Palaeomagnetism of the Permian Volcanic Rocks of Moissey (French Jura): Implications For the Palaeofield and Tectonic Evolution

Abstract

Rocks from the Massif de la Serre in the French Jura (latitude: 47.3"N longitude: 5.6"E) belonging to an ignimbritic assemblage dominated by vitrophyric rhyolites, and whose age of formation is probably Permian (Autunian to Saxonian) have been studied by applying thermal and alternating field demagnetization. The characteristic magnetization has a mean direction derived from 89 samples of D = 170", I = -16", k = 26.2", 0 1~~ = 3" and a corresponding north palaeopole at 41"N, 172"E, A g S = 5". The pole, which is very close to the Permian European poles, can thus be considered as a new contribution. Some samples are found to carry a unique normal polarity magnetization, others carry both normal and reverse polarities. It therefore seems that, similar to Permian series in the USSR, these west European rocks have registered a normal event in the Kiaman interval. From a structural point of view, we may conclude that during the Alpine tectonic phases the Massif de la Serre has not been subjected to substantial rotation.

Determination of flow directions by combining AMS and thin-section analyses: implications for Oligocene volcanism in the Kerguelen Archipelago (southern Indian Ocean)

“…An alternative method for inferring a flow direction from the AMS data is to use the vertical plane of symmetry of the distribution of susceptibility axes (Henry 1980; Thompson et al 1986). Although this method cannot be used for indicating a flow sense, the vertical plane of symmetry is usually relatively well highlighted by the scatter of the K min direction in the density diagrams (right part of Fig.…”

“…This can be clearly seen using density contours on a stereonet for a large set of samples (Rochette et al 1992). Such diagrams also often allow a better estimation of the distribution symmetry relative to the vertical plane of the eigenvectors and thus can be used to infer the emplacement direction (Henry 1980; Thompson et al 1986; Cañón Tapia et al 1997; Cañón Tapia & Coe 2000).…”

“…* and ** after Plenier et al (2002) and Henry et al (2003) (Rochette et al 1992). Such diagrams also often allow a better estimation of the distribution symmetry relative to the vertical plane of the eigenvectors and thus can be used to infer the emplacement direction (Henry 1980;Thompson et al 1986;Cañón Tapia et al 1997;Cañón Tapia & Coe 2000). Density contour plots of K max and K min for all the AMS data of each section (Fig.…”

Anisotropy of magnetic susceptibility data bearing on the transport direction of mid-tertiary regional ignimbrites, Candelaria Hills area, West-Central Nevada

“…The use of the K1 susceptibility axis alone as a proxy for flow direction is not always reliable (e.g., Knight et al 1986;Hillhouse and Wells 1991;Seaman et al 1991;Ort 1993;Le Pennec et al 1998), and a different approach must be used to interpret the AMS data. The imbrication angle of the magnetic foliation plane, which equals the deviation of the K3 axes from the normal to the macroscopic flow plane, provides an alternative method to discern the flow direction of ignimbrite deposits (Henry 1980;Thompson et al 1986). Application of the imbrication angle approach may result in an alternate interpretation of the flow direction (Alva-Valdivia et al 2005).…”

The Late Carboniferous to Early Triassic geodynamic evolution of Variscan Europe in the light of magnetic overprints in Early Permian rhyolites from the northern Vosges (France) and central Black Forest (Germany)

“…The Permian volcanics and sediments of western Europe have been the subject of extensive palaeomagnetic studies in the last three decades (Van Everdingen 1960;Nijenhuis 1961;Roche, Saucier & Lacaze 1962;Kruseman 1962;Birkenmaier, Krs & Nairn 1968;Krs 1968;Westphal 1972;Konrad & Nairn 1972;Berthold, Nairn & Negendank 1975;Zijderveld 1975;Mauritsch & Rother 1983;Courtillot et al 1986;Evans & Maillol 1986;Merabet & Daly 1986;Thompson, Guillaume & Daly 1986;Westphal et a/. 1987;Soffel & Harzer 1991;Merabet & Guillaume 1988;CognC, Brun & Van den Driessche 1990;Diego-Orozco & Henry 1992).…”