Christopher J. Rowan

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[1] First-order reversal curve (FORC) diagrams have become a standard tool in rock magnetism, yet magnetite is the only magnetic mineral that is well characterized using FORC diagrams. We present FORC diagrams for predominantly single-domain (SD) synthetic aluminous hematite (a-Fe2-xAlxO3) and goethite (a-(FeAl)OOH) and natural greigite (Fe3S4) and(More)
Detailed rock magnetic and electron microscope analyses indicate that the magnetic signature of Neogene marine sediments from the east coast of New Zealand is dominated by the authigenic iron sulphide greigite. The greigite is present as a mixed population of stable single domain and superparamagnetic grains, which is consistent with authigenic growth from(More)
[1] We report the magnetic properties of pure synthetic pseudo-single-domain (PSD) and multi-domain (MD) greigite and the grain size dependence of the magnetic properties of greigite for the first time. The dominantly PSD-like and MD-like behavior are demonstrated by hysteresis, first-order reversal curve diagrams, lowtemperature cycling (LTC) of room(More)
[1] We provide comprehensive low-temperature magnetic results for greigite (Fe3S4) across the spectrum from superparamagnetic (SP) to multidomain (MD) behavior. It is well known that greigite has no lowtemperature magnetic transitions, but we also document that it has strong domain-state dependence of magnetic properties at low temperatures. Blocking of SP(More)
Detailed scanning electron microscope observations, coupled with elemental microanalysis, confirm the presence of a chemical remanent magnetization carried by authigenic greigite (Fe3S4) in uplifted Neogene marine sediments from the Hikurangi Margin of New Zealand. Normal polarity samples from the studied section have declinations that are deflected ;608(More)
[1] Large, clockwise, vertical axis tectonic rotations of the Hikurangi margin, East Coast, New Zealand, have been inferred over both geological and contemporary timescales, from paleomagnetic and geodetic data, respectively. Previous interpretations of paleomagnetic data have laterally divided the margin into independently rotating domains; this is not a(More)
1National Oceanography Centre, University of Southampton, European Way, Southampton, SO14 3ZH, UK 2Istituto Nazionale di Geofisica e Vulcanologia, Via di Vigna Murata 605, 00143, Rome, Italy 3Department of Geosciences, 214 Bessey Hall, University of Nebraska, P.O. Box 880340, Lincoln, NE 68588-0340, USA 4Department of Geology and Environmental Geosciences,(More)
Earth's tectonic plates are generally considered to be driven largely by negative buoyancy associated with subduction of oceanic lithosphere. In this context, mid-ocean ridges (MORs) are passive plate boundaries whose divergence accommodates flow driven by subduction of oceanic slabs at trenches. We show that over the past 80 million years (My), the East(More)
The renal stroma is defined as a heterogeneous population of cells that serve both as a supportive framework and as a source of specialized cells in the renal capsule, glomerulus, vasculature, and interstitium. In this chapter, we review published evidence defining what, where, and why stromal cells are important. We describe the functions of the renal(More)
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