I am a geoscientist interested in the deformation of the lithosphere both in continental and oceanic areas. My expertise is in structural geology, tectonics, rock magnetism, and plaeomagnetism. Address: School of Geosciences, University of Louisiana at Lafayette, PO Box 44530, 330 Hamilton Hall, Lafayette, LA 70504, U.S.A.
Most of the large igneous provinces (LIPs) are hosted in sedimentary basins (e.g. the onshore Kar... more Most of the large igneous provinces (LIPs) are hosted in sedimentary basins (e.g. the onshore Karoo and Tunguska basins, and the offshore Vøring, Møre, and North Sea basins). A typical LIP plumbing system consists of sub-horizontal and vertical sheet-like magmatic intrusions (MI), respectively sills and dykes. Surface and subsurface mapping of these sedimentary basins show that the magma tends to
The Betic-Rif cordillera constitutes the western most part of the Alpine orogeny in the Mediterra... more The Betic-Rif cordillera constitutes the western most part of the Alpine orogeny in the Mediterranean area. Its formation and structural evolution are widely debated. An important piece of information is the origin and emplacement of the ultramafic bodies that outcrop in both sides of the cordillera. The bodies in the northern part, known as Ronda peridotites, have been studied from the structural point of view in order to elaborate geodynamical models. A study of the anisotropy of magnetic susceptibility (AMS) has been carried out with further correlation between the magnetic lineation and structural stretching lineation measured in the field. Additional rock magnetic measurements have allowed determining the carriers of the magnetic signal. Magnetite originated during the serpentinization process, has been identified as the main carrier of the magnetic susceptibility. The positive correlation between magnetic lineation and stretching lineation makes the method suitable for the eva...
The objectives for Expedition 352 were to drill through the entire volcanic sequence of the Bonin... more The objectives for Expedition 352 were to drill through the entire volcanic sequence of the Bonin fore arc to 1. Obtain a high-fidelity record of magmatic evolution during subduction initiation and early arc development, 2. Test the hypothesis that fore-arc basalt lies beneath boninite and understand chemical gradients within these units and across the transition, 3. Use drilling results to understand how mantle melting processes evolve during and after subduction initiation, and 4. Test the hypothesis that the fore-arc lithosphere created during subduction initiation is the birthplace of suprasubduction zone (SSZ) ophiolites. Expedition 352 successfully cored 1.22 km of igneous basement and 0.46 km of over-lying sediment, providing diverse, stratigraphically controlled suites of fore-arc basalts (FAB) and boninite related to seafloor spreading and earliest arc development. FAB were recovered at the two deeper water sites (U1440 and U1441) and boninites at the two sites (U1439 and U...
The Heart Mountain Detachment (HMD) in Wyoming constitutes one of the largest known rock slides (... more The Heart Mountain Detachment (HMD) in Wyoming constitutes one of the largest known rock slides (3400 km2) on Earth. This detachment took place along the stratigraphic boundary between the Bighorn Dolomite at the hanging-wall and the Snowy Range Formation at the footwall. The slide resulted in the formation of an up to 3 m-thick carbonate ultracataclasite (CUC) at the base of the slide. The origin of the CUC and the nature of the triggering mechanism responsible for the initiation of the catastrophic movement have long been controversial. The most widely accepted theory is a mid-Eocene eruption in the Absaroka volcanic province that triggered rupture and subsequent detachment of Paleozoic rocks. Rapid sliding was facilitated by basal fluidization generated by thermo-mechanical decomposition of carbonate rocks. Here I present a proof of concept study addressing the question of the consistent magnetic fabrics observed in the CUC, as well as new observations indicating the discovery of mineral grains of volcanic origin within the CUC. Additionally, some constraints are placed on the thermo-chemical conditions operating at the base of this catastrophic landslide. Overall, the CUC displays an average magnetic susceptibility one order of magnitude higher (1803 . -6 [SI]) than the overlying Bighorn Dolomite (148 . -6 [SI]) and underlying Snowy Range Fm (636 . -6 [SI]). Anisotropy of magnetic susceptibility (AMS) data, field observations and microstructural analysis suggest that ferromagnetic (s.l) minerals in the CUC originate from the Bighorn Dolomite, the Tertiary volcanics and synkinematic thermal decomposition of pyrite into pyrrhotite and magnetite. Thermomagnetic investigations revealed a Curie temperature of 525 °C which suggests that magnetite is the dominant magnetic carrier mineral in the CUC. Energy Dispersive Spectroscopy analyses confirm that this magnetite has a relatively low ulvöspinel content. Magnetic hysteresis properties point to an average pseudo-single domain magnetic grain size or, alternatively, a mixture of single domain and multi-domain grains. The origin of AMS is magnetostatic, elucidated by a high degree of consistency between AMS directions and 3–D SPO directions. The anisotropy of magnetic susceptibility (AMS) directional data displays two dominant fabric orientations suggesting possible strain partitioning in the CUC. The consistency of magnetic fabrics suggests that the CUC followed a dominantly transpressive regime. The deformation mechanism causing the consistent AMS is a homogeneous passive rotation of magnetite grains. Microstructural analysis of iron bearing minerals suggests that a high oxygen fugacity was present in the CUC at the onset of the slide. Evidence for elevated temperatures in the CUC is shown by broken twins in calcite which form as result of dynamic recrystallization. High pore fluid in the CUC is indicated by CUC dikes intruding the hanging wall and by accretionary grains (lapilli). Finally, the presence of unserpentinized and a few weakly serpentinized olivine clasts in the CUC brings the hot water weakening mechanism proposed by Ahranov and Anders (2006) into question
Journal of Volcanology and Geothermal Research, 2008
The Insizwa sill is an ~1 km-thick subhorizontal layered mafic intrusion and part of the Karoo La... more The Insizwa sill is an ~1 km-thick subhorizontal layered mafic intrusion and part of the Karoo Large Igneous Province in South Africa. This well-exposed intrusion consists of several superimposed petrologically and geochemically distinct units. Magnetic methods were used to study the intrusion in order to constrain the physical processes active in these types of bodies during crystallization. Rock magnetism studies indicate
Most of the large igneous provinces (LIPs) are hosted in sedimentary basins (e.g. the onshore Kar... more Most of the large igneous provinces (LIPs) are hosted in sedimentary basins (e.g. the onshore Karoo and Tunguska basins, and the offshore Vøring, Møre, and North Sea basins). A typical LIP plumbing system consists of sub-horizontal and vertical sheet-like magmatic intrusions (MI), respectively sills and dykes. Surface and subsurface mapping of these sedimentary basins show that the magma tends to
The Betic-Rif cordillera constitutes the western most part of the Alpine orogeny in the Mediterra... more The Betic-Rif cordillera constitutes the western most part of the Alpine orogeny in the Mediterranean area. Its formation and structural evolution are widely debated. An important piece of information is the origin and emplacement of the ultramafic bodies that outcrop in both sides of the cordillera. The bodies in the northern part, known as Ronda peridotites, have been studied from the structural point of view in order to elaborate geodynamical models. A study of the anisotropy of magnetic susceptibility (AMS) has been carried out with further correlation between the magnetic lineation and structural stretching lineation measured in the field. Additional rock magnetic measurements have allowed determining the carriers of the magnetic signal. Magnetite originated during the serpentinization process, has been identified as the main carrier of the magnetic susceptibility. The positive correlation between magnetic lineation and stretching lineation makes the method suitable for the eva...
The objectives for Expedition 352 were to drill through the entire volcanic sequence of the Bonin... more The objectives for Expedition 352 were to drill through the entire volcanic sequence of the Bonin fore arc to 1. Obtain a high-fidelity record of magmatic evolution during subduction initiation and early arc development, 2. Test the hypothesis that fore-arc basalt lies beneath boninite and understand chemical gradients within these units and across the transition, 3. Use drilling results to understand how mantle melting processes evolve during and after subduction initiation, and 4. Test the hypothesis that the fore-arc lithosphere created during subduction initiation is the birthplace of suprasubduction zone (SSZ) ophiolites. Expedition 352 successfully cored 1.22 km of igneous basement and 0.46 km of over-lying sediment, providing diverse, stratigraphically controlled suites of fore-arc basalts (FAB) and boninite related to seafloor spreading and earliest arc development. FAB were recovered at the two deeper water sites (U1440 and U1441) and boninites at the two sites (U1439 and U...
The Heart Mountain Detachment (HMD) in Wyoming constitutes one of the largest known rock slides (... more The Heart Mountain Detachment (HMD) in Wyoming constitutes one of the largest known rock slides (3400 km2) on Earth. This detachment took place along the stratigraphic boundary between the Bighorn Dolomite at the hanging-wall and the Snowy Range Formation at the footwall. The slide resulted in the formation of an up to 3 m-thick carbonate ultracataclasite (CUC) at the base of the slide. The origin of the CUC and the nature of the triggering mechanism responsible for the initiation of the catastrophic movement have long been controversial. The most widely accepted theory is a mid-Eocene eruption in the Absaroka volcanic province that triggered rupture and subsequent detachment of Paleozoic rocks. Rapid sliding was facilitated by basal fluidization generated by thermo-mechanical decomposition of carbonate rocks. Here I present a proof of concept study addressing the question of the consistent magnetic fabrics observed in the CUC, as well as new observations indicating the discovery of mineral grains of volcanic origin within the CUC. Additionally, some constraints are placed on the thermo-chemical conditions operating at the base of this catastrophic landslide. Overall, the CUC displays an average magnetic susceptibility one order of magnitude higher (1803 . -6 [SI]) than the overlying Bighorn Dolomite (148 . -6 [SI]) and underlying Snowy Range Fm (636 . -6 [SI]). Anisotropy of magnetic susceptibility (AMS) data, field observations and microstructural analysis suggest that ferromagnetic (s.l) minerals in the CUC originate from the Bighorn Dolomite, the Tertiary volcanics and synkinematic thermal decomposition of pyrite into pyrrhotite and magnetite. Thermomagnetic investigations revealed a Curie temperature of 525 °C which suggests that magnetite is the dominant magnetic carrier mineral in the CUC. Energy Dispersive Spectroscopy analyses confirm that this magnetite has a relatively low ulvöspinel content. Magnetic hysteresis properties point to an average pseudo-single domain magnetic grain size or, alternatively, a mixture of single domain and multi-domain grains. The origin of AMS is magnetostatic, elucidated by a high degree of consistency between AMS directions and 3–D SPO directions. The anisotropy of magnetic susceptibility (AMS) directional data displays two dominant fabric orientations suggesting possible strain partitioning in the CUC. The consistency of magnetic fabrics suggests that the CUC followed a dominantly transpressive regime. The deformation mechanism causing the consistent AMS is a homogeneous passive rotation of magnetite grains. Microstructural analysis of iron bearing minerals suggests that a high oxygen fugacity was present in the CUC at the onset of the slide. Evidence for elevated temperatures in the CUC is shown by broken twins in calcite which form as result of dynamic recrystallization. High pore fluid in the CUC is indicated by CUC dikes intruding the hanging wall and by accretionary grains (lapilli). Finally, the presence of unserpentinized and a few weakly serpentinized olivine clasts in the CUC brings the hot water weakening mechanism proposed by Ahranov and Anders (2006) into question
Journal of Volcanology and Geothermal Research, 2008
The Insizwa sill is an ~1 km-thick subhorizontal layered mafic intrusion and part of the Karoo La... more The Insizwa sill is an ~1 km-thick subhorizontal layered mafic intrusion and part of the Karoo Large Igneous Province in South Africa. This well-exposed intrusion consists of several superimposed petrologically and geochemically distinct units. Magnetic methods were used to study the intrusion in order to constrain the physical processes active in these types of bodies during crystallization. Rock magnetism studies indicate
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Papers by Eric C Ferre