Grotta Romanelli, located in southern Italy, is a natural coastal cave renowned for its exceptional stratigraphical record and its critical role in understanding the Middle Pleistocene‐Holocene geomorphological and paleoenvironmental evolution of the Mediterranean region. Its importance has long been recognized with numerous studies focusing on dating its deposits using radiocarbon analyses and biological proxies. In this study, we introduce the use of the Paleosecular Variation (PSV) of the geomagnetic field to compute a depth‐age model for the uppermost stratigraphic unit of Grotta Romanelli (Unit IUS5), traditionally referred to as “Terre Brune.” This Unit, previously associated with the Late Pleistocene‐Holocene transition, lacked a precise chronological framework. Using stepwise alternating field demagnetization, we obtained well‐defined paleomagnetic directions which were compared with the reference geomagnetic field curves calculated from the SHA.DIF.14k global geomagnetic field model. By incorporating the available radiocarbon dates, and considering the principle of stratigraphic superposition, we established a continuous age model, spanning the 14,000 to 8,000 years BP period. This model sheds light on the most recent phases of sedimentation and human activity in the cave before its complete infilling. The results demonstrate the high potential of PSV dating in providing absolute ages for fine‐grained cave deposits. Furthermore, the new age‐model offers a coherent timeline for the Final Epigravettian archeological and faunal records of Grotta Romanelli, revealing their connection with the climate changes at the Late Pleistocene‐Holocene boundary.

We present new absolute archaeointensity data from six archaeological sites situated in the Okayama Prefecture, Japan. The materials studied are well-dated fragments from pottery, ceramic coffins and haniwa artefacts. Their ages range from 160 AD to 675 AD, covering the Late Yayoi and Kofun periods. Rock magnetic experiments suggest the presence of magnetite and/or Ti-magnetite as the main carrier of the remanence, with a possible minor contribution of higher coercivity minerals. After thermal demagnetization experiments, the most magnetically stable samples were selected for archaeointensity analysis performed following the double-heating method proposed by Thellier and modified by Coe. Partial thermoremanent magnetization (pTRM) checks and pTRM tail-checks were performed for monitoring possible chemical alterations during heating. All measurements were corrected for both anisotropy and cooling-rate effects. Successful archaeointensity determinations, following rigorous selection criteria, were obtained for samples from all the investigated archaeological sites. Compared with literature data from Japan, the new high-quality data show significantly lower intensity values. They also reveal possible fast secular variation changes during the Late Yayoi period and very weak geomagnetic intensity field around 630 AD. Such values offer evidence of a possible recurrence of weak intensity field in East Asia, suggesting an ancient recurrence of the West Pacific Anomaly. The new data might change the archaeomagnetic field models interpretations in the area, even though more data are still necessary to better understand the secular variation in Japan and the temporal evolution of the geomagnetic field's behaviour in East Asia.

Investigating the heating temperatures of ancient ceramic artifacts can offer information about their production technology and enrich our knowledge about the fire control skills in ancient times. We present here the results of a multi-analytical approach, including magnetic, X-Ray Powder Diffraction (XRPD) and thermoluminescence (TL) analyses, applied on the investigation of the equivalent firing temperature of the ceramic coffin (No 2) found in the well-known Sada Nishizuka Kofun, Japan. Monitoring of the magnetic properties of the studied fragments versus laboratory heating showed clear magnetic enhancement at relatively low temperatures around 350-500 degrees C. The magnetic results were compared with independent data obtained from XRPD and TL analyses. The XRPD patterns showed the presence of quartz, plagioclases and clay minerals such as muscovite and smectite, which indicate firing temperatures lower than 850-950 degrees C. The presence of kaolinite in almost all the studied samples lower the estimate temperature below 550 degrees C. Such data were further confirmed by the TL analysis which suggest firing temperature lower than 525 degrees C. The results obtained indicate that the coffin was most probably produced in an open or covered kiln, following the Japanese Haji-type traditional production, reaching maximum firing temperature lower than 550 degrees C. This study offers the first archaeometric experimental data to better understand the production strategy of ceramic coffins during the Kofun period in Japan and highlights the potential of non-conventional archaeometric analyses, such as magnetic and thermoluminescence investigations, to obtain information on firing procedures for ancient ceramic artifacts. (c) 2023 Consiglio Nazionale delle Ricerche (CNR). Published by Elsevier Masson SAS. All rights reserved.

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.

We present the first Italian reference secular variation curves for both direction and intensity that cover the last 3000 years. Strict selection criteria were applied to guarantee the collection of the most reliable data within a 1000 km radius of Viterbo, including archaeomagnetic records from archaeological material and volcanic rocks. The new curves are calculated using Bayesian statistics and they depict interesting geomagnetic field features, such as high‐intensity periods. These are the first curves for Italy, including both directional and intensity data, and they can be used as reference curves for archaeomagnetic dating, not only in Italy but also in nearby countries.

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 ZAm(2). 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 ZAm(2)) in the different regions. Both events seem to span over a large region at the Earth's surface covering more than 60 degrees of longitude, verifying an Earth's outer core origin for these intensity features. (C) 2020 Elsevier B.V. All rights reserved.

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 degrees 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. (C) 2020 Elsevier B.V. All rights reserved.

In the last decades, palaeomagnetic research has provided important information about the past variation of the Earth's magnetic field (EMF) from its origin to the present day. However, questions regarding the origin and evolution of the EMF as well as the frequency and spatial distribution of its variations still remain open to debate. This Special Publication provides new insights into the study of the temporal and spatial evolution of the EMF presenting new data from palaeomagnetic and rock magnetic studies of archaeological materials, sediments and lavas. The papers presented cover a wide range of topics related to archaeology, stratigraphy and climate, including new data from several parts of the world, such as Europe, Africa, Australia, New Zealand, India and the Baltic Sea. This Special Publication aims to present an overview of the most recent secular variation studies and their use to disclose fundamental properties of the EMF evolution.

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 degrees and 800 degrees 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.

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 10000 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. (C) 2017 Elsevier B.V. All rights reserved.

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.

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.

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.

The distribution of ancient obsidian utensils is one of the few ways to trace trades during the Neolithic. Such material is suitable for provenance investigations due to the rarity of volcanic sources where magmatic rocks solidify as amorphous. Although obsidian provenance investigations base on chemical analysis, also chemical-physical properties revealed efficacious to relate tool fragments and geological deposits and during the last decades several studies have demonstrated that magnetic properties are useful too [1]. In the amorphous matrix, crystal grains have different compositions, distributions, and diameter dimensions. Some contain iron and their magnetic behaviour can be studied to highlight differences in distribution and size of ferrous particles through the associated magnetic state. The properties of 20 obsidian artefacts found in the Neolithic site of Via Guidorossi (Parma, Italy) have been investigated [2]. Magnetic grain-size analyses were performed including the measurement of susceptibility (), anhysteretic susceptibility (a), and saturation isothermal remanent magnetizations at room (SIRM293), and liquid nitrogen (SIRM77) temperatures. The measurement of SIRM at two temperatures allowed to estimate the amount of smaller grains ferromagnetic at low temperature, superparamagnetic at room temperature. SIRM77 revealed fundamental for provenance as the ratios St = SIRM77/SIRM293 and Qa = χa/χ discriminate samples from most Mediterranean sites [3]. Furthermore, the anisotropy degree of susceptibility, P, revealed useful to discriminate obsidians coming from Lipari and Sardinia– SA. Comparing magnetic properties of the artefacts with geological samples from outcrops in the Mediterranean suggests they come from Lipari. Moreover, SEM-EDS microanalyses were also performed on geological samples. Inclusions were mapped to relate the magnetic behaviours to the morphology of the iron-oxide particles. Obsidian from Lipari is characterized by relatively abundant and uniformly dispersed grains with diameter d < 10 μm, while samples from Sardinia–SA show less abundant crystallites with d values up to 100 μm.

We present the results of palaeomagnetic analysis on Late Bronge Age pottery from Santorini carried out in order to estimate the thermal effect of the Minoan eruption on the pre-Minoan habitation level. A total of 170 specimens from 108 ceramic fragments have been studied. The ceramics were collected from the surface of the pre-Minoan palaeosol at six different sites, including also samples from the Akrotiri archaeological site. The deposition temperatures of the first pyroclastic products have been estimated by the maximum overlap of the re-heating temperature intervals given by the individual fragments at site level. A new statistical elaboration of the temperature data has also been proposed, calculating at 95 per cent of probability the re-heating temperatures at each site. The obtained results show that the precursor tephra layer and the first pumice fall of the eruption were hot enough to re-heat the underlying ceramics at temperatures 160-230 A degrees C in the non-inhabited sites while the temperatures recorded inside the Akrotiri village are slightly lower, varying from 130 to 200 A degrees C. The decrease of the temperatures registered in the human settlements suggests that there was some interaction between the buildings and the pumice fallout deposits while probably the buildings debris layer caused by the preceding and syn-eruption earthquakes has also contributed to the decrease of the recorded re-heating temperatures.

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.

A detailed rock-magnetic and archaeomagnetic study has been carried out on two rescue excavation kilns discov-ered during the works to expand a highway at the location of Osterietta, in Northen Italy. Systematic archaeomagnetic sampling was carried out collecting 15 samples from the first kiln (OSA) and 8 samples from the second kiln (OSB), all of them oriented in situ with a magnetic compass and an inclinometer. Magnetic mineralogy mea-surements 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. Demagnetization results show a very stable characteristic remanent magnetization (ChRM). We averaged the directions for each kiln separately and calculated the statistical parameters assuming a Fisherian distribution. The archaeointensity of both kilns has also been recovered with both the classical Thellier-Thellier method and the multi-specimen procedure (MSP-DSC). During the Thellier experi-ments, regular partial thermoremanent magnetization checks have been performed and the effect of the anisotropy of the thermoremanent magnetization (TRM) and cooling rate upon TRM intensity acquisition have been inves-tigated in all samples. The multi-specimen procedure was performed with a very fast-heating oven developed at Montpellier (France). The intensity results obtained from both methods have been compared and the full geomag-netic field vector determined for each kiln has been used for archaeomagnetic dating. The obtained results show that the kilns were almost contemporaneous and their last use occurred in the 1750-1850 AD time interval.

We present new archaeointensity results from three Italian kilns situated at Ascoli Satriano, Vagnari and Fontanetto Po obtained with the Thellier modified by Coe double heating method. These data complement the directional results previously published. All sites are dated on the basis of archaeological information and/or thermoluminescence dating. The results are corrected for the anisotropy of the thermoremanent magnetization and the cooling rate effects. The new data are compared with previously published archaeointensity data from Italy and nearby countries within 900 km radius from Viterbo. An initial data set including archaeointesity data mainly coming from Italy, France, Switzerland, Czech Republic, Slovakia, Hungary, Greece and Bulgaria has been compiled. After the application of strict selection criteria, the most reliable data have been used for the calculation of a preliminary Italian intensity secular variation (SV) curve for the last 3000 yr. The new curve covers the 300 BC-400 AD and 1200-1900 AD periods. It is established by means of sliding windows of 200 yr shifted by 100 yr. The lack of reliable data for the 1000-200 BC and 400-1200 AD time intervals does not permit the calculation of a continuous curve. Clearly, more high-quality archaeointensity data from Italy and Europe are still needed to draw a robust intensity SV curve for the Italian Peninsula that could be used for archaeomagnetic dating in combination with the directional data.

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 degrees with alpha(95) = 2.4 degrees 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 mu T. 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. (C) 2012 Elsevier Ltd. All rights reserved.