Fo Ra Mini Fera from the Late Ju Ras Sic and Early Cre Ta Ceous Car Bon Ate Plat Form Fa Cies of the Southern Part of the Crimea Mountains; South Ern Ukraine
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Annales Societatis Geologorum Poloniae (2007), vol. 77: 291–311. FO RA MINI FERA FROM THE LATE JU RAS SIC AND EARLY CRE TA CEOUS CAR BON ATE PLAT FORM FA CIES OF THE SOUTHERN PART OF THE CRIMEA MOUNTAINS; SOUTH ERN UKRAINE Mar cin KRA JEWSKI1 & Bar bara OLSZEWSKA2 1 AGH Uni ver sity of Science and Tech nology, al. Mickiew icza 30, 30-059 Kraków, Po land, kra mar@ge olog.geol.agh.edu.pl 2 Polish Geo logi cal In sti tute Car pa thian Branch, ul. Skrzatów 1, 31-560 Kraków, Po land, bar [email protected]. Krajewsk i, M. & Olszewska, B. 2007. Fora mini fera from the Late Juras sic and Early Cre taceous car bonate platform fa cies of the south ern part of the Cri mea Mountains; South ern Ukraine. An nales So cie ta tis Ge olo go rum Po lo niae, 77: 291–311. Ab stract: Upper Ju ras sic and Lower Cre ta ceous de posits of the Cri mea Pen in sula are rich in micro fossils frequently used for stra tigraphic inter pre ta tions . In case of foramini fera the research has been car ried predom i- nantly on as semblages ob tained by washing the rock sam ples. The present pa per is based on in ves ti ga tions of thin sec tions from the more in du rated sedi ments that sel dom were objects of study. Its goal was to ob tain ad di tional in for mation on age and en vi ron ment of sedi ments studied. Over 250 thin sec tions from 16 surface out crops yielded abun dant fora mini fera from which over forty are de scribed herein. Many fo rami nif eral spe cies (e.g. Labiryn thina mirabilis, Pa rur gonina caelin en sis, Neok ili an ina ra honen sis, Amijella amiji, An chis pi ro cyclina lu si tanica) are stra tigraphi cally sig nifi cant and known from the Kim meridgian–Ti tho nian of the Medi ter ra nean Te thys. The Early Cre ta ceous fauna is repre sented by Pro topen eroplis ul tra granu lata, Ever ti cy clam mina kel leri, Nau ti lo cu lina bron ni manni, Mon sale via saleven sis, Mayn cina bul garica. Gen er ally, the in ves ti gated fauna is typi cal for pa leoen vi ron ment of the car bon ate plat form. Older (Kim me ridgian–Ti tho nian) as sem blages rep re sent in ner part, younger (Ber ria sian) outer part of the plat form. Paleo geo graphic dis tri bu tion of many spe cies de scribed from the stud ied area in di cates its af filia tion with cos mopoli tan bi ota known from the north Te thyan shelf. Ad di tion ally few cal care ous cysts of di no flag el lata have been iden ti fied and de scribed. Key words: fo ra mini fers, di no flag el lata, Up per Ju ras sic, Lower Cre ta ceous, Cri mea. Manu cript re ceived 9 July 2007, ac cepted 17 De cem ber 2007 IN TRO DUC TION from thin sec tions (Fig. 1A). The exam ined sam ples yielded rich foram inif eral fauna, which can be used for stra tigraphi - The Cri mean mi cro fos sil stra tigra phy of the Up per Ju- cal and en vi ron mental in ves ti ga tions. Based on mi cro fau nal rassic –Lower Creta ceous depos it s has been based mainly on data, the paper pres ents the result s of new studies from bed- fora mini fera de scribed by Rus sian and Ukrain ian pa le on - ded and massive fa cies of the Up per Ju ras sic sedi ments tolo gists (vide Kuznet sova & Gor batchik, 1985; Gorbatc hik which rep re sent cen tral part of the Cri mea Moun tains. & Kuznetsova, 1994). In major ity of cases, micro fos sil s were ex tracted from soft or mod er ately com pact rocks by wash ing sam ples with wa ter. Mi cro pa le on to logi cal stud ies GEO LOGI CAL SET TING of thin sec tions were rare (Vo loshina et al., 1965; Gorba- tchik & Moha m ad, 1997). Indu rated rocks, however, supply The Crim ea Moun tains occupy the southern, mari time very im por tant pa le on to logi cal in for ma tion use ful in strati- part of the Cri mea Pen insula and form a narrow belt extend - graph i cal or pa leoen vi ron men tal in ter pre ta tions (Sliter, ing nearly W–E at a distanc e of more than 150 km (Fig. 1989, 1999). This encour aged present authors to com plete 1A). The basem ent of the Up per Juras sic rock shows a com - mi cro bi os tra tigra phy of the Up per Ju ras sic sedi ments of the pli cated structure , includ ing a number of in trusive bod ies, SW segm ent of the Crim ea Moun tains based on the data thrusts of cha otic com plexes, faults and tec tonic melange s 292 M. KRAJEWSKI & B. OLSZEWSKA Fig. 1 Lo cal iza tion study area. A. Upper Ju ras sic–Lower Cre ta ceous de posits in the Cri mea Mountains; af ter Yudin 2001, simplified. B. Lo cal iza tion of sec tions be tween Iograf Ridge and At-Baœ Moun tain (Nik ishin et al. 1998; Yudin, 1999, 2001; Mileev et al., formably mainly overli es folded flysch strata of the Tauride 2006). se ries (Up per Trias sic–Lower Ju ras sic; Fig. 2). Five main The main ridge of the Crim ea Moun tains include s an al- se ries were dis tin guished within the Cri mea Moun tains: lochthonous com plex that is com posed of thrusts of Upper Eskiorda, Taurida, Kara dag, Sudak and Yaila (Fig. 2; Juras sic and Lower Cre taceous rocks. This com plex uncon - Mileev et al., 2006; cf. Leshukh et al., 1999). FORAMINIFERA FROM THE LATE JU RAS SIC AND EARLY CRE TA CEOUS, UKRAINE 293 Rocks build ing the main part of the Cri mea Moun tains span a time inter val be tween Cal lovian and Ber ria sian (Su - dak and Yaila Serie s), al though strati graphic se quence is some times dis turbed due to com pli cated tec tonic de for ma- tions (cf. Mileev & Bara bosh kin, 1999), and addi ti on ally in cer tain re gions strata of some stages do not oc cur at all. De- po siti on in the Crim ea Moun tains area procee ded in a back- arc ba sin, which was filled with shal low- to rela tively deep- wa ter marine sedim ents, close to land ar eas within marginal parts of an epicon ti nental basin that surrounded the Te thys from the north (Zonnen shai n & Le Pichon, 1986; Golonka, 2004). The Crim ea Moun tains are subdi vided into sev eral smaller massifs (called Yaila), up to 1.500 m a.s.l. Indi vid - ual massifs , al though situate d side by side, fre quently rep re- sent tec toni cally iso lated frag ments that are char ac ter ised by dif fer ent mor phol ogy, li thol ogy and stra tigraphic po si tion of Up per Ju ras sic and Lower Cre taceous strata. The sub ject of in ter est: the Aj- Petri and Jalta Yaila massifs (Fig. 1B) are mainly com posed of Titho nian and Ber ria sian rocks be long- ing to the Yaila Se ries (Kra jewski & Olszewska, 2006; Mileev et al., 2006). The gross part of Aj- Petri and Jalta Yai las is mainly com posed of thick com plexes of bedded limestone s, show- ing variable bed thicknesse s: from finely laminate d to thick-bedded ones. Thin- bedded marly limestone s are ubiq- ui tous. Mas sive lime stones fa cies of car bon ate build ups oc- cur rarely within car bon ates of the area. The stud ies of bed - ded and massive fa cies in the west ern Cri mea Moun tains in - di cate that the Aj- Petri and Jalta Yailas mas sifs are mainly built up of limestone s repre sent ing mostly shallow wa ter fa- cies (pe loi dal, on coi dal, de tri tal, coral, stro ma to por oid, mi- cro bial and marly) as well as sandy lime stones and sand - Fig. 2. Gen eral stra tig ra phy of the Cri mea Moun tains af ter Mileev et al., 2006; mod i fied stones (e.g., Leshukh et al., 1999; Kra jewski & Olszewska, 2006; Mileev et al., 2006) Further more, due to com pli cated tecton ics in some ar- eas, the strata are disturbe d (Mileev & Ba raboskhin, 1999) METH ODS and it is dif fi cult to es ti mate thick ness of the de pos its and its stra tigraphy. Ac cording to some older papers, the total The pre sented mate rial was col lected from mas sive and thickness reaches a few thou sand meter s, but it is proba bly a bedded limestone s and from marly limestone s. A few hun- tectonic ef fect (cf. Le shukh et al., 1999).