GEOL. CROA T. 50/2 261 - 268 3 Figs. ZAGREB 1997 Stratigraphy and Tectonic Relationships Along the Senj -Ogulin Profile (Velika Kapela Mt., Croatia) Dubravko MA TICEC, Igor VLAHOVIC , Ladis lav FUCEK, Nenad OSTRIC and Ivo VELIC Key words: Shallow-water carbonates, Compressive Tert iary tectonics, Transpressive Neotectonics, Stru­ ctures, Jurassic, Lower Cretaceous, Dinaridcs, Veli­ ka Kapela MI. , Croatia. Abstract T welve lilhostratigrcnding during the Tertiary cycle, rather than rotation during the NCOIectonic cycle. 1. INTRODUCTION Geological in ves tigati ons of the Senj -Ogulin profile th rough the Velika Kapela Mt. , were part of the project ent itled «Geological analysis of part of the Primorje and Gorski Kotar", perrormed by the Tnstitute of Geology, Zagreb, for the INA-Naflaplin company. Therefore, we are gratefu l to INA-NaftapJin for permission to publi sh some or the results. The Ill ost important contributions to the geological know ledge of study area were obtai ned by systematic geological investigations performed during work on the Basi c Geological Map I: 100,000 of the Ogu lin sheet (VELI C & SOKAC, 198 1; VELIC et aI., 1982) and parts or the Crikveni ea (SUSNJAR et aI. , 1970; GRT­ MAN I et al.. 1973) and Rab sheets (MAMUZIC et a \. , 1969; MAMUZTC & MILAN, 1973 ). In these works Mesozoic deposits were accurately subdivided, and the basic geological relationships in th is part of the Dinar­ ides were presented. Institute of Gcology, $achsova 2, P.O. Box 268, HR- 1OOOO Zagreb, Croatia. 2. STRATIGRAPHIC REVIEW The investigated area is composed of shallow-water platform carbonates of Jurassic anci Lower Cretaceous age (Fi g. I). Twelve lithostrat igrap hic units with an approximate total thickness of 5,000 m were es tabl ished (Fig. 2). Si nce the study area has a very compl ex geo­ logical composition, especially due to the intense post­ depositional tectonics, it was not possible to form al ise the unit s; therefore, the units descri bed in thi s paper represent informal lith ostratigraph ic units. All hou gh determined fossil assemblages were very rich , onl y the most im po rtant index fossils are mentioned in thi s revicw. Data on the thickness of the stratigraphic unit s are based upon our investigation, as well as on compar­ isons with the results presented in the aforemen ti oned sheets of the Basic Geological Map I: 100,000. 2. 1. LITHOSTRATIGRAPHI C UNIT A Deposits of Lithostratigraphic Uni t A are represent­ ed by mostly IS-50 em thi ck well-bedded dark gray to black mudstones with variable proport ions of peloids and bioelasts. Beds containing li ght-coloured gas­ tropods, onco id s, benthic foram inife ra, echinoderms and ostracods are infrequent. In the uppermost part therc are gra instoncs, scarce marly beds and beds con­ taining molluscs of the genus Lithio/is. The thickness of Unit A is approximately 400 m. On the bas is of the foss il assemblage (Orbilopsella praecursor and Lirilio/is prohlemalica) it has been dete­ rmined that depos its o f Uni t A are or Middle Liassic age. They were deposited mostly in the low-energy sub­ tidal environments with sporadic shallowing. 2.2. LITHOSTRATIGRAPHI C UN IT B Intense bioturbation, resulting in a mott led appear­ ance of the rocks (their common name is "spotty li me­ stones", or ':fleckenkalk" in German) is the main charac­ terist ic of the Unit B. Deposits are represented by alter­ nating 30-70 em thick beds of gray to almost black This paper was presented at the scientific meeting dedicated to the 80th anniversary of the life of Professor Milan Herak, held on March 5th, 1997 in Zagreb 162 III ;·Hreljin Ogutinski ,~ ..(' VI ;, 16 • ....... , .....: · OGULIN '\:.:\. ...... V . ~ : '- +/ IV-8 Geologia CrO:lIica son STRUCTURAL UNITS: I - Krivi Put II - Pepelarnica III - TomicH •••• ; Krivi Put IV - Dreinica "j..... 1-8 V - Klek ... VI - Hreljin Ogulinski ENJ I-A Skm D Lower Cretaceous D Maim Adriatic Sea D Dogger Fig. 1 Loca tion map with simplificd geological map and structural unit s described in the text. profile line Lias mudstones and nodul ar peloidal packstones . Skcletal ­ peloidal grainstone beds with swaley cross-stratification sporadically occu r, as well as ooid-oncoid-favreina packstones. At the top or the Un it, an approximately 15 m thick package of late-diagenetic dolomites occurs, which is a common characteristic of the uppermost part of contemporaneous deposits throughout the Dinarides. The complete thickness of Lithostratigraphic Unit B is approximately 130 m. Deposits of th is unit are of Upper Liassic age, and were deposited in somewhat deeper, lagoonal environ ­ ments, near to or just beneath fair-weather wave base. 2.3. LITHOSTRATIGRAPHIC UNIT C In the lowermost part of these deposits alternations of mudstones and hummocky cross-s trat ified peloid packstones predominates, while in the rest of the unit , only scarce mass ive beds of ooid-peloid packstones occur within the prevailing mudstones. Original grain­ stones are sporadicall y completely late-diagenetically do lom itized . The complete thickness of the Unit is approximately 400 m. Based on the microfossil assemblage (A1esoell­ dOlliyra croGrica and Selliporella dOllzellii ) a Lowe r Dogge r age has been determined fo r this unit. The depositional environment was a low-energy subtida l lagoon wit h sporadic progradation of shall ow-wate r sand bars. 2.4. LITHOSTRATIGRAPHIC UNIT D In the lower 100 m of Unit D there are numerOliS beds of skeletal-oncoid-peloidal wackeslones, intraclas­ tic-oncoid-gastropod fioalslones and ooid packstonc/ g rai nstones wit hin the prevailing thick-bedded mud ­ stones, as well as scarce beds indicating emers ions. In the upper part 1-2 m th ick beds of brown to gray-brown mudstones with interbeds of light-coloured int raclasts, oncoids and ostracods predomi nate. Lithostrat igraphic Unit D is approximately 400 m thick. According to the microfossil content (Pa/eop/ellde­ rina sa/erniwna and Salorino apuliensis) this Un it is of Upper Dogger age (Bathonian - Callovian). The deposi­ tional environment was a low-energy subt idal lagoon with infrequent shallowing. ." ~. ,0 0- '" ;; ~ ~. ~ o ~ ~ " N 2; 2.5. LITHOSTRATIGRAPHIC UNIT E Depos iLs o r Lhis uniL are represenLed by Lhiek-bed­ ded (0.5- 1 m), sLylol iLized dark-gray mudSLones and oncoid-foraminiferal wackestones with abundant Aeoli· saccus sections and oncoids. A large part of these depo­ Si LS is eompleLe ly laLe-diageneLieally dolomiLized , rep­ resenting coarse-crystalline dark gray to almost black dolomites of mass ive structure. The complete thickness of Lithostratigraphic Unit E is approximately 400 ITI. The Oxfordian age of this unit has been determined on the basis of a benthic foraminiferal assemblage (Ku ­ mlfbia pa/oslilliellsis, Nallli/oculinG Doli/hiea, TrocllO­ linG gr. a/pino-e/on gara) and green algae (Sa/pillgopo­ rella sellii). The depositional environment was subtidal of predominantly low energy level. 2.6. LITHOSTRATIGRAPHIC UNIT F In the centra l area of the Velika Kapc la Mt. , as observed in the Senj-Ogulin profi le, de pos its o f the Middle and Uppe r MaIm show important fac ies vari­ ability , as a consequence of the palaeogeographical dif­ fe rentiation caused by synsedimentary tectonics (VEL­ Ie eL aI., 1994). ConsequenLly, in the Midd le Maim LwO diffe re nt lateral developments have becn determined: the profi le mostly comprises typica l shallow-wa ter depos iLs (F,) - wel l-bedded gray Lo dark gray mudsLones with oncoi cl s, intracl as ts and frequent benthic forami ­ nifera, wh ile in the area of Dreznica very restri cted out­ crops of limes tones with chert (F2) occur, representing a somewhat deeper, lagoonal equivalent of the contempo­ raneous Fl de posits. On the basis of the available data , the thickness o f Lithostratigraph ic Unit F is estimated as 150 Ill. The micro foss il assemblage (Psel/doclypeifia cirici and COJlicokurllubia orbitolilllformis) and s tratigraphic re lat ions over a wider area indicate a Kimmeridgian age for these deposits. 2.7. LITHOSTRATIGRAPHIC UNIT G The lowermost part of the Tithonian in the Kriv i Put - Senj a rea is re presented by rarely preserved hydro­ zoan-coral-bryozoan-gastropod reefs, and large amo­ unts o f pe ri -ree fal mate rial produced by their dis inte ­ grat ion. The reefs were form ed in the marginal areas of a lagoon, while in the deeper parts limestones with che­ rts were contemporaneous ly deposi ted. The re fore, in the progradationa l succession, peri-reefal - reefal depo­ s it s are always fou nd overlying the limestones wi th c he ri (Lith ostrati graphic Unit F2), while this uni t is complete ly missing in areas where shallow-wate r depo­ sition during the Kimmeridgian, (as represented by Unit F 1) , continued into shallow-water Tithonian sedimenta­ tion. Bioc lasti c material is mixed with ooids formed in shallows with agitated water in back-reef areas , with a prog ress ively hi gher proport ion of ooids towards the uppe r pari of the Unit. The compleLe Lhiekness of UniL G de pos iL s is eSLimaLed aL 400 m. On the basis of biostratigraphic data , (mostly m ac­ rofauna including Ellipsaclinia ellipsoidea, Sphaerac­ linia dicholoma, Nerinea (/e/rancei, Ptygmatis brllnlru­ tana), as well as regional geological re la tionships, this uni t is de temlined as being Lower Tithonian in age . 2.8. LITHOSTRATIGRAPHI C UNIT H In the southern part of the study area, be tween Krivi Put and Senj, Tithonian peritidal deposit s concordantly overlie peri-reefal - reefal deposi ts of the Lowe r Titho­ nian (Lithostratigraphi c Unit G), while in the northern area be tween Dreznicko Polje and Ogulin they direc tly overlie Kimmeridgian shallow-water deposits. In the Kr ivi Pu t - Senj area the transition from the underlying deposi Ls is gradual. In the 10wellllosL 280 m well bedded lig ht gray mudstones and fe nes tra l mud­ stones with beds of peloida l-algal wackcstones (com­ pris ing Clypeina and Sa/pingoporella ) predominate, although infrequent in te rbed s containing hyd rozoan, and scarcer coral , gas tropod and bryozoan b ioclasts a lso occur. The proportion of ooids is highest in the lowe r pan, and gradually, although somewhat irregular­ ly , decreases Lowards the uppe r parL of the Unit. The remainder of the Unit, (approximate ly 1,200 m ), is characte rised by mudstones with variable proportions of 0.5 - 1 m thick laminites of differen t origin s : some lami nation is caused by se lec ti ve dolomitization and dedo lomi ti zation, some by fe nestral fabric , and others by the alte rnation of mudstones and gra instones . The amount s of Clypeina bioclasts is ve ry variable, and fro m the middle part towards the top of the Uni t Camp­ bel/iella striata and Favreina pe lle ts are freq ue nt in som e layers. In the uppermost part depos it s are Ih in­ bedded , and some beds with os treid bioc las ts were observed. The peritidal success ion in the northe rn area is generally similar, but is characterised by lesser amounts of ooids, and very infrequent bi oclas ts (as a con se­ quence of the distance from the reefs). Deposits of Lithostratigraph ic Unit I-I are of Tithon­ ian age. It is clear that depos ition of the uni t in the northern part of the s tudy area commenced during the earlies t Tithonian, while in the southe rn area peritidal deposition was established somewhat late r. The refore, the th ickness of the unit is variable, but can be es tima­ Led aL 1,500 m. 2.9. LITHOSTRATIGRAPHIC UNIT I Li thostratigraphic Unit I is characteri sed by thick­ bedded (>0.5 m), almosL eompleLe ly unross ilire rous brown mudstones w ith very rare bed s of fav reina wackestone-packstone, and , in the upper part , late-dia­ genetica lly dolomitized lam inites. Tn the Senj area mud­ stones comprise variable portions of small voids formed by solution of the unstable mineral compon e nts. The complete thickness of this Unit is approximately 400 m. It has been detennined that the lower 200 m of this unit contains a fossil assemblage characteris tic for the M;lliccc ct ;11.: Stratigraphy and Tt."Ctonic Relationships Along the Scnj-Ogu lin Profile ... 265 uppermost Tithonian to Neocomian, while its upper part is definit ely of Neocomian age (acco rdin g to the assemblage charac teri sed by Epil1lasropora cekici, Cly­ pC ina so/kalli, Favreina dinarica and F. njegosclIsis). Depositional environments were mostly characteristic of lagoonal conditions with infrequent shallowing to the upper subtidal/intert idal , cspecially in the upper part. 2. 10. LITHOSTRATIGRAPHIC UNIT J Deposits or Lithostratigraphic Unit J arc very infre­ quent in the study area, and arc represented by alternati­ on of wel l·bedded (30·50 em) gray· brown peloid-skele­ tal wackes tone-packstones with rare rnudslone laminae. The thi ckness of the Un it is approximately 250 m. Common green algae (Sn/pingoporel/G melilGc and S. 17ll1chlhergii) indicate a Barremian age for these shal­ low-water deposits. 2.1 I. LITHOSTRATIGRAPH IC UNIT K Lithost rati graphic Unit K is represented by thick­ bedded light-brown to brown-gray mudstones with a relat ively ri ch fossil assem bl age, dominated by palor­ bi t olin ids. Therefore, thi s Unit corresponds to the depo­ s its which arc in the Dinarides known as "the Lower Orbitolina Limestones". The upper 100 m of the Unit is thi n-bedded, charac te rised by predominating pel oid­ int raclast-ske letal wackestones and packstones. The Ihickness of Ihe unil is approximalely 150-250 m. The microfoss il assemblage (Sa/pingoporel/a dinar­ ica, Pa/orbitolina lemicillaris and OrbitolillG (M.) par­ va) indicates an Aptian agc. Deposits of thi s Unit arc characteristic of deeper lagoonal conditi ons wi th grad­ ual shallowing, ending with the regionally known Apt­ ian emersion in the upper part of the Unit. 2. 12. LITHOSTRATIGRAPHIC UNIT L Depos its of Lithostratigraphi c Un it L are charac­ lerised by Ihe allernalion of well -bedded (30 em) mud­ stones and pe lo id-intraclast-skeletal packstone/grain­ stoncs containing oncoids. Laminati on was sporadically observed, characte rised by the alternat ion of mudstone and packstone laminae. The most important fossils are mcsorbitolinids, and the Unit corresponds to the level of '"the Uppcr O rbitolina Limestones" in the Dinarides. The thickness of the unit is approximately 400 m. On the basis o r the dete rm ined foss il assemblage (Orbiroli lla (M.) teXGIIG, Va/danchella dercourti, Salp ­ iflgoporel/a turgida) this unit is of Albian age. Deposi­ tiona l envi ronments arc mostly charac teri stic of shal ­ low-subtidal cond itions. 3. STRUCTURAL RELATIONS Tracing of the determined lithostrat igraphic succes­ sion along the profile resulted in the geologi ca l map (s implified in Fig. I). From previous knowledge it was already possible to aSSume that the geological structure of this pan of the Dinarides represents the consequence of two periods of tectonic activity, characterised by different orientations of the reg ional stress . During the Tertiary tectonic cycle, which lasted from the Eoccne to the end of the Mi ocene, compressive movements orien ted NE-S W reached their cumulati ve maxi mum with o rogenesis of (he Dinarides. During the later, Neotectonic period, the main stress changed to N-S, resulting in furth er uplirt and transpress ive de formation of the older structures . Namely, faulls of Ihe Dinaric Slrike (NW-SE) , whieh were favourably oriented structures towards th e new stress regime (approximately under the angle of 45°), were reactivated int o faults with dex tral strike-s lip movement. Therefore, during the in ves ti gation of the Senj -Ogulin profile special a ttenti on was pa id to the contacts of the established structural units, in orde r to defi ne their mutual relations. Inves tigation of the field relationships of the di ITer­ ent lithostratigraphic unit s, and structural analys is of the tectonic fabri cs, has resulted in determinati on o r six different structural unit s, di vided by significant fa ult s with a relat ively high component of vertical movement (in some cases more Ihan 1,000 m). 3.1. TI-IE KRIVI PUT STRUCTURAL UNIT The Krivi Put Structural Unit encompasses the southwestern most part of the study area (Figs. I & 3, I). It represents a large anti clina l structure composed of Ti thon ian carbonates (Lithostratigraphic Uni ts G & I-T), with a b-axis orientation (N-S) very differen t from the Dinaric strike. The almost undisturbed wes tern limb of the structure, (Fig. 1 & 3, I-A), including the conti nu ­ ous transition into (he Lower Cretaceou s deposits (Lithostrati graphic Unit I), shows no signs of rotation. Furthermore, comm on traces of reverse int erl ayer movements indicate exclusively compression normal to the structure. Cons idering the intensity of the de forma­ tion during the Tertiary tectonic cycle, when elements of the older tectonics were more or less des troyed, it is not probable that this structure is inherited from the old­ er, Cretaceous tectonic cycle. Thi s structure probably result ed from deviated loca l stress during the Tertiary tecton ic cycle. The apical parts of the struc ture, as well as ils easlern limb (Figs. I & 3, I-B) were deSiroyed by faults o f Dinaric stri ke wi th traces of dextral movement. These faults represent the structures which are inherited from the Tertiary cyc le, and were subsequently react i­ vated by the Neotectonic activity. Geologia CroalJca :JUri. ~ Hreljin _ V ~gUlinSki .0 0 I-A I-B II III I IV-A IV-B V VI ·1000 - -- , , I - VI Structural Units ~i~~~~t~!~igr~~~ii~~~fitd~POSits of (Upper Liassic) Fig. 3 Schematic geological cross-section representing structural units and diagrams of bedding traces. 3.2 . THE PEPELARNICA STRUCTURAL UNIT The Pepelarnica Structural Unit (Figs. I & 3, II) is separated from the Krivi Put Unit by a wide crushed and doiomitised zone. Such a wide zone probably resulted from Neotectonic reactivation of the inherited reverse fault of Dinaric strike into the dextral strike-slip fault. This structure is only peripherally encompassed by the profile, in the part where it appears as a gentle syncline. However, northwestward it outcrops as a dis­ tinct structure. In its central part it is composed of the Dogger deposits, i.e. Lithostratigraphic Units C & D, while in the marginal parts Upper Liassic carbonates (Lithostratigraphic Unit B) outcrop. It is probable that the Krivi Put and Pepelarnica Units originally repre­ sented a single anticline-synclinc structure, which was subsequently destroyed by the reverse movement along the listric fault of SW vergence, with the vertical com­ ponent exceeding 1,000 III (Ti thonian and Upper Lias­ sic deposits are in contact). 3.3. THE TOMICI STRUCTURAL UNIT The Tomici Structural Unit (Figs. 1 & 3, III) is also in rcverse relation to the Pepelarnica unit, but with the opposite vergence. Along this backthrust, the vertical component of movement also exceeds 1,000 m (NW of the Tomici village a contact between Tithonian and Upper Liassic deposits also occurs). Deposits of this Unit, comprising Maim carbonates (Lithostratigraphic Units E, F & H) uniformly inclined towards the NE, are, in the area of the Lug polje, in a similar situation to the Dreznicko poljc arca in the neighbouring Dreznica Unit as they are compressed between a reverse listric fault with a large vertical movement from NE and a strong backthrust from SW. Both poljcs arc chara­ cterised by numerous large-scale sinkholes, which res­ ulted from Neotectonic reactivation of inherited Ter­ tiary faults. This reactivation, in the form of transpres­ sion, formed the new faults, the orientation of which (E-W strike) corresponds to the P ruptures in the newly established ellipsoid of deformation. Dcxtral moveme­ nts along their fault planes caused opening of deeply pcnctrative axial plane cleavage of the inherited Dinaric structures. 3.4. THE DREZNICA STRUCTURAL UNIT The Dreinica Structural Unit (Figs. 1 & 3, IV) could be divided into two parts. The southwestern part (Figs. I & 3, IV-A) is strongly tectonically disturbed, since the Oxfordian deposits (Lithostratigraphic Unit E) in its frontal part are uplifted in the form of an imbrica­ ted listric fan towards the west for approximate I y 650 III (the Oxfordian and Tithonian deposits are in contact). The backthrust along the southwestern margin of the Dreznicko polje has a vert ical componcnt of movement of approximately 700 m (uppermost Tithonian deposits of Lithostratigraphic Unit H are uplifted to the level of Aptian sedimentary rocks in the footwall). The polje represents a deformed syncline composed of Lower Aptian and Albian deposits (Lithostratigraphic Units K & L), pushed from the northeast along the fault with approximately 700 m of vertical movement (lowermost Neocomian and Albian are ill the contact). This fault forms a boundary with the northeastern part of the l"laticcc ct a l.: SIr.lIigraphy :mll T(.'c lon ic Relationships Along lhe Scnj · Ogulin Profile... 267 Drezn ica St ru ctural Uni t (Figs. I & 3, IV -B), which - The basic characteri st ics of 12 info rmallithost rati - represents a gcntl e, spaci ous antic line-syncline com­ posed mostly 01" Tithonian deposits (Lithostratigraphic Unit H), disturbed by a fault of uncertain characteris­ tics. Northeastward of thi s fault , the uppermost Kim ­ meridgian outcrops (Lithostratig raphic Unit F ,), but approximation of the amount of vertical movcment is very difficult. Namely, the major problem in the esti ­ mation of the vertica l component of movement in the northeastern part of the profile lies in the fac t that the Tithonian deposits, which were observed in the contacts along all fau lts, are very thick and lithologically homo­ ge neous. There fore, it is very difficult to de termine which part of the Tithonian succession is ex posed along thc rclat ively narrow area investigated by geological mapping along the profile line. 3.5. THE KLEK STRUCTURAL UN IT Along the profil e the Klek Structural Unit (Figs. & 3, V) begin s with a strongly tec tonically di sturbed zone. Ncotecton ic ac ti vity caused reacti va tion of the o lder rcvcrse fault s of Dinaric strike into the dextral strike-slip fau lts, which resulted in obscureness of the primary tectonic contac ts. However, from the sporadi­ cally visible rela tionships between the tectonic bound­ ary and the morphology it is clear that thi s is the inher­ ited reverse fault of NE vcrgence. The area near the fault is charac terised by strong crumbling of the foot ­ wa ll and a wide zone of tectonic brecc ia. With the exception of a narrow zone of Neocomian deposits (Lithostratigraphic Unit I) out cropping in the men­ ti oned tectonic zone, thi s Uni t is composed of the almo­ st com plete ly dol omi ti zed Tithonian deposits (Lithos­ tratig raphi c Unit I-I). Beds in the Kick Structural Unit are uniforml y incl ined towards the southwest. 3.6. THE HR ELJIN OGULINSKI STRUCTURAL UNIT The boundary between the I-lreljin Ogulinski Struc­ tural Unit (Figs. I & 3, VI) and the KIek Structu ral Unit is characterised by a reverse fault caused by movement of the Kick Uni t towa rds the northeast. Howcve r, because of the aforemen tioned problem with the esti­ mation of the thickness of the Tithoni an deposits, it is not possible 10 determine precisely the amount of verti­ ca l movemen t along the fau lt. However, the vertical com ponent of Ill ovement is important , since the cieposits of the footwall are of the uppermost Tithonian age (as ind icated in the vicinity by outcropping of the Lower Crctaceous in thc continuous succession). 4. REVIEW OF THE RES ULTS Some results of the present stu dy contribute to a bette r knowledge and undcrstand ing of the geo logical relat ionships in th is part of the Dinarides: graphic units, ranging in age from the Middle Liassic to the Albian have been determined, including their fo ssil assemblages, lithology and depositional environments. - The ex istence of laterall y different environments during the Kimmeridgian and Lowcr Tithonian is proven, as a consequence of palaeogeograph ic differ­ ences probably caused by synsedime ntary tectonic activity. - The tectogenesis of the Dinarides is the cUlllul ati ve effect of two tecLOnically act ive periods - Terti ary and Neotectonic. During the Tertiary tectonic cycle struc­ tures were formed by the NE-SW orientated compres­ sional tectonics (structures of the Dinaric strike). Sub­ sequentl y these structures were reshaped by the trans­ press ional Neotectonic activity, when the older faults were reactivated into the dextral strike-slip fault s by the change of regional stress direction to the N-S. However, in the study area traces of the Neotectonic activity are very common , and arc mainly represented by gent le striae, but the inherited Tertiary structures are still well preserved. Therefore, it may be concluded that the influence of the Neotectonic ac tivi ty in the area of the inves tigated profile should not be overstated. - The structures of the N-S strikc (i.e. the Krivi Put Structural Unit) , whi ch are different from the Dinaric strike, show no signs of subsequent rotation. This fac t, together with other indicators of Ncotectonic acti vi ty, indicate that thesc st ructu res are the result of the syn­ genetic bending along the strike, probably ca used by the local deviation of stress during the Tert iary tectonic cycle. Sincc the presented result s were obtained on a sin­ gle profile through the Dinar ides (although invest igated in deta il , and alm ost 4S km long) they do no t allow comprehensive concl usions to be drawn about the rela­ tionships of a regional area. However, they complement additional data, including seismi c in ves tigati on and study of other profiles, and certainly represent a contri ­ bution to a more complete knowledgc of the structure of the Dinarides. 5. REFER ENCES GRIMANI, I. , SUSNJAR, M. , BUKOVAC, J., MI­ LAN , A., NIKLER , L., CRNOLATAC, I. , S IKIC, D. & BLASKOVIC, I. ( 1973): Osnovna geo loska kana SFRJ 1:100.000. Tumac za li s t Crikvenica L33- 102 (Geology of the Crikvenica Shect).- Insl. geo l. istrai. Zagreb ( 1963), Say. geo l. zavod, Beograd, 47 p. MAMUZIC, P. & MILAN, A. ( 1973): Osnovna geo­ loska karta SFRJ I: 100.000. Tumac za list Rab L33- 11 4 (Geo logy of the Rab Sheet).- Institut za geoloska istrazivanja Zagreb (I966), Savezni gco­ loski zavod Bcograd, 39 p. 26S MAMUZIC, P. , MILAN , A. , KOROLIJA , B., BORO­ VIC, I. & MAJCEN, Z. ( 1969): Osnovna geoloska karta SFRJ I : 100.000. Li st Rab L33-1I4.- Institut za gcoloska iSlrai ivanja Zagreb ( 1959-1965), Savczni geo!oski zavad Beograd. SUSNJA R, M., BUKOVAC, J. , NIKLER, L., CRNO­ LATAC, I. , MILAN, A., SIKIC, D. , GRIM ANI, I. , VULlC, Z. & BLASKOVIC, l. (1970): Osnovna geo loska karta SFRJ 1: 100.000. Li st Crikveni ca L33- 102.- Insl. geol. istraz., Zagreb ( 1961 - 1969), Say. geo!. zavod, Beograd. VELlC, I. & SO KAC, B. (1981 ): Osnovna geoloska karta SFRJ I :100.000. List Ogulin L33-103.- Geol. Geologia Croaticil 5012 zavod OOUR za geol. paleonl. , Zag reb (1971- 1986), Sav. geol. zavod, Beograd. VELIC, I. , SOKAC, B. & SCA VNICA R, B. ( 1982): Osnovna geoloska kart a SFRJ I: 100.000. Tumac za list Ogulin L33-103 (Geology of the Ogulin Sheet).­ Geol. zavod OOUR za gco l. palconl. , Zagreb (1980), Say. geol. zavod, Beograd, 46 p. VELlC, 1. , VLAHOVIC, I. & TISLIAR, J. (1994): Late Jurass ic lateral and vertical facies distribution: from peritidal and inner carbonate ramps to pc ri recfai ancl peritidal deposits in SE Gorski Kotar (C roat ia). ­ Geologie Mediterraneennc, XXl/3-4, 177- 180. Manuscri pt received Apri l 14, 1997. Revised manuscript accepted November 10, 1997.