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The onset of the Acheulean, marked by the emergence of large cutting tools (LCTs), is considered a major technological advance in the Early Stone Age and a key turning point in human evolution. The Acheulean originated in East Africa at ~ 1.8–1.6 Ma and is reported in South Africa between ~ 1.6 and > 1.0 Ma. The timing of its appearance and development in North Africa have been poorly known due to the near-absence of well-dated sites in reliable contexts. The ~ 1 Ma stone artefacts of Tighennif (Algeria) and Thomas Quarry I-Unit L (ThI-L) at Casablanca (Morocco) are thus far regarded as documenting the oldest Acheulean in North Africa but whatever the precision of their stratigraphical position, both deserve a better chronology. Here we provide a chronology for ThI-L, based on new magnetostratigraphic and geochemical data. Added to the existing lithostratigraphy of the Casablanca sequence, these results provide the first robust chronostratigraphic framework for the early North African Acheulean and firmly establish its emergence in this part of the continent back at least to ~ 1.3 Ma.

The Ladinian/Carnian boundary (LCB) is defined at Prati di Stuores (GSSP of the Carnian Stage) with the First Appearance Datum (FAD) of ammonoid Daxatina canadensis and approximated by the FAD of conodont Paragondolella polygnathiformis. The age of the Carnian is currently estimated at ca. 237 Ma using the composite magnetostratigraphy of the main late Ladinian basinal sequences from literature, calibrated with a U-Pb radiometric age of 237.77±0.14 Ma from the Rio Nigra section in Alpe di Siusi (Dolomites, NE Italy). In the attempt to improve the precision of the Geomagnetic Polarity Time Scale (GPTS) around the LCB we investigated for magnetostratigraphy the Punta Grohmann section in the Dolomites. The Punta Grohmann section is calibrated with ammonoids (the FAD of Zestoceras cf. lorigae is considered a proxy of the LCB) and is chronologically constrained by two U-Pb radiometric ages from zircons (237.58±0.04 Ma; 237.68±0.05 Ma). The magnetostratigraphy of the Punta Grohmann section has been successfully correlated to other Ladinian-Carnian magnetostratigraphic sections (Prati di Stuores, Mayerling, Rio Nigra) and compared to the most recent version of the Triassic Geomagnetic Polarity Time Scale (GPTS). The LCB at Prati di Stuores is calibrated through magnetostratigraphy with the U-Pb radiometric datings of Punta Grohmann, obtaining an age of the LCB of ca. 237.4 Ma. Therefore, the Ladinian should be ca. 4 Myr long and the Carnian ca. 10.4 Myr long.

The latest Triassic was an interval of prolonged biotic extinction culminating in the end-Triassic Extinction (ETE). The ETE is now associated with a perturbation of the global carbon cycle just before the end of the Triassic that has been attributed to the extensive volcanism of the Circum-Atlantic Magmatic Province (CAMP). However, we attribute the onset of declining latest Triassic diversity to an older perturbation of the carbon cycle (delta13Corg) of global extent at or very close to the Norian/Rhaetian boundary (NRB). The NRB appears to be the culmination of stepwise biotic turnovers that characterize the latest Triassic and includes global extinctions of significant marine and terrestrial fossil groups. These biotic events across the NRB have been largely under- appreciated, yet together with a coeval disturbance of the carbon cycle were pivotal in the history of the Late Triassic. Here, we present new and published delta13Corg data from widespread sections (Italy, Greece, ODP, Australia, New Zealand, USA, Canada). These sections document a previously unknown perturbation in the carbon cycle of global extent that spanned the NRB. The disturbance extended across the Panthalassa Ocean to both sides of the Pangaean supercontinent and is recorded in both the Northern and Southern Hemispheres. The onset of stepwise Late Triassic extinctions coincides with carbon perturbation (delta13Corg) at the NRB, indicating that a combination of climatic and environmental changes impacted the biota at a global scale. The NRB event may have been triggered either by gas emissions from the eruption of a large igneous province pre-dating the NRB, by a bolide impact of significant size or by some alternative source of greenhouse gas emissions. As yet, it has not been possible to clearly determine which of these trigger scenarios was responsible; the evidence is insufficient to decisively identify the causal mechanism and merits further study.

The base of the Rhaetian stage (Norian/Rhaetian boundary, NRB) is still awaiting formal designation by the International Commission on Stratigraphy. At present, only the 4.30-m-thick Steinbergkogel section (Austria) has been proposed as GSSP (Global Stratotype Section and Point) candidate for the base of the Rhaetian. Here we present data from the 63-m-thick Pignola-Abriola section (Southern Apennines, Italy) that we consider an alternative candidate for the Rhaetian GSSP. The Pignola-Abriola basinal section, represented by hemipelagic-pelagic carbonate successions belonging to the Lagonegro Basin, matches all the requirements for a GSSP: 1, it is well exposed with minimal structural deformation; 2, it is rich in age diagnostic fossils (e.g. conodonts and radiolarians); 3, it yields a geochemical record suitable for correlation (e.g. d13Corg/carb); and 4, it has a robust magnetostratigraphy and is correlated with the Newark APTS for age approximation of the NRB and additional Rhaetian bioevents. In the Pignola-Abriola section, we opt to place the NRB at the 44.4 metre level, coincident with a prominent negative shift of ca. 6& of the d13Corg. This level is located 50 cm below the FAD of conodont Misikella posthernsteini s.s within the radiolarian Proparvicingula moniliformis Zone. Both the negative d13Corg shift and the FAD of Misikella posthernsteini occur within Pignola-Abriola magnetozone MPA-5r, at ~205.7 Ma, according to magnetostratigraphical correlation to the Newark APTS. We also illustrate the coeval Mt. Volturino stratigraphical section deposited below the calcite compensation depth (CCD) within the same Lagonegro Basin and characterized by a detailed radiolarian biostratigraphy and strong d13Corg negative shift around the NRB.

This paper investigates the magnetostratigraphy of the ~750 m-thick Costa Grande Member (lower Miocene) from the Castagnola Basin of NW Italy, which represents the turbidite fill of a structurally confined basin where flow ponding resulted in a complete record of deposition from diverse sediment gravity flow types. The magnetostratigraphic profile of the Costa Grande Mb was correlated to the Geomagnetic Polarity Timescale using a well-established statistical method devised to be applied to sedimentary successions with steady accumulation rate. The results of the correlation exercise, validated with the available biostratigraphy, indicate an early Miocene age (from Chron C6AAr.3r to C6Bn.2n) between 21.7 and 22.3 Ma. The obtained age model was then used to calculate accumulation rates and frequencies of small volume and low-density vs. large volume and high-density gravity flows over an estimated 650 kyr time span. Results show that low-density flows contributed at a constant pace of 545 m Myr−1 to sediment accumulation, depositing relatively thin-bedded turbidites with a minimum recurrence time of 1.7 kyr, whereas the high-density flows, which are at least four times less frequent, are clustered in the stratigraphy, and become more abundant up-section. We also show that the minimum sediment volumes discharged by high-density flows suggest triggering by submarine failures whose recurrence and magnitude were probably not random. Lastly, we propose that the statistical method used in this study to correlate the Costa Grande Mb magnetostratigraphy to the GPTS provides best results when the products of episodic but voluminous depositional events are carefully identified and removed.

A global carbon-isotope curve for the Late Triassic has the potential for global correlations and new insights on the complex and extreme environmental changes that took place in this time interval. We reconstruct the global δ 13 C org profile for the late Norian, improving on sparse published data from North American successions that depict a “chaotic carbon-isotope interval” with rapid oscillations. In this context, we studied three sections outcropping in the Lagonegro Basin (southern Italy), originally located in the western Tethys. The carbon-isotope profiles show four negative excursions correlatable within the Lagonegro Basin. In particular, a negative shift close to the Norian/Rhaetian boundary (NRB) appears to correlate with that observed in the North American δ 13 C org record, documenting the widespread occurrence of this carbon cycle perturbation. The 87 Sr/ 86 Sr and 187 Os/ 188 Os profiles suggest that this negative shift was possibly caused by emplacement of a large igneous province (LIP). The release of greenhouse gases (CO 2 ) to the atmosphere-ocean system is supported by the 12 C enrichment observed, as well as by the increase of atmospheric p CO 2 inferred by different models for the Norian/Rhaetian interval. The trigger of this strongly perturbed interval could thus be enhanced magmatic activity that could be ascribed to the Angayucham province (Alaska, North America), a large oceanic plateau active ca. 214 ± 7 Ma, which has an estimated volume comparable to the Wrangellia and the Central Atlantic Magmatic Province (CAMP) LIPs. In fact, these three Late Triassic igneous provinces may have caused extreme environmental and climate changes during the Late Triassic.

By applying advanced spatial statistical methods, spatial taphonomy complements the traditional taphonomic approach and enhances our understanding of biostratinomic and diagenetic processes. In this study, we elaborate on a specific aspect – spatial anisotropy – of taphonomic processes. We aim to unravel the taphonomic history of the Early Pleistocene vertebrate assemblage of Tsiotra Vryssi (Mygdonia Basin, Greece). Circular statistics are used for the fabric analysis of elongated elements; geostatistics (directional variograms), wavelet and point pattern analyses are applied for detecting anisotropy at the assemblage level. The anisotropy of magnetic susceptibility (AMS) of sedimentary magnetic minerals is also investigated. The results, integrated with preliminary remarks about the differential preservation of skeletal elements, sedimentological and micromorphological observations, suggest multiple dispersion events and recurrent spatial re-arrangement of a lag, (peri)autochthonous assemblage, consistent with the cyclical lateral switching of a braided fluvial system. Furthermore, this study offers a contribution to the building of a spatial taphonomic referential framework for the interpretation of other fossil vertebrate assemblages, including archaeo-palaeontological ones.