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Sökning: WFRF:(Bouchal Johannes M.)

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1.
  • Bouchal, Johannes M., 1979- (författare)
  • Reconciling the stratigraphy and depositional history of the Lycian orogen-top basins, SW Anatolia
  • 2019
  • Ingår i: Palaeobiodiversity and Palaeoenvironments. - Heidelberg : Springer Science and Business Media LLC. - 1867-1594 .- 1867-1608. ; 99, s. 551-570
  • Tidskriftsartikel (refereegranskat)abstract
    • Terrestrial fossil records from the SW Anatolian basins are crucial both for regional correlations and palaeoenvironmental reconstructions. By reassessing biostratigraphic constraints and incorporating new fossil data, we calibrated and reconstructed the late Neogene and Quaternary palaeoenvironments within a regional palaeogeographical framework. The culmination of the Taurides in SW Anatolia was followed by a regional crustal extension from the late Tortonian onwards that created a broad array of NE-trending orogen-top basins with synchronic associations of alluvial fan, fluvial and lacustrine deposits. The terrestrial basins are superimposed on the upper Burdigalian marine units with a c. 7 myr of hiatus that corresponds to a shift from regional shortening to extension. The initial infill of these basins is documented by a transition from marginal alluvial fans and axial fluvial systems into central shallow-perennial lakes coinciding with a climatic shift from warm/humid to arid conditions. The basal alluvial fan deposits abound in fossil macro-mammals of an early Turolian (MN11–12; late Tortonian) age. The Pliocene epoch in the region was punctuated by subhumid/humid conditions resulting in a rise of local base levels and expansion of lakes as evidenced by marsh-swamp deposits containing diverse fossilmammal assemblages indicating late Ruscinian (lateMN15; late Zanclean) age. A second pulse of extension, accompanied by regional climatic  changes, prompted subsequent deepening of the lakes as manifested by thick and laterally extensive carbonate successions. These lakes, which prevailed c. 1 myr, later shrank due to renewed progradation of alluvial fans and eventually filled up and dried out, reflected by marsh-swamp deposits at the top of a complete lacustrine succession that contains diverse micro-mammal assemblages indicating a latest Villanyian (MN17; Gelasian) age. A third pulse of tectonic reorganisation and associated extension dissected the basins into their present-day configuration from the early Pleistocene onwards under warm/humid climatic conditions. The new age data provide means to correlate deposits across various basins in the region that help to place the basin development into a regional tectonic framework, which can be attributed to the consequence of the well-articulated regional phenomena of slab-tear/detachmentinduced uplift followed by crustal extension and basin formation (late Tortonian), the outward extension of the Aegean arc (early Pliocene) and eventually accompanied by westward extrusion of the Anatolian Plate (early Pleistocene).
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2.
  • Denk, Thomas, et al. (författare)
  • The Pleistocene flora of Bezhan, southeast Albania: early appearance of extant tree species
  • 2021
  • Ingår i: Historical Biology. - : Taylor & Francis. - 0891-2963 .- 1029-2381. ; 33, s. 283-305
  • Tidskriftsartikel (refereegranskat)abstract
    • The piggyback basin of Bezhan, southeastern Albania, was formed during the late Neogene and contains Pliocene/Pleistocene deposits. These continental deposits consist of marls, siltstones and clays separated by a thin series of lignite-seams alternating with clays (Bezhan formation). We investigated leaf fossils and dispersed pollen from marls of the upper portion of this formation. Fifty-two plant taxa comprising algae, gymnosperms, and angiosperms were recovered. Of these, at least 19% belong to extant species and less than 16% belong to taxa today extinct in western Eurasia. Tsuga is represented by three pollen taxa with affinities to modern Chinese, Japanese, and North American species. Herbaceous taxa indicative of steppe (Artemisia, Amaranthaceae) occur in low quantities (≤1%)suggesting an interglacial setting. Four vegetation units are recognised: Wet riparian and aquatic vegetation, mesic oak forest, dry sub-Mediterranean woodland, and montane conifer forest. A comparison of the Bezhan flora with well-dated Pliocene and Pleistocene floras of Italy suggests a Calabrian (late early Pleistocene) age for the upper unit. This estimate is based on the abundance of extant taxa, the absence of subtropical taxa, and threshold values of particular taxa (Tsuga, Carya). The findings are in agreement with age estimates for extant tree species from molecular studies.
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3.
  • Adroit, Benjamin, et al. (författare)
  • Are morphological characteristics of Parrotia (Hamamelidaceae) pollen species diagnostic?
  • 2022
  • Ingår i: Review of Palaeobotany and Palynology. - Amsterdam : Elsevier BV. - 0034-6667 .- 1879-0615. ; 307, s. 104776-104776
  • Tidskriftsartikel (refereegranskat)abstract
    • Parrotia persica is one of the most notable endemic relict tree species growing in the Hyrcanian forest at the southern Caspian Sea. The recent discovery of sibling species Parrotia subaequalis, occurring in the temperate forests of south-eastern China, offers the opportunity to compare their morphology and ecological preferences and to dig deeper into the paleophytogeographic history of the genus from a perspective. Since pollen morphology of these species would be essential to unravel the origin and evolution of these Arcto-Tertiary species, the present study aimed to investigate whether it is possible to segregate pollen from these two species. Therefore, a detailed combined light- and scanning electron microscopy-based pollen-analysis of each taxon was conducted, the pollen was described, measured, and compared using statistical approaches and principal component analyses to establish unbiased results. The correlation-based principal component analysis achieved for each species shows an overall good superposition of pollen grains measured in equatorial and polar views in the first principal plane, revealing that the P. persica pollen is morphometrically as homogeneous as that of P. subaequalis. Then, the significant difference, mainly driven by lumen density, has been highlighted between the two species. Ultimately, the cross-validation of the resulting two-species linear discriminants classifier shows that based upon this reference dataset, (sub)fossil pollen grain can now be confidently assigned to either of the two species with an 85.8% correct-assignment rate. This opens new doors in the affiliation of fossil Parrotia pollen and suggests that previous pollen records need to be revised.
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4.
  • Bouchal, Johannes M., 1979-, et al. (författare)
  • An overview of the palynoflora of the Miocene Yatağan basin, Turkey
  • 2014
  • Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
    • The palynoflora of the lignite strip mines of the Yatağan basin, located in the Muğla province of western Turkey, is the focus of this study. Samples were taken from the Eskihisar, Salihpasalar and Tinaz mines. In the Yatağan basin two Miocene formations, formed from river and lake deposits, Eskihisar Formation (middle Miocene) and Yatağan Formation (late Miocene) have been designated. Both show a general lithology consisting of conglomerate, sandstone, claystone, limestone and tuffite, the mined/excavated lignite bearing strata are restricted to the Eskihisar Formation.Until now, pollen from the Yatağan basin has mostly been described according to conventional morphological nomenclature, using light microscopy (LM) only. In this study, the same individual pollen grains are investigated by using both, LM and scanning electron microscopy (SEM). The  high resolution pictographs allow a higher taxonomic resolution.The rich palynoflora (Table 1) is comprised of diverse spores (at least nine morphotypes), gymnosperm pollen from Cupressaceae, Gnetales, Pinaceae, and angiosperm pollen from Poaceae, Typhaceae, Altingiaceae,  Amaranthaceae (Chenopodieae), Anacardiaceae, Apiaceae, Betulaceae, Buxaceae, Caprifoliaceae (Dipsacoideae, Lonicera) Caryophyllaceae, Compositae (Asteroideae, Cichoriodeae), Cornaceae, Eucommiaceae, Fabaceae, Fagaceae (Fagus, Quercus, Trigonobalanopsis) Geraniaceae, Juglandaceae, Malvaceae, Myricaceae, Nymphaeaceae, Oleaceae, Palmae, Plumbaginaceae (Armeria, Plumbago), Polygonaceae (Rumex), Salicaceae, Sapindaceae (Acer), Smilacaceae, and Ulmaceae (Cedrelospermum, Ulmus, Zelkova).
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5.
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6.
  • Bouchal, Johannes M., 1979-, et al. (författare)
  • Low taxonomic resolution of papillate Cupressaceae pollen (former Taxodiaceae) impairs their applicability for palaeo-habitat reconstruction
  • 2020
  • Ingår i: Grana. - London : Taylor & Francis. - 0017-3134 .- 1651-2049. ; 59:1, s. 71-93
  • Tidskriftsartikel (refereegranskat)abstract
    • The former family Taxodiaceae is currently treated as nine genera in five subfamilies of the family Cupressaceae. Pollen ofthe ‘taxodiaceous’ Cupressaceae typically has a papilla in the leptoma area and is common in Cenozoic strata because someof its genera were key elements in lignite forming swamp forests. Dispersed fossil pollen of this group are often assigned toparticular genera and, based on the modern ecologies of these taxa, to particular palaeoenvironments. In this study, weinvestigated pollen of all nine genera of the former Taxodiaceae using light and scanning electron microscopy to evaluatewhether pollen morphology can be used to discriminate modern genera of this paraphyletic group. We found few genus- orsubfamily-diagnostic characters among members of taxodiaceous Cupressaceae. Features such as orbiculae and pollen andleptoma size cannot be used to discriminate subfamilies. However, three basal subfamilies share short papillae, whereas intwo more derived clades (Sequoioideae and Taxodioideae) papillae are markedly longer. In the generally non-papillate coreCupressaceae, the leptoma (aperture) area may or may not possess a distinct circular thinning as also found in the basalgrade of taxodiaceous Cupressaceae. Our results show that it is difficult if not impossible to distinguish genera of theecologically distinct Taxodioideae and Sequoioideae based on pollen morphology. In view of a much wider ecologicalamplitude of many taxodiaceous Cupressaceae during large parts of the Cenozoic, we conclude that it is not recommendableto infer particular palaeoenvironments on the basis of dispersed taxodiaceous pollen grains alone.
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7.
  • Bouchal, Johannes M., 1979-, et al. (författare)
  • Messinian vegetation and climate of the intermontane Florina–Ptolemais–Servia Basin, NW Greece inferred from palaeobotanical data: how well do plant fossils reflect past environments?
  • 2020
  • Ingår i: Royal Society Open Science. - London : The Royal Society. - 2054-5703. ; 7, s. 1-30
  • Tidskriftsartikel (refereegranskat)abstract
    • The late Miocene is marked by pronounced environmentalchanges and the appearance of strong temperature andprecipitation seasonality. Although environmental heterogeneityis to be expected during this time, it is challenging to reconstructpalaeoenvironments using plant fossils. We investigated leavesand dispersed spores/pollen from 6.4 to 6 Ma strata inthe intermontane Florina–Ptolemais–Servia Basin (FPS) ofnorthwestern Greece. To assess how well plant fossils reflectthe actual vegetation of the FPS, we assigned fossil taxa tobiomes providing a measure for environmental heterogeneity.Additionally, the palynological assemblage was compared withpollen spectra from modern lake sediments to assess biases inspore/pollen representation in the pollen record. We found aclose match of the Vegora assemblage with modern Fagus–Abiesforests of Turkey. Using taxonomic affinities of leaf fossils, wefurther established close similarities of the Vegora assemblage with modern laurophyllous oak forests of Afghanistan. Finally, using information from sedimentaryenvironment and taphonomy, we distinguished local and distantly growing vegetation types.We thensubjected the plant assemblage of Vegora to different methods of climate reconstruction and discussedtheir potentials and limitations. Leaf and spore/pollen records allow accurate reconstructions ofpalaeoenvironments in the FPS, whereas extra-regional vegetation from coastal lowlands isprobably not captured.
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8.
  • Bouchal, Johannes M., 1979-, et al. (författare)
  • Middle Miocene climate of southwestern Anatolia from multiple botanical proxies
  • 2018
  • Ingår i: Climate of the Past Discussions. - Vienna : European Geosciences Union (EGU). - 1814-9340 .- 1814-9359 .- 1814-9332. ; 14, s. 1427-1440
  • Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
    • The middle Miocene climate transition (MMCT) was a phase of global cooling possibly linked to decreasing levels of atmospheric CO2. The MMCT coincided with the European  Mammal Faunal Zone MN6. From this time, important biogeographic links between Anatolia  and eastern Africa include the hominid Kenyapithecus. Vertebrate fossils suggested mixed  open and forested landscapes under (sub)tropical seasonal climates for Anatolia. Here, we  infer the palaeoclimate during the MMCT and the succeeding cooling phase for a middle Miocene (14.8–13.2 Ma) of an intramontane basin in southwestern Anatolia using three2palaeobotanical proxies: (i) Köppen signatures based on the nearest-living-relative principle. (ii) Leaf physiognomy analysed with the Climate Leaf Analysis Multivariate Program (CLAMP). (iii) Genus-level biogeographic affinities of fossil floras with modern regions. The three proxies reject tropical climates for the MMCT of southwestern Anatolia and instead infer warm temperate C climates. Köppen signatures reject summer-dry Cs climates but cannot discriminate between fully humid Cf and winter-dry Cw; CLAMP reconstructs Cf climate based on the low X3.wet/X3.dry ratio. Additionally, we assess whether the palaeobotanical record does resolve transitions from the warm Miocene Climatic Optimum (MCO, 16.8–14.7 Ma) into the MMCT (14.7–13.9 Ma), and a more pronounced cooling at 13.9–13.8 Ma, as reconstructed from benthic stable isotope data. For southwestern Anatolia, we find that arboreal taxa predominate in MCO floras (MN5), whereas in MMCT floras (MN6) abundances of arboreal and non-arboreal elements strongly fluctuate indicating higher structural complexity of the vegetation. Our data show a distinct pollen zone between MN6 and MN7+8 dominated by herbaceous taxa. The boundary MN6 and MN7+8, roughly corresponding to a first abrupt cooling at 13.9–13.8 Ma, possibly might be associated with this herb-rich pollen zone.
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10.
  • Bouchal, Johannes M., 1979-, et al. (författare)
  • Miocene palynofloras of the Tınaz lignite mine, Muğla, southwest Anatolia: taxonomy, palaeoecology and local vegetation change
  • 2017
  • Ingår i: Review of Palaeobotany and Palynology. - Amsterdam : Elsevier. - 0034-6667 .- 1879-0615. ; 243, s. 1-36
  • Tidskriftsartikel (refereegranskat)abstract
    • Middle Miocene deposits exposed at the Tınaz lignite mine, Yatağan Basin, Muğla, southwestern Turkey, were palynologically investigated. The Tınaz lignite mine section belongs to the Eskihisar Formation. The lignite seam at the base of the section represents the uppermost part of the Turgut Member. Above, c. 65 m of clayey siltstone, limestone, and marls represent the Sekköy Member. Nine spores, zygospores and cysts of fungi and algae, seven moss and fern spores, 12 gymnosperm pollen types, and more than 80 angiosperm pollen taxa were recovered from the Tınaz lignite mine section. Three pollen zones were recognized, of which pollen zone 1 corresponds to the formation of the main lignite seam and reflects the change from a fluviatile to a lacustrine depositional setting. Pollen zones 2 and 3 and a transitional zone 2-3 reflect different stages of lake development and a shift in local vegetation from forested (pollen zones 1 and 2) to more open (transitional zone 2-3, zone 3). Interpreting changes in regional vegetation from pollen zones 1 to 3 is not straightforward as changes in the pollen spectra may be affected by changing contributions of airborne and water transported pollen and spores to the observed palynoassemblages. Age inference for the Tınaz lignite mine section has been complicated by the absence of datable ash layers, associated mammal faunas, or marine sediments. However, pollen zone 3 shares key features with the pollen spectrum recovered from the nearby mammal site Yenieskihisar (upper part of Sekköy Member) for which an age of 12.5-11.2 Ma has been suggested, and to the youngest pollen zone recovered from the mammal locality Çatakbağyaka, 10 km south of Tınaz, that probably represents mammal zone MN7/8 instead of MN5 or MN6 as previously suggested. In contrast, pollen zones 1 and 2 are fairly similar to the basal parts of the Çatakbağyaka pollen flora (uppermost parts of Turgut Member, basalmost parts of Sekköy Member). Furthermore, new mammal data from the Yatağan basin suggest that the layers below pollen zone 1 are MN4/5, and that carnivores cooccuring with pollen zone 1 in the main lignite seam of Eskihisar probably belong to MN6. Hence, a Langhian to Serravallian age can be inferred for pollen zones 1 and 2 of the Tınaz lignite mine section, and a late Serravallian age for pollen zone 3. Palaeobiogeographic relationships of the palynofloras are generally northern hemispheric, with many north temperate tree taxa showing modern disjunctions East Asia- NorthAmerica (Tsuga, Carya), East Asia- western Eurasia (Zelkova), East Asia- North America- western Eurasia (Liquidambar), or restricted to East Asia (Cathaya, Eucommia) or North America (Decodon). A few taxa belong to extinct lineages that have complex biogeographic patterns (Engelhardioideae, Cedrelospermum). The presence of Picrasma (Simaroubaceae) in the lower lignite layers of pollen zone 1 is remarkable, as the botanical affinities with the enigmatic flower Chaneya present in early to middle Miocene deposits of Turkey and Central Europe have recently been shown to be with Picrasma. 
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