Possibilities and limitations of ESR dating applied to Pliocene and Pleistocene units of western central mainland Portugal

Summary: This work aims to give a short description of the applicability of ESR method for dating Pliocene and Pleistocene units of western central mainland Portugal ranging between 2.5 and 0.2 Ma. The vast culminant unit of the sedimentary infill only was previously dated, at the base, in one site. The dating of the topmost deposits of this unit will allow to date the transition from the stage of sedimentary infilling to that of fluvial incision and to understand the controls of this. Only the lower coastal terraces are dated to <ca. 300 ka provided by OSL methods. The ESR dating will support stratigraphic correlations and estimate the local uplift rates and the identification of the main active tectonic structures in central western mainland Portugal

The origin of early Acheulean expansion in Europe 700 ka ago: new findings at Notarchirico (Italy)

Notarchirico (Southern Italy) has yielded the earliest evidence of Acheulean settlement in Italy and four older occupation levels have recently been unearthed, including one with bifaces, extending the roots of the Acheulean in Italy even further back in time. New 40Ar/39Ar on tephras and ESR dates on bleached quartz securely and accurately place these occupations between 695 and 670 ka (MIS 17), penecontemporaneous with the Moulin-Quignon and la Noira sites (France). These new data demonstrate a very rapid expansion of shared traditions over Western Europe during a period of highly variable climatic conditions, including interglacial and glacial episodes, between 670 and 650 (i.e., MIS17/MIS16 transition). The diversity of tools and activities observed in these three sites shows that Western Europe was populated by adaptable hominins during this time. These conclusions question the existence of refuge areas during intense glacial stages and raise questions concerning understudied migration pathways, such as the Sicilian route

The origin of early Acheulean expansion in Europe 700 ka ago: new findings at Notarchirico (Italy)

Notarchirico (Southern Italy) has yielded the earliest evidence of Acheulean settlement in Italy and four older occupation levels have recently been unearthed, including one with bifaces, extending the roots of the Acheulean in Italy even further back in time. New 40Ar/39Ar on tephras and ESR dates on bleached quartz securely and accurately place these occupations between 695 and 670&nbsp;ka (MIS 17), penecontemporaneous with the Moulin-Quignon and la Noira sites (France). These new data demonstrate a very rapid expansion of shared traditions over Western Europe during a period of highly variable climatic conditions, including interglacial and glacial episodes, between 670 and 650 (i.e., MIS17/MIS16 transition). The diversity of tools and activities observed in these three sites shows that Western Europe was populated by adaptable hominins during this time. These conclusions question the existence of refuge areas during intense glacial stages and raise questions concerning understudied migration pathways, such as the Sicilian route

Levantamento diferencial evidenciado pelas escadarias de terraços marinhos do Cabo Espichel e do Cabo Raso durante o Plistocénico

This study focuses on two marine terrace staircases of central Portugal: Cabo Raso (west of Lisboa) and Cabo Espichel (western Arrábida chain). Four emerse marine terraces were found in the Cabo Raso area, while twelve were found at Cabo Espichel, according to geomorphological and stratigraphical studies. Electron Spin Resonance and luminescence dating were used to establish a chronology for the coastal staircases, from which uplift rates were calculated. The present elevations of the culminating marine abrasion platform represented at Cabo Raso and Cabo Espichel, express the differential uplift between these areas over the last ~3,7 Ma

Multi-omic analysis in injured humans: Patterns align with outcomes and treatment responses

Trauma is a leading cause of death and morbidity worldwide. Here, we present the analysis of a longitudinal multi-omic dataset comprising clinical, cytokine, endotheliopathy biomarker, lipidome, metabolome, and proteome data from severely injured humans. A "systemic storm" pattern with release of 1,061 markers, together with a pattern suggestive of the "massive consumption" of 892 constitutive circulating markers, is identified in the acute phase post-trauma. Data integration reveals two human injury response endotypes, which align with clinical trajectory. Prehospital thawed plasma rescues only endotype 2 patients with traumatic brain injury (30-day mortality: 30.3 versus 75.0%; p = 0.0015). Ubiquitin carboxy-terminal hydrolase L1 (UCHL1) was identified as the most predictive circulating biomarker to identify endotype 2-traumatic brain injury (TBI) patients. These response patterns refine the paradigm for human injury, while the datasets provide a resource for the study of critical illness, trauma, and human stress responses

Contribution of cathodoluminescence to the characterization and selection of quartz for ESR dating

International audienceElectron Spin Resonance (ESR) applied to optically bleached quartz grains extracted from sediment provides an age estimate for the last exposure of sediment to sunlight. This method has been increasingly used in archaeological, geological and geomorphological contexts for the last 30 years. However, its successful application is highly dependent on the geological context, the type and quality of the sampled material, but also its preparation. In most of the ESR dating studies, Equivalent Dose calculation uses the multiple ali-quot additive dose (MAAD) approach. Accuracy of the ED is the slightly correlated with the dose response of different aliquots of quartz grains to irradiation. In most of the measured quartz samples, a single saturating exponential dose response curve or a two components combining an exponential with a linear term are classically used in ESR dating to fit the experimental ESR data points derived from the aluminum (Al) or the titanium (Ti-Li, Ti-H) centers in quartz. However, large deviation and large associated errors may occasionally be observed. Heterogeneous bleaching (incomplete resetting) of the ESR dating signal can sometimes explain such deviations. Scattering of the dose response to irradiation may also be due to heterogeneous dose response of the different aliquots related to various nature and/or origin of the quartz grains constituting the dating sediment. Quartz grains extracted from several sediments were measured by ESR and observed using cathodoluminescence (CL) technique. The CL colours of quartz are weak, compared with emission of other minerals such as carbonates or phosphates, but are highly variable and can be related to genetic conditions of quartz formation. Hence, lumines-cence microscopy can be used to reveal internal structures, growth zoning and lattice defects in quartz crystals not discernible by means of other analytical techniques, but also to reveal heterogeneity of the quartz grains within the sample, or even the presence of other minerals, not removed during the chemical process of quartz purification. The cathodoluminescence gave evidence of several types of situation within our quartz samples. Some of them are made of monocrystalline quartz grains, emitting a uniform CL within the grain but with a light heterogeneity of the wavelength emission between the grains. Some are made of polycrystalline quartz grains, displaying a strong heterogeneity of the luminescence within and between the quartz grains. Finally we also observed some CL attributed to plagioclase and K-feldspar, which may contaminate, even strongly, the quartz samples. The presentation will report this variability and discuss about its effect on the dose response curve when using the ESR dating of quartz grains