17 - 19. The Barremian-Aptian carbonate platform from the Resita-Moldova Noua Zone. (S.W. Romania). Paleontological markers and configuration. I. I. BUeUR·.
Glolo,M MIdUIln'llAMIIA6 Tame XXI. n- 3-4. 1994. pp. 17 - 19.
The Barremian-Aptian carbonate platform from the Resita-Moldova Noua Zone (S.W. Romania). Paleontological markers and configuration.
I. I. BUeUR·
The carbonate platform deposits of BarremianAptian age from the Resita-Moldova Noua zone (S.W. Romania) have been divided into two lithostratigraphic units :
e,elacea, BakaJovaella elitzae and Ko,kyrella ? ivanovici account few the Upper Barremian-Aptian age of the Va1ea Minisului Limestones. Considering these ass0ciations I have auempted (BUOJR, 1991 a) a biozonatim of the Barremian-Aptian interVal (Fig., A).
1) The Valea Nerei Limestone Member (the upper subunit of the Pl~ Limeslooe Foonation).
The various typeS of sediments in the two lithostratigraphic units can be ascribed, to 8 specirlC environment, of the carbonate platfonn system. Carbonate sediments from inu:r-supratidal, 10 the upper slope (tircalillOOll) are identified. These types of deposits underwent 8 certain areal distribution and 8 significant sequential position in time, whicb characterised the plalfonn configuration in the various saeps of its evolution (Fig. B),
2) The Valca Minisului Limestone Formation (RAl-
LEANU .. Ill.• 1957 ; BUCUR. 1991b). The two units represent a bioscdimentary system of urgonian type. Both units contain a rich foraminifera and calcareous a1gae assemblage, some spedes being good bios tratigraphical markers. ParacoskinoUfUJ ? jourdan.tflSis, C,~llopsis lhieuloyi and Palaeodictyocontu cJlvillie,i were recorded in the Valca Nerei LimesIOneS. Acoo«ling 10 ARNAUD-VANNEAU (1980) this orbilOlinid assemblage characterises the Lower Barremian. AngioporeUa ! o Jlryae, lIeteropo-,dla ? paucicalearea and Salingopo,ella genelleflSis are the species of a rich dasyclad association that occur only in this lithostratigraphic uniL On the other hand, the pre-sence of an orbitoUnid assemblage with Paracoskiltolilla maynci, PaJ~odiCryoCO,.1U arabiclLS , P,~o,bilolifUJ cormyi, Palo,biIolina knJicuJaris, Mesorbi1OliM taana, and of a dasyclad assemblage in which the most significant species are Praturlonella danilovcu:, Neomuis
., University Babca.BoIyai, Dcp.nmmt01 Geoqy-Paleootoloo. M. Kosalniccanu m . 1, 3400 Ouj·Napoca, Romania.
During the Lower Barremian (Valea Nerei limestones) the carbanare platform was locally rimmed by coral reefs (less frequently by oolitic sboals), behind which "lagoons" with dasyclads and foraminifera largely developed. Rudist assemblages were also presenL Within the intertidal envirroment, thick fenesara.l dep0sits were fonned, while in the supraliUOtal (supratidal) environment penecontemporaneous dolomitization occured sometimes. Within the Upper BarremianGargasian interval, Ihe plalform configuratioa underwent some changes. The coral reefs were stiD present. mostly in the upper pan of the interval (Gargasian), but the oolitic facies had 8 greater extension, forming sometimes oolitic barries. Rudists are more frequenL The "lagoons" with dasyclads and ftnminifera, as well as the fenesual facies are also present, but 8 new element is represented. by the IUrigenous channels with orbilOtinids. They generated the orbitolinid beds, s0metimes true " lumachelles" characterizing the Valea Minisului Limestones.
18
A BIOZONES MINIS VALLEY NERA VALLEY
700
o
7EI5lZB:lli 3[';1';] 4 9 5~ 6~
MiTd
~ 91jloEd1~
F1gw-e A · UtllOItnti&raptlk: -=eeIIIOII ud bkwMla&.l_ of Ute BarTalLa.-Apu.. arbolla&e depoIMI " - Ute Il.tlltII· MoIdoq Nwa . . . . l -micritic tune.tone.. ; 2 • biopehpuilic Jimea1onet; ; 3 • biocIaJQc ~ ; .. . oolitic IimeaoneI ; 5 '(c:natnJ ~ ; 6 • ..tal ~ ; 7 • marlylimellOneS; 8 • marlJ ; 9 - tandyd ayl ; 1(l · IIDdROnel : J 1 - metamorpbic rockJ (MWPE : referlO the rawn] I)'pet at OunbIm'. c1uWlCIo -
"'"
19
--
B
1!llIi!l' Ill> mil> ~ I!!Il'
§
UPPER APTIAN
LOWER BARREMIAN
F\eure B - Tentatlv~ reconstnacUon oItbt "'uri!onLaIl" alrbona&e platform from the iteslta·Mo&do.-. NOIUI zone durina tlIe 1.0"".. BarranLa. and tbe Upper A.ptian - I - pre-Cretaceoul T(l(:;k. ; 2 - oonl ~; 3 - oolitic-bioclutic lirneltOne&; 4 - bicmiailic limwonea Milt duycladl. fonminifenl and rudiru: ; ~ • b&opWparitic limef;tonef; : 6 - f-.trallimwone.l.
REFERENCES ARNAUD·VANNEAU A. (1980) - Micropaleontologie. palootcologie et stdimentoiogie d'une platefocme carbonatre de 1a marge passive de 1a Tethys:
DUCUR I.-I. (1991b) - Propositioo pour une nomenclature formelle des depOts paleozoiques et mesozoiques de 1a zone de Resita-Moldova Noua (Carpathes
I'Urgonien du Vercors seplenuionaI et de Ia chartreuse (Alpes occidema1es). G~ologu AlpiM. mtm. 11,874 p., Grenoble.
Mmdionales. Roumanie). Sludia Univ. Babes-Bolyai, Geologia, XXXVI. 2. 3-14, Cluj-Napoc.a.
DUCUR 1.·1. (1991a) - Studiul Jurasicuiui si Cretacicului din unele perimetre de perspecliva pentru carbunii liasici. intre Yalea Minisului si Valea Nerei
(companimcnwi central at zooci Resita, Banal). Ph. D Thesis, 223 p., 100 pL, Quj-Napoca.
RAlLEANU G.-R., NASTASEANU S. et MUTI· HAC V. (1957) - Cercelari gcologice io regiunea diotte Anina si Doman (zona Resita-Moldova Noua). Bill. Acad. R. P. R.• Geol.-Geogr .• II. 2. 289-310, Bucuresti
