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<jats:title>Abstract</jats:title><jats:p>The SHRIMP U–Pb dating of zircons from felsic subvolcanic rocks in the Carboniferous formations of the Intra-Sudetic Basin in SW Poland verifies previous views on the timing of Late Palaeozoic magmatic activity in this area and constrains the links between regional tectonics and intra-basinal volcanism in the mid-European Variscides. Two main stages of magmatism are identified: the Late Carboniferous late orogenic stage, and the Early Permian post-orogenic stage. The Carboniferous late orogenic subvolcanic to volcanic activity was contemporaneous with the formation of the Karkonosze granite pluton to the west and comprised episodic emplacement of predominantly felsic laccoliths and sills within the basin fill during the Westphalian–Stephanian in two sub-stages at ca. 313–310 Ma and 306–305 Ma. Local folding of the Carboniferous succession peaked at ca. 303–300 Ma adjacent to the Intra-Sudetic Fault, in relation to late-stage sinistral movements along this regional wrench fault. The emplacement of minor subvolcanic intrusions at ca. 293 Ma completed the activity in the northern Intra-Sudetic Basin; this Permian post-orogenic volcanism, however, developed fully in areas further south. The predominance of subvolcanic intrusions over extrusions in Carboniferous can be linked to the trapping of rising magmas within the several kilometres thick sedimentary basin fill. Zircon xenocrysts in the Carboniferous subvolcanic rocks indicate that older crustal lithologies, possibly metamagmatic and metasedimentary rocks of dominantly Neoproterozoic–Palaeozoic ages, were involved in petrogenesis as magma sources and/or contaminants. The crustal influence on magma formation was stronger during the earlier magmatic events.</jats:p>

<jats:title>Abstract</jats:title><jats:p>The bituminous black pelite of the Messel UNESCO world heritage site is an exceptional palaeobiological archive from the Middle Eocene greenhouse climate. The pronounced homogeneity of the annually laminated pelite through a time interval of 640 kyr complicates the relative stratigraphic classification of fossil remains and is, thus, largely dependent on particular marker horizons within the uniform sedimentary column. We analyzed the most prominent marker horizon M using petrographic microscopy, X-ray powder diffraction, and electron probe microanalyses to identify and characterize its structure and phosphate-dominated mineralogy. Based on our analytical data, we suggest that this phosphatic marker horizon resulted from the exceptional combination of external tephra enclosed in bacteria and algae-rich layers, producing a coupled phosphorus and cation diffusion during diagenesis. Mantienneite (KMg<jats:sub>2</jats:sub>Al<jats:sub>2</jats:sub>Ti(PO<jats:sub>4</jats:sub>)<jats:sub>4</jats:sub>(OH)<jats:sub>3</jats:sub> • 15H<jats:sub>2</jats:sub>O) is documented for the first time in the Messel fossil deposit. The diagenetic succession of messelite, montgomeryite, and mantienneite precipitation reflects the internal heterogeneities in primary mineral composition of an ash layer. Kerogen maturation and hydrocarbon migration produced acidic, reducing pore fluids with high P concentration, which enhanced the mobility of Al and Ti. The mantienneite-forming reaction marks the change from a regime of reducing to oxidizing conditions. With the deposition and diagenesis of the marker horizon M, a singular event is preserved in a sedimentary sequence otherwise regarded as largely uniform over a time span of about 640 kyr.</jats:p>

<jats:title>Abstract</jats:title><jats:p>Some recent models challenge the position and extension of the assumed oceanic basins formed through the break-up of Rodinia, and the tectonic processes involved in the Gondwana assembly, making the investigation of the Early Neoproterozoic record of great relevance. Within the South-American Atlantic margin, the Punta del Este Terrane (PET) of the Dom Feliciano Belt (DFB) comprises a unique Tonian to Ediacaran record, and has a strategic position to reconstruct spatio-temporal relationships with the southern African orogenic belts. Novel zircon U–Pb and Lu–Hf data from the PET basement orthogneisses display Tonian magmatic ages (805–760 Ma) and Hf isotopic signatures indicative of mainly crustal/metasedimentary sources, (Nd T<jats:sub>DM</jats:sub> ages: 2.2–1.9 Ga, and εHf(t): − 12 to − 4). The basement paragneisses yielded late Paleoproterozoic to Neoproterozoic U–Pb ages, but dominantly positive εHf(t) values. The presented results confirm the correlation of the PET with the Coastal Terrane of the Kaoko Belt, and discard the idea of the Nico Pérez Terrane as a source. Detrital zircon U–Pb and Lu–Hf data from the Rocha Formation yielded a main peak at ca. 660 Ma, with the Neoproterozoic grains showing a εHf(t) between + 1 and + 14. The deposition age of the Rocha Formation is constrained by the youngest detrital zircon age peak (660 Ma), and the beginning of the deposition of the Sierra de Aguirre Formation (580 Ma). The data indicate common sources with the Marmora Terrane, and it is thus proposed that the Rocha Formation belongs to the Gariep Belt, and it was juxtaposed during the Ediacaran to the DFB.</jats:p>