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The Kofun Period is an important epoch of the Japanese protohistory, spanning from the early 3rd to the early 7th century AD. It takes its name from the large megalithic mound tombs, called kofuns (“ancient graves”), which characterize and define this period. Such monumental burial mounds comprised a central stone funeral chamber, inside which a wood, clay or stone coffin was positioned together with offerings to the dead, such as jewelry, ornaments, weapons and pottery. Kofuns are of great importance for better understanding the Japanese archaeology and the social evolution that took place during the Kofun period in Japan. At the same time, the study of the pottery style and the technology of the baked clay coffins offers information about the ancient ceramic technology and the evolution of the funeral practices over time. In this study, we use rock magnetic analysis to investigate the firing temperatures and production technology of a clay coffin excavated at the Sada Nishizuka archaeological site, in Okayama prefecture, Japan. Thermal demagnetization, magnetic susceptibility, thermomagnetic curves and hysteresis loops performed before and after laboratory heating at increasing temperatures were used to determine the ancient firing temperatures. The results showed that all samples, even if belonging to different fragments coming from different parts of the coffin, experienced important enhancement on their magnetic properties at temperatures around 300-400 oC. Such important changes suggest that the coffin was fired at relative low temperatures, which were not enough to cause complete magnetic mineralogy transformations. The magnetic results were further compared with independent data obtained from X-ray powder diffraction analysis (XRPD). The clay mineral pattern obtained from the XRPD data indicates firing temperatures around 400 °C, based on the presence of kaolinite, while in some samples clay minerals characterized by thermal stability up to higher temperatures were also observed. Such results suggest that the coffin, probably due to its large dimensions, has not experienced homogeneous heating during its production, and thermal equilibrium was reached at relatively low temperatures, much lower than those applied in the pottery production. Nevertheless, such firing was sufficient to harder the coffin and make it suitable for its use. This study aims to highlight the potential of magnetic analyses to investigate ancient baked clays and the importance of multidisciplinary archaeometric analysis to better understand our past.

Northern Zealandia is a continent submerged for more than 90% under the water of the southwest Pacific Ocean and separated from Australia by the Tasman Sea ocean basin. Its absolute position since its drift form Australia in the Cretaceous is determined by means of global absolute plate motion models, as local paleomagnetic constraints are completely missing. We present new absolute paleolatitudes for northern Zealandia using paleomagnetic data from sediments drilled in International Ocean Discovery Program Sites U1507 and U1511 (Expedition 3711,2). After correcting for paleomagnetic inclination shallowing, typical of sediments, we derived five paleolatitude estimates that provide a trajectory of northern Zealandia past position from the middle Eocene to early Miocene, spanning geomagnetic polarity chrons C21n to C5Er (~48–18 Ma). Generally, our results support previous works on global absolute plate motion, including a rapid 6° northward migration of northern Zealandia between the early Oligocene–early Miocene. However, paleomagnetic-determined absolute paleolatitude is systematically lower, and this difference is significant in the Bartonian and Priabonian (C18n–C13r). This discrepancy may be explained by some degree of true polar wander, a solid Earth rotation with respect to the spin axis that can be resolved only using paleomagnetic data. These new paleomagnetic dataset anchors past latitudes of Zealandia to Earth’s spin axis, with implications not only for global geodynamics, but for addressing paleoceanographic problems, which generally require precise paleolatitude placement of proxy data3.Figure 1. Present-day map of northern and southern Zealandia, enveloped respectively by the yellow and orange dashed line. The yellow stars indicate the location of International Ocean Discovery Program Sites U1507 (26.4886°S, 166.5286°E) and U1511 (37.5611°S, 160.3156°E). Solid and dashed white lines indicate active and inactive subduction zones, respectively, with arrows lying on the overriding plate. LHR = Lord Howe Rise, NCT = New Caledonia trough, NR = Norfolk Ridge, RB = Reinga basin.(1) Sutherland, R. et al. Proc. Int. Ocean Discov. Progr. 371, 1–33 (2019); (2) Dallanave, E. & Chang, L. Newsletters Stratigr. 53, 365–387 (2020); (3) Dallanave, E. et al. J. Geophys. Res. Solid Earth 127, 1–19 (2022).

The absolute position during the Cenozoic of northern Zealandia, a continent that lies more than 90% submerged in the southwest Pacific Ocean, is inferred from global plate motion models, because local paleomagnetic constraints are virtually absent. We present new paleolatitude constraints using paleomagnetic data from International Ocean Discovery Program Site U1507 on northern Zealandia and Site U1511 drilled in the adjacent Tasman Sea Basin. After correcting for inclination shallowing, five paleolatitude estimates provide a trajectory of northern Zealandia past position from the middle Eocene to the early Miocene, spanning geomagnetic polarity chrons C21n to C5Er (∼48–18 Ma). The paleolatitude estimates support previous works on global absolute plate motion where northern Zealandia migrated 6° northward between the early Oligocene and early Miocene, but with lower absolute paleolatitudes, particularly in the Bartonian and Priabonian (C18n–C13r). True polar wander (solid Earth rotation with respect to the spin axis), which only can be resolved using paleomagnetic data, may explain the discrepancy. This new paleomagnetic information anchors past latitudes of Zealandia to Earth's spin axis, with implications not only for global geodynamics, but also for addressing paleoceanographic and paleoclimate problems, which generally require precise paleolatitude placement of proxy data.

We present new experimental results on the variation of the magnetic properties of baked clays as a function of the temperature reached during laboratory treatments. Such experiments, including continuous monitoring of the magnetic susceptibility and magnetic moment versus temperature, were applied to a set of natural clays experimentally heated in the laboratory at 200 °C, 400 °C and 600 °C as well as to archaeological baked clays collected from two archaeological sites in Northern Italy (Santhia and Carbonara Scrivia). The aim of this study is to investigate the reliability of the magnetic properties to identify the equivalent firing temperatures of ancient baked clay artefacts based on the reversible behavior of thermomagnetic diagrams. The results obtained indicate that the magnetic properties do not always succeed in estimating the firing temperature of the baked clays, mainly when clays have been heated only once and at relatively low temperatures, e.g. less than 300–400 °C. On the contrary, magnetic properties of ancient clays that have been repeatedly heated at the past at temperatures higher than 400 °C appear to be more stable and representative of the equivalent firing temperature. This study confirms that the reversibility of thermomagnetic curves can be a useful indicator of ancient firing temperatures in the case of baked clays that have experienced multiple heatings at the past while caution should be paid on its general use as archaeo-temperature marker.

The first directional archaeomagnetic results from Cyprus are presented, based on the study of seven baked clay structures excavated at the copper smelting site of Agia Varvara-Almyras, situated some 20 km south of Nicosia. This ancient copper working site represents a unique example of complete primary production of the copper metal in Cyprus. In total five furnaces, one ore roasting pit and an oven were sampled in situ for an archaeomagnetic investigation. All the studied structures are well dated, based on pottery finds and radiocarbon dates, with ages ranging from 600 BCE to 50 BCE. Several rock magnetic experiments were performed to determine the main magnetic carrier and to investigate the thermal stability of the studied material. The direction of the Characteristic Remanent Magnetization (ChRM) for each structure has been determined by demagnetization of 7–15 specimens in alternating magnetic fields up to 100–120 mT. Mean directions were calculated assuming a Fisherian distribution and are well defined for five out of the seven structures studied. The new directions are compared with the directional data and the secular variation curves available from the surrounding area, and with the predictions of global geomagnetic field models. They are an important contribution to improving our knowledge of the geomagnetic field variations in the Eastern Mediterranean and offer new insights about fast geomagnetic directional changes during the first millennium BCE that were not previously identified by the available geomagnetic field models’ predictions in this area.

Even though multidisciplinary approaches applied to the investigation of archaeological findings are widely used, the use of rock magnetic properties is still poorly exploited in the determination of the use of ancient artefacts. In this study, we present the results of a combined archaeological, morphological and magnetic analyses applied on the ring-shape clay artefacts found at the archaeological site of Villa del Foro, in Northern Italy. The materials studied are dated between the sixth and the first half of fifth century BC and are found in large quantities in different trenches of the archaeological excavation. To investigate their thermal history and to exploit their possible use as kiln supports, cooking stands, or loom weights, we have investigated their natural remanent magnetization (NRM) and the magnetic mineralogy changes occurred during laboratory heating. Magnetic analysis used for the determination of the firing temperatures show thermal stability up to 500-600 o C, while further laboratory heating at 700 o C introduces magnetic alteration. Thermal demagnetization of the samples generally shows a strong and stable thermal remanent magnetization. In few cases, a clear secondary component is present, suggesting partial re-heating or displacement at temperatures ranging from 200 oC to 450 °C. Such secondary magnetic component can be indicative of a secondary heating or of a displacement of the rings from their initial firing position while still hot. Even though the studied rings belong to casually different morphological typologies, no connection among type and magnetic behavior was observed, suggesting that the ring’s morphology does not define neither their production conditions nor the final use of the artefacts. The estimated firing temperatures of around 600-700 oC are compatible with the heating of the rings during their manufacture rather than related to cooking activities. In combination with the archaeological evidence and the morphological analysis it is thus suggested that the rings were used as weight looms and baked only during their production procedures. Such a pilot study can be used as reference for the identification of similar objects found in Italy and Europe during the Iron Age and confirms the great potential of rock magnetic analysis in the investigation of the technology and use of ancient baked clays.

The aim of this study is to investigate how structural deformation in shear zones is documented by the anisotropy of magnetic susceptibility (AMS). The study area is located in the Pliocene outer thrust of the Northern Apennines, which involved Cretaceous to Neogene calcareous and marly rocks. Here, brittle-ductile tectonites show different characteristics along two differently oriented thrust ramps: the NNE-SSW-trending oblique thrust ramp is characterized by the presence of S tectonites, while the NW-SE-trending frontal ramp is characterized by the presence of SC tectonites.Samples for AMS fabric investigation were collected on shear zones from three sectors of the belt, at different distance from the main thrust to detect possible magnetic fabric variations. The three study area are characterized by different combinations of simple and pure shear, thus different degree of non-coaxiality, which has been quantified through the vorticity number Wk.Specimens were measured with an AGICO KLY-3 Kappabridge at the CIMaN-ALP Laboratory (Italy) on 15 different directions mode. Only measurements with all three F-statistics of the anisotropy tests higher than 5 were accepted as reliable. Moreover, outliers characterized by ± 2σ difference with respect to the mean value of AMS scalar parameters were excluded from further analysis. In order to distinguish groups of specimens affected by different sedimentary or tectonic processes, we identified clusters of AMS scalar parameters; when clusters were not defined by these parameters, we applied a combination of contouring and cluster analysis on each principal axis to identify different subfabrics.The magnetic fabric revealed straightforward correlations with structural data and specific changes of AMS axis orientation depending upon the increasing of deformation (lower vorticity number) and proximity to the main thrust. Similar evolution was detected in different deformation regimes. Overall, the magnetic fabric is more sensitive to the simple shear deformation, as the magnetic lineation tends to parallelize mostly with the computed slip vector; however in pure-shear dominated regimes, the magnetic lineation becomes parallel to the transport direction when the deformation is really intense (sites at less than 15-30 cm from the thrust plane).The applied combination of density diagrams and cluster analysis on AMS data successfully allowed discriminating subfabrics related to different events, and shows a great potential to unravel mixed sedimentary and/or tectonic features in magnetic fabrics.

We present new insights on the directional occurrence of the Levantine Iron Age Anomaly (LIAA) through the analysis of new and previously published directional archaeomagnetic data from Cyprus and nearby countries. The new directions, obtained from in situ baked clay structures such as small hearths and ovens from five Cypriot archaeological sites, dated from 2000 BCE to 1400 CE, are very well defined and are added to the scant reference dataset for Cyprus. The new records together with literature data from nearby countries are used to investigate the directional variations of the geomagnetic field in the Eastern Mediterranean and Middle East. The first directional palaeosecular variation curve for Middle East is calculated using a critical selection of reference data from Cyprus, Israel, Turkey and Syria. The curve covers the last four millennia and shows several periods characterized by abrupt directional changes. A maximum change in curvature is clearly observed around 900 BCE, characterized by a change rate as high as 13.2° per century. The new curve confirms that during the Levantine Iron Age Anomaly notable for extreme intensity values, the geomagnetic field was characterized by steep inclinations and important directional change too. The maximum curvature is shifted by around one century from the two distinct intensity spikes previously observed in Levant around the 10th and 8th centuries BCE. Other periods of important curvature change are also identified and deserve further investigation.

Absolute past geomagnetic intensity values can mainly be recovered by fired archaeological materials and volcanic rocks. Here, we present 10 new archeointensities from the Mediterranean region that help to better constrain geomagnetic field intensity changes in Europe over the last two millennia. The new archeointensity results were obtained from the Thellier classical method including thermoremanent magnetization (pTRM) checks and both the TRM anisotropy and cooling rate corrections and were derived from at least three specimens. The new data presented, together with a selection of previous archeointensities satisfying a set of quality criteria, confirm the presence of several intensity maxima in Europe over the last 2000 years. In particular, the new archeointensities allow to better define the starting point of the double-oscillation feature that occurred in Europe during the second half of the first millennium CE, and reinforce the existence of a relative maximum at the end of the 14th century - beginning of the 15th century in Western Europe. From selected European archeointensities two new paleosecular variation curves are constructed for Western and Eastern Europe using temporal cubic b-splines in a bootstrap approach. The obtained curves suggest that the occurrence of the intensity maxima is characterized by a period of about 300 ± 50 years. In addition, our results suggest that the maxima do not occur simultaneously in Western and Eastern Europe, pointing out an intensity eastward drift with a mean lag-time of about 100 years.

In this paper we present a revised compilation of directional and intensity Italian archaeomagnetic data, coming from both archaeological material and volcanic rocks. The quality of the data has been carefully investigated, with particular attention on the reliability of the dating of Italian historical volcanic eruptions, and on the quality of the archaeointensity determinations. Data from volcanic rocks with disputable age has not been considered. Comparison between the available archaeomagnetic data from archaeological material and volcanic rocks of reliable age shows very good agreement. Strict selection criteria were applied to gather the most reliable Italian reference data, both from archaeological material and volcanic rocks, in order to guarantee the high quality of the reference data used for curve building. Our selection was limited in the last 3000 years, as archaeomagnetic records from older periods are very scarce for further considerations. To enrich the Italian reference dataset and to cover the time periods that were poorly investigated in Italy, we have also included high-quality archaeomagnetic data available within a 1000 km radius around Viterbo, situated in central Italy. The new directional and intensity secular variation (SV) curves were computed using the Bayesian statistics. The obtained directional curve is very well constrained while the intensity curve is characterized by larger error envelops, highlighting the need of new high-quality intensity data from Italy. Thanks to the privileged geographical position of the Italian peninsula, situated almost in the center of the Mediterranean, the new SV curves were used to analyze the evolution of the geomagnetic field in Europe by comparing them with other recently published SV curves for Western and Eastern Europe as well as with global geomagnetic field models.

Japan is a country with very rich cultural heritage and with many archaeological sites that can offer precious information about the geomagnetic field secular variation in the past. However, even though archaeomagnetic research in Japan started more than 60 years ago, with numerous studies focused on archaeodirection determinations of in situ archaeological structures, the available up to now archaeointensity data are still scarce. Most of the absolute intensity records come from archaeomagnetic studies carried in 60’s, 70’s and 80’s, mainly obtained with the original Thellier-Thellier method and/or its modifications. In none of these data, cooling rate and anisotropy corrections were applied. During the last 20 years, only two more archaeointensity studies have been published, applying the Tsunakawa-Shaw palaeointensity method on baked clays from Japanese kilns. This current status of archaeointensity studies in Japan makes evident the need of new high-quality reference data in order to reconstruct the geomagnetic intensity secular variation path in Japan. In this perspective, in the frame of the “Be-Archaeo” MSCA-RISE project, we have collected a total of 56 fragments of archaeological artifacts from the archaeological sites of Sada Higashizuka, Sada Nishizuka, Tatezaka, Tenguyama, Tatetskuki and Nima Ohtsuka, situated at the Okayama prefecture. The baked clays studied belong to ancient coffins, haniwa artifacts and pottery and their ages range from 100 AD to 675 AD. Preliminary rock magnetic and archaeomagnetic analysis including magnetic susceptibility, Q-ratio, isothermal remanent magnetization (IRM) curves, thermal demagnetization of a composite IRM component as well as stepwise thermal and alternating field (AF) demagnetizations were performed to investigate the magnetic mineralogy of the samples and their suitability for archaeointensity experiments. The results show the presence of a magnetic mineral with Curie temperature ranging from 480 to 560 oC, most probably magnetite and/or Ti-magnetite. IRM curves and AF demagnetization suggest also the presence of a high coercivity component in some samples, as saturation is not reached at 1 T and samples are not completely demagnetized at 180 mT. Demagnetization diagrams reveal a stable single component of magnetization for most of the samples. However, some samples demonstrate disturbed Zijderveld diagrams and/or two components of magnetization; no correlation between the quality of the results and the material studied (pottery, haniwa or coffin fragments) was found. These preliminary results were used to select promising samples for archaeointensity experiments, aiming to obtain new high-quality archaeointensity records for the Late Yayoi and Kofun periods.

We present the results of an integrated structural and anisotropy of magnetic susceptibility (AMS) investigation in calcareous and marly rocks from thrust shear zones. A total of 17 sites from six localities along the frontal and oblique ramp of the Olevano-Antrodoco-Sibillini thrust and back thrust (Northern Apennines, Italy) were studied to investigate both magnetic fabric and structural characteristics of Cretaceous to Neogene calcareous and marly rocks. In most of the sites AMS is controlled by the paramagnetic minerals (prevailingly phyllosilicates), with minor contribution of ferromagnetic (sensu latu) ones. Structural analysis shows the presence of SC- and S-tectonites associated to predominant simple and pure shear, respectively. The combination of density diagrams and cluster analysis allowed discriminating the contributions of sedimentary and tectonic processes to the bulk magnetic fabric. Six different subfabrics were distinguished, related to the structural data and associated to deformation stages and regimes: A. sedimentary fabric; B. intersection lineation; C. magnetic foliation parallel to S planes with k1 parallel to the S/C intersection; D. k1 moving toward the slip vector; E. magnetic foliation parallel either to the S or the C planes, with k1 parallel to the slip vector or the transport direction; F. k1 parallel to extensional planes intersection. The magnetic foliation has a double tendency to parallelize to pressure solution cleavage (S) and shear planes (C), while the magnetic lineation tends to progressively align with the slip vector, except for pure-shear-dominated sites at less than 15–20 cm from the thrust, where it aligns with the transport direction. The magnetic fabric is dominated by simple shear deformation. The protocol applied for AMS analysis shows a great potential to unravel mixed sedimentary and/or tectonic features in magnetic fabrics. AMS can be considered as a useful tool in unravelling the variation of simple-pure shear deformation regime in shear zones.

Archaeomagnetic dating is a chronometric dating technique, based on the ability of baked clay archaeological structures and artifacts to acquire a thermal remanent magnetization (TRM) when heated at high temperatures and cooled in the presence of the Earth's magnetic field. The precision of archaeomagnetic dating depends on several factors, among others the availability of a detailed reference secular variation (SV) curve for a given territory. In this study, we investigate the precision that archaeomagnetic dating can reach in Europe. We used the SCHA.DIF.3K European geomagnetic field model to calculate the dating uncertainties for the last 3000 years, taking into consideration only the uncertainties depending on the change rate of the geomagnetic field in the past and the reference SV curve's uncertainty envelope. Such uncertainties were calculated both in time and space, they are usually asymmetrically distributed around the considered year and it have been represented as dynamic maps of uncertainties. The obtained results show that archaeomagnetic dating based solely on directional data (declination and inclination) can be very precise for the last four centuries, with total uncertainties being almost always lower than 100 years all around Europe. Inherent dating uncertainties are also low for the last millennium, with values ranging from 50 to 300 years. These results underline the great potential of archaeomagnetism on dating baked clays belonging to the last 1000 years. For older periods, the uncertainty maps show that the dating precision may importantly vary from place to place, but with local non-symmetric uncertainty ranges generally below 400 years. The obtained maps also show that adding the intensity to the computation of the inherent uncertainties does not always reduce the uncertainty. The temporal and spatial analysis presented here does not give the total dating imprecision of archaeomagnetic dating (that definitely depends on numerous, often uncontrollable, factors), but aims at offering a useful tool to archaeomagnetic and archaeological research to check the feasibility of archaeomagnetic dating for determining the age of an archaeological structure below a desired precision.

Reconstructing the distribution of ancient obsidian tools is one of the few ways to trace ancient trade routes during the Neolithic. The use of magnetic properties for obsidian provenance studies has already been applied as a useful inexpensive and non-destructive tool. It is mainly based on the variation of the type, concentration and grain size of the magnetic particles within the vitreous matrix coming from different sources. In this study, we present the results of a rock magnetic investigation carried out on archaeological obsidian tools collected from six Neolithic sites situated in Northern Italy (Castello d’Annone, Brignano Frascata, Cascina Chiappona, Casalnoceto, Garbagna and Parma). A total of 57 archaeological samples were analysed by measuring several magnetic parameters such as low-field and anhysteretic susceptibility, saturation isothermal remanent magnetization at room and liquid nitrogen temperature, remanence and saturation magnetization from hysteresis cycles and anisotropy of low-field susceptibility. The obtained results were compared with the magnetic properties of geological samples from five Mediterranean islands (Lipari, Sardinia, Palmarola, Pantelleria and Melos). Cluster analysis was applied to the whole set of parameters, allowing the correlation of the pertinent group of artefacts and geological obsidians. Such analysis shows that most of the studied archaeological tools come from Lipari, with few exceptions consisting of samples coming from Pantelleria and Sardinia. Our results are in good agreement with other studies based on chemical analyses that also show that Lipari is the most common Neolithic obsidian source in Northern Italy, despite its longer distance in respect to other obsidian sources.

We present the results of a combined archaeomagnetic and thermoluminescence (TL) investigation on a baked clay kiln discovered near Santhia, Northern Italy. The site, brought to light during a rescue excavation for the installation of methane tubes, provides important evidence for the presence of a brick production workshop in the area. Standard thermal demagnetization was applied to isolate the direction of the Characteristic Remanent Magnetization (ChRM). The mean ChRM direction was used for the archaeomagnetic dating of the kiln, suggesting that it was abandoned around the 16th century CE. TL analysis carried out on the same kiln further confirms this dating. The comparison between the archaeomagnetic and TL results shows excellent agreement, underlining the great potential of these two techniques in dating baked clays. Moreover, thanks to the independent TL dating, the new archaeomagnetic data can be used as a reference point for the reconstruction of the past secular variation path in Italy. Such combined multidisciplinary dating is extremely important in the case of rescue excavations, particularly in urban centers where the rapid expansion of new constructions inevitably causes the destruction of our cultural heritage and the loss of important information about our past.

The magnitude and origin of the Levantine Iron Age geomagnetic Anomaly (LIAA), which spanned the first half of the first millennium before the common era, are not yet well understood. Recent archeomagnetic studies from the Levant and Western Europe suggest a western drift of this feature, stressing the importance of investigating the temporal and spatial behaviour of this event over the Central Mediterranean area. To analyse this issue, we here present 37 new archeointensity data obtained from the archeomagnetic study of 118 ceramics and brick fragments collected in 8 archeological sites in Greece and Italy with ages ranging between 1500 BCE and 150 CE. The samples were analysed using the classical Thellier and Thellier method for paleointensity determination, including the correction for the anisotropy effect of the thermoremanent magnetization (TRM) and for the cooling rate dependence upon TRM acquisition. The results reveal the first evidence of a high-intensity peak in Greece between 1070 and 1040 BCE associated to high virtual axial dipole moment (VADM) values of around 140 ZAm2. A global analysis of available paleointensities suggests that the origin of these high values is the same to the one which produced the maximum VADM of the LIAA in the Levantine region. Our results suggest that the source of the LIAA is located in the Levantine region vanishing to the north, to the west and to the east where lower VADMs are observed. In addition, another high intensity maximum, less pronounced than the one of the LIAA, seems to be present around 500 BCE all over Europe, from the Canary Islands to Turkey showing similar VADM values (around 150 ZAm2) in the different regions. Both events seem to span over a large region at the Earth's surface covering more than 60° of longitude, verifying an Earth's outer core origin for these intensity features.

Combined stratigraphic and bio-magnetostratigraphic analyses on a fluvial sequence from the southern margin of the Alessandria Basin (at the junction between the Alps and the Apennines) provide evidence for the first documentation of a late Piacenzian–Gelasian continental record in northern Italy. The basin experienced general growth at the margins and ongoing subsidence in the depocentre, during overthrusting onto the Po Foreland Basin. The studied fluvial succession is 25–30 m thick and can be divided into three units (MRZ1, MRZ2 and MRZ3) delimited by erosional unconformities (S1, S2 and S3). The MRZ1 and MRZ2 units (shallow to confined braided systems) are chronologically restricted between 2.8 and 2.58 Ma based on bio-magnetostratigraphic analyses. The overall stratigraphic framework indicates deposition and erosion during the progressive uplift of the Alps/Apennines system. The frequency of unconformities and sedimentary changes, compared to other coeval successions of other syn-orogenic basins of northern and central Italy, suggests the interaction between high-amplitude global cold stages and tectonic deformation. Tectonic climax occurred in the Gelasian, as revealed by the 450- to 600-ka-long hiatus associated with the S3 unconformity, whereas the subsequent deposition of the MRZ3 unit (meandering alluvial system) including a Gelasian magnetic reversal points to the fading of tectonic activity. The stratigraphic reconstruction provided in this study enriches the current knowledge of the European continental biota: the absence of thermophilous elements in the MRZ1 carpoflora reflects the late Piacenzian cooling phase after 2.8 Ma, whereas the persistence of several extra-European taxa in MRZ3 (e.g. Ampelopsis cf. ludwigii, Boehmeria lithuanica, Cryptomeria rhenana) rules out an age younger than 1.4 Ma. The freshwater mollusc assemblage of MRZ2 shows the occurrence of Pomatias elegans and Tournouerina belnensis, identified for the first time in the Pliocene of northern Italy. Copyright © 2015 John Wiley & Sons, Ltd.

International audience; Archaeomagnetic records from low-latitude sites are very scarce. Thus, the information about the geomagnetic field evolution in South America or Ecuador is sparse and more data are needed to constrain the field evolution in South America. In this study we present new absolute archaeointensity results from a set of 14 C well-dated (i.e. calibrated ages) prehistoric archaeological sites in northern Ecuador (South America). Potsherd fragments were sampled during archaeological excavations of 2 earthen mounds in the vicinity of Atuntaqui and Otavalo cities, and pits at La Chimba site. The pottery covers 2 distinct archaeological periods defined as 1) Ecuadorian Formative period (700 BC-1AD) and 2) the prehistoric Late period (1250-1505/1525 AD). Successful archaeointensity determinations were obtained from 56 sherds using the Thellier-Coe protocol and their rock magnetic properties. The absolute palaeointensity determinations have yielded AI values of 43.6 ± 1.3 μT for Atuntaqui, 34.2 ± 1.4 μT for the Otavalo Mound 3 (lower charcoal lens), 39.5 ± 1.4 μT for Otavalo Mound 3 (upper charcoal lens) and a range of absolute archaeointensities from 7.0 ± 0.97 μT up to 42.2 ± 2.06 μT, with a mean average of 21.20 ± 1.15 μT for La Chimba. Archaeointensity (AI) determinations of the successful mean abolute archaeointensity for the early phase (700-440BC) excavation levels 27.8 ± 1.315 μT, middle levels phase (440-40BC), 15.07 ± 0.78 μT and the late levels phase (44BC-250AD) 25.52 ± 1.575 μT. These results are in good correlation with the data from Palpa in South Peru as well as a few data results from Colombia, South America.

International audience; Speleothems are potentially excellent archives of the Earth's magnetic field, capable of recording its past variations. Their characteristics, such as the continuity of the record, the possibility to be easily dated, the almost instantaneous remanence acquisition and the high time-resolution make them potentially unique high-quality Paleosecular Variation (PSV) recorders. Nevertheless, speleothems are commonly characterized by low magnetic intensities, which often limits their resolution. Here we present a paleomagnetic study performed on two cores from a flowstone from the Rio Martino Cave (Western Alps, Italy). U/Th dating indicates that the flowstone's deposition covers almost the entire Holocene, spanning the period ca. 0.5-9.0 Ica, while an estimation of its mean growth rate is around 1 mm per 15 years. The flowstone is composed of columnar calcite, characterized by a highly magnetic detrital content from meta-ophiolites in the cave's catchment. This favorable geological context results in an intense magnetic signal that permits the preparation and measurement of thin (similar to 3 mm depth equivalent) samples, each representing around 45 yr. The Characteristic Remanent Magnetization (ChRM), isolated after systematic stepwise Alternating Field demagnetization, is well defined, with Maximum Angular Deviation (MAD) generally lower than 10 degrees. Paleomagnetic directional data allow the reconstruction of the PSV path during the Holocene for the area. Comparison of the new data with archeomagnetic data from Italian archeological and volcanic records and using the predictions of the SHA.DIF.14k and pfm9k.1 a global geomagnetic field models shows that the Rio Martino flowstone represents an excellent recorder of the Earth's magnetic field during the last 9,000 years. Our high resolution paleomagnetic record, anchored by a high-quality chronology, provides promising data both for the detection of short term geomagnetic field variations and for complementing existing regional PSV curves for the prehistoric period, for which well-dated data are still scarce.

We present new chronological constraints for a reference European palaeoflora based on integrated stratigraphic, palaeobotanical, palaeomagnetic and micropalaeontological analysis carried out on the Pliocene section of Ca′ Viettone, northwestern Italy. This site is characterized by rich fossil plant records of high taxonomic diversity, good preservation, and varied taphonomic mode. Palaeofloral analysis shows that the Ca′ Viettone assemblage reflects a chronologically delimited and distinguishable stage of vegetation development in northern Italy (called Ca′ Viettone Florenkomplex). Palaeomagnetic analyses show a dominant normal polarity that, however, seems to be the result of a remagnetization process due to secondary oxidation. Layers with no evidence of oxidation have registered a reverse polarity, which likely represents the original magnetization of the sediments. These results, in combination with biochronological indications, suggest that deposition of the succession preceded the Gilbert-Gauss reversal and took place during the final part of the Gilbert chron. This confirms a late Zanclean age for the rich Ca′ Viettone palaeoflora and allows us to propose this locality both as reference for a regional Florenkomplex and as a representative example of terrestrial vegetation in Europe during the early Pliocene warm interval.

We present here the results of a detailed archaeomagnetic and thermoluminescence investigation performed on bricks from two ancient kilns excavated at Kato Achaia, Greece. Magnetic mineralogy measurements have been carried out to determine the main magnetic carrier of the samples. The directions of the characteristic remanent magnetization of each structure have been obtained from standard thermal demagnetisation procedures and the absolute archaeointensity has been determined with the Thellier modified by Coe method, accompanied by regular partial thermoremanent magnetization (pTRM) checks. The full geomagnetic field vector was used for the archaeomagnetic dating of the two kilns, after comparison with the reference secular variation curves calculated directly at the site of Kato Achaia. Independent dating has also been obtained from thermoluminescence (TL) analysis on four brick samples from each kiln. The dating results obtained from the two methods have been compared and the last firing of each kiln has been estimated from the combination of the two techniques. Using the independent date offered by TL dating, the new archaeomagnetic data have been compared with other data from the same time period and they can further be used as reference points to enrich our knowledge about the past secular variation of the Earth's magnetic field in Greece.

We present absolute geomagnetic intensities from iron smelting furnaces discovered at the metallurgical site of Korsimoro, Burkina Faso. Up to now, archaeologists recognized four different types of furnaces based on different construction methods, which were related to four subsequent time periods. Additionally, radiocarbon ages obtained from charcoal confine the studied furnaces to ages ranging from 700–1700 AD, in good agreement with the archaeologically determined time periods for each type of furnace. Archaeointensity results reveal three main groups of Arai diagrams. The first two groups contain specimens with either linear Arai diagrams, or slightly curved diagrams or two phases of magnetization. The third group encompasses specimens with strong zigzag or curvature in their Arai diagrams. Specimens of the first two groups were accepted after applying selection criteria to guarantee the high quality of the results. Our data compared to palaeosecular variation curves show a similar decreasing trend between 900–1500 AD. However, they reveal larger amplitudes at around 800 AD and 1650 AD than the reference curves and geomagnetic field models. Furthermore, they agree well with archaeomagnetic data from Mali and Senegal around 800 AD and with volcanic data around 1700 AD.

International audience; Hawaii is an ideal place for reconstructing the past variations of the Earth's magnetic field in the Pacific Ocean thanks to the almost continuous volcanic activity during the last 10 000 yrs. We present here an updated compilation of palaeomagnetic data from historic and radiocarbon dated Hawaiian lava flows available for the last ten millennia. A total of 278 directional and 66 intensity reference data have been used for the calculation of the first full geomagnetic field reference secular variation (SV) curves for central Pacific covering the last ten millennia. The obtained SV curves are calculated following recent advances on curve building based on the Bayesian statistics and are well constrained for the last five millennia while for older periods their error envelopes are wide due to the scarce number of reference data. The new Bayesian SV curves show three clear intensity maxima during the last 3000 yrs that are accompanied by sharp directional changes. Such short-term variations of the geomagnetic field could be interpreted as archaeomagnetic jerks and could be an interesting feature of the geomagnetic field variation in the Pacific Ocean that should be further explored by new data.

The Balkan area provides an almost continuous record of the geomagnetic field variations during the last eight millennia but important data dispersion and chronological gaps are still observed. In order to improve this pattern, we oriented our research towards the study of Greek prehistoric ceramics and pottery collections. We present here new archaeointensity and mineralogical results from pottery and ceramics collected in two Bronze Age sites in Northern Greece, corresponding to the middle third and middle second millennium BC. Thermal demagnetization experiments, thermomagnetic curves, thermal demagnetization measurements of three axes composite isothermal magnetization and first-order reversal curves (FORC) diagrams were performed in order to define the main magnetic carriers and select the most promising samples for archaeointensity determination. The results suggest that the majority of the studied materials are dominated by a mixture of superparamagnetic and stable single domain grains, with very little magnetic interactions. In almost all samples the main magnetic carrier observed is a low coercivity mineral, most probably magnetite and/or Ti-magnetite. Classical Thellier experiments, including both the thermoremanent magnetization anisotropy and cooling rate corrections were performed on the selected samples. Two new archaeointensities were obtained and compared with previous data available for Greece and neighbouring countries and with global geomagnetic field models results. In order to investigate the causes of the high rate of failure observed in our archaeointensity experiments, we re-examined the results obtained from the study of four collections already published by better characterizing the magnetic and mineralogical properties of the studied fragments. Specific hysteresis curves performed at different layers of ceramic fragments reveal an important degree of inhomogeneity. Mineralogical analysis of selected samples from the totality of six Greek prehistoric sites studied, including new X-ray powder diffraction analysis and a detailed description of the different geological contexts, is provided. The results suggest that the sherds were all fired in medium-high temperatures (mostly between 500° and 800 °C). The nature of the baked clay paste in response to the local geology appears to account for a part of the variability in magnetic properties. We suggest that X-ray powder diffraction analyses and thorough examination of the geological environment in combination with a satisfactory knowledge of the corresponding excavations history might provide an additional tool to appropriately select pottery fragments before performing future archaeointensity experiments., The INSTAP Center has substantially contributed to the funding of this research during the years 2012–2014. MGP acknowledges the Ram´on y Cajal Program and the CGL2015–63888-R research project of the Spanish Ministry of Economy and Competitiveness.

International audience; We present new, full geomagnetic field vector results from three Neolithic ovens discovered at the archaeological site of Portonovo (Marche, Italy). The discovered structures are a rare example of very well preserved underground ovens from the Early Neolithic period. Standard thermal demagnetization procedures were used to isolate the direction of the Characteristic Remanent Magnetization acquired by the baked clay during the ovens' last firing. The corresponding archaeointensities were determined by the multi-specimen procedure (MSP-DSC) and show a clear intensity low during the Neolithic period. Both directional and intensity results are of high quality, offering the first contribution of full geomagnetic field vector data for this period in Italy. The new data are compared with other contemporaneous data from Europe and with global geomagnetic field models. Independent archaeomagnetic dating of the three ovens was also performed by means of the SCHA.DIF.14k model. The obtained results are in excellent agreement with available radiocarbon dates and confirm that all ovens belong to the Neolithic. These new data importantly enrich our knowledge of the geomagnetic field during the Neolithic period that is poorly documented by data, not only in Italy but also in the whole of Europe and show that archaeomagnetic dating can provide precise results even for prehistoric periods.

Στην παρούσα εργασία μελετήθηκε η παραμένουσα μαγνήτιση θραυσμάτων λιθικών που βρέθηκαν μέσα στις αποθέσεις ελαφρόπετρας που κάλυψαν τον αρχαιολογικό χώρο του Ακρωτηρίου με σκοπό την εκτίμηση της θερμοκρασίας απόθεσης των πρώτων ηφαιστειακών υλικών που έφτασαν και αποτέθηκαν στον αρχαίο οικισμό. Συνολικά συλλέχτηκαν 50 λιθικά θραύσματα από τέσσερα διαφορετικά σημεία της ανασκαφής. Όλα τα δείγματα απομαγνητίστηκαν με σταδιακή θέρμανση και η ανάλυση των αποτελεσμάτων πραγματοποιήθηκε διαμέσου του διαχωρισμού των κυρίων συνιστωσών μαγνήτισης. Η θερμοκρασία απόθεσης που εκτιμήθηκε αντιπροσωπεύει την θερμοκρασία των λιθικών μετά την αποκατάσταση της θερμικής ισορροπίας μεταξύ αυτών και της θερμότερης ελαφρόπετρας και διαφέρει από λιθικό σε λιθικό. Παρ' όλα αυτά, στο μεγαλύτερο μέρος τους τα λιθικά δείχνουν ότι έχουν αναθερμανθεί σε θερμοκρασίες της τάξεως 240-280oC. Αυτές οι θερμοκρασίες είναι ανάλογες με τις θερμοκρασίες απόθεσης που εκτιμήθηκαν από την μελέτη λιθικών από το ορυχείο του Μεγαλοχωρίου ενώ είναι υψηλότερες από αυτές που εκτιμήθηκαν διαμέσου κεραμικών από την ανασκαφή του Ακρωτηρίου. Τα νέα αποτελέσματα θερμοκρασίων απόθεσης από λιθικά στο εσωτερικό του αρχαίου οικισμού δείχνουν ότι το στρώμα ελαφρόπετρας ήταν ακόμη ζεστό όταν αποτέθηκε μέσα στον αρχαιολογικό χώρο και παρότι ήρθε σε επαφή με τα κτίρια προκαλώντας σε ορισμένες περιπτώσεις την πτώση των οροφών, παρ' όλα αυτά παρέμεινε θερμό με μέση θερμοκρασία περίπου 260 οC., Rock magnetic and palaeomagnetic analyses on lithic clasts collected from the pumice fall deposited inside the archaeological site of Akrotiri have been applied in order to estimate the deposition temperature of the first volcanic products of the Minoan eruption. A total of 50 lithic clasts have been collected from four different locations inside the excavation of Akrotiri. All samples have been stepwise thermally demagnetized and the obtained results have been interpreted through principal component analysis. The equilibrium temperature obtained after the deposition of the pumice fall varies from sample to sample but generally shows temperatures around 240-280oC. These temperatures are in good agreement with those estimated from lithic clasts from the Megalochori Quarry while they are higher compared with those from ceramic fragments from Akrotiri. The new temperature data presented here show that the pumice fall was still relatively hot when deposited inside the archaeological site and even if it interacted with the buildings, often causing the collapse of roofs, it still remained hot with mean temperature around 260oC.

The main objective of this work is to compare directional (declination and inclination) volcanic and archaeomagnetic data for the last four centuries (~1600–1990) with the historical geomagnetic predictions given by the GUFM1 model which spans from 1590 to 1990. The results show statistical agreement between archaeomagnetic data and directions given by the geomagnetic field model. However, when comparing the volcanic data with the model predictions, marked inclination shallowing is observed. This systematically lower inclination has already been observed in local palaeomagnetic studies (Italy, Mexico and Hawaii) for the 20th century, by comparing recent lava flows with the International Reference Geomagnetic Field (IGRF) model. Here, we show how this inclination shallowing is statistically present at worldwide scale for the last 400 years with mean inclination deviation around 3° lower than the historical geomagnetic field model predictions., They are also grateful to the Spanish research project CGL2011-24790. F.J. Pavón-Carrasco thanks ME-Fulbright contract CT-2010-0663 at the Spanish Institution FECYT.

International audience; A detailed tephrostratigraphic study supported by stable isotope (δ 18 O) analyses and AMS 14 C dating was carried out on a high sedimentation rate deep-sea core recovered in the northern Ionian Sea. Eight tephra layers were recognised, all originated from explosive eruptions of southern Italian volcanoes. These tephra layers are correlated with terrestrial proximal counterparts and with both marine and lacustrine tephra already known in the central Mediterranean area. The oldest tephra (dated at ca. 19.4 ka cal BP) is tentatively correlated to the Monte Guardia eruption from Lipari Island. Two other rhyolitic tephra layers were correlated with the explosive volcanic activity of Lipari Island: Gabellotto-Fiumebianco/E-1 (8.3 ka cal BP) located close to the interruption of Sapropel S1 deposit, and Monte Pilato (ca. AD 1335) in the uppermost part of the core. The Na-phonolitic composition of the other five recognised tephra layers indicates the Somma-Vesuvius as the source. The composition is quite homogeneous among the five tephra layers, and fits that of the Mercato proximal deposits. Beyond the striking chemical similarity with the Mercato eruption, these tephra layers span over ca. 2000 years, preventing correlation with the single well known Plinian eruption of the Somma-Vesuvius. Therefore, at least two of these tephra layers were assigned to an interplinian activity of the Somma-Vesuvius between the eruptions of Mercato and Avellino, even though these eruptions remains poorly constrained in the proximal area. By contrast, the most prominent tephra layer (2 mm white tephra visible at naked eyes) was found within the S1a Sapropel interval. Despite the possible complication for the presence of similar eruption with different ages we argue that Mercato is probably a very good marker for the onset of sapropelic condition in the Ionian Sea and can be used for land-sea correlations for this important climatic event. More in general, these data allow a significant update of the knowledge of the volcanic ash dispersal from Lipari and Somma-Vesuvius volcanoes.

SUMMARY The first archaeomagnetic secular variation (SV) curves for the whole Southern Balkan Peninsula are presented. These are based on all data within a 700 km circle centred at Thessaloniki (40.60oN, 23.00oE). This data set consists of 325 directional and 625 intensity data mainly from Greece, Bulgaria, Serbia and southern Hungary. Some data from southern Italy are also included. The sliding moving window technique, was used to calculate a continuous SV curve for intensity while the directional SV curves were calculated using the bivariate extension of the Fisher statistics. These curves are well constrained and clearly show the main features of the geomagnetic field variation in this region during the last eight millennia. Comparisons with the predictions of the SCHA.DIF.3K and SCHA.DIF.8K regional and the CALS7K.2 and ARCH3K.1 global geomagnetic field models show a good agreement for the last 3000 years but differences for older times. The Balkan SV curves identify several rapid changes of the geomagnetic field in eastern Europe and can be used as reference curves for archaeomagnetic dating in the Balkan Peninsula.

The magnetic fabric of 59 bricks coming from 5 ancient kilns has been studied by measuring the anisotropy of magnetic susceptibility (AMS) and the anisotropy of isothermal (AIRM), anhysteretic (AARM) and thermal (ATRM) remanent magnetization. The bricks are characterized by a well developed magnetic fabric that matches their flat shape. The shape of the anisotropy ellipsoids is in almost all cases oblate with the maximum and intermediate axes lying parallel to the large face of the brick and the minimum axis perpendicular to it. The directions of the principal axes are almost the same irrespectively of the type of anisotropy measured, whereas the degree of anisotropy of the AIRM, AARM and ATRM is much higher than the AMS. As the bricks lie horizontally within the kiln, the planar magnetic fabric results in an inclination shallowing of the archaeomagnetic direction with respect to that of the Earth's magnetic field at the time of their last cooling. Estimation of this effect on the grounds of ATRM measurements yields a shallowing that varies from 4° to 10° for individual samples. Such inclination difference may significantly bias archeomagnetic dating; for the case of the Canosa late-Roman kiln it leads to a dating error of more than two centuries.

Public works in progress in the Campanian plain north of Somma-Vesuvius recently encountered the remains of a prehistoric settlement close to the town of Afragola. Rescue excavations brought to light a Bronze Age village partially destroyed and buried by pyroclastic density currents (PDCs) of the Vesuvian Pomici di Avellino eruption (3.8 14C ka BP) and subsequently sealed by alluvial deposits. Volcanological and rock-magnetic investigations supplemented the excavations. Careful comparison between volcanological and archaeological stratigraphies led to an understanding of the timing of the damage the buildings suffered when they were struck by a series of PDCs. The first engulfed the village, located some 14 km to the north of the inferred vent, and penetrated into the dwellings without causing major damage. The buildings were able to withstand the weak dynamic pressure of the currents and deviate their path, as shown by the magnetic fabric analyses. Some later collapsed under the load of the deposits piled up by successive currents. Stepwise demagnetization of the thermal remanent magnetization (TRM) carried by potsherds embedded in the deposits yields deposition temperatures in the order of 260–320 °C, fully consistent with those derived from pottery and lithic fragments from other distal and proximal sites. The fairly uniform temperature of the deposits is here ascribed to the lack of pervasive air entrainment into the currents. This, in turn, resulted from the lack of major topographical obstacles along the flat plain. The coupling of structural damage and sedimentological analyses indicates that the currents were not destructive in the Afragola area, but TRM data indicate they were still hot enough to cause death or severe injury to humans and animals. The successful escape of the entire population is apparent from the lack of human remains and from thousands of human footprints on the surface of the deposits left by the first PDCs. People were thus able to walk barefoot across the already emplaced deposits and escape the subsequent PDCs. The rapid cooling of the deposits was probably due to both their thinness and heat dissipation due to condensation of water vapour released in the mixture by magma–water interaction.

An archaeomagnetic study was carried out as part of a rescue operation on a lime kiln discovered during the exploitation of a gravel quarry at Bazzano, near Bologna (northern Italy). Based on very poor archaeological information the kiln is dated around 3rd–4th century AD but no other structures have been found in the area to support this age. A hierarchical sampling process has been followed; twelve independently oriented bricks were collected from the circular wall of the baking room from which 35 cylindrical specimens were cut and measured. Demagnetization procedures reveal a single-component, stable remanent magnetization. The dispersion of the mean direction is low, even though some deviations in the remanence direction as a function of the position of the samples in the kiln wall are observed. The archaeomagnetic age of the kiln has been obtained using recent advances on data elaboration involving Bayesian statistics and the preliminary secular variation (SV) curve of Italy. For comparison, the kiln has been also dated using the French SV curve. The ages obtained are in good agreement and suggest that the last firing of the kiln could have occurred as late as at the end of 6th century AD.

We present a detailed rock-magnetic and archaeomagnetic study of two brick kilns, named OSA and OSB, discovered at the location of Osterietta, in northern Italy. The magnetic properties of representative samples have been investigated to identify the nature of the magnetic carriers, their domain state and thermal stability, and investigate their suitability for archaeomagnetic determinations. Thermally stable, mainly pseudosingle domain (PSD) magnetite is identified as the main magnetic carrier. The full geomagnetic field vector has been determined for the two kilns, including directional and intensity analysis. Archaeointensities have been recovered with both the classical Thellier and the multi-specimen protocols. The multi-specimen procedure was performed with a very fast-heating oven developed at Montpellier, France. A Matlab® code for anisotropy correction during the Thellier experiment is provided. The archaeointensity results obtained from both techniques for the OSA kiln are of high quality and in good mutual agreement. For the OSB kiln, Thellier results are characterized by large standard deviation and the multi-specimen (MSP) technique was not successful. The obtained full geomagnetic field vector (declination, inclination and intensity) has been used for the archaeomagnetic dating of the two structures suggesting that the OSA kiln was for the last time used between 1761?1841 A.D. and the OSB kiln between 1752?1831 A.D., at 95% probability. This study shows that intensity determinations do not restrict the dating results when referring to the last few centuries, as this period is characterized by very small intensity variations.

0 already noted by previous authors (Rolph et al., 1987; Incoronato et al., 2002; Tanguy et al., 2003) was better substantiated. 2) The thermal remanent magnetization (TRM) direction of most flows was shown to deviate from the corresponding historical direction by a small angle θ. In most cases, this angle was larger than the experimental error on the TRM direction as given by the α95 semi-angle of confidence of Fisher’s statistics, i.e. θ >α95.

Direct measurements of the Earth's magnetic field in Italy since 1640 a.d. have been used to check the remanence directions derived from historically dated volcanic rocks of Etna and Vesuvius. Direct measurements consist of the records of L’Aquila and Pola geomagnetic observatories, the repeat stations of the Italian Magnetic Network and the data base of the Historical Italian Geomagnetic Data Catalogue. All have been relocated to the same reference site (Viterbo — lat. 42.45°N, long. 12.03°E) in order to draw a reference secular variation (SV) curve. The direction of the Earth's field at Viterbo has also been calculated from the historical records (2000–1600) of ref. [Jackson, A., Jonkers, A.R.T., Walker, M.R., 2000. Four centuries of geomagnetic secular variation from historical records. Phil. Trans. R. Soc. London, Ser. A 358, 957–990] database. The remanence directions from Etna show a general agreement with the trend of the SV curve, although their inclination is usually lower than that from the direct measurement. The directions from Vesuvius are more scattered. Large discrepancies occur at both volcanoes and in some cases have been ascribed in the literature to poor geographic information, making it difficult to identify the flows actually emplaced during the eruptions reported in the chronicles. Closer examination shows that the great majority of the best-defined remanence directions (semi-angle of confidence α95 600 km) to confidently relocate magnetic directions.

Combining different dating techniques is fundamental to constrain the ages of archaeological findings, mainly when direct evidences for their chronological context are not available. This paper presents the results of a combined archaeological, archaeomagnetic and thermoluminescence study of a kiln discovered during a rescue excavation at Chieri, northern Italy. The archaeological site is quite complex mainly due to the interposition of different stratigraphic levels that span from Roman times to present day. The studied kiln belongs to the post-medieval stratigraphic level but the lack of datable diagnostic objects strongly limits the possibility of its accurate dating only by means of archaeological evidences. Archaeomagnetic study was performed on 26 baked clay samples, isolating stable characteristic remanent magnetizations. The statistic comparison of the averaged direction with reference secular variation curves suggests two possible dating intervals. Independent dating from thermoluminescence study of 2 samples is consistent with the second time interval proposed by archaeomagnetism, suggesting that the kiln was abandoned at the beginning of the 17th century. The successful combination of the two independent laboratory techniques provides accurate dating of archaeological baked clays and can be used as routine for future archaeological investigations of rescue excavations.

National audience; We present an updated compilation of Greek directional archaeomagnetic data for the last 4.5 millennia. The data set comprises 89 directions from archaeological artefacts and volcanic rocks. Most of the data come from the Late Bronze Age (1700-1400 BC) that is the flourishing period of the Minoan civilization in Crete, while parts of the classical (480-323 BC), Hellenistic (32-31 BC) and Roman (146 BC-330 AD) periods are also well covered. The dataset has been analysed using the Bayesian approach for curve building and a directional secular variation (SV) curve for Greece is proposed. Comparisons with regional and global model predictions show a general agreement even though some discrepancies are observed for some time intervals. The new curves together with the previously published intensity SV curve for Greece, also using the Bayesian approach, form a homogeneous set and enrich our knowledge of the full geomagnetic field vector variation in Greece during the last millennia.

Η Μινωική έκρηξη του ηφαιστείου της Σαντορίνης που έλαβε χώρα κατά την Ύστερη Εποχή του Χαλκού (17ο αιώνα π.Χ.) απέθεσε έναν τεράστιο όγκο ηφαιστειακών προϊόντων που κάλυψαν όλο το νησί και έθαψαν κάθε ανθρώπινο κτίσμα. Στην παρούσα μελέτη, παρουσιάζονται τα αποτελέσματα της θερμικής απομαγνήτισης κεραμικών θραυσμάτων που βρέθηκαν στην επαφή του προ-Μινωικού παλαιοεδάφους με τις πρώτες πυροκλαστικές αποθέσεις, με σκοπό την μελέτη της θερμικής επίδρασης των θερμών ηφαιστειακών υλικών στο παλαιοέδαφος όπου κατοικούσαν οι άνθρωποι πριν την έκρηξη. Συνολικά μελετήθηκαν 70 δείγματα που προέρχονται από 45 κεραμικά θραύσματα. Τα δείγματα συλλέχθηκαν από τρεις διαφορετικές τοποθεσίες στο νότιο μέρος του νησιού. Τα αποτελέσματα της σταδιακής θερμικής απομαγνήτισης των δειγμάτων δείχνουν ότι τα κεραμικά φέρουν δύο συνιστώσες μαγνήτισης που υποδεικνύουν ότι τα περισσότερα από αυτά αναθερμάνθηκαν σε θερμοκρασίες της ξεως 160-260 oC. Αυτές οι θερμοκρασίες αντιπροσωπεύουν τις θερμοκρασίες απόθεσης των πρώτων πυροκλαστικών προϊόντων που αποτέθηκαν πάνω στο Μινωικό έδαφος, μετά την αποκατάσταση της θερμικής ισορροπίας ανάμεσα στις θερμές αποθέσεις και το κρύο υπόβαθρο. Η μελέτη αυτή δείχνει ότι τα πρώτα πυροκλαστικά υλικά που αποτέθηκαν σε αποστάσεις 6 με 9 χιλιομέτρων από τον κρατήρα της Μινωικής έκρηξης, ήταν αρκετά ζεστά έτσι ώστε να προκαλέσουν αναθέρμανση των κεραμικών σε τέτοιες θερμοκρασίες., The Minoan eruption of Santorini volcano (Greece) took place in the Late Bronze Age (17th century BC) and produced a great volume of volcanic products that covered the whole island and buried every human settlement under meters of pyroclastic deposits. In this study we used thermal analysis of the magnetic remanence carried by pottery fragments buried under the pyroclastic deposits in order to estimate the thermal effect of the Minoan volcanic products on the pre-eruption habitation level. A total of 70 samples, prepared from 45 independent pottery fragments, have been studied. Samples were collected from three different sites, situated at the southern part of the island. Stepwise thermal demagnetizations reveal that the pottery fragments generally carry a two-component remanent magnetization. Interpretation of the demagnetization results using the normalised intensity decay curves and the orthogonal projection diagrams indicates that most samples were re-heated at temperatures around 160-260o C. The obtained results represent the equilibrium temperatures reached after the deposition of the pyroclastic fall and show that the pyroclastic fall deposits at distances around 6 to 9 km from the eruption vent were still hot enough to reheat the buried pottery at such temperatures.

Στην παρούσα εργασία παρουσιάζονται τα αποτελέσματα από την αρχαιομαγνητική μελέτη δυο αρχαίων κλιβάνων που ανακαλύφθηκαν στην Κάτω Αχαΐα. Σύμφωνα με τα ευρήματα της αρχαιολογικής ανασκαφής, οι δυο αυτοί κλίβανοι αποτελούσαν μέρος ενός μεγαλύτερου κεραμικού εργαστηρίου που λειτουργούσε στην περιοχή, πιθανότατα για την παραγωγή τούβλων ή κεραμικών. Συστηματική αρχαιομαγνητική δειγματοληψία πραγματοποιήθηκε σε συνεργασία με τους αρχαιολόγους και συνολικά λήφθηκαν 9 δείγματα από τον πρώτο κλίβανο (KL3) και 12 από τον δεύτερο (KL5). Συστηματικές μετρήσεις της μαγνητικής ορυκτολογίας των δειγμάτων πραγματοποιήθηκαν με σκοπό τον καθορισμό του βασικού φορέα της μαγνήτισης των δειγμάτων. Η διεύθυνση της Χαρακτηριστικής Παραμένουσας Μαγνήτισης καθορίστηκε κατόπιν ανάλυσης της κύριας συνιστώσας μαγνήτισης και οι μέσες τιμές διεύθυνσης για τους δυο κλιβάνους υπολογίστηκαν σύμφωνα με την στατιστική του Fisher. Η ηλικία των κλιβάνων υπολογίστηκε χρησιμοποιώντας τις πιο σύγχρονες εξελίξεις στην αρχαιομαγνητική έρευνα και κατόπιν σύγκρισης της διεύθυνσης των XLVII, No 3 – 1279 κλιβάνων με τις καμπύλες αναφοράς, όπως αυτές υπολογίστηκαν από το SCHA .DIF .3K γεωμαγνητικό μοντέλο που περιγράφει την μεταβολή του μαγνητικού πεδίου στον Ευρωπαϊκό χώρο. Τα αποτελέσματα της αρχαιομαγνητικής χρονολόγησης συμφωνούν πολύ ικανοποιητικά με τις αρχαιολογικές ενδείξεις για την περίοδο χρήσης των κλιβάνων και υποδεικνύουν ότι οι κλίβανοι ήταν σε χρήση κατά την διάρκεια της ελληνιστικής περιόδου και εγκαταλείφτηκαν προς το τέλος αυτής., New archaeomagnetic results from two ancient kilns excavated at Kato Achaia, southern Greece, are presented. According to archaeological evidence, both kilns were part of a bigger ceramic workshop, probably used for the production of bricks or ceramics. Systematic archaeomagnetic sampling was carried out collecting 9 brick samples from the first kiln (KL3) and 12 brick samples from the second kiln (KL5). Magnetic mineralogy measurements have been carried out in order to determine the main magnetic carrier of the samples and to check their thermal stability. Standard thermal demagnetization procedures have been used to determine the archaeomagnetic direction registered by the bricks during their last firing. The direction of the Characteristic Remanent Magnetization (ChRM) has been obtained from principal component analysis and the kilns mean directions were calculated using Fisher statistics. The archaeomagnetic ages of both kilns were determined using the most recent developments in data elaboration and were calculated after comparison of the kilns declination and inclination with the reference curves produced by the SCHA.DIF.3K European regional geomagnetic field model. Dating results are in good agreement with archaeological evidence of the site and suggest that both kilns were in use during Hellenistic times.

International audience; A combined archaeomagnetic and thermoluminescence study was carried out as part of a rescue archaeological excavation on a kiln discovered during the installation of methane gas pipelines beneath a rice field, along the southern border of Fontanetto Po village (Vercelli province, Italy). A total of 23 independent brick samples have been collected, oriented in situ with an inclinometer; the use of magnetic and sun compass was not possible due to the existence of metallic tubes beneath the kiln and a plastic cover above it. Standard archaeomagnetic procedures have been used for the determination of the archaeomagnetic inclination and absolute geomagnetic intensity. Stepwise thermal demagnetization shows a very stable characteristic remanent magnetization and the calculated mean inclination of the 23 samples is I = 65.3° with α95 = 2.4° and k = 156. Archaeointensity experiments have been performed using the classical Thellier method as modified by Coe, with regular partial thermoremanent magnetization (pTRM) checks. The cooling rate and remanence anisotropy effects upon thermoremanent magnetization (TRM) have been investigated in all the specimens. A total of 19 archaeointensity determinations (at specimen level) that correspond to linear NRM–TRM plots were used for the calculation of the site mean archaeointensity that is 46.4 ± 2.9 μT. Archaeomagnetic dating results show two possible dating intervals for the last 1000 years, calculated at 95% confidence interval: a first one from 1511 to 1614 AD, and a second one from 1768 to 1872 AD. Thermoluminescence (TL) study has been also performed on two brick samples from the kiln's internal wall, using conventional laboratory procedures. According to the thermoluminescence results the kiln's last usage lies between 1796 and 1914 AD. This age is in good agreement with the second dating interval obtained by the archaeomagnetic analysis. The combined archaeomagnetic and thermoluminescence results suggest that the last firing of the kiln could have occurred between the end of the 18th century and the beginning of 20th century.

Thermal remanent magnetization analyses were carried out on ceramic fragments and lithic clasts embedded in the first pumice fall deposits of the Minoan eruption. The aim of this study is to estimate the equilibrium temperature after deposition of these pyroclastic fall deposits and their thermal effect on the pre-Minoan surface. A total of 30 samples from 22 independent ceramic fragments and 20 samples from 14 lithic clasts have been studied. Samples were collected from the Megalochori Quarry, located at the southern part of Santorini island. Stepwise thermal demagnetization reveals that the ceramics were mostly re-heated at temperatures around 140–180°C; in few ceramics a higher temperature component is also present, probably related to the original heating or the use of the ceramics before the eruption. Thermal demagnetization of the lithic clasts shows similar results with slightly higher re-heating temperatures, around 180–240°C. The estimated temperatures represent the equilibrium temperatures obtained after the deposition of the pumice fall and show that the pyroclastic fall deposits at a distance of around 6 km from the eruption vent maintained a temperature high enough to re-heat the buried ceramics at temperatures around 140–180°C.

The Pirro Nord palaeontological and archaeological locality has been the object of recent field research to investigate the fossil content of its Early Pleistocene vertebrate palaeocommunities, and to understand the genesis of the karst network and related deposits that delivered the lithic industry representing the earliest human occupation of Europe known so far, spanning 1.7e1.3 Ma. The succession of the Pirro 10 site has been described in terms of facies and fossil vertebrate content of the 37 distinguished Sedimentary Units (SU). On the whole, the succession is made of chemical and clastic sediments that include debris fall and alluvial deposits. SU are distinguished according to lithology, colour, discontinuities, lamination, fossil concentration, and taphonomical parameters. Palaeomagnetic data and biochronological characteristics refer the Pirro 10 site to the latest Late Villafranchian Mammal Age of the Italian biochronological mammal scale. The fossil content is quite homogenous. Common taxa are Axis eurygonos, Hystrix refossa, Ursus etruscus, Canis mosbachensis together with small mammal remains mainly represented by Chiroptera and the arvicolid Microtus (Allophaiomys )e x gr.ruffoi. A significant change in the taxonomic record occurs in

During the last two decades, important advances in archaeomagnetic research in Italy have been made, both in the acquisition of new data and in the improvement of methodologies and data elaboration techniques. Nowadays, 73 directional and 23 intensity results are available, mainly obtained from archaeological sites situated in southern Italy. Most of the data come from the study of ancient kilns and ceramics and their ages range from 1300 BC to 1600 AD. The quantity and quality of the available Italian directional data have permitted the construction of reference secular variation (SV) curves for declination and inclination, using the latest improvements on curve building techniques. These curves describe, with reasonable accuracy, the variations of the Earth’s magnetic field in Italy for the 600 BC to 600 AD period, for which many data are available. For older BC periods and for the Medieval times data are still very scarce. Archaeomagnetic dating of in situ archaeological materials is now possible but still caution is needed for the time periods where the reference SV curves are accompanied by large error envelopes. Certainly more new, high quality directional and intensity data of well dated archaeological material are necessary to better describe the variations of the Earth’s magnetic field during the past and to make reliable archaeomagnetic dating possible, based on the full description of the Earth’s magnetic field vector.

International audience; Three kilns and a collection of baked bricks from Italian archaeological sites have been studied for archaeointensity determination using the Thellier method as modified by Coe. All sites are dated based on archaeological information and their ages range from 500 to 800 AD and 1500 to 1700 AD. Rock magnetic studies identify magnetite, Ti- magnetite and hematite as the main magnetic minerals, and magnetic susceptibility versus temperature shows a good thermal stability of the samples. The intensity results have been corrected for anisotropy of the thermoremanent magnetization and cooling rate effects. The new data together with 136 previously published results are used to estimate the variation of the Earth's magnetic field over the past three millennia. The time distribution of the Italian absolute intensity data is irregular with the majority of determinations concentrated during the last four centuries, while older periods are very poorly covered. Most of the data come from volcanic rocks and show significant discrepancies. All data have been compared with archaeointensity results from Europe and regional and global models predictions. This work indicates the need to obtain more high quality archaeointensity results, in particular for the periods older than 200 BC and between 200 and 1000 AD, in order to determine a robust Italian intensity secular variation curve that, in combination with directional data, could be used for archaeomagnetic dating.