ACTA PALAEONTOLOGICA ROMANIAE V. 6 (2008), P 253-277.

GEOTECTONIC CONTEXT AND PALYNOLOGICAL ARGUMENTS FOR / BOUNDARY IN THE METAMORPHITES OF TULGHEŞ GROUP FROM EAST CARPATHIANS, ROMANIA

Leonard OLARU1

Abstract: Establishing the stratigraphical boundaries within the metamorphic formations is difficult to achieve due to the complexity of the geological and tectonic factors, which contributed to the spatial definition of these formations. During our study, we focused our investigations on the upper formations of Tulgheş Group from East Carpathians, also known as Arşiţa Rea Formation (Tg. 4) from Bălan area. The present metamorphic formations of Tulgheş Group initially had a sedimentary feature, subsequently being affected by tectonic factors and by metamorphism. In spite of this, they preserve the arguments of the sedimentary stage, represented by the content with acritarch and assemblages. The tectonic and structural changes of these initially sedimentary formations are mainly the result of the collision between East-European Craton (EEC) and the rigid Central European Platform. As a result of this collision, there was a repeated overthrust of these formations from Tulgheş Group, E-W oriented, over the stable and calcareous platform of Rebra Group (Munteanu, Tatu, 2003). All these formations were initially affected by the Caledonian metamorphism and subsequently by the Varistic one. Besides the overthrusting and the metamorphism phenomena, there was a lithological, structural and palynological mixture of all the affected formations. The initial organic elements, the acritarchs and the , due to their constitution, survived the metamorphic and tectonic phenomena, which affected these formations, and nowadays it represents the only important arguments for the biostratigraphical study and the regional correlation. The stratigraphical boundary for Cambrian/Ordovician is difficult to be established due to the lack of the faunistic remains (trilobites, graptolites, conodonts), or because of the mixture between the existent acritarch and chitinozoan assemblages. In spite of all, the presence of some marker-elements for a stratigraphical boundary, such as Coryphidium bohemicum, Acanthodiacrodium angustum, Conochitina symmetrica, Conochitina raymondii, Lagenochitina esthonica, Desmochitina bulla, allowed us to establish that the Cambrian/Ordovician boundary is included within Arşiţa Rea Formation (Tg. 4), considered to be Arenigian age (Lower Ordovician). This boundary was also established by correlating the classical regions from Peri- Gondwanaland, Central and Western Europe, Baltic region, Laurentia and East-European Platform, using the comparison with the marker-assemblages of trilobites, graptolites and conodonts. With this correlation, there was established also the amalgamation feature of the acritarch and chitinozoan assemblages, also using the common coexistence of the Gondwanian, Laurential, Baltic, Central and East-European elements.

Key words: Palynology, Geotectonic context, Cambrian / Ordovician boundary, Metamorphites, Tulgheş Group, East Carpathians, Romania

Introduction represents an important safety factor for the The problem of the stratigraphical limits resulted conclusions. represents one of the main conclusions of Concerning the approached subject in the each study in the geological research. Thus, present study, on Cambrian - Ordovician the correct delimitation of the studied boundary within metamorphites from East formations is a first guarantee for the best Carpathians, we focused on the upper results every stratigraphical investigation. In formation of Tulgheş Group (Tg.4), also called order to have properly outlined stratigraphical Arşiţa Rea Formation. limits, the studies should impose solid Choosing this as an example is due to the arguments to justify these conclusions. fact that, generally, the lithological formations In approaching the problems of the of this group have a larger spreading nappes stratigraphical limits, firstly, there is necessary within East Carpathians (Vodă, Balintoni, a thorough and analytical study of the 1996), being present along all Central - East biostratigraphy and lithology of the under- Carpathian nappes: Bucovinic Nappe, study geological formation. Secondly, there is Subbucovinic Nappe and Infrabucovinic necessary a certain knowledge of a proper Nappe (Vodă, 2000). Thus, the formations of work methodology and of the work resources. Tulgheş Group, from the entire East On this basis, there is also necessary the Carpathian range, are the best studied, being existence of a comparison and correlation compared and correlated with other orogenic possibility of the obtained data to other studies and platform regions. and conclusions from classical regions. Not at least, for the metamorphites, the geotectonical Investigation methods context of their settlement has a major To approach the Cambrian - Ordovician importance in establishing a proper geological boundary within Tulgheş Group, we chose the and stratigraphical limit. At last, using multiple method of palynological investigations, with investigation methods for stratigraphical limits arguments from acritarch and chitinozoan 1 “Al. I. Cuza” University of Iaşi, Department of Geology, Bd. Carol I, no. 20A, 700505, Iasi, Romania, e-mail: [email protected]

L. OLARU assemblages, the only markers of the organic rocks. Both types of rocks suffered deep world, preserved in the aquatic basin where transformations during the different the primary sediments deposited, and which, metamorphic and geotectonic phases. subsequently, were tectonized and Therefore, parametamorphites and metamorphosed, representing today the orthometamorphites came out, which form the formations of Tulgheş Group. The other present assemblage of metamorphic rocks arguments of the biostratigraphical from the Mesozoic - Crystalline of East investigation, using the sedimentary rocks Carpathians. equivalent in age, but unmetamorphosed and tectonically not disordered, such as Lithological content and geotectonic conodonts, graptolites, and trilobites, or other context of Tulgheş Group macroorganic rests are totally lacking within Tulgheş Group includes a series of these metamorphic formations. lithostratigraphical successions, named During our investigations we were always lithological formations or lithozones (Vodă, related and compared to the results and the Balintoni, 1996; Balintoni, 1997), recognized conclusions of geochronological, lithological, within the entire spreading area of East structural, and geotectonical studies on the Carpathians. same formations, which helped us a lot in Considering other opinions (Munteanu, having a real interpretation of our results Tatu, 2003), Tulgheş Group does not include a (Balintoni, 1997; Balintoni et al., 1983; Bercia succession of lithostratigraphical terms, but et al., 1976; Kräutner, 1987, 1997; Kräutner, discontinuous parts of an insular arch. The Bindea, 2002; Munteanu, Tatu, 2001, 2003; complicated problems appear at the lower and Mureşan, 2000; Săndulescu, 1976, 1980a, the upper parts of this group, where the limits 1980b, 1984; Zincenco, 1995). For verification of the succession or of the compounding and for the safety our interpretations we had elements are much affected by the geotectonic permanently made biostratigraphical phases (Vodă, 2000; Olaru et al., 2003-2004; correlations with the platform regions, with Munteanu, Tatu, 2003) (Figure 4). As we sedimentary rocks, tectonically not disordered mentioned, Tulgheş Group has the largest and unmetamorphosed, where continuous spreading in East Carpathians, starting with lithological successions were able to be Maramureş Mountains, go on with Bistriţa tracked, within drillings approached in complex Mountains, Giurgeu and Ciuc Mountains, with stratigraphical studies. Thus, there were its last emergence in Perşani Mountains, created parallel acritarch, chitinozoan, respectively Gârbovei Massif (Balintoni, 1997; conodont, graptolite, and trilobite biozones. Vodă, 2000). Therefore, in these regions not only Tulgheş Group presents a varied lithology, biostratigraphical conclusions came out, but prevailing quartzitic - feldspar rocks, besides also palaeoecological, palaeoenvironmental, black and white quartzites (Balintoni, 1997; palaeogeographical and palaeotectonical, too. Vodă, 2000). The carbonatic rocks are weakly The chances and the advantage of using represented, occurring mainly at the lower part acritarch and chitinozoan assemblages in the of Tulgheş Group; in the rest – as rare biostratigraphical study and in approaching the intercalations, same as the metabasites. At the stratigraphical limits in metamorphic lower and the median parts of Tulgheş Group formations are represented by the fact that (Tg.2 and Tg.3) it stands out the abundance of these cellulose or chitinous palynomorphs manganese in the quartzitic - graphitous rocks fossilized themselves within the primary and of metallic sulphures in volcanic - sedimentary rocks, deposited in the pre- sedimentary rocks. These types of rocks, metamorphic oceanic basins. Subsequently, besides feldspar quartzites lead to the these sediments, including the comprised hypothesis that Tulgheş Group formed in a organic elements, were metamorphically nearby insular arch basin (Balintoni, 1997). transformed and affected by the successive Also, the presence of metarhyolites in the orogenic and geotectonic phases, therefore median formation (Tg.3) from Bistriţa nowadays these palynomorphs represent Mountains shows they occur in a volcanic arch organic evidence of an initial, oceanic, tectonic environment (Munteanu et al., 1999). primitive organic life from the pre- On the other hand, the basic rocks represent metamorphical stage of the present day intercalations at the basis of the metamorphites. Thus, all metamorphic rocks lithostratigraphical succession of the acid which include microorganic rests initially were metavolcanites (metarhyolites) formation sedimentary rocks, and those having no (Tg.3) from Bistriţa Mountains, organic rests come from former magmatic

254 GEOTECTONIC CONTEXT AND PALYNOLOGICAL ARGUMENTS FOR CAMBRIAN / ORDOVICIAN BOUNDARY IN THE METAMORPHITES OF TULGHEŞ GROUP FROM EAST CARPATHIANS, ROMANIA

Figure 1. Lithostratigraphical succession of the Tulghes Group on Bucovinic Nappe from Bistritei and Bucovinei Mountains (Lucina – Pojorata – Brosteni Region after Kräutner et al. 1988).

255 L. OLARU from Crucea – Broşteni - Borca region and in the left flank of Puzdra Brook (Vodă, 1986, from the phyllitous, quartzitic formation (Tg.4) 2000). Considering the lithological limit, it is from the regions of Fundu Moldovei, Broşteni, interesting the normal position of this formation Bălan and Sândominic. These intercalations over the acid vulcanite formation (Tg.3). Arşiţa have intermediary characteristics between Rea Formation (Tg.4) starts with a terrigenous oceanic ground basalts and insular arch sequence of thin black quartzites, followed by basalts, a compatible interpretation with the blackish schists and quartzites in plates, sedimentation hypothesis of Tulgheş Group in graded and with microconglomerations at the a back-arch basin, with oceanic crust (Vodă, base of the lithological banks (Figure 3). Thin 2000). The content of organic rests, acritarchs layers of tuffogenous, basic, greenish schists, and chitinozoans of the metamorphites from grey phyllites, crystalline limestones and Tulgheş Group shows they have an initially quartzitic - feldspar rocks with chlorite occur as sedimentary origin, thus, they are intercalations (Vodă, 1986; 2000). Other paramorphites. authors even encourage the idea of a mixture Lithologically, Tulgheş Group or Tulgheş between Tg.3 and Tg.4 formations, Lithogroup (Balintoni, 1997) includes a subsequently metamorphosed into green succession of four formations (Vodă, Balintoni, schist facies, possibly representing fragments 1996; Vodă, 2000), or lithozones (Balintoni, of the oceanic crust (Bercia et al., 1976). This 1997). Considering other authors (Munteanu, mixture of the rocks from Tg.4 formation is Tatu, 2003), Tulgheş Group consists in four also confirmed by the amalgamation of discontinuous parts of an insular arch. In order different age palynomorph assemblages to ease the explanation, these formations are (acritarchs and chitinozoans). This formation noted as Tg.1 - Tg.4 (Vodă, 2000). These ends the lithostratigraphical succession of formations are best represented in Bucovinic Tulgheş Group in East Carpathians. Nappe, from Broşteni region (Vodă, 1986), in The geotectonic context the sediments of stratigraphical order (Figure 1), as it follows: Tulgheş Group deposited may be observed on 1. Căboaia Formation (Lithozone) (Tg.1) is the normal succession of constitutive deposits, mainly terrigenous, non-graphitous, occurring considering the characteristics of the acid and on restrained areas southward Zugreni, in the basic volcanic products and the products of basement of Bucovinic Nappe and on the the associated metallogenesis. upper stream of Vaser, in Maramureş, in the The lithological succession of Tulgheş basement of Subbucovinic Nappe. Group is monotonous, terrigenous, 2. Holdiţa Formation (Lithozone) (Tg.2) is represented by sericitic-chloritous schists, quartzitic, graphitous, occurring on the entire often with graphite, black and white quartzites, spreading area of East Carpathians, both in metagraywacke and rare intercalations of the basement of Bucovinic, and Subbucovinic carbonatic rocks and products of an acid and Nappes. The presence of graphite confers a basic volcanism (Figure 1, 3). The large black color, therefore easy to recognized, with thickness of the deposited sediments shows a as a guiding mark lithological position by the powerful subsidence, the rich pyroclastic presence of black quartzites, and as a material deposited in this sedimentary basin palynostratigraphical guiding mark for the significantly influenced the composition of “explosion” of many genders and species of different lithological sequences, as well as the Lower Cambrian acritarchs. This formation basinal sedimentation conditions. After ending also includes premetamorphic mineralizations the volcanic processes, the sedimentation of Fe-Mn and barite. continued in the same conditions, with 3. Leşu Ursului Formation (Lithozone) prevailing black, terrigenous, graphitous (Tg.3) is well represented in the area of East deposits, rich in organic rests. This situation Carpathians, being characterized by an acid also may be observed in Arşiţa Rea Formation volcanogenous - sedimentary sequence (Tg.4). It is possible the sedimentary basin (metarhyolites) with important accumulations should have a smaller depth, and a greater of stratiform metallic sulphures. mobility (Vodă, 2000), also to be observed in 4. Arşiţa Rea Formation (Lithozone) (Tg.4) Arşiţa Rea Formation (Tg.4), where it is is phyllitous, quartzitic and has a reduced situated the shift between graded quartzites to spreading, although has a large thickness fine schists, and then to thicker (2,000 m). This formation occurs only in metagraywacke sequences. If we consider the Bucovinic Nappe and in the digitations from its manganese abundance in quartzitic - front, Bălan and Sândominic (Figure 2a, 2b). graphitous Holdiţa Formation (Tg.2), as well as The best representation occurs in Broşteni the metallic sulphures from volcanic- region, open in the right flank of Neagra sedimentary Leşu Ursului Formation (Tg.3), Broştenilor Brook (Arşiţa Rea) and northward, besides the prevailing types of rocks, the

256 GEOTECTONIC CONTEXT AND PALYNOLOGICAL ARGUMENTS FOR CAMBRIAN / ORDOVICIAN BOUNDARY IN THE METAMORPHITES OF TULGHEŞ GROUP FROM EAST CARPATHIANS, ROMANIA

Figure 2a Geological column of the Upper Formation (Tg. 4) Tughes Group from the Balan Formation (after Kräutner & Bindea, 1995).

257 L. OLARU

Figure 2b Geological column of the Upper Formation (Tg. 4) Tulghes Group from the Sândominic Formation (after Kräutner & Bindea, 1995).

258 GEOTECTONIC CONTEXT AND PALYNOLOGICAL ARGUMENTS FOR CAMBRIAN / ORDOVICIAN BOUNDARY IN THE METAMORPHITES OF TULGHEŞ GROUP FROM EAST CARPATHIANS, ROMANIA

Figure 3. Lithostratigraphical column of the Tulghes Group on Bucovinical Nappe from Brosteni (1:20 000) after Voda (1986, 2000) 1. feldspar greenish quartzites; 2. graphitous black quartzites; 3. crystalline limestones; 4. metagraywackes; 5. basic – tuffs green schists; 6. white quartzites; 7. sulfure mineralizations; 8. acid metavolcanites (rhyolites); 9. white quartzites and microconglomerates; 10. sericite – chlorite ± graphite schists with albite porphyroblasts.

259 L. OLARU feldspar quartzites and the quartzous rocks, it 1994, 1997, 2001, 2002, 2005; Olaru, comes out the hypothesis that Tulgheş Group Apostoae, 1994-1995, 2003; Olaru, Apostoae, formed in a nearby volcanic arch basin Apostoae, 2003-2004; Olaru,Lazăr, 2005; (Balintoni, 1997). Vodă (2000) stands for a Vaida, 1999; Horaicu, 2000; Mureşan, 2000. similar conclusion, mentioning that the metarhyolites from volcanic-sedimentary Geotectonic and palynological aspects formation (Tg.3) shows a depositing in a at Cambrian - Ordovician boundary and of volcanic arch tectonic environment. According Arşiţa Rea Formation (Tg.4) of Tulgheş to a quite similar hypothesis, other authors Group (Munteanu et al., 1999, 2000; Munteanu, Tatu, From the beginning, we remind that the 2001, 2003) assert that Tulgheş Group spatial position of this boundary should be, includes discontinuous parts of an insular considering some data known until now, volcanic arch. The fact that, in the phyllitous - between Leşu Ursului (Tg.3) and Arşiţa Rea quartzitic formation (Tg.4) from the regions of (Tg.4) lithological formations of Tulgheş Fundu Moldovei, Broşteni, Bălan and Group. As we mentioned before, there are Sândominic, the basic rocks have intermediary some hypothesis (Munteanu, Tatu, 2003), characteristics, between oceanic ground according to some older opinions (Bercia et basalts and insular arch basalts, the basic al., 1976; Kräutner, 1987), which consider that there is possible the sediments of Tulgheş the lithological formations of Tulgheş Group do Group to had deposited in a back-arch basin not represent stratigraphical sequences, but with oceanic crust (Vodă, 2000). correspond to different complex discontinuous Tulgheş Group is polymetamorphic, as well parts of an insular arch. As a result, Leşu as other lithological groups from East Ursului Formation (Tg.3) represents a part of Carpathians. The first metamorphism took the volcanic arch, and Arşiţa Rea Formation place in Early Caledonian, being proved by the (Tg.4) would represent the accretion wedge as K-Ar oldest ages (Kräutner et al., 1976), a result of the collision between Central - representing 470 M.a. Subsequently, the European Plate (CEP) with East - European second Varistic regional type metamorphism is Craton (EEC). Therefore, it is confirmed the known by the proof of some earlier K-Ar ages, lithological mixture of Arşiţa Rea Formation of 360-310 M.a. (Kräutner, in: Săndulescu, (Tg.4), including prevailing sericitous - 1989; fide Vodă, 2000). This second chloritous schists (Bălan Nappe), or sericitous- metamorphism is characterized by a high graphitous phyllites (Sândominic Nappe), with thermal gradient and low pressure. One of the intercalations of quartzites, recent hypothesis (Munteanu, Tatu, 2003) microconglomerates, green schists, endorsing that the structure of the crystalline metabasites, rhyolitic metavolcanites (Figure from East Carpathians is a mixture of 2a, 2b). It is possible this tectonic compounding parts from Gondwanaland amalgamation process to be included together (Avalonia) and from the East - European with the sediments of Tg.3 and Tg.4 Craton (EEC), and that these were affected by formations, therefore the impossibility of a single metamorphism (Caledonian), and the outlining the limit between these formations. second metamorphism (Varistic) affected only The weak consolidation of the initial sediments the Varistic lithological successions. This and their rough collision contact with East - hypothesis was previously put by Balintoni European Craton (EEC) represented the (1997), Kräutner (1997) and subsequently cause of the westward overthrust of the upper retaken by Kräutner, Bindea (2002). part of the latest, namely the deposits of The age of Tulgheş Group is approached Bretila Group, over the deposits of Rebra and by two methods, radiometric and Tulgheş Groups from the sedimentation basin palynological. The Pb-Pb radiometric method (Figure 4). The depositional finalization of the gave the most realistic age data (545-470Ma), sequences from Tulgheş Group took place in equivalent to the palynological data Upper Ordovician, and then in these corresponding to Lower Cambrian - Lower were affected by a Caledonian metamorphism, Ordovician (Arenigian). These values are also corresponding to the PT conditions, equivalent mentioned in the most recent Geological Time to the zone of garnets facies (Zincenco, 1995 Scale (Gradstein, Ogg, 1996). References fide Munteanu, Tatu, 2003). Thus, the over the age of the different formations from sediments of the accretion wedge, meaning of Tulgheş Group appeared in numerous studies Arşiţa Rea Formation (Tg.4), were intense of many authors: Iliescu, Mureşan, 1972; folded in a nape system, lithologically mixed Iliescu, Kräutner, 1975; Iliescu et al., 1983; and overthrusting the sediments of Leşu Olaru, Oniceanu, 1984, 1985; Olaru, Gunia, Ursului Formation (Tg.3), represented by more 1988; Olaru, Horaicu, 1989; Olaru, 1991, competent volcanic masses. As we mentioned

260 GEOTECTONIC CONTEXT AND PALYNOLOGICAL ARGUMENTS FOR CAMBRIAN / ORDOVICIAN BOUNDARY IN THE METAMORPHITES OF TULGHEŞ GROUP FROM EAST CARPATHIANS, ROMANIA before, there is possible that, in this collision metamorphism, in green schists facies, would and ovethrust process, a lithological had affected not only the Varistic successions amalgamation would also had place between (Balintoni et al., 1983; Balintoni, 1997), the two contact formations (Figure 4). The deposited on a continental crust, such as phenomena of tectonic distention started Repedea, Rusaia, Cimpoiasa Groups subsequently, in Silurian, after the depositional (Kräutner, 1997; Kräutner, Bindea, 2002). In ending of Arşiţa Rea Formation (Tg.4) and fact, the implication of low pressure continued until the end of Palaeozoic. metamorphism in the collisional event is very Moreover, the second Varistic-type improbable (Kräutner et al., 1975).

Figure 4. Tentative reconstruction of the Paleozoic amalgamation of the Crystalline - Mesozoic Zone. No scale implied. Rb – the Rebra Group; Ptr – the Pietrosu Bistritei porphyroids; Tg (Tg.1 – Tg. 4) – the Tulghes Group and its four formations; Br – the Bretila Group; Rb – Tg – the Rebra – Tulghes terrane. A - drift of the Rebra – Tulghes terrane toward EEC. B and C – colision of the Rebra – Tulghes terrane with EEC and thrusting of the Bretila terrane; onset of the pre-alpine thrustings. D – pre-alpine nappe stack is established and sedimentation is active in the Rodna rifting basin. E – the Rodna basin is closed and the thrusting of the Infrabucovinian Nappes in the Rodna Mountains has ceased. (after Munteanu, Tatu, 2003).

261 L. OLARU

If we analyze the microfloristic content of Laurentian Shield, Baltic Shield, East - Arşiţa Rea Formation (Tg.4), we find out a European Platform, Siberian Platform, and notable palynomorph mixture (acritarchs and Sinian Shield (Olaru, Apostoae, 2004; Olaru, chitinozoans), of different ages, Cambrian and Apostoae, Apostoae, 2003-2004; Olaru, 2005). Ordovician, also typical for other regions of Within the acritarch assemblage, there Upper Cambrian and Lower Ordovician (Olaru, were separated several subassemblages 1991, 2001, 2005; Olaru, Apostoae, 2004; which characterize more age intervals, Olaru, Apostoae, Apostoae, 2004; Olaru, between Upper Cambrian and Lower Lazăr, 2005). Ordovician (Arenigian). These show the All these studies were made on the palynological mixture from the members of constitutive rocks of Arşiţa Rea Formation Arşiţa Rea (Tg.4) Formation, proved by the (Tg.4) from Bălan area, Bălan and Sândominic lithological mixture of this formation, due to the Nappes. This lithological and, implicitly, overthrusting on the members of Leşu Ursului palynological mixture was previously Formation (Tg.3), considering the collisional mentioned in other studies (Codarcea - context they formed. Dessila et al., 1964; Kräutner, 1997; Kräutner, Bindea, 2002). These authors considered the The Upper Cambrian acritarch existence of Arşiţa Rea Formation (Tg.4) as assemblage the result of the frequent collision irregularities This assemblage is typical for Upper along the Crystalline - Mesozoic area that Cambrian and disappearing at its end (Table generated its varied and complex lithological 1). We found it incorporated within Arşiţa Rea composition, or even of the mixture between Formation (Tg.4), of younger age. It seems Tg.3 and Tg.4 formations, subsequently that the typical Upper Cambrian rocks were metamorphosed (Bercia et al., 1976). involved and incorporated within this Tg.4 Due to the collisional effect and to the rocks formation during the geotectonic collision and metamorphism, except the microfossils – such overthrusting events, because in the present as acritarchs and chitinozoans, which resisted lithological succession of Tulgheş Group there these phenomena –, there is no other organic is no Upper Cambrian Formation. This or macrofaunistic rest in these formations. formation has the following structure: Although there are lithological similitudes, Acanthodiacrodium snookense, between Arşiţa Rea Formation (Tg.4) and Veryhachium dumontii, Leiofusa formations from Avalonia and Baltica, just the stoumonensis, Orthosphaeridium extensum, presence of the organic microfosil rests above Pirea orbicularis, Ooidium cf. clavigerum, mentioned and their mixture create difficulties Cristallinium cf. randomense, of comparing and correlating with Acado-Baltic Trichosphaeridium annolovaense. (Avalonian) interval. In spite of all these Among the determined taxa, we remind as difficulties, there were possible zone taxa Acanthodiacrodium sp. and biostratigraphical correlations, both with Peri- Orthosphaeridium extensum, typical for RA5 Gondwanaland (Avalonian) space, and with zone, equivalent to the trilobite zone with the Baltic one (Olaru, 2001, 2005; Olaru, Peltura precursor and Peltura minor from Apostoae, 2004; Olaru, Apostoae, Apostoae, Random Isle, Newfoundland, Canada 2003-2004; Olaru, Lazăr, 2005). (Parsons, Anderson, 2000). From RA6 zone, corresponding to the Acritarch assemblages trilobite zone with Peltura scarabeoides, we An important argument for discussing the determined only Acanthodiacrodium Cambrian - Ordovician boundary was snookense, which was moving up from the represented by the establishing of a complex previous zone, and Calyxiella izhoriensis is acritarch assemblage (Table 1) from Arşiţa missing from our samples. Rea Formation (Tg.4), Bălan area, Bălan and From RA7 zone, equivalent to the lower Sândominic Nappes (Olaru, Lazăr, 2005 – in part of Acerocare zone, probably a subzone of press). Palynologically there were studied the previous one with Peltura scarabeoides, Arama Oltului Member from Bălan Nappe and we determined Poikilofusa squama, and the Başca and Pârâul Crucii Members from second typical species, Ladogiella Sândominic nappe (Table 1). Considering this rotundiformis, is missing in our samples. This assemblage, there were made correlations subzone was recognized also in with regions such as Gondwanaland, Avalonia, Newfoundland and in Scandinavia.

262 GEOTECTONIC CONTEXT AND PALYNOLOGICAL ARGUMENTS FOR CAMBRIAN / ORDOVICIAN BOUNDARY IN THE METAMORPHITES OF TULGHEŞ GROUP FROM EAST CARPATHIANS, ROMANIA Table 1. Range chart showing of stratigraphic distribution of acritarch assemblage in the Upper Formation (Tg.4) of the Tulgheş Group, Balan Zone (East Carpathians).

TAXONOMIC UNITS ANALYSED SAMPLES CHRONOSTRATIGRAPHIE 1 2 3 4 5 6 7 8 9 10 11 12 1 3 4 5 6 9 10 11 Cb.3 Trem. Aren. Acantodiacrodium angustum ● ● ● ● ● ● ● (Dow.) Comb. Leiosphaeridia sp. A. ● ● ● ● ● ● ● ●

Baltisphaeridium crinitum ● Martin Acantodiacrodium snookense Parsons & ● ● ● Anderson Acantodiacrodium golubii ● ● ● ● Fensome et al. Leiosphaeridia sp. B. ● ● ● ● ● ● ● ●

Veryhachium dumontii ● ● ● ● ● ● Vang. Baltisphaeridium aciculare ● (Tim.) Lunulidia lunula (Eis.) Eis. ● ● ● ●

Leiofusa stoumonensis ● ● ● ● Vang. Acanthodiacrodium lanatum ● ● (Tim.) Martin Orthosphaeridium extensum ● Parsons & Anderson Saharidia cf. fragilis (Dow.) ● ● ● Combaz. Polygonum minimum (Tim.) ● Volkova Impulviculus bibulbulus ● Parsons & Anderson Tasmanites sp. ● ● ●

Elenia armilata (Vanderflit) ● ● Volkova Polygonum sexradiatum ● (Tim.) Volkova Vulcanisphaera tuberculata ● (Downie) Eis. Cristallinium cambriense ● ● (Slavikova) Vanguestaine Buediingisphaeridium ● ● tremadocum Rasul Izhoria angulata Golub et ● Volkova Cymatiogalea gorkae ● Rauscher Acanthodiacrodium sp. ● ●

Pirea orbicularis Volkova ● ● ●

Dactylofusa squama ● ● (Deunff) Martin

263 L. OLARU

Baltisphaeridium setaceum ● (Tim.) Arbusculidium ornatum ● (Deunff) Martin Cristallinium pilosum ● Golub. et Volkova Vulcanisphaera capillata ● Jardiné Dactylofusa velifera Cocchio ● ● ●

Poikilofusa squama (Deunff) ● ● ● Martin Stelliferidium cf. stelligerum ● ● (Gorka) Deunff et al. Timofeevia estonica ● ● Volkova Cristallinium cf. randomense Martin Fensom et al., Ribb. ● & Vang. Ooidium cf. rossicum ● Timofeev Ooidium timofeevii Loeblich ●

Leiofusa sp. ● ● ● ●

Trachydiacrodium ● coarctatum Tim. Ooidium cf. clavigerum ● ● Parsons & Anderson Trichosphaeridium ● annovaelense Tim. Lophodiacrodium valdaicum ● (Tim.) Defl. et Defl.-Rigaud.

For RA8 zone, from Newfoundland, we Leiosphaeridia sp., Baltisphaeridium determined Ooidium cf. clavigerum, and crinitum, Acanthodiacrodium golubii, Striatotheca randomnensis is missing from our Acanthodiacrodium lanatum, Saharidia cf. samples. This zone might be equated to the fragillis, Polygonum minimum, Impulviculus median zone with Acerocare (Parsons, bibulbulus, Vulcanisphaera tuberculata, Anderson, 2000). Cristallinium cambriense, Izhoria angulata, For RA9 zone, equivalent to the upper part Cymatiosphaera gorkae, Arbusculidium cf. with Acerocare, we determined Ooidium destombesii, Cristallinium pilosum, Poikilofusa rossicum, and Nellia acifera is missing from squama, Ooidium cf. rossicum, Ooidium our samples. timofeevii, Leiofusa sp., Lophodiacrodium As we notice from the above mentioned valdaicum, Cymatiogalea cf. cuvillierii, data, there is possible a correlation between Cymatiogalea velifera. our separated assemblages and the biostratigraphical zones from West of Avalonia Tremadocian acritarch assemblage (Newfoundland region, Canada), where there Within the established complex is an obvious correlation with the trilobite assemblage, there is a subassemblage, biozones; the analyzed deposits that offered representative only for Tremadocian (Table 1), these faunistic assemblages are not where we mention: Acanthodiacrodium tectonized or metamorphosed. angustum, Baltisphaeridium aciculare, Lunulidia lunula, Elenia armillata, Polygonum Upper Cambrian - Tremadocian sexradiatum, Buedingiisphaeridium acritarch assemblage temadocum, Dactylofusa squama, Dactylofusa This transitional assemblage is also rich velifera, Baltisphaeridium setaceum, (Table 1), being represented by the following Vulcanisphaera cf. briatnnica, Stelliferidium cf. species: stelligerum, Vulcanisphaera cf. capillata.

264 GEOTECTONIC CONTEXT AND PALYNOLOGICAL ARGUMENTS FOR CAMBRIAN / ORDOVICIAN BOUNDARY IN THE METAMORPHITES OF TULGHEŞ GROUP FROM EAST CARPATHIANS, ROMANIA The taxa of this assemblage and part of the previous one (Upper Cambrian-Tremadocian) Arenigian acritarch assemblage are represented in the UK4B and OT1, OT2 Some species from our acritarch and OT3 “acritarch complexes”, from East - assemblage pass the Tremadocian - Arenigian European Platform, respectively Baltic boundary, continuing their evolution besides province (Volkova, 1995) and Moscow typical Arenigian taxa (Table 1). Among them, Syneclise (Volkova, 1999). These we mention: Acanthodiacrodium angustum, assemblages are equivalent in the mentioned Acanthodiacrodium lanatum, regions with the zones with conodonts, Acanthodiacrodium sp., Dactylofusa squama, graptolites and trilobites. Poikilofusa squama, Leiofusa sp., Therefore, for the UK4B acritarch Leiosphaeridia sp. assemblage (“acritarch complex”), equivalent An interesting case is represented by the to the zone with Peltura scarabeoides and species of Coryphidium bohemicum Vavrdova, Acerocare and that of the conodonts with whom Arenigian starts in the Prague Protoconodontus and Cordylodus andresi, we Basin, also being identified in Klabava found in our samples species such as: Formation (Vavrdova, 1965). This species Cristallinium cambriense, Cristallinium marks the entire Lower Arenigian-Upper pilosum, Ooidium rossicum, Elenia armillata. Arenigian interval from the Peri- This assemblage represents the Upper Gondwanaland region. Determining this Cambrian - Tremadocian boundary zone. species was difficult in the analyzed The typical OT1 assemblages formations, but several exemplars were found (Tremadocian from Estonia) starts with in Sândominic Formation, Pârâul Crucii acritarchs from Diacromorphita family (Lower Member, defining the Arenigian age of this Tremadocian), being equivalent to the trilobite formation. Coryphidium bohemicum zone with Acerocare, to the conodont zone represents a constitutive element of the with Cordylodus proavus and Cordylodus “messaoudensis - trifidum” acritarch intermedius, as well as to the graptolite zone assemblage from Prague region (Fatka et al., with Rhabdinipora flabelliforme. 2000), and from other locations from Bohemia, Also, in the Moscow Syneclise area, the Germany, Walles, England, Spain, Upper Cambrian - Tremadocian boundary is assemblage which includes besides marked by the UK4B-1 “acritarch complex”, acritarchs, chitinozoans and graptolites. This from the basis of OT1 assemblage with assemblage marks the Tremadocian - Cordylodus andresi. For equivalence with OT1 Arenigian interval in cold water marine assemblage, we determined the assemblage environment, around Gondwanaland with Acanthodiacrodium angustum, Izhoria (Avalonia), and among others includes species angulata, Cristallinium pilosum, Ooidium of Conochitina symmetrica (from rossicum, Ooidium timofeevii. chitinozoans), typical for Lower Arenigian, The second Lower Tremadocian which we also determined in the analyzed assemblage, OT2, from Baltic region (Estonia) samples in numerous exemplars. is represented by the species we determined, From the successive presentation of the among them we mention: Vulcanisphaera cf. acritarch assemblages, separated from the britannica, Baltisphaeridium setaceum, analyzed samples and correlated with the Lunulidia lunula, Baltisphaeridium aciculare, classical zone from regions of Newfoundland, Elenia armillata, Dactylofusa squama, East - European Platform and Prague Basin, Saharidia cf. fragillis, Acanthodiacrodium where there were established equivalences angustum. with the typical zone with conodonts, For this assemblage the equivalents are graptolites and trilobites, we are able to the conodont zones with Cordylodus establish the Lower Ordovician (Arenigian) lindstroemi and Cordylodus rotundatus – age to Arşiţa Rea Formation (Tg.4) from Bălan Cordylodus angulatus. area, where it was analyzed. The Cambrian - A third acritarch assemblage, OT3, from Ordovician boundary stands within this Upper Tremadocian, Estonia, is probably formation, being included in the transition equivalent with the graptolite zone with interval for the palynological Upper Cambrian - Clonograptus – Didymograptus deltifer Tremdocian and Tremadocian - Arenigian pristinus. elements. Due to the lithological and From our acritarch assemblage, we microfloristic mixture, this limit cannot be mention the characteristic Upper Tremadocian outlined on a lithological guide mark, species: Acanthodiacrodium angustum, representing a stratigraphical limit. Baltisphaeridium aciculare, Baltisphaeridium Chronostratigraphically, Tremadocian is setaceum, Leiosphaeridia sp. considered the lower stage of Lower

265 L. OLARU

Ordovician, with a radiometric age of 495 - 485 As in the case of acritarchs, Conochitina M.a., while Arenigian, representing the upper symmetrica was found in all analyzed samples stage of Lower Ordovician, is about 485 - 470 from the Arenigian stratigraphical interval, M.a. (Zincenco, 1995; Gradstein, Ogg, 1996). which also indicates a lithological and microfloristic amalgamation of Arşiţa Rea Chitinozoan assemblage Formation (Tg.4), as a effect of the collisional Besides acritarchs, chitinozoans are geotectonical event it was submitted. Also in present in all yielded and analyzed samples this case, this fact makes impossible the from Arşiţa Rea Formation (Tg.4), from Bălan outlining of the Cambrian - Arenigian boundary area, Bălan and Sândominic Nappes. The at a lithological guide mark, the limit being chitinozoan assemblage comes from the same included within Arşiţa Rea Formation (Tg.4), analyzed samples as the acritarchs (Olaru, with a characteristic of stratigraphical limit. Apostoae, 2004; Olaru, Apostoae, Apostoae, In Baltic region, the species of Conochitina 2003-2004). Chitinozoans were found in symmetrica is lacking, considered as the result Northern Gondwanaland, Baltica and of a lithological hiatus, or of some unfavorable Laurentia, where they form characteristic palaeogeographical and palaeoclimatic zones, being used for stratigraphical conditions (Paris, 1992). biozonations at large distances. Beside Conochitina symmetrica, in the Chitinozoans came out form Tremadocian, analyzed samples, we also determine in Northern Gondwanaland, with the species of Lagenochitina esthonica and Conochitina Lagenochitina destombesi, which characterize raymondii which form together a characteristic a typical biozone for this age, equivalent to the Lower Arenigian biozone in Laurentia, and graptolite zone with Rhabdinipora flabelliforme which, considering the spatial condition, is (Paris, 1992). In our analyzed samples, this right above the Conochitina symmetrica zone species is missing, but we established a (Paris, 1992). The Conochitina symmetrica Tremadocian acritarch assemblage, which is zone is equivalent in Baltica with the conodont equivalent with the graptolite zone with zone with Prionodus proteus, and in Northern Rhabdinipora flabelliforme. Gondwanaland with the graptolite zone with In Bălan region, where the chitinozoan Tetragraptus approximatus. In exchange, the assemblages come from, Arenigian starts with Lagenochitina esthonica / Conochitina Conochitina symmetrica, as in Northern raymondii zone, which ends the upper Gondwanaland and Laurentia (Achab, 1986; boundary of Lower Arenigian, is equivalent Paris, 1992). We found this species in all the with the conodont zone with Prionodus samples coming from phyllites, black elegans in Baltica and the graptolite zone with quartzites and sericitous - chloritous schists Didymograptus deflexus in Northern from the lithological members Arama Oltului, Gondwanaland and China (Paris, 1992). Pârâul Crucii and Başca, Bălan and This limit species are also mentioned in the Sândominic Nappes, Arşita Rea Formation low latitude deposits from Laurentian Shiled, at (Tg.4), Tulgheş Group (Olaru, Apostoae, 2004; the lower part of Levis Formation from Quebec Olaru, Apostoae, Apostoae, 2003-2004). This (Achab, 1980; 1986) and in Nambeet species is characteristic for the biozone with Formation from Canning Basin, Australia the same title also from Prague Basin, being (Achab, Millepied, 1980), as well as the south present in the “messaoudensis – trifidum” of the Sinian Palaeoplate (China) in Dawan acritarch assemblages, which also includes Formation (Geng, 1984). the acritarch species of Coryphidium From these exemplifications, there stands bohemicum, as well as other acritarch species out that the lower and the upper Arenigian determined by us (Olaru, Apostoae, Apostoae, boundaries are very well outlined all over the 2003-2004; Olaru, Lazăr, 2005 – in press). globe, especially in the sedimentary Therefore, we are able to appreciate that the formations where it is possible a biozonation lower boundary of Arenigian in East and a very good correlation on large Carpathians is marked by this chitinozoan distances. Although in the analyzed species, which stands beside the typical metamorphic formations we found many of the acritarchs, previously mentioned, included in characteristic species, of stratigraphical limit, the “messaoudensis – trifidum” acritarch from different classical zone, the correlation, assemblage, equivalent in Prague Basin with the biozonation and especially the establishing the graptolite biozone with Tetragraptus of the stratigraphical limits in these approximatus,(Kraft, Mergl,1979;Fatka et metamorphic formations might be realized with al.,2000) and it coexists with the Clonograptus some difficulties, due to the geotectonic zone at the lower part of Klabava Formation, amalgamation of the initial sediments and its Prague Basin (Paris,Mergl,1984). subsequent metamorphic transformation. In

266 GEOTECTONIC CONTEXT AND PALYNOLOGICAL ARGUMENTS FOR CAMBRIAN / ORDOVICIAN BOUNDARY IN THE METAMORPHITES OF TULGHEŞ GROUP FROM EAST CARPATHIANS, ROMANIA the analyzed metamorphic formations from interval, leads us to the conclusion that, also East Carpathians, the zone characteristic considering the new palynological arguments, species, such as Conochitina symmetrica, the lower Arenigian stratigraphical boundary, Lagenochitina esthonica, Conochitina as well as the upper limit of the same stage, raymondii, are associated with other cannot be outlined at the levels of a lithological chitinozoan species, typical for Arenigian from guide mark, these being included inside the different regions on the globe: lithological succession of the Arenigian Arşiţa Lagenochitina cf. combazi – Arenigian, Rea Formation (Tg.4) (495-470 M.a.) Australia, Québec, Terra Nova (Zincenco, 1995; Gradstein, Ogg, 1996; Lagenochitina brevicollis – Arenigian, Mureşan, 2000). As a matter of fact, the Montagne Noire, France Cambrian - Ordovician boundary stands Conochitina decipiens – Arenigian, Sahara, evident as a stratigraphical limit, considering Quebec, Terra Nova the successive presence of several acritarch Clavachitina decipiens – Arenigian, and chitinozoan palynological assemblages, of Sahara, Quebec, Terra Nova different ages, which are amalgamated within Conochitina brevis – Arenigian, Sahara, Arşiţa Rea Formation (Tg.4), with no possibility Russian Platform, Quebec of its precise outlining at a lithological guide Euconochitina brevis – Arenigian, mark level. Montagne Noire, France Euconochitina parvicola – Arenigian, Conclusions Montagne Noire, France As a result of this study, the following Conochitina kryos – Arenigian, conclusions could be synthesized: Spitzbergen Archipelago, Quebec The geological and stratigraphical limits in Fustichitina grandicula – Lower Arenigian, the metamorphic formations of East Quebec, Levis Formation (holotype) Carpathians depend very much of the Rhabdochitina magna – Ordovician, geotectonic context which affected the Baltica; Lower Arenigian, Quebec respectively geological formations and of the Clathrochitina oblonga – Arenigian, stratigraphical arguments, typical for each Sahara, Quebec, SW Europe, Bohemia, formation. Baltica, Terra Nova In the case of Arşiţa Rea Formation (Tg.4) A special importance belongs to from Bălan area of Tulgheş Group, the Desmochitina bulla, which we separated in the geotectonic context it formed, place it in an analyzed samples, yielded from black accretion wedge position, in the collision quartzites and grey sericitous - chloritous process between East-European Craton phyllites from Pârâul Crucii Member, (EEC) and Central European Shield, on its Sândominic Nappe (Olaru, Apostoae, 2004; edges East Carpathians formed. Olaru, Apostoae, Apostoae, 2003-2004). The The accretion wedge position of the yielded phyllites have thin intercalations of analyzed formation had an effect its lithological black quartzites and they periodically repet in and microfloristic (palynological) Pârâul Crucii Member (Figure 2b). The cause amalgamation. of this repeated lithological succession is also Due to the collisional geotectonic context the effect of the lithological amalgamation of and to the metamorphic transformation of the the initial sediments, in the collisional initial sedimentary deposits, in the lithological geotectonic context; as a result Arşiţa Rea composition of this formation there are Formation (Tg.4) took the place of an preserved only the acritarch and chitinozoan accretion wedge. Desmochitina bulla is typical assemblages, as the only proves of the initial for the upper boundary of Arenigian for a sediments, missing the micro and normal lithological succession. It was macrofaunistic remains. described in this position in Klabava Formation These microfloristic assemblages contain from Prague Basin (Paris, Mergl, 1984), in typical and zonal species which could be Gondwanaland and Baltic regions (Paris, correlated to other classical regions on the 1981; 1996), and it was mentioned in Tadla globe from Central and Western Europe, Basin from Morocco, Sahara (Soufiane, Gondwanaland, Baltica, Laurentia, East - Achab, 1993), in other localities from Bohemia, European Platform, where they could be in Baltic region and Russia (Achab, 1982; equated to parallel zones with conodonts, 1991). graptolites and trilobites. The presence of this typical species at the Based on these acritarch and conodont upper boundary of Arenigian in our analyzed assemblages we defined the stratigraphical samples, besides characteristic species for the limit between Cambrian - Ordovician, but lower boundary and for the entire Arenigian which as a result of the microfloristic mixture

267 L. OLARU cannot be precisely positioned in space, at the Thus the lower and the upper Arenigian level of some lithological guide marks, but it is boundaries may be defined. included in Arşiţa Rea Formation (Tg.4), of The radiometric age of Arşiţa Rea Arenigian age, in the transition zones for the Formaition (Tg.4) is 495-470 M.a. palynological assemblages.

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268 GEOTECTONIC CONTEXT AND PALYNOLOGICAL ARGUMENTS FOR CAMBRIAN / ORDOVICIAN BOUNDARY IN THE METAMORPHITES OF TULGHEŞ GROUP FROM EAST CARPATHIANS, ROMANIA Geologic al Romaniei, Bucharest, 59, 7- (Carpates Orientales). Romanian 17. Journal of Mineral Deposits, 79, Suppl, Kraft, J., Mergl, M. (1979) New graptolite 66- 68. fauna from Klabava Formation of Olaru, L. (1991) Stratigraphical evolution of the Bohemia. Věstnyk Ǔstrědy Ǔstavu palynological assemblages from the Geologiczny, 54(5):291- 295. crystalline formations of the Romanian Kräutner, H. G. (1987) The metamorphic East Carpathians and the correlation Paleozoic of the Romanian Carpathians with other areas from Europe. Evolution In: Flugel, H. W., Sassi, F. P., Grecula and Adaptation, Cluj-Napoca, 4, 77 – (Eds.). Pre-Variscan and Variscan 87. events in the Alpine – Mediteranian Olaru, L. (1994) Biostratigraphical value of mountain belts. Mineralia slovaca - Acritarch assemblages of the monography, Alfa Publishing, metamorphic formations of the East Bratislava, 329 – 350. Carpathians of Romania. CIMP Kräutner, H., G. (1997) Alpine and pre-Alpine Symposium on Palynologie, terranes in the Romanian Carpathians Palaeoenvironment and Stratigraphy, and Apuseni Mts. Annales Géologiques Sheffield,England,Abstract, 29. des Pays Helléniques, Athens, 37, 330 Olaru, L. (1997) Sur la corrélation des – 400. différentes zones des formations Kräutner, H., G., Sassi, F., P., Zirpoli, G., metamorphiques de la Roumanie, par Zulian, T. (1975) The pressure les associations des acritarches. characters of the pre-Alpine XVéme Symposium, APLF Lyon, metamorphisms in East Carpathians Volume des Résumes, 46. (Romania). Neues Jahrbuch Mineral Olaru, L. (2000) Palynostratigraphical Abhandlungen Sttutgart, 125/3, 278- correlation of Cambrian Formations 296. from the East Carpathians of Romania. Kräutner, H., G., Kräutner, FL., Tanasescu, A., Xth International Palynological Neacsu, V. (1976) Interprétation des Congress, Nanjing, China, Abstracts, âges radiométriques pour les roches 126-127. métamorphiques régénérees. Anuarul Olaru, L. (2001) Using acritarch assemblages Institutulul de Geologie si Geofizica a to correlate Upper Proterozoic and Romaniei, Bucuresti, L, 167- 229. Lower Paleozoic metamorphic Kräutner, H., G., Bindea, G. (2002) Structural sequences in Romania. Proceedings of units in the pre-Alpine basement of the the IX International Palynological Eastern Carpathians. Geologica Congress, Houston, Texas, USA, 1996, Carpathica, 53, Spl. Issue, 143-176. AASP, Foundation, 115- 127. Munteanu, M., Rosu, E., Vodă, A. (1999) Olaru, L. (2002) New palynological and Caledonian metavolcanics from the palynostratigraphical data about black Eastern Carpathians: geochemistry and quartzites and graphite schists of the tectonic setting. Romanian J. Tectonics Tulghes Group. Acta Palaeotologica Regional Geology, Bucharest, 77, 70- Romaniae, Iasi, III, 299- 308. 71. Olaru, L. (2005) Some problems of Munteanu, M., Dumitrascu, C., Tatu, M. (2000) biostratigraphy and palynological Tulghes Group: Depositional sequence correlation of Upper Formation (Tg. 4) or collisional stacking?. Anuarul from Tulghes Group, East Carpathians Institutului Geologic al Romaniei, (Romania). Acta Palaeontologica Bucharest, 72, p. 55. Romaniae, Bucuresti, V, 351- 366. Munteanu, M., Tatu, M. (2001) The East - Olaru, L., Oniceanu, M. (1985) Sur la Carpathian metamorphic terranes présence de quelques associations (Romania): evolution from Gondwana to d’acritarches du Protérozoïque the East European Platform. Gondwana supérieur et du Paléozoïque inférieur Research, 4, pp. 712. dans les Carpates Orientales de Munteanu, M., Tatu, M. (2003) The East - Roumanie. Science Géologique Carpathian Crystalline - Mesozoic Zone Bulletin, Strasbourg, 38, 1, 131- 136. (Romania): Paleozoic Amalgamation of Olaru, L., Gunia, T. (1988) Palynological Gondwana - and East European correlation between the Cambrian Craton- derived Terranes. Gondwana Formations in the Sudetic Mountains Research, 6, 2, 185-196 (Poland) and the East Carpathians Muresan, M. (2000) Age des (Romania). Analele stiintifice ale épimétamorphites du Grupe de Tulghes

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Universitatii”Al. I. Cuza”Iasi, II b, Eastern Newfoundland and its Geologie-Geografie, XXXIV, 23-30. comparison to coeval microfloras Olaru, L., Horaicu, C. (1989) Palynological particularly those of the East European studies on the metamorphic formations Platform. AASP, Contribution Series, of the Tulghes Group in the East no.38,Dallas Texas, p. 129. Carpathians of Romania. Analele Sandulescu, M. (1976) La correlation stiintifice ale Universitatii “Al. I. Cuza” structurale du tronçon Oriental avec Iasi, Stiinte Naturale, b, Geologie- celui Meridional des Carpates Geografie, XXXV. Orientales Roumaines. Dari de Seama Olaru, L., Apostoae, L. (1994-1995) La ale Sedintelor Institutului de Geologie si présence de quelques acritarches dans Geofizica, Bucuresti, LXIII/5, 177- 194. le Groupe de Tulghes (Tg. 3, la zone Sandulescu, M. (1980 a) Analyse Balan, Carpates Orientales). Analele géotectonique des chaines alpines stiintifice ale Universitatii “Al. I. Cuza” situees autour de la Mèr Noire Iasi, Geologie, 40-41, 277-282. occidentale. Anuarul Institutului de Olaru, L., Apostoae, L. (2003) Arenigian Geologie si Geofizica, Bucuresti, LVI, 5- chitinozoans from the Tulghes Group, 54. Upper Formation (Tg. 4) from Balan Sandulescu, M. (1980 b) Sur certaines Zone (Eastern Carpathians Romania). problèmes de la correlation des Acta Palaeontologica Romaniae, Cluj- Carpates Orientales roumaines avec Napoca, IV, 299-314 les Carpates ucraïniennes. Dari de Olaru, L., Apostoae, L., Apostoae, L. (2003- Seama ale Sedintelor Institutului de 2004) Contributions à l’étude Geologie si Geofizica, Bucuresti, LXV/5, palynologique de la formation supérieur 163 - 180. (Tg. 4) de la region de Balan, (Carpates Sandulescu, M. (1984) Geotectonica Orientales, Roumanie). Analele Romaniei. Editura Stiintifica, Bucuresti, stiintifice ale Universitatii “Al. I. Cuza” 336p. Iasi, Geologie, XLIX – L, 133-159. Soufiane, A., Achab, A. (1993) Quelques Olaru, L., Lazar, A. (2005) New data on typical assemblages de chitinozoaires de acritarch assemblage from the Upper l’Ordovicien de Maroc, Bassin de Tadla. Formation (Tg. 4) from Tulghes Group, GEOBIOS, 26, 5 : 535-553. Balan area, Eastern Carpathians Vaida, M. (1999) Datarea si corelarea pe baza (Romania). Analele stiintifice ale asociatiilor palinologice a formatiunilor Universitatii « Al. I. Cuza” Iasi, cristalofiliene si mineralizatiilor Geologie, 51, (in press). associate din partea sudica a masivului Paris, F., (1981) Les chitinozoaires dans le cristalin al Carpatilor Orientali si partea Paléozoïque de sud- oust de l’Europe estica a Carpatilor Meridionali. Teza de (Cadre géologique - Etude doctorat, Universitatea”Al. I. Cuza’Iasi. systématique-Biostratigraphie). Vavrdova, M. (1999) Ordovician acritarchs Mémoire de la Societé Géologique et from Central Bohemia. Vestnic Miniére de Bretagne, 26, 1-496. Ǔstredniho Ǔstavu Geologickeho, 40: Paris, F. (1992) Application of chitinozoans in 351- 357. long-distance Ordovician correlations. Vodă, Al. (1986) Central East Carpathians Global Perspectives on Ordovician Formations in the Brosteni-Borca Geology. In: Webby, B. D., Laurie, J. Region. Dari de Seama ale Sedintelor R. (Eds.), Balkema, A. A. / Rotterdam / Institutului de Geologie si Geofizica a Brookfield. Romaniei, Bucuresti, 70- 71/5, 269-275. Paris, F. (1996) Chitinozoan biostratigraphy Vodă, Al. (2000) Sinteza zonei cristalino- and palaeoecology. In: Jansonius, J. & mezozoice a Carpatilor Orientali. Date Mc Gregor, D. C. (Eds.), Palynology: regionale, geologie si metalogeneza principles and applications. AASP regionala. Tema V/15, 1997, S. C. Foundation, 2, 531- 552. “Prospecţiuni” S. A., Bucuresti, 18 p. Paris, L., Mergl, M. (1984) Arenigian Vodă, A., Balintoni, I. (1996) Corelari chitinozoans from Klabava Formation, litostratigrafice in cristalinul Carpatilor Bohemia. Review Palaeobotany and Orientali. Studia Universitatis “Babes- Palynology, 43:33-35. Bolyai”,Cluj-Napoca, Geologie,XXXIX Parsons, G. M., Anderson, M. M. (2000) /1-2,61-66. Acritarch microfloral succession from Volkova, N. A. (1995) Akritarhi pogranicinâh the Late Cambrian and Ordovician otlojenii Kembria-Ordovika, Baltiiskoi (Early Tremadoc) of Random Island, fitoplanktonoi provintii. Stratigrafia.

270 GEOTECTONIC CONTEXT AND PALYNOLOGICAL ARGUMENTS FOR CAMBRIAN / ORDOVICIAN BOUNDARY IN THE METAMORPHITES OF TULGHEŞ GROUP FROM EAST CARPATHIANS, ROMANIA Gheologhiceskaia Korreliatia, 3, 4, 31- Zincenco, D. (1995) Chronostratigraphic Scale 43. of the pre- metamorphites and Volkova, N. A. (1999) Acritarchs from Upper granitoids from Romanian Carpathians. Beds of the Upper Cambrian – Lower Carpathian - Balkan Geological Tremadocian of the Moscow Syneclise. Association, XVth Congress. Spl. Stratigraphy and Geological Published, Geological Society, Greece, Correlation, 7/5, 452 – 464. Athens, 4/2, 647- 652.

EXPLANATION OF PLATES

PLATE I

1. Leiosphaeridia sp. A (2 specimens) 2. Acanthodiacrodium angustum (Downie) Combaz 3. Acanthodiacrodium angustum (Downie) Combaz 4. Arbusculidium cf. destombesii Deunff 5. Dactylofusa squama (Deunff) Martin 6. Dactylofusa velifera Cocchio 7. Lunulidia lunula Eisenack 8. Dactylofusa squama (Deunff) Martin 9. Lunulidia lunula Eisenack 10. Cymatiogalea cf. cuvillieri (Deunff) Martin 11. Baltisphaeridium setaceum (Timofeev) Martin 12. Baltisphaeridium aciculare (Timofeev) Martin 13. Acanthodiacrodium lanatum (Timofeev) Martin 14. Pirea orbicularis Volkova 15. Pirea cf. orbicularis Volkova 16. Pirea sp. 17. Dactylofusa cf. squama (Deunff) Martin 18. Poikilofusa squama (Deunff) Martin 19. Dactylofusa squama (Deunff) Martin

All figures increased by 1000 X

PLATE II

1. Orthosphaeridium extensum Parsons & Anderson 2. Leiofusa stoumonensis Vanguestaine 3. Veryhachium cf. dumontii Vanguestaine 4. Acanthodiacrodium angustum (Downie) Combaz 5. Leiosphaeridia sp. A 6. Cymatiosphaera deunffi Jardiné et al. 7. Ooidium cf. clavigerum Parsons & Anderson 8. Saharidia cf. fragilis (Downie) Combaz 9. Dactylofusa velifera Cocchio 10. Leiosphaeridia sp. A 11. Veryhachium dumontii Vanguestaine 12. Leiospharidia sp. B (3 specimens) 13. Cristallinium cf. cambriense Slaviková 14. Acanthodiacrodium golubii Fensome et al. 15. Vulcanisphaera cf. britannica Rasul 16. Coryphidium aff. bohemicum Vavrdová 17. Veryhachium dumontii Vanguestaine 18. Baltisphaeridium crinitum Martin 19. Buedingiisphaeridium tremadocum Rasul 20. Acanthosphaeridium angustum (Downie) Combaz 21. Lunulidia lunula (Eisenack) Eisenack

All figures increased by 1000 X

271 L. OLARU

PLATE III 1. Lagenochitina esthonica Eisenack (39 x 23 µm); sample no. 1, black quartzites, Şindrila de Sus Brook, Pârâul Crucii Member, Sândominic Formation. 2. Lagenochitina esthonica Eisenack (39 x 26 µm); sample no. 3, grey phyllites, Fagul Înalt Brook, Pârâul Crucii Member, Sândominic Formation. 3. Lagenochitina esthonica Eisenack (36 x 23 µm); sample no. 3, grey phyllites, Fagul Înalt Brook, Pârâul Crucii Member, Sândominic Formation. 4. Lagenochitina esthonica Eisenack (38 x 26 µm); sample no. 3, grey phyllites, Fagul Înalt Brook, Pârâul Crucii Member, Sândominic Formation. 5. Lagenochitina esthonica Eisenack (43 x 23 µm); sample no. 5, grey phyllites, Pârâul Scurt Brook, Pârâul Crucii Member, Sândominic Formation. 6. Lagenochitina esthonica Eisenack (38 x 24 µm); sample no. 3, grey phyllites, Fagul Înalt Brook, Pârâul Crucii Member, Sândominic Formation. 7. Lagenochitina esthonica Eisenack (37 x 24 µm); sample no. 4, black quartzites, Babaşa Brook, Pârâul Crucii Member, Sândominic Formation. 8. Lagenochitina esthonica Eisenack (38 x 27 µm); sample no. 4, black quartzites, Babaşa Brook, Pârâul Crucii Member, Sândominic Formation. 9. Lagenochitina esthonica Eisenack (40 x 28 µm); sample no. 4, black quartzites, Babaşa Brook, Pârâul Crucii Member, Sândominic Formation. 10. Lagenochitina esthonica Eisenack (38 x 23 µm); sample no. 9, black graphitous phyllites with intercalations of black quartzites, Pârâul Crucii Member, Sândominic Formation. 11. Lagenochitina esthonica Eisenack (39 x 24 µm); sample no. 5, grey phyllites, Pârâul Scurt Brook, Pârâul Crucii Member, Sândominic Formation. 12. Lagenochitina esthonica Eisenack (43 x 27 µm); sample no. 5, grey phyllites, Pârâul Scurt Brook, Pârâul Crucii Member, Sândominic Formation. 13. Lagenochitina esthonica Eisenack (35 x 21 µm); sample no. 9, black graphitous phyllites with intercalations of black quartzites, Pârâul Crucii Member, Sândominic Formation. 14. Lagenochitina esthonica Eisenack (47 x 28 µm); sample no. 4, black quartzites, Babaşa Brook, Pârâul Crucii Member, Sândominic Formation. 15. Desmochitina bulla Taug. & Jekh. (20 x 15 µm); sample no. 1, black quartzites, Şindrila de Sus Brook, Pârâul Crucii Member, Sândominic Formation. 16. Desmochitina bulla Taug. & Jekh. (22 x 18 µm); sample no. 3, grey phyllites, Fagul Înalt Brook, Pârâul Crucii Member, Sândominic Formation. 17. Desmochitina bulla Taug. & Jekh. (17 x 12 µm); sample no. 3, grey phyllites, Fagul Înalt Brook, Pârâul Crucii Member, Sândominic Formation. 18. Desmochitina bulla Taug. & Jekh. (17 x 13 µm); sample no. 6, grey sericitous-graphitous phyllites, Şipoş Valley, Başca Member, Sândomonic Formation. 19. Desmochitina bulla Taug. & Jekh. (15 x 10 µm); sample no. 9, black graphitous phyllites with intercalations of black quartzites, Pârâul Crucii Member, Sândominic Formation. 20. Conochitina symmetrica Taug. & Jekh. (46 x 31 µm); sample no. 3, grey phyllites, Fagul Înalt Brook, Pârâul Crucii Member, Sândominic Formation. 21. Conochitina symmetrica Taug. & Jekh. (47 x 32 µm); sample no. 3, grey phyllites, Fagul Înalt Brook, Pârâul Crucii Member, Sândominic Formation. 22. Conochitina symmetrica Taug. & Jekh. (45 x 30 µm); sample no. 4, black quartzites, Babaşa Brook, Pârâul Crucii Member, Sândominic Formation. 23. Conochitina symmetrica Taug. & Jekh. (47 x 33 µm); sample no. 5, grey phyllites, Pârâul Scurt Brook, Pârâul Crucii Member, Sândominic Formation. 24. Conochitina symmetrica Taug. & Jekh. (52 x 35 µm); sample no. 6, grey sericitous-graphitous phyllites, Şipoş Valley, Başca Member, Sândomonic Formation.

Without dimensions scale

PLATE IV

1. Conochitina symmetrica Taug. & Jekh. (47 x 33 µm); sample no. 9, black graphitous phyllites with intercalations of black quartzites, Pârâul Crucii Member, Sândominic Formation. 2. Conochitina symmetrica Taug. & Jekh. (46 x 30 µm); sample no. 9, black graphitous phyllites with intercalations of black quartzites, Pârâul Crucii Member, Sândominic Formation. 3. Conochitina symmetrica Taug. & Jekh. (46 x 34 µm); sample no. 9, black graphitous phyllites with intercalations of black quartzites, Pârâul Crucii Member, Sândominic Formation. 4. Fustichitina grandicula Achab (77 x 20 µm); sample no. 1, black quartzites, Şindrila de Sus Brook, Pârâul Crucii Member, Sândominic Formation. 5. Fustichitina grandicula Achab (76 x 19 µm); sample no. 1, black quartzites, Şindrila de Sus Brook, Pârâul Crucii Member, Sândominic Formation. 6. Rhabdochitina magna Eisenack (87 x 18 µm); sample no. 1, black quartzites, Şindrila de Sus Brook, Pârâul Crucii Member, Sândominic Formation.

272 GEOTECTONIC CONTEXT AND PALYNOLOGICAL ARGUMENTS FOR CAMBRIAN / ORDOVICIAN BOUNDARY IN THE METAMORPHITES OF TULGHEŞ GROUP FROM EAST CARPATHIANS, ROMANIA 7. Rhabdochitina magna Eisenack (101 x 16 µm); sample no. 9, black graphitous phyllites with intercalations of black quartzites, Pârâul Crucii Member, Sândominic Formation. 8. Clavachitina decipiens Taug. & Jekh. (54 x 30 µm); sample no. 3, grey phyllites, Fagul Înalt Brook, Pârâul Crucii Member, Sândominic Formation. 9. Clavachitina decipiens Taug. & Jekh. (53 x 31 µm); sample no. 1, black quartzites, Şindrila de Sus Brook, Pârâul Crucii Member, Sândominic Formation. 10. Conochitina decipiens Taug. & Jekh. (49 x 23 µm); sample no. 3, grey phyllites, Fagul Înalt Brook, Pârâul Crucii Member, Sândominic Formation. 11. Conochitina decipiens Taug. & Jekh. (48 x 23 µm); sample no. 3, grey phyllites, Fagul Înalt Brook, Pârâul Crucii Member, Sândominic Formation. 12. Conochitina decipiens Taug. & Jekh. (47 x 23 µm); sample no. 3, grey phyllites, Fagul Înalt Brook, Pârâul Crucii Member, Sândominic Formation. 13. Conochitina decipiens Taug. & Jekh. (43 x 23 µm); sample no. 3, grey phyllites, Fagul Înalt Brook, Pârâul Crucii Member, Sândominic Formation. 14. Clavachitina decipiens Taug. & Jekh. (52 x 30 µm); sample no. 4, black quartzites, Babaşa Brook, Pârâul Crucii Member, Sândominic Formation. 15. Clavachitina decipiens Taug. & Jekh. (54 x 33 µm); sample no. 9, black graphitous phyllites with intercalations of black quartzites, Pârâul Crucii Member, Sândominic Formation. 16. Conochitina decipiens Taug & Jekh. (46 x 23 µm); sample no. 1, black quartzites, Şindrila de Sus Brook, Pârâul Crucii Member, Sândominic Formation. 17. Lagenochitina cf. combazi Finger (29 x 18 µm); sample no. 1, black quartzites, Şindrila de Sus Brook, Pârâul Crucii Member, Sândominic Formation. 18. Lagenochitina cf. combazi Finger (19 x 11 µm); sample no. 5, grey phyllites, Pârâul Scurt Brook, Pârâul Crucii Member, Sândominic Formation. 19. Lagenochitina cf. combazi Finger (18 x 10 µm); sample no. 9, black graphitous phyllites with intercalations of black quartzites, Pârâul Crucii Member, Sândominic Formation. 20. Euconochitina brevis conica (Taug. & Jekh.) (40 x 20 µm); sample no. 3, grey phyllites, Fagul Înalt Brook, Pârâul Crucii Member, Sândominic Formation. 21. Euconochitina brevis conica (Taug. & Jekh.) (40 x 20 µm); sample no. 3, grey phyllites, Fagul Înalt Brook, Pârâul Crucii Member, Sândominic Formation. 22. Euconochitina parvicola (Taug.) (23 x 19 µm); sample no. 3, grey phyllites, Fagul Înalt Brook, Pârâul Crucii Member, Sândominic Formation. 23. Conochitina raymondii Achab (57 x 17 µm); sample no. 3, grey phyllites, Fagul Înalt Brook, Pârâul Crucii Member, Sândominic Formation. 24. Conochitina raymondii Achab (55 x 19 µm); sample no. 3, grey phyllites, Fagul Înalt Brook, Pârâul Crucii Member, Sândominic Formation. 25. Conochitina raymondii Achab (38 x 20 µm); sample no. 4, black quartzites, Babaşa Brook, Pârâul Crucii Member, Sândominic Formation. 26. Conochitina raymondii Achab (46 x 21 µm); sample no. 6, grey sericitous-graphitous phyllites, Şipoş Valley, Başca Member, Sândomonic Formation. 27. Conochitina raymondii Achab (37 x 20 µm); sample no. 9, black graphitous phyllites with intercalations of black quartzites, Pârâul Crucii Member, Sândominic Formation. 28. Conochitina kryos Bockelie (72 x 25 µm); sample no. 9, black graphitous phyllites with intercalations of black quartzites, Pârâul Crucii Member, Sândominic Formation. 29. Lagenochitina brevicollis (Taug. & Jekh.) (43 x 28 µm); sample no. 3, grey phyllites, Fagul Înalt Brook, Pârâul Crucii Member, Sândominic Formation. 30. Lagenochitina brevicollis (Taug. & Jekh.) (42 x 31 µm); sample no. 5, grey phyllites, Pârâul Scurt Brook, Pârâul Crucii Member, Sândominic Formation. 31. Conochitina brevis Taug. & Jekh. (37 x 25 µm); sample no. 9, black graphitous phyllites with intercalations of black quartzites, Pârâul Crucii Member, Sândominic Formation. 32. Clathrochitina oblonga Ben. & Taug. (46 x 30 µm); sample no. 9, black graphitous phyllites with intercalations of black quartzites, Pârâul Crucii Member, Sândominic Formation. 33. Lagenochitina brevicollis (Taug. & Jekh.) (43 x 24 µm); sample no. 9, black graphitous phyllites with intercalations of black quartzites, Pârâul Crucii Member, Sândominic Formation. 34. Lagenochitina cf. combazi Finger (23 x 18 µm); sample no. 6, grey sericitous-graphitous phyllites, Şipoş Valley, Başca Member, Sândomonic Formation. 35. Lagenochitina cf. combazi Finger (30 x 23 µm); sample no. 5, grey phyllites, Pârâul Scurt Brook, Pârâul Crucii Member, Sândominic Formation.

Without dimensions scale

273 L. OLARU PLATE I

274 L. OLARU PLATE II

275 L. OLARU PLATE III

276 L. OLARU PLATE IV

277