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Timing of magnetite formation in basaltic glass: Insights from synthetic analogs and relevance for geomagnetic paleointensity analyses
(2011-02-09)
Absolute paleointensity estimates from submarine basaltic glass (SBG) typically are of high technical quality and accurately reflect the ambient field when known. SBG contains fine-grained, low-Ti magnetite, in contrast ...
Geology of the Alarcon Rise, Southern Gulf of California
(2018-03-15)
Abstract Meter-scale AUV bathymetric mapping and ROV sampling of the entire 47 km-long Alarcon Rise between the Pescadero and Tamayo transforms show that the shallowest inflated portion of the segment hosts all four active ...
Curie temperatures of titanomagnetite in ignimbrites: Effects of emplacement temperatures, cooling rates, exsolution, and cation ordering
(2014-11-06)
Pumices, ashes, and tuffs from Mt. St. Helens and from Novarupta contain two principal forms of titanomagnetite: homogeneous grains with Curie temperatures in the range 350–500°C and oxyexsolved grains with similar bulk ...
Absolute Paleointensity Study of Miocene Tiva Canyon Tuff, Yucca Mountain, Nevada: Role of Fine‐Particle Grain‐Size Variations
(2019-12-04)
Fine‐grained, Ti‐poor titanomagnetite in the ~12.7 Ma Tiva Canyon (TC) Tuff systematically increases in grain size from superparamagnetic (SP) at the flow base to single domain (SD) at a few meters height. This allows us ...
Behavior of oceanic crustal magnetization at high temperatures: Viscous magnetization and the marine magnetic anomaly source layer
(1999-08-01)
Although the source layer for marine magnetic anomalies has been assumed to be the extrusive basalts of uppermost ocean crust, recent studies indicate that lower crustal rocks may also contribute. Because the temperature ...
Multicomponent cubic oxide exsolution in synthetic basalts: Temperature dependence and implications for magnetic properties
(2012-01-01)
Although the compositional unmixing of cubic-structured iron oxides has profound effects on the magnetic properties of rocks that contain them, a basic understanding of the kinetics and thermodynamics of this process has ...
Full vector low-temperature magnetic measurements of geologic materials
(2015-01-14)
The magnetic properties of geologic materials offer insights into an enormous range of important geophysical phenomena ranging from inner core dynamics to paleoclimate. Often it is the low-temperature behavior (
Magnetic and petrologic characterization of synthetic Martian basalts and implications for the surface magnetization of Mars
(2009-01-01)
A suite of synthetic Martian basalts is generated with the objective of providing fundamental material properties data for use in modeling and interpretation of mission data. We systematically evaluate the effects of major ...
Paleointensity applications to timing and extent of eruptive activity, 9°–10°N East Pacific Rise
(2006-06-08)
Placing accurate age constraints on near-axis lava flows has become increasingly important given the structural and volcanic complexity of the neovolcanic zone at fast spreading ridges. Geomagnetic paleointensity of submarine ...
Eruptive timing and 200 year episodicity at 92°W on the hot spot-influenced Galapagos Spreading Center derived from geomagnetic paleointensity
(2014-01-01)
Eruptive timing in mid-ocean ridge systems is relatively poorly constrained, despite being an important variable in our understanding of many mid-ocean ridge processes, including volcanic construction; magma recharge, flux, ...