ACTA PALAEONTOLOGICA ROMANIAE (2017) V. 13(2), P. 37-90 NEW TREES IDENTIFIED IN THE PETRIFIED FOREST OF MIDDLE MIOCENE FROM ZARAND, APUSENI MOUNTAINS, ROMANIA. Stănilă Iamandei1* & Eugenia Iamandei1 Received: 31 December 2017 / Accepted: 13 March 2018 / Published online: 16 March 2018 Abstract The systematic study of the Mid-Miocene Petrified Forest of Zarand, Apuseni Mountains, Romania led till now to the identification of over 40 arboreal taxa, allowing a complex phytoecological, palaeoenvironmental and pal- aeoclimatic analysis during Late Badenian in Tălagiu island, of Paratethys realm, where the Zarand Basin evolved. The geological evolution of the Tălagiu caldera allowed best conditions to bury and preserve by silicification of the remains of the Mid-Miocene forest, which lived on the slopes of the volcano. From there, in the last years, species of the following genera were described: Tetraclinoxylon, Thujoxylon, Chamaecyparixylon, Cupressinoxylon, Taxodioxy- lon, Sequoioxylon, Pinuxylon, Magnolioxylon, Cinnamomoxylon, Spiroplatanoxylon, Liquidambaroxylon, Eucaryoxy- lon, Rhysocaryoxyton, Pterocaryoxylon, Fagoxylon, Quercoxylon, Alnoxylon, Populoxylon, Salicoxylon, Nyssoxylon, Paraphyllanthoxylon, Piranheoxylon, Aceroxylon, Fraxinoxylon and Rhizopalmoxylon, taking into account all the palaeoxylotomical identifications. That forest was a Mixed Mesophytic Forest with Lauraceae and Conifers altitudi- nally storeyed, and with remains of pre-Miocene sempervirent elements of paratropical or subtropical climate. Thus, the evaluated climatic parameters suggest a humid subtropical palaeoclimate toward warm-temperate of Mediterrane- an type (Cfa to Csa in Köppen classification) according to the island mountainous relief, where the altitudes probably did not exceeded 1200 m Keywords: Tălagiu island, Badenian petrified wood, Mixed Mesophytic Forest, phytoecological analysis, palaeoclimate. INTRODUCTION and extra-Carpathian territories were emerged, and the terrigenous formations attributed to the Early Miocene The Petrified Forest ofthe Middle Miocene in Zarand was (Aquitanian and Burdigalian) corresponding in fact to the outlined and partially described in the Zarand basin, the Badenian transgression. The erosion in Metaliferous Apuseni Mountains, the fossilization of which was relat- Mountains (Southern Apuseni) during ca. 50 Ma of ed to the late Badenian volcanic activity, developed in emergence led to the apparition of the hydrographic sys- Tălagiu Caldera (Fig. 1A, B), a complex island volcano tem of White Palaeocriș, corresponding to Crișul Alb which buried with its pyroclastites the tree vegetation that river of today. lived on its slopes. Even if fossil proves for this interval doesn't exist it is The blanket of Neogene deposits of the intramontaneous supposed that the zonal vegetation covering that emerged depressions of Western Apuseni were deposited after the area was probably similar to those identified in other Middle Miocene transgression of the Pannonian Sea in Badenian deposits from Romania (Țicleanu, 1986; the gulfs from inside the mountains, drowning a paleore- Givulescu, 1997). The simple listing of the Prebadenian lief formed in an active erosion stage - tending even to a Tertiary Floras may suggests a slight trend of the palaeo- peneplainization of this region formed by crystalline for- climatic evolution - by the decreasing number of the pal- mations known in the surrounding mountainous areas aeotropical elements and the increasing the arcto-tertiary (Highiș, Biharia, Codru Moma), from sedimentary and ones. This indicates a variation to a gradual cooling to the volcano-sedimentary rocks belonging to the Palaeozoic end of the Paleogene, a situation expressed by the MAT and to the Mesozoic as the ophiolites and the Jurassic- diagram (Mean Annual Temperatures) deduced by Neocomian limestones of Căpâlnaș-Techereu Unit, and Givulescu (1997), both by floristic analysis and by the also as Late Cretaceous (+ Paleogene?) sedimentary analysis of the morphological parameters of the leaf im- rocks with the banatites of the Drocea-Criș and Bucium pressions identified in various Paleogene plant deposits in Units, formations which appear as tectonic nappes in the Transylvania (Givulescu, 1997). neighboring mountains. Sporadically they appear from The hydrographic basin of the White Paleocriș had a qua- beneath the Neogene rock blanket. The Paleogene geo- si-identical trajectory with the today river (Crișul Alb) logic evolution and the emergence of important parts of and the triggering of a quasi-linear tectonic on WNW- the Carpathian area were manifested in the Apuseni ESE direction favorized the apparition of some local Mountains after the Palaeocene (probably post-Cuisian), crashes under the sea level and the invasion of Pannonian with variable intensities. Most probably during Egerian Sea water simultaneously with the initiation of a very (Late Oligocene) were intensified the movements that led active and explosive volcanic activity. to the emergence, at least for some areas of Apuseni These deposits included a lot of vegetal material, even Mountains (see Ianovici et al., 1976). determining coal levels, sometimes cantitatively im- Otherwise Paucă (1954, 1976) supposed even that post- portante, even exploitable at Țebea (see Givulescu, Oligocene and until Early Badenian inclusively, the intra- 1997), but usually as centimetric to decimetric size as in ________________________________ 37 1*Geological Institute of Romania (GIR), 1st Caransebeş Street, 012271 – Bucharest, Romania, [email protected] Stănilă Iamandei & Eugenia Iamandei Fig. 1 a Geological sketch of Romania, with location of Tălagiu caldera in the Apuseni Mountains (Geological Institute edi- tor); b Detail of Tălagiu caldera with the studied area, in rectangle (Excerpt from Geological Map of Romania, Scale 1:200,000 - Sheet 17-Brad, Geological Institute editor). Basarabița valley, Măgura-Prăvăleni Valley and in many of the regional units of the Neogene of Paratethys com- other points also (see Istocescu, 1971; Berbeleac et al., piled by Marinescu (1994), Marinescu et al. (1998) and 1984). Andreyeva-Grigorovich (2001), it is clear that the abso- This fact determined the deposition of a couverture hav- lute ages are placed into Kossovian, representing the in- ing a dominant volcano-sedimentary character, attributed terval 11.8-13.6 Ma. by palaeontological basis to Badenian, Sarmatian and The volcano-sedimentary levels intercalated within the Pannonian, probably partially including the Pontian (Ci- post-Badenian formations represent post-eruptive epiclas- oflică & Popescu, 1966; Istocescu, 1971). The explosive tic deposits, generated by active erosion and remobiliza- volcanic activity, in Zarand area, was triggered at the tion of the unconsolidated pyroclastics of the Badenian Middle Badenian (Berbeleac et al., 1984; Roșu et al., strato-volcano or/and the products of the final volcanic 1997), but the presence of the volcanic rocks in the de- stage in Zarand (Fig. 2), deposited in more distal areas of posits from the basis of the stratigraphic succession source, have a tuffaceous character which preserve a shows that it was produced simultaneous with the birth of fresh water fauna and a microfauna, and also a microflo- a new basin of sedimentation, i.e. during Early Badenian, ra, based on which was established their relative age and had a strongly explosive character, producing huge (Nicorici, 1963; Antonescu, 1964; Cioflică & Popescu, quantities of tephra (pyroclastics) rising a strato- volcanic 1966; Nicorici & Sagatovici, 1970, 1973; Istocescu, structure. Tălagiu volcano was a typical lahar volcano. 1971). Anyway the sedimentation processes continued up Unconsolidated deposits of tephra moved as lahar de- to the Pontian, and led to the entire filling of the basin. stroying, transporting and burying the vegetal remains on Due to the rise of the entire edifice of the Apuseni Moun- the volcano slopes until the neighbor aquatic basin, creat- tains during the Pliocene, the sedimentation ceases. In the ing an excellent preservation environment by silicifica- west of the basin (to the west of Gurahonț), the Quater- tion of the vegetal remains, the volcanic ash being a per- nary terrigenous deposits (Pleistocene-Holocene) defini- fect provider of easy levigable silica (Fig. 1 A, B). tively end the sedimentation in this basin. The volcanism seems to have developed in an island area, The volcanic and volcano-sedimentary deposits from the probably in few more eruption centers, some of them proximal areas of eruption centers have a dominant pyro- unknown as localisation, but the most important were the clastic character, and were considered non-fossiliferous. calderas Tălagiu - Bratosin and Gura Văii - Iosășel (Ber- Their Badenian-Sarmatian age was attributed by strati- beleac et al., 1984). graphic correlation with those documented in the rest of Here the volcanic activity intensely continued during all the sedimentation basin (Berbeleac et al., 1984). However the Badenian and maybe during Early Sarmatian too the abundance of fossil vegetal remains was known, and (Istocescu, 1971; Berbeleac et al., 1984). Analysing the mentioned in many published papers (see Istocescu, litho- and biostratigraphic data of the cited authors, and 1971; Nagy & Mârza, 1967; Petrescu & Nuțu, 1969- the absolute age of 12.4±0.7 – 13.4±1.2 Ma, given by the 1972; Roșu et al., 1997). The palaeogeographic recon- eruptive products of Zarand area (Roșu et al., 1997), cor- structions of Paratethys