Palynological Assemblages Research Articles

Holocene landscape changes in response to sea level oscillations and agricultural intensification in a coastal plain of southeastern South America

This study identified landscape changes in response to variations in mean sea level (MSL) and anthropogenic intervention, from the Early to Late Holocene in Southestern South America. Ananalysis based on palynology and sedimentary bacterial DNA from two sediment cores from the Patos-Mirim System (PMS) is introduced for the first time, to achieve an integrated paleoenvironmental and ladscape reconstruction. The data indicated an east-west migration of the freshwater and forest environments set in the lowlands during the transgressive period (6000–5000 cal yr BP) and an increase in external total biomass input during this MSL rise. A consolidated vegetation onset was inferred, especially of forest environments, after the Holocene Climatic Optimum (5000 cal yr BP). During the last century, landscape changes especially associated with anthropogenic factors were clearly identified from the palynological assemblages. That is, an alternation between Poaceae and Cyperaceae, the first occurrence of Pinus spp. and an increase in the influx of herbs and trees flagged the increase in cultivated areas due to the agricultural and agroforestry intensification. Extreme values of palynological influx appear to be a good proxy for the impact of El Niño events on the sedimentary record, which were associated to increased precipitation. The study also clearly demonstrates the high environmental stress generated by human activities, e.g. loss of plant diversity and changes in the bacterial abundance due to the higher agrochemicals input.

Miocene evolution of vegetation, climate, and elevation in the Wulan Basin of northeast Tibetan Plateau based on a CRACLE analysis of palynological assemblages

The uplift of the Tibetan Plateau (TP) during the Cenozoic has played a pivotal role in shaping global climate and vegetation evolution, however, understanding the uplift history of its various tectonic blocks remains complex. In this paper, we analyze palynological samples from the Miocene Xiayoushashan and Shangyoushashan formations in the Wulan Basin to explore the relationship between climate change and TP uplift. The analysis identified four distinct pollen zones: Zone I (18–15.3 Ma) characterized by Artemisia-Lycopodium-Aster-Polygonaceae; Zone II (15.3–12.7 Ma) dominated by Pinus-Picea-Aster-Artemisia; Zone III (12.7–11.7 Ma) featuring Lycopodium-Picea-Pinus-Polygonaceae; Zone IV (11.7–8.7 Ma) characterized by Picea-Chenopodiaceae-Lycopodium-Artemisia. Results indicate that the whole study interval was dominated by shrubs and grasses, interspersed with conifers and broad-leaved trees, exhibiting an altitudinally zonal pattern. Using the Coexistence Likelihood Estimation (CRACLE) method, we estimate a mean annual temperature (MAT) ranging from 6.0 to 14.7 °C and a mean annual precipitation (MAP) between 919.1 and 1612.4 mm during Miocene times. While minor climatic fluctuations occurred, the region experienced a cool-temperate and sub-humid climate significantly warmer and more humid conditions compared to the present. Based on MAT differences, the paleoelevation of the Wulan Basin during the Miocene was estimated to be c. 1655–2025 m, suggesting an uplift of c. 1275–1645 m since that time. These findings corroborate previous suggestions that the northeastern TP had not reached its current elevation prior to the Late Miocene.

The latest Carboniferous-earliest Permian palynological assemblage from the Sauce Grande Formation, Claromecó Basin, Argentina: Implications for the local palynostratigraphic scheme and correlations in Western Gondwana

The Sauce Grande Formation of the Ventania System and Claromecó Basin, east-central Argentina, is a geological unit of glaciomarine origin showing evidence of the glaciation that affected the supercontinent of Gondwana during the late Paleozoic. The age of this unit was previously determined from scarce and poorly preserved fossils, but mainly from radiometric dating and the fossil content of the overlying geological units. This study presents a palynological assemblage obtained from the Sauce Grande Formation in the PANG 0002 borehole, drilled in the Upper Paleozoic Claromecó Basin. Based on the identification of key species, such as Converrucosisporites confluens, Pakhapites ovatus, P. fusus, Vittatina spp., and Weylandites magmus, an age no older than Gzhelian is inferred for the interval studied. The inferred age allows us to relate the glaciomarine deposits of the Sauce Grande Formation to the last episode of the late Paleozoic Ice Age. The palynological assemblage of the Sauce Grande Formation is correlated with the Converrucosisporites confluens-Vittatina vittifera (CV) Biozone of the Claromecó Basin. Based on updated information and new correlations of the CV Biozone with palynostratigraphic schemes established in neighboring basins (Chacoparaná, Paraná, and central-western Argentina), its age is adjusted to the Gzhelian-late Artinskian interval, encompassing the Carboniferous-Permian boundary. This new information contributes to refining the current biostratigraphic scheme of the late Paleozoic Claromecó Basin.

Palynostratigraphy from the Allen and Jagüel formations at the Cerro Gutiérrez locality, Lago Pellegrini area, South Argentina

This work provides new stratigraphic information from the Allen and Jagüel formations (Neuquén Basin) at the Cerro Gutiérrez locality, Río Negro province. The distribution of palynomorphs allowed the definition of two palynologic assemblages: A1 corresponding to the Allen Formation, and A2 from the Jagüel Formation. The presence of taxa such as Catinipollis geiseltalensis, Gabonisporis vigorouxii, Nevesisporites vallatus, Callialasporites, Gemmamonocolpites, and Quadraplanus brossus suggests a Maastrichtian age. Due to the presence in A1 of Quadraplanus brossus, which range is Late Maastrichtian in Australia, New Zealand, and Antarctica, the age of the middle member of the Allen Formation, previously considered Late Campanian, could now be assigned to Late Maastrichtian. The palynoflora of the locality corresponds to the transitional paleoflora.

Stanley and Acetolysis: Enhanced Method for Pollen Identification and Geolocation of Cocaine Samples

The concept of palynological assemblage, a set of all identifiable pollen grains and spores, is very useful in geolocation determinations in Forensic Studies. To identify plant genera, palynologists must recognize detailed aspects of apertures, ornamentation and layers on the cell wall. Pollen and spores recovered from higher purity cocaine samples represent an alternative to indicate drug source regions. After following the method established by Stanley in 1992, we added the acetolysis procedure in samples seized by the Civil Police of the State of Sao Paulo, Brazil, in 2017, in order to enhance morphological traits observation and taxonomical identification of different pollen taxa, allowing reliable environmental and geolocation reconstructions.

Evolution of West‐East Contrast in the Subarctic Pacific Gyre During the Plio‐Pleistocene Based on Palynological Evidence at ODP Sites 882 and 887

AbstractFragmentary and contradictory evidence prevents a clear understanding of the possible role of the North Pacific Ocean surface on the ice‐sheet evolution. New palynological data encompassing the Pliocene and Pleistocene at Ocean Drilling Program Site 882 in the northwest Pacific document sea‐surface conditions from dinoflagellate cysts in addition to atmospheric trajectories from pollen grains and spores. The comparison of the Site 882 record with that of Site 887 from the northeast Pacific also permits documenting West to East contrasts across the subarctic North Pacific. The dinocyst assemblages at the two sites indicate strong temperature contrasts until 4.2 Ma, with much warmer conditions in the East. From 4.2 to 3.6 Ma, dinocyst assemblages of both sites are characterized by alternated dominance of the extinct taxa Habibacysta tectata and Impagidinium detroitense suggesting homogenous and cool conditions across the subarctic Pacific gyre. A major transition is recorded in the palynological assemblages at Site 882 around 2.7 Ma. It is marked by the highest occurrence of Habibacysta tectata and high percentages of Filisphaera microornata additionally to thermophilic taxa. Dinocyst record indicates high seasonality and warmer surface conditions due to reinforced stratification, which support the hypothesis of high evaporation at the origin of atmospheric moisture supply to high latitudes. During the last 1.2 Ma, the increase of Operculodinium centrocarpum relative to Nematosphaeropsis labyrinthus is tentatively interpreted as a reinforced influence of the subtropical waters. Hence, we suggest that the warm surface ocean fostered the inception and growth of northwestern North American ice‐sheets during the Pliocene and Pleistocene.

The Cretaceous to Eocene: a biostratigraphical review and a new detailed palynostratigraphy of Greenland and adjacent areas

The present paper compile and correlate for the first time Cretaceous to Eocene palynostratigraphies across the Arctic. It focus on Greenland and adjacent areas, including the Labrador–Baffin Seaway, onshore Nuussuaq Basin in central West Greenland, onshore southern East Greenland, central East Greenland, North-East Greenland, eastern North Greenland and the Danmarkshavn Basin, but also extends to Canadian Arctic Archipelago and the Barents Sea region off Norway. The paper compile data from more than three decades of detailed Arctic palynological analyses, based mainly on dinoflagellate cysts. The paper gives a historical overview of the Cretaceous to Palaeogene paleontological studies of Greenland and presents an overview of 85 palynological intervals and numerous events. The palynological assemblages from the Labrador–Baffin Seaway, Nuussuaq Basin and north-east Baffin Bay reflect the opening of the Labrador–Baffin Seaway from brackish to freshwater environment in a large embayment in the Early Cretaceous to an open marine seaway in the Late Cretaceous. Assemblages reveal in dinoflagellate cyst provincialism between the opening stages of the Labrador–Baffin Seaway and the already opened Greenland–Norwegian–Barents seaway. The Upper Cretaceous global Oceanic Anoxic Event 2 (OAE2) spanning the Cenomanian/Turonian boundary is recognised from Arctic Canada, north-east Baffin Bay, Nuussuaq Basin in central West Greenland, and North-East Greenland, and is mapped and correlated based on dinoflagellate cyst stratigraphy and carbon isotope (δ13Corg) curves. The dinoflagellate cysts assemblages of the Cretaceous/Palaeogene boundary are correlated from the Labrador Sea across to the Nuussuaq Basin in central West Greenland; in both areas the earliest Danian palynological assemblage is represented by incoming warm-water species. The presence of the global Paleocene–Eocene Thermal Maximum (PETM) in the Palaeogene successions in North-East Greenland and in exploration wells in the Labrador–Baffin Seaway is indicated by the incoming of the warm-water dinoflagellate cyst species Axiodinium augustum.

Palynology of strata associated with the Hercynian Unconformity across the Arabian Plate, from the Levant to southern Arabia

Abstract A survey of the palynostratigraphy of the strata above and below the Hercynian Unconformity indicates that the range of its associated hiatus, due to either non-deposition or erosion (or both), varies considerably across the Arabian Plate depending on the position of the succession in relation to the three main highs or arches, the Levant, Al Batin and Oman-Hadhramaut arches, and any Hercynian faulting or other uplift in basinal regions, for example in the Ghawar region. As expected, the succession spanning the Hercynian Unconformity is most complete in basinal areas, for example in the Faydah-Jafurah and Nafud-Ma'aniya basins. The well with the shortest hiatus, corresponding approximately to a maximum duration of part of the Serpukhovian and Bashkirian, appears to be KH-5/1, close to the axis of the Nafud-Ma'aniya Basin. Palynological assemblages in rocks above the Hercynian Unconformity indicate the diachronous onset of the basal Khuff clastics NW through the Arabian Plate over a period of c. 15 Myr. The oldest strata above the Hercynian Unconformity across the Arabian Plate also indicate systematic variation, probably due to palaeoclimate, with assemblages of similar age in Iraq and northern Saudi Arabia showing some similarities to those of Oman, but differences probably due to a strong climatic gradient at the time.

Dinoflagellate cysts from the Shillong Plateau, Meghalaya (India): Palynological signature during the late Palaeocene–early Eocene Transition

AbstractThe paper presents a new section of the late Palaeocene‐early Eocene, palynological assemblages and stable carbon isotopes from the Lakadong sandstone member of the East Khasi Hills of Meghalaya (India). The Palaeocene‐Eocene transition (PET) is marked by stratigraphic markers of dinoflagellate cysts (taxa of Apectodinium augustum, now Axiodinium augustum) and negative carbon isotope excursion. The palynofloral assemblage indicates the sequence represents warm, humid tropical to subtropical conditions with heavy rainfall. The depositional environment of the Lakadong Sandstone Member is interpreted to be neritic. The new insights of this study in this section suggest the PET with the occurrence of Apectodinium acme consisting of A. augustum at CS5‐15a.

Palaeodepositional environment, implications of Glossopteris flora, and organic matter characteristics from the Lower Permian, Karo Open Cast Mine, East Bokaro Coalfield, Damodar Basin, India

The present study deals with the Early Permian floral diversity, palaeoenvironment, palaeoclimate and depositional setting using a multiproxy approach that includes morphotaxonomy, palynology, and organic geochemistry of Karo OCM (Open Cast Mine), East Bokaro Coalfield, Damodar Gondwana Basin, India. The Permian sediments of Peninsular India are widely regarded as fluvial, along with some marine incursions. The macroplant fossil assemblage exhibits the presence of Glossopteridales, comprising Glossopteris, Gangamopteris, and Vertebraria, as well as Coniferales, which includes Noeggerathiopsis. The palynological assemblage encompasses the dominance of the striate bisaccate pollen Faunipollenites sp. and the sub-dominance of the non-striate bisaccate pollen Scheuringipollenites sp. with glossopterid affinities. The megafloral and palynofloral assemblage confirms the biostratigraphical age to be Late Barakar palynoflora of Kungurian affinity. The studied morphological characteristics, including small to large Glossopteris leaves exhibiting a lanceolate shape, acute apices, and acute cuneate or tapering bases, as well as entire margins with narrower lamina and narrow meshes, suggest the existence of a dense forest with the prevalence of a warm and humid climate during their deposition. The organic geochemical characterization based on functional group and biomarker analyses reveals the diagenetic effects on organic matter. Aliphatic symmetric (∼2865–2855 cm-1) and asymmetric stretching (∼2930–2910 cm-1) peaks are identifiable in coal samples, whereas they are absent in carbonaceous shale. The A-factor vs. C-factor plot suggests that the kerogen type is type III, which can generate mainly gaseous kerogen. The vitrinite reflectance studies (Rr av. 1.1%) show increased maturity of the samples, which is supported by the n-alkane distribution pattern and the absence of hopane terpenoids. The Indian floral assemblages in contemporary of southern Gondwana continents reveal a stronger inclination/affinity with the flora of Africa than that of South America, thereby supporting the age to be of Artinskian–Kungurian.

Lead-up and manifestation of the Oceanic Anoxic Event 2 at the DSDP Site 398 (Vigo Seamount, NW Iberian offshore): Palynological and geochemical insights

Extreme climatic conditions, volcanism, and paleogeographical distribution presumably led to the Oceanic Anoxic Event 2 (OAE 2), one of the most disruptive events for Cretaceous ecosystems. Although the terrestrial response to this issue is barely studied, a turnover within the plant communities seems to be linked to the OAE 2, besides the well-known extinction of several marine groups. In this study, palynological and δ13Corg analyses were combined to research the sediments from DSDP Site 398 (Vigo Seamount) cores 398D-58 to 398D-56 (upper Albian to lower Turonian). The δ13Corg curve exhibits a Carbon Isotopic Excursion (CIE) observed between the interval 948,60 and 947,77 m below seafloor (mbsf), corresponding to the OAE 2. Four palynological assemblages were differentiated, ranging from the uppermost Albian to the lower Turonian. These assemblages comprised diverse marine and terrestrial communities with generally excellent preservation. In addition to previous biostratigraphic works, we present a more detailed chronostratigraphy of DSDP Hole 398D based on palynomorphs. The paleoecological reconstruction reveals the significant changes during the OAE 2 period: a decrease in the diversity and abundance of dinoflagellate cysts and a shift to angiosperm-dominated terrestrial communities (i.e., Normapolles) which, unlike other sites, occurs prior to the maximum values of δ13C.

Geochemical and palynological records of the Early‐Middle Jurassic in the Turpan‐Hami Basin, NW China: Implications for paleoenvironment and paleoclimate change

The Early‐Middle Jurassic is one of the crucial coal‐forming geologic periods in the world and an important target for hydrocarbon exploration in the Turpan‐Hami Basin, China. The paleoenvironment and vegetation reconstruction of the Early‐Middle Jurassic have been investigated using elemental geochemistry and palynological analysis to reveal paleoclimate evolution. A total of 48 genera of pteridophyte spore and 35 genera of gymnosperm pollen were identified, and 5 palynological assemblages were longitudinally divided, which showed significant differences in geochemical behaviours. The paleoenvironment was a transition from suboxidation to anoxia and then to an oxidation environment under freshwater conditions. The paleowater in the northern Taibei Sag was deeper than that in the southern part during the Middle Jurassic, which coincided with the sedimentary background of the sublacustrine fan in the north and the shallow braided river delta in the south. The paleovegetation evolved from mixed lowland–upland forest in the Hettangian‐Toarcian, to lowland fern forest in the Aalenian‐Bajocian, to upland conifers forest in the early Bathonian, to upland Cheirolepidiaceae forest in the late Bathonian‐Callovian. The Toarcian and Bathonian‐Callovian arid climate and the Hettangian‐Pliensbachian and Aalenian‐Bajocian warm‐humid climate were responses to the continued global warming events and the intensification of the East Asian monsoon circulation, respectively. The influence of the Bathonian‐Callovian aridification event on the sedimentary response in the southern Taibei Sag will be delayed due to the gradual southward migration of the depositional centre.

Palynological assemblages from the Majaditas Formation (Carboniferous), Argentina: An example of reworking in glacial sediments

Reworked palynomorphs are commonly found in sedimentary deposits of glacial environments. However, instances of reworking were few times identified in the Carboniferous assemblages of central-western Argentina. In this study, two well-preserved palynological assemblages recovered from shales bearing dropstones of the Majaditas Formation in San Juan province are described for the first time. The palynoflora comprises spores, monosaccate pollen, acritarchs, and prasinophyte. Although in a low proportion (at least 2%), some palynomorphs correspond to reworked specimens of the underlying Devonian and Mississippian successions. The assemblages are indicative of the Subzone A of the Raistrickia densa/Convolutisporamuriornata Biozone that characterizes the late Serpukhovian-early Bashkirian in the country. Close similarities are evident with other palynofloras described for glaciogenic deposits of the same age in the region.

A contribution to the knowledge of Cretaceous to Neogene Palynology in the Colombian Caribbean.

The palynological study of a composite section of 14 cores drilled from the Sinu-San Jacinto Basin in the Colombian Caribbean (NW South America) provides for the first time a Cenozoic palynostratigraphic zonation scheme for this region. In addition, the study of calcareous nannofossils and planktonic foraminifera allowed an independent calibration of the palynomorph assemblages to the international chronostratigraphic chart. The palynological results were compared with other studies for the northern part of South America and Colombia. Twelve Late Paleocene-Pliocene palynological zones are proposed for the Caribbean, some of which differ from those proposed for the Llanos and Llanos Foothills basins. A Paleocene palynological assemblage is reported for this part of the basin. Variations in the biostratigraphic ranges of some palynomorphs and new species with stratigraphic value are described. High diversity and abundance of dinoflagellate cysts in some stratigraphic intervals require more detailed study. Evidence of reworking in some stratigraphic intervals (e.g., Cretaceous and Oligocene in Miocene sediments), makes it necessary to be careful about the last appearance record of microfossils in exploration and geologic mapping.

Pteridium (Dennstaedtiaceae) from Miocene of Patagonia (Río Negro, Argentina): the southernmost evidence of bracken fern in South America

ABSTRACT With only four species, Pteridium is one of the most-known fern genera for its role as pioneer in ecological succession and for being an aggressive weed. Despite its current wide distribution that extends to almost the entire world, there is a relatively small number of fossil records of macrofossils and palynological assemblages related to or compared with this genus. The majority of these belong to Oligocene ─ Pliocene deposits from the United States, Europe, Asia and New Zealand and only one has been described for South America, in upper Pliocene? – Quaternary deposits from Brazil. In this contribution, we describe the oldest and southernmost record of Pteridium for South America, based on frond impressions from Miocene deposits of the Ñirihuau Formation, exposed in the North Patagonian Andes (Argentina) and interpreted as deposited in alluvial, lacustrine, deltaic, and fluvial environments. We illustrate the finding and compare it with previous records of Pteridium and Pteris and with the current Neotropical species Pteridium esculentum. Additionally, we characterise the palaeoenvironmental framework in which the palaeoflora developed and we discuss the association of the fossil with other taxa fossils found in the same deposits, and of Pteridium with other species in current floras.

Palynological assemblages from Hongguleleng Formation of Western Junggar, Northwest China and their correlation with conodont zonation

The Upper Devonian Hongguleleng Formation is a significant stratigraphic unit near the Frasnian/Famennian and Devonian/Carboniferous boundaries of the Kazakhstan Paleoplate. However, its age is still under debate. A new palynostratigraphic analysis was conducted at the Gennaren section to provide a more accurate biostratigraphic assignment. In this study, we identified 43 species belonging to 26 spore genera, including those in open nomenclature. Despite the poor preservation of the palynofloras, the spore taxa were categorized into two assemblages. Assemblage I is established at the lower part of the lower member of the Hongguleleng Formation, containing Cornispora varicornata, cf. Auroraspora pseudocrista, and Cyrtospora cristifera. Assemblage II is from the upper part of the lower member of the Hongguleleng Formation, including Grandispora cornuta, Grandispora famennensis var. famennensis, Grandispora cf. famennensis var. minutus, Grandispora microseta, and Rugospora radiata. These assemblages are compared with the Western European DV Oppel Zone (lower-middle Famennian), and the GF to VCo Oppel zones. The assemblages are equivalent to the conodont crepida–rhomboidea and marginifera to Lower trachytera zones (middle-upper Famennian).

PALYNOSTRATIGRAPHIC AND PALAEOENVIRONMENTAL INVESTIGATIONS OF THE MAASTRICHTIAN FROM OARDA DE JOS (SOUTHWESTERN TRANSYLVANIAN BASIN)

A palynological, palynofacies and organic geochemical investigation of the Upper Cretaceous continental vertebrate site of Oarda de Jos allowed us to constrain its age and to make more detailed inferences about its depositional environment. The recovered palynomorph assemblage is represented mainly by angiosperm pollen and fern spores, alongside rare taxa of gymnosperms. Biostratigraphically significant taxa identified in the assemblage restrict the age of the studies deposits to the later early Maastrichtian. The palynofloral evidence indicates plant communities that mainly preferred higher-altitude areas and cooler-wetter conditions. However, a spore and pollen assemblage which derives from vegetation typical of lacustrine areas or riverbanks also occurs in the studied deposits. The studied palynoflora shows quite significant differences compared to previously published palynological assemblages from the same geological unit (the Sebeș Formation), although from deposits located slightly to the north, at Pâclișa. Organic geochemical data show that certain organic biomarkers such as n-alkanes n-C16 to n-C18 reach the highest values, and indicate that they may derive from freshwater colonial green algae such as Scenedesmus. The palynofacies constituents used to reconstruct the depositional environment suggest an exclusive terrestrial organic matter deposited in a stagnant-water fluvial/lacustrine environment.

New palynological record for the Puesto Albornoz Formation (Golfo San Jorge basin, Argentina): Stratigraphic and paleoenvironmental implications

Palynomorph assemblages were recovered from the Puesto Albornoz Formation (Golfo San Jorge Basin, Southern Argentina) at its type locality. The scarcity of outcrops with a continental Lower Cretaceous sedimentary record in this basin, and its marginal position in the western sector of the studied area, make Puesto Albornoz a unique and key locality for determining the timing of the basin evolution during the Cretaceous. The palynological content includes thirty-five spore species, twenty-one pollen taxa, and two algae. Among the fifty-eight species identified, forty-eight were identified for the first time for the unit. Based on the previous records of the analyzed taxa, a late Valanginian to Barremian, and more probably late Valanginian to Hauterivian age is inferred for the studied palynoflora. The palynological assemblages studied here closely resemble the Interulobites-Foraminisporis Zone (late Valangian-Hauterivian) of the Argentinian Patagonia, and the Cyclusphaera psilata-Classopollis association (late Valanginian-Barremian) of the Neuquén Basin.

Human colonisation and vegetation response to Late Pleistocene to mid-Holocene climate variability in Northern Iberia based on a multiproxy analysis of the Atxurra cave-fill

Atxurra Cave (Berriatua, Northern Spain) contains an important Magdalenian archaeological assemblage comprising evidence of ephemeral occupation in the lower cave level and a unique assemblage of rock art. With the aim of understanding the palaeoenvironmental conditions and the nature of the human occupation, detailed micromorphological, mineralogical, palynological and anthracological analyses were undertaken near the entrance of the cave. The lower part of the excavated sequence comprises almost unfossiliferous silty units deposited over a thick speleothem deposit, which alternates with a sandy-silt matrix-supported microfacies dated about 33.4 kyr B.P. Palynological assemblage in this unit suggest regional vegetation was formed by montane pines, junipers and broadleaved elements like birch and hazel. Overlying units of brown clayey material, dated to ca. 19.7–18.4 kyr B.P., contain evidence of a Gravettian occupation with Noailles burins, and a palynoflora indicative of localized conifers with a dense herbaceous steppe understory, in an arid and cold climate. At ca. 15.5–14.5 kyr B.P. there is a return to meso-thermophilous tree and shrub taxa within a warmer and humid climate background, which may have favored the regional development of the Magdalenian culture. The uppermost unit, dated ca. 7.7–7 kyr B.P., reveals postglacial expansion of a mixed Atlantic forest with no signals of anthropization before the start of the Neolithic.

Palynological assemblages and paleoenvironmental evolution in the Gyirong Basin since Middle Miocene

Palynological assemblages and paleoenvironmental evolution in the Gyirong Basin since Middle Miocene