A N N A L E S D E L A S O C I É T É G É O L O G I Q U E D E P O L O G N E
V ol.. L — 2: 175—182 K r a k ó w 1980
Rafał Unrug *
ANCIENT CONTOURITES IN THE MENILITE BEDS (OLIGOCENE) OF THE CARPATHIAN FLYSCH, POLAND
(Pl. I —II and 2 Figs.)
Konturyty w warstwach memlitowych (oligocen) jednostki skolskiej fliszu karpackiego
(Pl. I— II i 2 fig.)
A b s t r a c t . Tractionite deposits in the M enilite Beds (Oligocene) of the Skole nappe of the Carpathian F lysch show a consistent paleocurrent direction at right a n g le to regional paleocurrents directions in sand flo w deposits and turbidites of th e overlying K liw a Sandstone. This paleogeographic context suggest that the tractionite deposits of th e M enilite Beds represent ancient contourites.
INTRODUCTORY REMARKS
From an earlier study of ancient traction currents deposits from the Carpathian Flysch (Unrug, 1977) the author concluded that contourites — deposits of geostrophic currents of therm ohaline circulation should be considered as a special case of tractionites — deposits of deep-sea trac
tion currents. The traction currents may represent therm ohaline circula
tion currents follow ing or not follow ing izobaths, tide induced currents (Shepard and Marshall, 1973), internal w aves or currents of clear water induced by passage of turbidity currents.
The general term „tractionite” for -deposits of traction currents, as opposed to turbidites — deposits of sedim ent-laden turbidity currents, proposed by the present author w ith some reservations (Unrug, 1977), received support from various sources (personal communications of Dr.
E. D. McKee and Prof. H. Okada), and w ill be used also’ in this paper.
The present author suggested that criteria for distinguishing ancient con
tourites w ithin the broader class of tractionite deposits are lacking, and
* Institute of G eological Sciences, Jagiielloman Uniiversdity, O leandry 2a, 30-063 Kraków.
will be probably based upon palaeogeographical considerations rather than upon textural and structural characters of ancient sedim ents, which are likely to be sim ilar in all types of tractionite deposits (Unrug 1977).
Tractionite deposits found recently in the M enilite Beds (Oligocene) of the Skole nappe of the Carpathian Flysch may represent true con- tourites as indicated by the päleogeographical context of their occur
rence.
TRACTIONITES OF THE MENILITE BEDS
O c c u r r e n c e s
The tractionites occurring in the M enilite Beds are associated with the K liwa Sandstones. The K liwa Sandstones form sandstone lithosom es lenticular in transverse .cross-section and channelized in the mudstones
1
Fig. 1. Area o f occurence of contouxites in th e M enilite beds of th e S k o le nappe.
1 — northern thrust front o f th e Skole nappe; 2 — localities studied and paleocur- rent direction in contoim tes; 3 — regional paleocurxent direction in th e K liw a
sandstones overlying contourites; 4 — sta te boundary
Fig. 1. B adane odsłonięcia z konturytam i w łupkach m en ilito w ych jednostki skol- skdej. 1 — północna granica jednostki skolskiej ; 2 — odsłonięcia konturytów w łu p kach m en ilito w y ch , d kierunek paleoprądu w konturytach; 3 — regionak iy kieru
nek paleoprądów w piaskow cach k liw sk ich przykryw ających utw ory z konturytam i;
4 — granica państw ow a
of the M enilite Beds. The K liwa Sandstones are represented m ostly by thick-bedded sand-flow s and turbidite deposits, fine- to coarse-grained, composed of w ell sorted and w ell rounded quartz grains w ith a signifi
cant admixture of glauconite (Slączka and Unrug, 1966).
The tractionites occur across the whole w idth of the b elt of expo
sures of the Skole nappe in the eastern part of the Polish Flysch Car
pathians. The occurrence of beds interpreted here as tractionites was noted earlier (Dżułyński and Kotlarczyk, 1962; Slączka and Unrug, 1976),
but no detailed interpretations w ere given then.
In the present study tractkmite deposits were exam ined at four lo
calities (Fig. 1):
— at Koniusza near Aksmanice south of Przem yśl, in the profoile ex posed in the Koniusza stream w ithin the outermost thrust slice of the
Skole nappe;
— at Korzeniec in the road cut of the Bircza-Przem yśl highway;
— at Tem eszow in the exposures of the left slope of the San River valley;
— at Dobra Szlachecka north of Mrzygłód in the valley of the small n g h t bank tributary of the San River north of the village, in the pro
file of the southern limb of the Wara anticline, that is in the innermost part of the belt of exposures of the Skole nappe.
D e s c r i p t i o n s
At Korzeniec, Temeszów and Dobra Szlachecka the tractionite de
posits are present in the sam e position in the profile of the M enilite Beds above the basal chert horizon, and below the low est lithosom e of
the K liw a Sandstone.
The tractionite deposits are represented by sandstone lenses 1,5—
5 cm thick, and 40— 50 cm long, fine- to very fine-grained, cross-lam ina
ted, consisting of single sets of cross-laminae, occasionally of 2— 3 super
posed sets (Fig. 2). The sandstone lenses are embedded in dark-brown micaceous silty shales and spaced vertically at’ intervals of 5— 20 cm.
The top and base surfaces of the sandstone lenses are sharp. In all three localities the transport direction of the tractionites indicated by cross- -lam ination ds at right angle to th e transport direction of the thick-bed
ded Kliwa Sandstones occurring higher in the profile.
At Koniusza the tractionites occur above the basal chert horizon of the M enilite Beds but they are not covered by the thick ^bedded K liw a Sandstones which are absent in the profile of the outermost thrust slice of the Skole nappe. The basal chert horizon is overlain by dark-brown m udstones w ith very numerous thin beds, lenses and laminae composed of w ell sorted, rounded very fine sand grains. Cement is nearly absent and the sandstones are friable. The top and base surfaces of these stra
tification units are sharp (Plate I, Figs. 1, 2). The sandstone laminae are up to a few m ilim etres thick, w hile the isolated ripples and the lam i
nated and cross-laminated beds are up to 5 cm thick. Load deformations at the base of the isolated ripples are common. The beds have irregular top and -base surfaces resulting from coalescence of ripples (Pl. II, Fig. 1).
Fig 2. Types of lam ination iin the con tour it e beds. A, В — specim ens from Dobra Szlachecka locality; С — Specim en from Koraerd-ec locality
F ig 2. T ypy lamiinacjii w soczew kow atych ław icach kontur ytów. А, В — okazy z Dobrej Szlacheckiej; С — okaz и K orzeńca
Cross lamination is ubiquitous and indicates a constant transport di
rection from ENE to WSW. The Koniusza locality is situated w ithin the sigmoidal bend of the front of the Skole nappe. The direction of this front extending here north-south is local and obviously related w ith a cloc- w ise rotation of c. 40°. An anticlockwise rotation adjusting the local strike of beds to the regional NW -SE strike is giving the azimuth of pa- leocurrent directions as c. 210°, a value similar to that measured at Ko
rzeniec, and roughly perpendicular to the regional direction of trans
port of the thiick-lbedded K liwa Sandstones.
P e t r o g r a p h y
Thin sections of the thin sandstone lenses from Tem eszów and Ko- rzeniec were examined. Very good sorting and the presence of laminae rich in heavy 'minerals are characteristic features (Plate II, Figs. 1 ,2 ). La
m inae of w ell sorted silt are also present and som etim es they accompany the lam inae enriched in heavy minerals. Laminae containing clay m atrix are rare. The sandstones are composed of quartz and rare glauconite grains. The cem ent is opalline silica (present at Temeszów, Korzeniec and Dobra), w hile in the profile at Koniusza the cem ent content is extrem ely low and the sandstones are friable. Petr ographieally the de
scribed sandstones represent the fine grades of the sedim entary m aterial form ing the thick-be.dded K liw a Sandstones.
INTERPRETATION AND DISCUSSION
The described deposits display a combination of textural features and sedim entary structures w hich is considered as diagnostic for contourites (Stow and Lowell, 1979, Table II m odified after Hollister and Heezen, 1972). H owever it should be stressed upon that these features are indi
cative only Of transport, rew orking and sorting of sand-sized sedim ent by bottom currents. Other criteria are needed for recognition of a parti
cular type of traction 'currents and for identification of contourites w ithm the broader dlass of traction currents deposits or tractionites. This state
m ent, published already in an earlier paper (Umrug, 1977) is repeated here, since Stow and L ow ell (1979, p. 279) in a review paper referred erronously traction current deposits described from the Carpathian F lysch as „candidates for the description contourites” w hile the present author termed them „tractionites”.
Paleocurrent analysis is lik ely to provide the most important criteria for identification of contourites w ithin the broader class of tractionites (Unrug, 1977; A nketell and Lowell, 1976).
In the case of tractionite deposits of the M enilite Beds described here, the highly persistent paleocurrents direction sim ilar over the whole in
vestigated area, and perpendicular to the regional paleocurrent direction in th e sand flow s and turbidites deposits of the thick-bedded K liwa Sand
stones strongly suggest currents flow ing across the submarine slope. The interpretation of the decribed tractionites as fine-grained overbank tur- bidites is discarded because of the occurrence of the tractionites below the sand flow s and turbidites deposits in the stratigraphie profile, w hile the interpretation as distal turbidites is discarded, as the m ost typical and num erous beds of tractionites are present at Koniusza, that is at
the outer margin of the sedim entary basin, which is lik ely to represent a submarine slope.
The dark-brown mudstones accompanying the thin-bedded lenticular tractioniite sandstones are probably also tractionite (possibly contouriite) deposits. There are no direct criteria for this conclusion other than the relatively coarse grains in these mudstones, as compared w ith the fis
sile clayey shales of the M enilite Beds present in other parts o f the sedim entary basin. The identification of muddy contourites is difficult as stressed upon by Stow and L ow ell (1979) and the association w ith tractionite, possibly contourite sandstones in the case described here is the m ost important support of the hypothesis of tractionite, possibly contourite nature of the m udstones of the M enilite Beds of the Skole nappe.
The possible source o f heavy water in the sedim entary basin of the Carpathian Flysch during the deposition of the M enilite beds is not known. However, the facies of brown m udstones and shales of the Me
nilite beds is widespread in the whole Outer Carpathians, suggesting the existence of a large basin in w hich som e kind of geostrophic circulation of contour currents was possible. It is highly significant that a coeval lithofacies of brown pelites w ith thin siltite beds — interpreted as con
tour,ites — is present aJiso at the opposite m argin of Late Alpine system of sedim entary basins in the Numidian Flysch of Sicifly (Wezel, 1970;
Kotlarezyk, 1976).
Specim ens pertaining to this study are housed in the Geological Mu
seum, Institute of Geological Sciences, Jagellonian U niversity, collection sym bol UJ 23 — thin sections, U J 5D — rock samples.
The author expresses his thanks to A. Radomski for his company in the field and assistance in taking photographs of outcrops.
M anuscript r e ce ive d O ctober 1979 accepted N o v e m b er 1979
REFERENCES — WYKAZ LITERATURY
A n k e t e i l J. M. , L o w e l l J. P. В. (1976). Upper L landoverian G rogal sand
stones and A b erystw yth G rits /in th e N ew Quay area, Central W ales: a possib le upward transition from contauxiftes to turbidites. Geol. J., 1(1: 107—108.
D ż u ł y ń s k i S., K o t l a r e z y k J. (1062), O pogrzęźniętych pręgach fa listy ch (riplem arkach). On load-casted ripples. Rocz. Pol. T ow . Geol. 32: 147— 160.
H o l l i s t e r C. D., H e e n z e n В. C. (1972), G eologie effects of ocean bottom currents:
w estern North A tlantic. In: Ai. L. Gordon (Ed.) Stu d ies in P hysical Oceano
graphy, 8. Gordon and Breach, N ew York N.Y., pp. 37—66.
K o t l a r e z y k J. (1976). Fliisz num idyjski a w arstw y memlŁtowe (uw agi porów naw cze). Sp ra w . K om . Nauk. P A N Oddz. K r a k ó w 19, 1: 187— 139.
S h e p a r a F. P., M a r s h a l l N. F. (1973), Currents along floors of subm arine canyons. Bull. A m . Assoc. Petrol. Geol., 57 : 244— 264.
Ś l ą c z k a A., U n r u g R. (1966), Z badań nad strukturam i sedym entacyjn ym i
■i petrografią niektórych serii piaskow cow ych z łupków m en ilitow ych K arpat (Sedim entary structures and petrology of som e sandstone m em bers of the M e- nilite Beds, Carpathians). Rocz. Pol. T ow . Geol. 36: 155— 180.
S t - o w D. A. V., L o w e l l J. P .B., (1979), Contounites: their recognition in m o
dern and ancient sedim ents. Earth Sei. R e v ie w s 14: 251—291.
U n r u g R. (1977), A n cient deep-sea traction currents deposits in the Lgota beds (Albian) o f the Carpathian Flysch. Rocz. Pol. Tow . Geol. 47: 355—370.
W e z e l F. C. (1970), Numiddan F lysch: an O ligocene-E arly M iocene continental rise deposit o ff the A frican pOatform. Nature 228, no. 5268: 275—276.
STRESZCZENIE
W warstwach m enilitow ych powyżej poziomu rogowców, a pod pias
kowcami kliw skim i w ystępują wśród m ułowcowych brunatnych łupków nieciągłe soczewkowate ław ice, izolowane riplemarki i pojedyncze la
m iny piaszczyste, złożone z bardzo drobnoziarnistego materiału, bardzo dobrze w y sortowanego pod względem w ielkości ziarna. W ławicach i ri- plemarkach w ystępuje laminae ja pozioma i przekątna, podkreślona kon
centracjami ziarn m inerałów ciężkich (fig. 2, Pl. II, fig. 2). N ajlepsze odsłonięcia tych utw orów w ystępują w m iejscow ości Koniusza koło A ks- manic na S od Przem yśla w brzeżnej łusce płaszczowiny Skolskiej (fig. 1, PI. I, fig. 1 i 2, Pl. II, fig. 1). W profilu tej brzeżnej łuski piaskowce kliw skie nie występują, i cały profil warstw m enilitow ych zawiera tylko cienko ław icow e i soczewkowate utw ory opisane wyżej. Cechy tekstu- ralne — drobne ziarno, bardzo dobre wysortowanie, brak m atrix iłow ej, koncentracja ziarn m inerałów ciężkich w laminach oraz struktury sedy
m entacyjne wskazują, że omawiane osady deponowane b yły przez przy- denne prądy trakcyjne. Pod względem petrograficznym osady te re
prezentują drobnoziarniste frakcje m ateriału osadowego piaskowców kliwskich.
W arstwowanie przekątne w osadach prądów trakcyjnych w skazuje kierunki paleoprądów prostopadłe do paleoprądów w w yżej leżących piaskowcach kliwskich. Pozwala to na interpretowanie opisanych trakcjo- nitów jako osadów geostroficznych prądów płynących po izobatach pod
morskiego stoku. Osady te mogą w ięc być określone term inem ,,kon- tu ry ty ”.
EX PLA NA TIO N OF PLATES — O BJAŚNIEN IA TABLIC
P late — Plansza I
Fig, 1. Thin beds, len ses and lam inae of sand in dark-brow n m udstones. M enilite Beds, exposures in th e K oniusza stream at Koniusza. The diam eter of coin is 29 mm. Beds are vertical, bases at right. Phot. R. Unrug
Fig. 1. C ienkie Ławice, soczew ki i łam m y piaskow ca w brunatnych m ułow cach w arstw m em ilitowych. O dsłonięcia w ipaboku K oniusza w K oniuszy. Średnica m on ety 29 mm. W arstw y pianow e, spągi z prawej strony. Fot. R. Unrug Fig. 2. L enses {isolated rdpples) and lam inae o f sand in dark brow n m udstones. Me- nili/fce Beds, exposures in th e Komdiusza stream a t K oniusza. The diam eter o f coin is^EÔ m m. Bedis are vertical, baises at right. Phot. R. Unrug
Fig. 2. Soczew ki (izolow ane ripLemarki) ii lam iny piaskow ca w brunatnych m u
łow cach w arstw m enilitow ych. O dsłonięcia w potoku K oniusza w K oniuszy.
Średnica m on ety 2Э mm. W arstw y pianow e, spągi z prawej strony. Fot.
R. Unrug
P late — Plansza II
Fig. 1. Close up v ie w of len ses and lam inae o f sand in dark-brow n m udstone. Me- niliite Beds, specim en collected at Koniusza. The height of specim en is
30 m m . Phot. K. Fedorow icz
Fig. 1. Szczegóły lam in d soczew ek piaskow ca w brunatnych m ułow cach w arstw meniłiitowych. W ysokość okazu 30 mm. Potok K oniusza. Fot. K. Fedorow icz Fig. 2. Photom icrograph o f a lam ina enriched in h eavy m inerals grains. Sandstone len s from M enilite Beds, K orzeniec. The w h ite bar represents 0.2 m m. Phot.
R. Unrug
Fig. 2. M ikrofotografia lam in y wzbogaconej w ziarna m inerałów ciężkich. S o czew ka piaskow ca z łu p k ó w m en ilitow ych, K orzeniec. B iała kreska reprezentuje 0,2 mm. Fot. R. Unrug
Fig. 3. Photom icrograph of a silt lam ina in v ery w e ll sorted sandstone w ith opaline cem ent. Sandstone lens from M enilite Beds, T em eszów . The w h ite bar represents 0,2 mm. Phot. R. Unrug
Fig. 3. M ikrofotografia lam iny m ułow ca w bardzo dobrze w ysortow anym piaskow cu o sp oiw ie opalow ym . Soczew ka piaskow ca z łupków m en ilitow ych, T em e
szów. B iała kreska reprezentuje 0,2 mm. Fot. R. Unrug
Rocznik Pot. Tow. Geo/., t.L, z.2
Rocznik Poi. Tow. Geo I., t.L, z.2
