vesicular and am ygdaloidal m elaphyre, violet, vio let-red in colour, and of re d sand­

stone blocks 5— 10 cm in diam eter. The m assive violet-red, brow n, or green m elap h y re of w hich 10 m is exposed, dips 130° SW 30°. It shows brec- ciation and jasper-like veins in th e low er p art, and is m ore m assive in th e u p p er p art.

The sam ples for palaeom agnetic m easurem ents w ere ta k e n from the m assive zone of th e second lava flow.

P ł a w n a D o l n a - I

(Fig. 4d)

N ear a ra ilw a y cutting, W of point 301 m, two m elap h y re lava flows crop out. Of th e low er flow only th e u p p er 2— 3 m is exposed. It is com­

posed of w eath ered m assive violet-red m elaphyre, w hich passes into vesicular and am ygdaloidal m elaphyre. The second flow has a 3— 5 m basal breccia consisting of vesicular and am ygdaloidal m elap h y re blocks passing up into m assive w eath ered m elap h y re of w hich 10 m is exposed.

T he lava flows lie in a syncline, as indicated b y opposite dips of the contact surface of the flows: 80° SSE 8° in th e n o rth ern , and 60° NW 10°

in the southern p a r t of th e outcrop.

Sam ples w ere collected from th e u p p er p a rt of the firs t flow. The resu lts are om itted from Table 5 because of th e exceedingly scattered n a tu re of th e results. This m ay be an effect of strong w eathering.

^---- --- Fig. 3. Struktura geologiczna Gór K aczaw skich (depresja północnosudecka). 1 — osa­

dy k red ow e i triasow e; 2 — osady górnoperm skie (cechsztyńskie); 3 — o sad y d oln o- p erm sk ie (czerw ony sp ą g o w iec); 4 — sk ały w u lk a n iczn e d oln op erm sk ie (stanow iska 1— 11) i górnokarbońskie ? (stanow isko 16); 5 — osady górnokarbońskie (w estfa l D -stefa n ); 6 — osady dolnokarbońskie (w depresji śródsudeckiej); 7 — w a ry scy jsk i granit K arkonoszy; 8 — kom pleks m etam orficzn y Gór K aczaw sk ich (starszy p a- leozoik-prekam br); 9 — kom p lek s m etam orficzn y Gór Izerskich (prekambr); 10 — g łó w n e dyslokacje; 11 — m iejsca pobrania prób (liczby jak w tab. 5) S k ały k en o-

zoiczne pom inięto

Fig. 3. G eological structure o f the Góry K aczaw sk ie (North S u detic D epression).

I — C retaceous and T riassic sedim ents; 2 — U pper Perm ian (Zechstein) sed im en ts;

3 — L ow er P erm ian (R otliegende) sed im en ts; 4 — L ow er P erm ian (Sites 1— 11) and ?Upper Carboniferous (Site 16) v olcan ic rocks; 5 — U pper C arboniferous (W estphalian D — Stephanian) sedim ents; 6 — L ow er C arboniferous sed im en ts (Inner S u detic D epression); 7 — V ariscan g ran ite of K arkonosze; 8 — M etam orphic co m p lex of th e Góry K a cza w sk ie (older P alaeozoic — Pre-C am brian); 9 — Meita- m orphic com p lex of th e Góry Izersk ie (Pre-Cam brian); 10 — M ain dislocations;

II — Sam p lin g lo ca lities (site num bers correspond to Tab. 5). P ost-M esozoic rocks n ot m arked

NNE

SSW

ПХПЯ

2 ^ 3 /

5 ^ 6

— 445 — P ł a w n a D o l n a - I I

(Tab. 5: S ite 7)

In an outcrop n ea r th e railw a y statio n at P ła w n a D olna th e re occur rocks reg ard ed by M i l e w i c z (1965) as belonging to th e „ th ird m ela­

p h y re com plex” of th e Rotliegende. We found here fin e-g rain ed sa n d ­ stones w ith mica, in d u ra te d by iron oxides, som etim es form ing a hard , m assive rock, superficially resem bling m elaphyre. It seems probable th a t ferric oxide solutions t h a t in d u ra te d th e sandstone w ere re la te d to post- -m agm atic solutions. The altered sandstones dip 90° N 15°.

B etw een M a r c z ó w and Z a d o 1 e east of P ła w n a Dolna th e sam e „th ird m elap h y re com plex” of Milewicz is poorly exposed and rep rese n ted by fin e-g rain ed sandstones of sim ilar ty p e as those a t P ła w ­ na D olna-II. No sam ples w ere ta k en for palaeom agnetic m easurem ents.

S im ilar rocks crop out also at G o r c z y c a , on th e rig h t b an k of the Bóbr riv e r in th e e a ste rn p a r t of th e Lw ów ek G raben. The sam ples ta k en fro m grey or v arieg ated h a rd siltstones dipping 20° W NW 30° gave ne­

gative results.

B e ł c z y n a

(Fig. 5a, Tab. 5: (Site /8)

Two m elaphyre lav a flows are exposed in a road cu ttin g betw een Bełczyna and Wleń, W of Bełczyna. The low er flow has th e u su a l basal breccia, 0.5— 1.5 m in thickness, succeeded by about 9— 10 m of massive, th en vesicular and am ygdaloidal m e lap h y re in succession. The second flow is rep rese n ted b y a 1 m basal breccia only.

The su b stra tu m of th e first flow is rep rese n ted b y hard , cleaved sandstones, red and v io let-red dipping 90° N 45°, resem bling those of P ła w n a D olna-II. The la v a flows are tilte d in th e sam e direction as the sandstones.

The sam ples w ere collected from th e firs t flow, from b o th th e lower, m assive m elap h y re zone an d the u p p er vesicular p art.

S o k o ł o w i e c

(Fig. 5b, Tab. 5: S ite 9)

The exposure in an old q u a rry face 8— 10 m high exposes rocks of the Rotliegende. H ard, g re y or greenish fine-grained sandstones appear in th e low er p a r t of th e exposure. T hey are irre g u la rly jointed, and show traces of large-scale cross bedding. The sandstones contain some m ica and carbonized p la n t d etritu s, and sm all bioglyphs m a y be encountered on bed surfaces. The dip of the rocks is 20° WNW 10°. In th e u p p e r p a r t of th e exposure the sandstones are h a rd e r still, th e y are bluish, w ea­

th e rin g to yellow ish colour. Bedding disappears and a v ertic al joint

<--- Fig. 4. S ch em atyczn e p ro file geologiczn e o d sło n ięć dolnoperm skich la w m ela firo - w y ch w d epresji p ółnocnosudeckiej (skala przybliżona): a — P łóczk i Górne; b — P ła w n a Górna; c — Pławina Średnia; d — P ła w n a D olna I; 1 — m e la fir gąbczasty i m igd ałow cow y; 12 — m e la fir m a sy w n y ; 3 — brekcja spągow a; 4 — p ia sk o w ce i zle­

pień ce (czerw ony spągow iec); 5 — m ela fir zb rek cjow an y tektonicznie; 6 — uskok Fig. 4. S ch em atic g eo lo g ica l section s o f th e L o w er P erm ian (R otliegende) m elap h yre la v a flo w s of th e N orth S u d etic D epression (scale approxim ate): a — P łóczki Górne;

b — P ła w n a Górna; c — P ła w n a Średnia; d — P ła w n a D olna I; 1 — V esicu lar and am ygd aloid al m elaphyre; 2 — M a ssiv e m elap h yre; 3 — B ottom breccia; 4 — S an d ­ stones and conglom erates (Rotliegende); 5 — T ecto n ica lly b recciated m elap h yre;

6 — F au lt

system is developed w hich resem bles th a t of th e m elap h y re lava flows.

It seems possible th a t the sandstone m ay have form ed th e su b stra tu m of the m elap h y re lav a flow exposed n ea rb y (see R aw ka m ount), and was altered by ferruginous solutions connected w ith volcanic activity.

The sam ples for palaeom agnetic w ork w ere ta k en from th e u p p er p a r t of th e exposure.

W

o _mJ^{5 m}

C ^{20 m}

Pig. 5. S ch em atyczn e profile g eologiczn e odsłonięć dolnoperm skich la w m ela firo - w y ch , zm ienion ych o sa d ó w i w y lew n eg o porfiru w depresji p ółnocnosudeckiej (skala przybliżona): a — B ełczyn a; b — S ok ołow iec; c — góra R a w k a (Rząśnik); d — W ie- lisła w Z łotoryjski (porfir); e — W ielisła w Z łotoryjski, struktury flu id a ln e w por­

firze. (O bjaśnienia oznaczeń do fig. 5 a— c — jak n a fig. 4)

Fig. 5. S ch em atic geo lo g ica l sections of th e L ow er P erm ian (R otliegende) m elap h yre la v a flow s, altered sed im en ts and e ffu s iv e porphyry of th e N orth S u detic D epression (scale approxim ate): a — B ełczyna; b — S ok ołow iec; c — R aw k a m t. (Rząśnik);

d — W ielisła w Z łotoryjsk i (porphyry); e — W ielisła w Z łotoryjski, d etail of flo w structures in th e porphyry. (For ex p la n a tio n s to Figs. 5 a— c — see Fig. 4)

R a w k a M o u n t ( R z ą ś n i k )

(Fig. 5c, Tab. 5: S ite 10)

A t R aw ka m ount (427 m), n ea r Rząśnik village, sam ples w ere collected from green am ygdaloidal and vesicular m elaphyre exposed in th e old, w estern, q u a rry . In th e old, eastern, q u a rry th e contact zone of m ela­

p h y re flow and the underly in g Rotliegende sedim ents (Fig. 5c) is exposed.

The sandstone is of the sam e type as th a t a t Sokołowiec, i. e., altered black or bluish sandstone, dipping 70° NW 20°. The lava flow only locally begins w ith a basal breccia (up to 2 m thick), and th e m ain body is rep resen ted by massive reddish or greenish m elaphyre. W hen the m assive m elaphyre comes d irectly into contact w ith th e underlying san d ­ stone, it becomes vesicular.

W i e l i s ł a w Z ł o t o r y j s k i

(Figs. 5d, e, Tab. 5: S ite 11)

In a big old q u a r r y situated at th e rig h t bank of th e K aczaw a riv e r close to W ielisław Złotoryjski, an extrusive p o rp h y ry has colum nar jointing arran g ed in a fan-like form , norm al to the surfaces of successive

— 4 4 7 —

lav a flows. T hin zones of vesicular p o rphyry, som etim es only 5— 20 cm thick, are p re se n t in th e top p a rts of th e individual lav a flows, an d fine fluidal lav a folds are visible (Fig. 5e). The o v e rtu rn of th e folds indicates th e direction of lava m otion tow ards th e N or NNW (azim uths 345°, 330°, 320°, 0°). Occasionally la rg e r flow stru c tu re s appear, w ith fold am plitudes up to 0.5— 1 m.

O riented sam ples w ere collected in th e central, and low er p a r t of th e q u arry .

R e m a r k s

The m elap h y re la v a flows belong to a single effusive complex. This is consistent w ith th e palaeom agnetic m easurem ents (Tab. 5). Locally th e y m ay split into subordinate complexes sep arated b y clastic sedim ents as show n b y M i l e w i c z (1965, Fig. 1). The m ax im u m n u m b e r of lava flows a t a single outcrop nev er exceeds th ree. The flows v a r y in thickness from 11 to 27 m, w ith th e low est lava flows u su ally th in n e r th a n th e u p p er ones. N early all th e lava flows have a basal breccia m ade up of vesicular and am ygdaloidal m elap h y re blocks often w ith an a d m ix tu re of Rotliegende sandstone fragm ents. The hig h er p a r t of th e flows u sually consist of m assive colum nar jointed m elaphyre, w ith th e joints m ostly

T a b l e 2 D and I v a lu es for th e L ow er P erm ian m ela p h y re and porp h yry la v a s

and altered sed im en ts of the N orth S u d etic D ep ression (cf. Tab. 5)

S ite No. D I

P łóczki 1 F lo w 1 196 - 1 8

Górne 2 F lo w 2 196 - 1 4

3 F lo w 3 206 - 7

V

P ław n a (1 Flow ) — — —

Górna 2 F lo w 4 193 - 3 6

3 F lo w 5 200 — 29

P ła w n a (1 F low ) — — —

Średnia 2 F lo w 6 196 - 2 5

B ełczyn a 1 F lo w 8 214 - 6

(2 Flow ) — — —

Mt. R aw k a 1 F lo w 10 200 + 4

Pław n a

D oln a-II sed im en t 7 180 + 10

S ok ołow iec sed im en t 9 199 + 0.5

W ielisław Z łotoryj ski

porphyry 11 200 + 2 8

4 Rocznik P T G t. XXXVIII, z. 4

transverse, b u t occasionally also p arallel to th e surface of th e flow. The top p a r t of th e flow is u sually rep rese n ted by vesicular and am ygdaloidal m elaphyre, originally a scoriaceous lava. The s tru c tu re of th e lava flows stro n g ly resem bles th a t recognized in th e L ow er P e rm ia n m elap h y re lavas of th e K raków D istrict ( B i r k e n m a j e r , N a i r n , 1964). The presence of scoriaceous lava in m ost cases im m ediately below th e basal breccia of th e successive flow points to sh o rt-tim e in te rv a ls b etw een th e subsequent flows, w hen n e ith e r stronger erosion, nor clastic sedi­

m en tatio n intervened. As a result, conform able lava sheets w ere form ed.

The low est la v a flow in m ost cases rests conform ably upon th e sand­

stones and conglom erates of the Rotliegende. O nly locally th e top surface of th e underlying clastics shows signs of bottom erosion caused by moving lava.

The sandstones of Rotliegende underlying th e lava flows som etim es show a lteratio n zones up to 10 m thick, p resu m ab ly caused by in filtra tin g iron oxide solutions, w here the sandstones are in d u rated , th e ir original re d colouration being changed to grey, blue or black. F u rth e r alteratio n

a

b

o

c A

- I

ItO 30 20 20 30 HO

Fig. 6. Z m iany w d ek lin acji i in k lin a cji m agn etyczn ej w czasie dolnego perm u, w oparciu o pom iary m a g n ety zm u szczątkow ego sk a ł d epresji p ółn ocn osud eckiej i n a stęp stw o zjaw isk w u lk a n iczn y ch depresji śródsudeckiej (por. tab. 4). L iczby oznaczają m iejsca pobrania prób (por. tab. 5). a — porfir; b — m elafir; c — p rze­

obrażone sk a ły osa d ow e (a— c — depresja północnosudecka); d — „ m elafir” (doleryt, sp ilit itd.) i p orfir w depresji śródsudeckiej

Fig. 6. S eq u en tia l changes in d eclin ation and in clin ation during th e L o w er Perm ian, based on m ea su rem en ts on rocks from th e N orth Sudetic D epression, and th e v o lca n ic su ccession of th e In ner S u detic D epression (cf. Tab. 4). S ite num bers as in Tab. 5. a — P orp h yry; b — M elaphyre; c — A ltered sed im en t (a— c — N orth S u detic D epression); d — „M elaphyre” (dolerite, sp ilite etc.) and porphyry, Inner

S u detic D epression

— 449 —

results in th e acquisition of a system of jointing m uch resem bling th a t of th e tran sv e rse jointing in th e m elap h y re lava flows. It seems probable th a t th e above alteratio n s p o st-d ated th e lava effusions. These altered rocks b ea r a striking resem blance to th e buchites described by S p r y a nd S o l o m o n (1964).

S im ilar a ltered clastic rocks at P la w n a D olna-II, M arczów -Zadole and Gorczyca are reg ard ed as younger th a n th e effusive com plex dealt w ith in th e p rese n t paper.

The acid volcanism rep rese n ted b y p o rp h y ry extrusions at W ielisław Złotoryj ski seems to be younger th a n m elaphyre extrusions, and coeval w ith th e th e rm a l alteratio n s of th e sandstones.

F ig u re 6 shows grouping of Low er P e rm ia n sites of th e N o rth S udetic Depression in a p p a re n t stratig ra p h ic order. The m elap h y re lavas have declinations betw een 193° and 214° w ith progressively low er inclination values, w h ilst the altered sedim ents of Rotliegende have declinations delim ited by D = 180° and 199°. T here is considerable v a ria tio n in th e inclination values, th e flows in general w ith negative inclinations and th e sedim ents and th e p o rp h y ry w ith positive values.

Taking into account th e succession of m elaphyre lavas as based on th e com bination of stra tig ra p h ic and palaeom agnetic d ata (Tabs. 2, 4), and th e geographical position of th e lav a flow sites of th e N o rth S udetic Depression, it appears th a t th e oldest m elap h y re extrusions are in th e southw est p a r t of th e D epression (Fig. 3, Tab. 3), a t P ła w n a G órna (Sites 4, 5), a m inim um th re e flows. The centres of effusion th e n m ig rated

T a b l e 3

Supposed stratigrap h ical su ccession of D ow er Perm ian m elap h yre la v a flo w s o f th e N orth S u detic D epression

I

Porphyry extrusions

+

A l t e r a t i o n s in th e

sediments

-

Melaphyre ex trusions

10. Mt fawtci ] / ri ( 1 Flow >6me

8

_(( j

, ¹ . ( 2 Fl o w >l5m

l-S P t o c z k l 1 2 F l ow c 20m C o r n e ( 1 F l o w C.l7m

l & a w n a < 2 Flow y 15 m

V

Gornct \ ( i r i ew) >2/n

1

n o t exposed b ^ l o w the lava flows _^ ^ e t p c r ?0/ £l/ovv the l a v a fl o w s m

f a rth e r N (NE) to P ła w n a Ś rednia (Site 6) — m inim um tw o lav a flows, and reap p e ared in th e southw est zone a t Płóczki Górne (Sites 1— 3) — th re e lava flows. The youngest m elap h y re lavas w ere e x tru d e d in th e central p a r t of th e D epression a t Bełczyna (Site 8), tw o lava flows, and a t R aw ka m t. (Site 10), one (?) lava flow. T he strongest volcanic a c tiv ity was centered in th e southw est p a r t of th e N o rth S udetic Depression, w h ere altogether six lava flows have been recognized (P ław na G órna + Płóczki Górne), the la v a flows are here thickest (up to 27 m), w ith the

4*

to tal thickness of the lava sheet exceeding 100 m. This m ay point to the p ro x im ity of a deep fra c tu re in th e su b stra tu m th a t served as th e feeder for the m elaphyre la v a-sh eet volcanoes.

LOWER PER M IA N VOLCANIC A N D SEDIM ENTARY ROCKS OF THE INNER SUDETIC D E PR ESSIO N

D e s c r i p t i o n o f L o c a l i t i e s Ś w i e r k i - I

(Figs. 7 a, b, 8 a— c, Tab. 5: S ite 12)

In th e new q u a r r y at Św ierki peculiar Low er P e rm ia n rocks d e te r­

m ined as m elaphyres ( K o z ł o w s k i , 1958) or as q u a rtz dolerites and spilites ( D z i e d z i c o w a , 1958) crop out. K o z ł o w s k i reg ard ed th em to be extrusive m elap h y re lavas w hich strongly d istu rb e d plastic clays (now shales) of th e Rotliegende, so th a t baked sedim ents a rran g ed in diapir-like stru c tu re s often came to th e contact w ith top surface of th e lava body. P a r t of th e lava th e n cooled u n d er a th in cover of th e displaced bottom sedim ents, an d gave rise to th e form ation of „subvolcanic bodies”

( K o z ł o w s k i , 1963).

According to our observations th e rocks have obvious differences w hen com pared w ith th e extru siv e m elaphyres of th e N o rth S udetic Depression.

N eith er bottom breccias nor scoriaceous top p a rts of th e lavas, so cha­

racteristic of the m elaphyres of th e N o rth S udetic Depression, are p rese n t w ith in th e „m elap h y res” a t Świerki. The rocks superficially closely r e ­ sem ble those d e a lt w ith as th e a ltered sandstones in th e N o rth Sudetic Depression.

The „m ela p h y re” a t S w ierki-I is q u a rrie d at five exploitation levels.

A t th e first level th e re is a fine-grained black, greenish and bluish rock w ith v ertical jointing, superficially resem bling a fin e-g rain ed a lte re d sandstone (it is th e q u a rtz dolerite, D z i e d z i c o w a 1958). S im ilar rocks at th e Ilnd, I llr d and IV th exploitation levels correspond to q u artz dolerite and, in th e u pper p a r t of th e q u a rry , to th e spilite of D z i e ­ d z i c o w a , and to m elap h y re of K o z ł o w s k i (1958). The rocks are here fine-grained, greenish, som etim es reddish and bluish in colour, w ith v ertical jointing, as a t th e 1st exploitation level. Im m ed iately upon the

„spilite” of th e V th exploitation level th e re appear (Figure 8a) th e rm a lly alte re d (baked) reddish and w hitish shales and, f a r th e r from th e contact, u n a lte re d red and violet shales of the M iddle Rotliegende. I t should be noted th a t the basal jointing planes w ith in the q u a rtz dolerite at I llr d exploitation level (20° WNW 30— 35°) are a rran g ed in a w ay sim ilar to th a t of th e bedding planes of th e „B au san d stein ” u n d erly in g th e

„e x tru siv e ” rock, w here K o z ł o w s k i (op. cit.) m easured 160° WSW 15° dips.

O riented sam ples w ere collected from th e Iln d (quartz dolerite), the I llr d (quartz dolerite), and IV th (spilite) exploitation levels.

In th e o l d q u a r r y a t Ś w i e r k i - I (Fig. 7a, b), th e bottom contact of th e m elap h y re (quartz dolerite) is exposed w ith th e sedi­

m e n ta ry su b stra tu m form ed by th e rm a lly altered p u rp le or v arieg ated shales w ith yellow lim onitic spots (Fig. 8c). The shales are tra v e rse d by v ertical joints in th e u pper p a r t close to th e contact w ith th e dolerite;

th e joints disappear quickly dow nw ards. The contact surface of shales and dolerite dips 55° NW 12°. The „dolerite” , w hich superficially r e ­

— 4511 —

sembles m etasom atic sandstones, shows relics of sed im en tary c u rre n t bedding and load casting in th e low er part.

In a higher p a r t of th e exposure in th e old q u a rry a t S w ierki-I we see the top surface of th e rock („spilite”) dipping ca. 45° tow ards SW. J u s t above th e „spilite” th e re occurs a th in band (0.5— 1 cm) of th e rm a lly altered violet, black and w h itish shale, w hile u n altered b rig h t red M iddle Rotliegende clay shales and clays w ith m arl concretions appear hig h er still.

/

V V 3 ^{a *a}

a

new quarry old quarry

Fig. 7. a. O dsłonięcia sk ał dolnoperm skich w Ś w ierk ach — depresja śród su d eck a (budowa geologiczna uproszczona w ed łu g K o z ł o w s k i e g o , 1958, tabl. III). 1 — osady n a p ły w o w e; 2 — p orow aty p orfir k w arcow y; 3 — d o lery t-sp ilit itd . (skały in tru zyjn o-m etasom atyczn e, „m elafiro w e”); 4 — m elafir w y le w n y ; 5 — tu f m e la - firow y; 6 — łupki; 7 — p ia sk o w iec „b u dow lan y” : p ia sk o w ce i łu p k i (2— 7 — czer­

w o n y spągow iec); 8 — uskoki; 9 — m iejsca pobrania próbek

b. Przekrój geologiczny przez „m elafir” (doleryt k w a r co w y -sp ilit itd.) w Ś w ie r - k a ch -I (w edług K o z ł o w s k i e g o , 1958, fig. 12, zm odyfikow ane). 1 — łupki;

2 — in tru zy jn o -m eta so m a ty czn e ciała „m ela firo w e” ; 3 — p orow aty porfir k w a rco w y Fig. 7. a. D ow er P erm ian site s at Ś w ierk i, Inner S u detic D ep ression (geological fea tu res after K o z ł o w s k i , 1958, PI. I ll, sim plified). 1 — A llu v ia l deposits; 2 — Porous quartz porphyry; 3 — D o lerite-sp ilite etc. (in tru siv e-m eta so m a tic „m ela­

ph yre” rocks); 4 — E ffu siv e m elaphyre; 5 — M elap hyre tu ff; 5 — Shales; 7 —

„B au sand stein ” : sa n d sto n es and shales (2— 7 — R otliegende); 8 — F au lts; 9 — Sam p lin g lo ca lities

b. G eological cross-section of „m elaphyre” (quartz d o ler ite-sp ilite etc.) at S w ie r ­ k i-I (after K o z ł o w s k i , 1958, Fig. 12, m odified). 1 — Shales; 2 — In tr u siv e-

-m etasom atic bodies of „m elap h yre” ; 3 — Porous quartz porphyry

The m elaphyre rocks in question (dolerites and spilites) rep rese n t intrusions r a th e r th a n extrusions; p a r t of th em could re su lt from m e ta- som atic alteratio n s of some clastic sedim ents (cross-bedded arkoses) of

E N E

N W SB

F ig. 8. a. In truzyjny kontakt stropow y sp ilitu z łu p k am i d olnoperm skim i w S w ie r - k a ch -I (nowy kam ieniołom ) — depresja śród su d eck a

b. In truzyjny k on takt strop ow y sp ilitu z osadam i dolnoiperm skim i w Ś w ierk a ch -I (stary kam ieniołom ) — depresja śródsudecka

c. In truzyjny k o n ta k t sp ą g o w y dolerytu k w arcow ego z osadam i dolnoperm skim i w Ś w ierk a ch -I (sitary k am ieniołom ) — depresja śródsudecka

O b j a ś n i e n i a o z n a c z e ń : 1 — d o lery t-sp ilit; 2 — przeobrażone łupki; 3 — n iezm ien ion e łu p k i (3a — z k on krecjam i marglistym ii); 4 — usypisko

Fig. 8. a. In tru siv e top contact o f ithe sp ilite w ith th e D ow er P erm ian shales. Ś w ie r - k i-I (new quarry), Inner S u d etic D epression

b. In tru siv e to p contact of ispilite w ith th e L ow er P erm ian sed im en ts. S w ierk i-I (old quarry), Inner S u detic D epression

c. In tru siv e bottom cointact o f quartz d olerite w ith th e L o w er P erm ian sed im en ts.

S w ie r k i-I (old quarry), Inner Sudetic D epression

E x p l a n a t i o n s : 1 — D olerite-sp ilite; 2 — A ltered sh ales; 3 — U naltered shales (3a — w ith m arl concretions); 4 — Scree

— 45i3 —

th e M iddle Rotliegende, the m etasom atizing solutions being re la te d to Low er P e rm ia n volcanic activity. The in tru siv e ch aracter of th e rocks (sills or laccoliths) is corroborated by th e presence of th e rm a l contacts w ith both th e und erly in g and overlying sedim ents. The lack of typical lava stru ctu re s, i. e. bottom breccias, scoriaceous top surfaces, fluidal stru ctu re s, etc., preclude th e possibility of lava sheets.

Ś w i e r k i - II

W of Ś w ierki village (near point 670 m a.s.l. — Fig. 7 a) a porous p o rp h y ry (Upper porous porp h y ry , Iln d eruptive cycle of K o z ł o w s k i , 1958) is poorly exposed. It form s sm all cliffs, slig h tly d istu rb e d by dow n- slope g ra v ity m ovem ents. No reliable m easu rem en ts w ere obtained from th e oriented sam ples collected.

A f u rth e r locality of „porous p o r p h y ry ” was recognized by K o z ł o w ­ s k i at K r a j a n ó w . H ere tu ff-lik e rocks composed of frag m en ts of w ea th ered p o rp h y ry , of sandstone and re d siliceous shales (contact shales ?), u su ally angular, sometim es subrounded, cem ented by a m a trix resem bling rew orked p o rp h y ry are exposed. These rocks show th e p re ­ sence of c u rre n t bedding (azim uth 325°, dips of foresets 40°). P a r t of the rock, m ore resem bling w e a th ered p o rp h y ry , form s a lens, b u t seems to be sim ply a m ore stro n g ly cem ented tu ff-lik e rock. The lens shows the presence of joints resem bling th e rm a l joints, w hile some p a rts of th e rock are vesicular. The voids how ever are the re su lt of th e w ea th erin g out of clastic fragm ents, a n d show an o rientation p arallel to foreset lam inae (dipping NW 40°, azim uths 310— 320°), i.e. in th e same direction as at th e previous site. Typical pyroclastic m aterial is lacking, and the

„ p o rp h y ry ”, regarded b y th e au th o rs as w ate r-la id rew orked volcanic deposit, is u n d erlain b y a „m elaphyre” analogous to th a t from Ś w ierki-I

(„m elaphyre of K ra ja n ó w ” of K o z ł o w s k i , 1958).

A typical q u artz p o rp h y ry w as found b e t w e e n K r a j a n ó w a n d D w o r k i , b u t could not be sam pled because of inadequate

exposures.

A t D w o r k i fragm ents of a typical effusive m elaphyre, red or violet-red, strongly resem bling the m elaphyres of th e N o rth S udetic Depression, w ere found as a w eath erin g cover („m elaphyre of D w orki”

of K o z ł o w s k i , 1958, PI. III). According to D z i e d z i c o w a (1958) th e rock belongs to th e b asalt group.

G ł u s z y c a G ó r n a

(Figs. 9a, b, Tab. 5: S ite 13)

In a w orking q u a rry a t Głuszyca G órna th e re occur rocks determ ined by K o z ł o w s k i (1958) as m elaphyres (rhyobasalts — K o z ł o w s k i , 1963), w hich lithologically resem ble th e q u a rtz dolerites of Ś w ierki-I (old and new quarries). The rocks form two sill-like horizons separated by shales w hich dip 130° SW 30°. The shales are th e rm a lly altered (baked) a t th e contact w ith th e low er „m ela p h y re” . According to K o z ł o w s k i (1958, p. 25) porous and am ygdaloidal stru c tu re s w ere p rese n t in the top p a r t of the u p p er m elaphyre. The sm all and sc atte re d voids found, how ever, occur not in th e m elaphyre, b u t in the altered shales, and m ay have been form ed b y th e dissolving out of m a rly concretions (see — old q u a r r y a t Świerki-I).

The m elaphyre resem bles m etasom atized sandstones (as at Świerki-I), its geological form is th a t of a sill, and not a lav a flow. The sam ples for

Fig. 9. a. O dsłonięcia sk ał dolnoperm skich w G łuszycy Górnej i Ł om nicy — d e­

p resja śródsudecka (budowa geologiczna uproszczona w ed łu g K o z ł o w s k i e g o 1958, tabl. II). 1 — osady n ap ływ ow e; 2 — porow aty p orfir k w a rco w y i tu f p o rfi­

row y; 3 — „m elafir” (praw dopodobnie intruzy jn o -m eta so m a ty czn y doleryt); 4 — zbity porfir sk a len io w o -k w a rco w y (intruzja ryolitow a); 5 — łupki; 6 — p iask ow iec

„b u dow lan y” : p ia sk o w ce i łu p k i (2—5 — czerw ony spągow iec); 7 — m iejsca p o ­ brania próbek

b. Przekrój geologiczn y przez „m elafir” w G łuszycy Górnej (w edług K o z ł o w - s k i e g o , 1958, fig. 9, nieco zm odyfikow ane). 1 — łupki (z tu fem m ela fir o w y m );

2 — intruzja „m elafirow a” ; 3 — p orow aty p orfir k w a rco w y