Publication Date:
2024-02-16
Description:
A multi-proxy study of an offshore core in Saldanha Bay (South Africa) provides new insights into fluvial deposition, ecosystems, phytogeography and sea-level history during the late Paleogene-early Neogene. Offshore seismic data reveal bedrock topography, and provide evidence of relative sea levels as low as -100 m during the Oligocene. 3D landscape reconstruction reveals hills, plains and an anastomosing river system. A Chattian or early Miocene age for the sediments is inferred from dinoflagellate taxa Distatodinium craterum, Chiropteridium lobospinosum, Homotryblium plectilum and Impagidinium paradoxum. The subtropical forest revealed by palynology includes lianas and vines, evergreen trees, palms and ferns, implying higher water availability than today, probably reduced seasonal drought and stronger summer rainfall. From topography, sedimentology and palynology we reconstruct Podocarpaceaedominated forests, Proto-Fynbos, and swamp/riparian forests with palms and other angiosperms. Rhizophoraceae present the first South African evidence of Palaeogene/Neogene mangroves. Subtropical woodland-thicket with Combretaceae and Brachystegia (Peregrinipollis nigericus) probably developed on coastal plains. Some of the last remaining Gondwana elements on the sub-continent, e.g., Araucariaceae, are recorded. Charred particles signal fires prior to the onset of summer dry climate at the Cape. Marine and terrestrial palynomorphs, together with organic and inorganic geochemical proxy data, suggest a gradual glacio-eustatic transgression. The data shed light on Southern Hemisphere biogeography and regional climatic conditions at the Palaeogene-Neogene transition. The proliferation of the vegetation is partly ascribed to changes in South Atlantic oceanographic circulation, linked to the closure of the Central American Seaway and the onset of the Benguela Current ~14 Ma.
Keywords:
Achomosphaera ramulifera; Achomosphaera sp.; Aizoaceae; Anacardiaceae; Araliaceoipollenites reticuloides; Araucariacites; Araucariacites australis; Arecipites cf. otagoensis; Arecipites plectilimuratus; Arecipites spp.; Artemisiaepollenites; Baculatisporites; Baumannipollis variaperturatus; Bequaertiodendron; Blaeria-type; Botryococcus; Brachylaena-type; Brachysporisporites; Bruguieria-type; Caesalpiniaceae; Camarazonosporites; Camarazonosporites bankiensis; Canthiumidites spp.; Caprifoliipites viburnoides; Celastraceae; Celtipollenites sp.; cf. Aceripollenites; cf. Byttneripollis; cf. Dacrydiumites; cf. Dichrostachys-type; cf. Dicolpopollis spp.; cf. Fraxinipollis; cf. Quercoidites henrici; cf. Slovakipollis; cf. Styraxipollis stuchliki; cf. Triporotetradites sp.; cf. Verrucatiporites rotundiporus; Charcoal; Chenopodiaceae; Chiropteridium lobospinosum; Chiropteridium sp.; Christensenia-type; Clavatipollenites spp.; Combretaceae; Commiphora-type; Cooksonidium capricornium; Cordosphaeridium minimum; Core; CORE; Corrugatisporites sp.; Crotonipollis spp.; Cryptogrammasporis spp.; Cupaniedites indeterminable; Cupaniedites major; Cupressaceae/Taxodiaceae; Cupuliferoipollenites oviformis; Cyathidites australis; Cymatiosphaera; Cyperaceae; Cyperaceaepollis piriformis; Debarya; DEPTH, sediment/rock; Dinoflagellate indeterminata; Dinoflagellates, total; Diospyropollenites sp.; Distatodinium craterum; Equisetum sp.; Ericipites callidus; Ericipites spp.; Euphorbiaceae; Fabaceae; Foraminifera, linings; Fungal fruit-bodies; Fungal germling; Fungal spores; Fungi; Galium-type; Geraniaceae; Glaphyrocysta sp.; Gleicheniidites; Gleicheniidites spp.; Glencopollis ornatus; Graminidites cf. crassiglobosus; Graminidites cf. neogenicus; Graminidites spp.; Grewia-type; Grootipollis sp.; Hafniasphaera septata; Homotryblium plectilum; Hygrophila-type; Hypha; Hystrichokolpoma rigaudiae; Ilexpollenites margaritatus; Ilexpollenites spp.; Illexpollenites illiacus; Impagidinium paradoxum; Involutisporis; Laevigatosporites haardtii; Leiotriletes maximus; Leiotriletes maxoides; Leiotriletes wolffii; Liliacidites; Liliacidites minutes; Liliacidites spp.; Ludwigia-type; Lycopodiella inundata; Malvaceae; Manilkara-type; Meliaceoidites sp.; Microcachrydites antarcticus; Microfoveolatisporis fromensis; Microsclerotium; Mohria-type; Momipites sp.; Monocolpopollenites; Monocolpopollenites spp.; Mutisiae; Mutisiapollis viteauensis; Myricipites harrisii; Myricipites spp.; Myrtaceidites parvus; Neuradaceae; Oleoidearumpollenites spp.; Operculodinum centrocarpus; Ovoidites sp.; Palmae-trichotomosulcate; Parthenopollenites formosus; Parthenopollenites marcodurensis; Parthenopollenites neshobensis; Peregrinipollis nigericus; Phoenix-type; Podocarpidites; Podocarpidites kamiesberg; Podocarpidites spp.; Podocarpidites torquatus; Pollen, land, total; Polygala-type; Polypodiaceoisporites sp.; Potamogeton-type; Prasinophytes; Propylipollis meyeri; Propylipollis sp.; Proteacidites; Proteacidites bakkeri granulatus; Proteacidites spp.; Pseudoschizaea sp.; Pseudowinterapollis couperi; Psilatricolporites cf. atalangensis; Psilatricolporites crassiexinus; Psilatricolporites operculatus; Psilatricolporites quenua; Pterocelastrus-type; Pterospermella spp.; Quercoidites spp.; Quercopollenites cf. asper; Quercopollenites cf. granulatus; Restionaceae; Reticulatosphaera cf. actinocoronata; Retitriletes spp.; Rhamnaceaepollenites sp.; Rhizophoraceae; Rhoipites alveolatus; Rhoipites arnotiensis; Rhoipites couperi; Rhoipites spp.; Rhuspollenites sp.; Rhynchosia-type; Rosaceae; Rubiaceae; Rugulasporites spp.; Saldanha Bay, South Africa; Santalaceae; Sapotaceoidaepollenites spp.; SBQW4; Scrophulariaceae; Sigmopollis sp.; Simpsonipollis grandis; Solanum-type; Sparganiaceaepollenites barungensis; Spiniferites mirabilis; Spiniferites pseudofurcatus; Spiniferites ramosus; Spiniferites spp.; Spinitricolpites jennerclarkei; Spinitricolpites spp.; Spirostachys-type; Spores, monolete; Spores, trilete; Stereoisporites sp.; Sum; Sum algae; sum aquatics and water plants; Sum charcoal; sum Cryptogams; sum Fungi; sum herbs and shrublets; sum trees and shrubs; Tetracolporopollenites sapotoides; Tetraploea; Thymelipollis sp.; Todisporites spp.; Tricolpites; Tricolpites gillii; Tricolporopollenites; Tricolporopollenites brinkiae; Tricolporopollenites coetzeeae; Tricolporopollenites eofagoides; Tricolporopollenites marginatus; Triorites operculatus; Triporopollenites namaquensis; Tubulifloridites anthemidearum; Tubulifloridites antipodica; Tubulifloridites gigans; Tubulifloridites macroechinatus; Tubulifloridites spp.; Umbeliferoipollenites spp.; Unknown pollen and spores; Urticales; Varia; Verrucatisporites alienus; Verrucatisporites favus; Verrucatisporites spp.; Vitaceae; Zonalapollenites spp.; Zonalopollenites cf. gracilis; Zonalopollenites perisaccate; Zonocostites ramonae; Zygnemataceae
Type:
Dataset
Format:
text/tab-separated-values, 5302 data points
Permalink
