Late Permian magnetostratigraphy on the eastern Russian platform

The Late Permian is characterized palaeomagnetically by the transition from the long-lasting Permo-Carboniferous reversed polarity superchron (PCRS; also called: Kiaman reversed superchron) to the subsequent Permo-Triassic mixed polarity superchron, often called Illawarra mixed polarity superchron. Many discussions have been devoted to the exact time of the onset of the Illawarra reversals. Apparently contradictory data have been obtained from magnetostratigraphic sediment successions formed in different environments in many regions of the world. These sediments have been dated using classical geological or palaeontological correlation methods without the possibility of absolute age control because volcanogenic materials are missing. Application of the local or regional stratigraphic schemes leads to difficulties and apparent diachronous age estimates of the end of the PCRS. This paper shows that in agreement with earlier investigations, the continental red beds of the Upper Permian Tatarian stage on the eastern Russian platform record the Kiaman/Illawarra boundary. The Illawarra reversal sequence measured in a type section at the Volga river can be correlated well with the corresponding polarity pattern found in the Tethyan realm if one assumes a longer duration of the Tatarian than previously suggested

A catalogue of Spanish archaeomagnetic data

International audienceA total of 58 new archaeomagnetic directions has been determined from archaeological structures in Spain. Together with five previous results they allow the compilation of the first archaeomagnetic catalogue for Spain, which includes 63 directions with ages ranging between the 2nd century BC and the 20th century AD. Characteristic remanence directions have been obtained from stepwise thermal and alternating field demagnetization. The hierarchical structure has been respected in the calculation of the mean site directions. Rock magnetic experiments reveal that the main magnetic carrier is magnetite or titanomagnetite with different titanium contents. The age estimate of the studied structures is generally well justified by archaeological constraints. For six structures the proposed date is also supported by physical methods. The data are in close agreement with the French secular variation (SV) curve. This catalogue represents the first step in the construction of a SV curve for the Iberian Peninsula, which will be of much use in archaeomagnetic dating and in modelling of the Earth's magnetic field in Western Europe

Updated Iberian archeomagnetic catalogue: new full vector paleosecular variation curve for the last three millennia

In this work, we present 16 directional and 27 intensity high‐quality values from Iberia. Moreover, we have updated the Iberian archeomagnetic catalogue published more than 10 years ago with a considerable increase in the database. This has led to a notable improvement of both temporal and spatial data distribution. A full vector paleosecular variation curve from 1000 BC to 1900 AD has been developed using high‐quality data within a radius of 900 km from Madrid. A hierarchical bootstrap method has been followed for the computation of the curves. The most remarkable feature of the new curves is a notable intensity maximum of about 80 μT around 600 BC, which has not been previously reported for the Iberian Peninsula. We have also analyzed the evolution of the paleofield in Europe for the last three thousand years and conclude that the high maximum intensity values observed around 600 BC in the Iberian Peninsula could respond to the same feature as the Levantine Iron Age Anomaly, after travelling westward through Europe

Preliminary magnetostratigraphic data of a Tatarian (Upper Permian) section on the Volga river (Russia)

A magnetostratigraphic profile of the uppermost Tatarian (Upper Permian) of a section of continental sediments from Eastern Platform is presented. Around 300 samples across an Upper Permian sequence o f red beds Monastirskoje on the Volga River Valley (South-West of Tatarian, Russia) have been collected. The characteristic primary component defined nearly for all the examined samples has a normal as well as reversed polarity, therefore a clear polarity zonation Is defined. The fold test, carried out on samples collected In the nearby section of Titjuschin where the sediments are exposed in a fold structure, indicates that the characteristic magnetization pre-dates the foldingSe presenta el perfil magnetoestratigráflco del Tatariense (Pérmico Superior) de una sección de sedimentos continentales de la plataforma del Este. Se recogieron alrededor de 300 muestras a lo largo de una serie continua de red beds en Monastirskoje, en el valle del Volga, (Suroeste de Tataria, Rusia). La componente característica primaria en todas las muestras examinadas presenta tanto polaridad normal como invertida, por lo que se ha definido una clara secuencia de polaridad. Se ha llevado a cabo un test del pliegue en rocas próxima a la sección de Titjuschin donde los sedimentos han experimentado fuertes plegamientos, que ha indicado que la magnetización característica es previa al plegamient

Geomagnetic secular variation through the last 3500 years as recorded by lake Aslikul sediments from eastern Europe (Russia)

A paleomagnetic record of geomagnetic secular variation during the last 3500 yr has been obtained from three lake sediment cores from lake Aslikul in the western Pre-Ural region (Russia). Pollen data provide a time-scale and relative paleotemperatures which can be compared with radiocarbon dated paleotemperature data for this region. Magnetic susceptibility measurements have been used for correlation between cores and reconstruction of composite core data. The paleosecular variations which have been recorded in the lake Aslikul sediments are consistent with results from West-European lakes. Westward shifting inclination features are observed between the more western European and the Pre-Ural regions which have apparent age differences between 200 and 600 years resulting in drift rates which are of the order of 0.1 degrees/year

Geomagnetic secular variation through the last 3500 years as recorded by lake Aslikul sediments from eastern Europe (Russia)

A paleomagnetic record of geomagnetic secular variation during the last 3500 yr has been obtained from three lake sediment cores from lake Aslikul in the western Pre-Ural region (Russia). Pollen data provide a time-scale and relative paleotemperatures which can be compared with radiocarbon dated paleotemperature data for this region. Magnetic susceptibility measurements have been used for correlation between cores and reconstruction of composite core data. The paleosecular variations which have been recorded in the lake Aslikul sediments are consistent with results from West-European lakes. Westward shifting inclination features are observed between the more western European and the Pre-Ural regions which have apparent age differences between 200 and 600 years resulting in drift rates which are of the order of 0.1 degrees/year

Geomagnetic secular variation through the last 3500 years as recorded by lake Aslikul sediments from eastern Europe (Russia)

A paleomagnetic record of geomagnetic secular variation during the last 3500 yr has been obtained from three lake sediment cores from lake Aslikul in the western Pre-Ural region (Russia). Pollen data provide a time-scale and relative paleotemperatures which can be compared with radiocarbon dated paleotemperature data for this region. Magnetic susceptibility measurements have been used for correlation between cores and reconstruction of composite core data. The paleosecular variations which have been recorded in the lake Aslikul sediments are consistent with results from West-European lakes. Westward shifting inclination features are observed between the more western European and the Pre-Ural regions which have apparent age differences between 200 and 600 years resulting in drift rates which are of the order of 0.1 degrees/year

Late Permian magnetostratigraphy on the eastern Russian platform

The Late Permian is characterized palaeomagnetically by the transition from the long-lasting Permo-Carboniferous reversed polarity superchron (PCRS; also called: Kiaman reversed superchron) to the subsequent Permo-Triassic mixed polarity superchron, often called Illawarra mixed polarity superchron. Many discussions have been devoted to the exact time of the onset of the Illawarra reversals. Apparently contradictory data have been obtained from magnetostratigraphic sediment successions formed in different environments in many regions of the world. These sediments have been dated using classical geological or palaeontological correlation methods without the possibility of absolute age control because volcanogenic materials are missing. Application of the local or regional stratigraphic schemes leads to difficulties and apparent diachronous age estimates of the end of the PCRS. This paper shows that in agreement with earlier investigations, the continental red beds of the Upper Permian Tatarian stage on the eastern Russian platform record the Kiaman/Illawarra boundary. The Illawarra reversal sequence measured in a type section at the Volga river can be correlated well with the corresponding polarity pattern found in the Tethyan realm if one assumes a longer duration of the Tatarian than previously suggested

Late Permian magnetostratigraphy on the eastern Russian platform

The Late Permian is characterized palaeomagnetically by the transition from the long-lasting Permo-Carboniferous reversed polarity superchron (PCRS; also called: Kiaman reversed superchron) to the subsequent Permo-Triassic mixed polarity superchron, often called Illawarra mixed polarity superchron. Many discussions have been devoted to the exact time of the onset of the Illawarra reversals. Apparently contradictory data have been obtained from magnetostratigraphic sediment successions formed in different environments in many regions of the world. These sediments have been dated using classical geological or palaeontological correlation methods without the possibility of absolute age control because volcanogenic materials are missing. Application of the local or regional stratigraphic schemes leads to difficulties and apparent diachronous age estimates of the end of the PCRS. This paper shows that in agreement with earlier investigations, the continental red beds of the Upper Permian Tatarian stage on the eastern Russian platform record the Kiaman/Illawarra boundary. The Illawarra reversal sequence measured in a type section at the Volga river can be correlated well with the corresponding polarity pattern found in the Tethyan realm if one assumes a longer duration of the Tatarian than previously suggested

Late Permian magnetostratigraphy on the eastern Russian platform

The Late Permian is characterized palaeomagnetically by the transition from the long-lasting Permo-Carboniferous reversed polarity superchron (PCRS; also called: Kiaman reversed superchron) to the subsequent Permo-Triassic mixed polarity superchron, often called Illawarra mixed polarity superchron. Many discussions have been devoted to the exact time of the onset of the Illawarra reversals. Apparently contradictory data have been obtained from magnetostratigraphic sediment successions formed in different environments in many regions of the world. These sediments have been dated using classical geological or palaeontological correlation methods without the possibility of absolute age control because volcanogenic materials are missing. Application of the local or regional stratigraphic schemes leads to difficulties and apparent diachronous age estimates of the end of the PCRS. This paper shows that in agreement with earlier investigations, the continental red beds of the Upper Permian Tatarian stage on the eastern Russian platform record the Kiaman/Illawarra boundary. The Illawarra reversal sequence measured in a type section at the Volga river can be correlated well with the corresponding polarity pattern found in the Tethyan realm if one assumes a longer duration of the Tatarian than previously suggested