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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 ...
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 ...
Geomagnetic paleointensity in historical pyroclastic density currents: Testing the effects of emplacement temperature and postemplacement alteration
(2015-10-26)
Thellier-type paleointensity experiments were conducted on welded ash matrix or pumice from the 1912 Novarupta (NV) and 1980 Mt. St. Helens (MSH) pyroclastic density currents (PDCs) with the intention of evaluating their ...
Paleointensity estimates from ignimbrites: An evaluation of the Bishop Tuff
(2010-03-16)
Ash flow tuffs, or ignimbrites, typically contain fine-grained magnetite, spanning the superparamagnetic to single-domain size range that should be suitable for estimating geomagnetic field intensity. However, ignimbrites ...
Source of tiny wiggles in Chron C5: A comparison of sedimentary relative intensity and marine magnetic anomalies
(2003-06-14)
In addition to the well-established pattern of polarity reversals, short-wavelength fluctuations are often present in both sea-surface data ("tiny wiggles") and near-bottom anomaly data. While a high degree of correlation ...
Effects of open and closed system oxidation on texture and magnetic response of remelted basaltic glass
(2010-10-13)
As part of an experimental and observational study of the magnetic response of submarine basaltic glass (SBG), we have examined, using ion backscattering spectrometry (RBS), transmission and scanning electron microscopy, ...
Paleointensity Estimates From Ignimbrites: The Bishop Tuff Revisited
(2018-09-18)
Volcanic ash flow tuffs (ignimbrites) may contain single domain‐sized (titano) magnetite that should be good for recording geomagnetic field intensity, but due to their complex thermal histories also contain other magnetic ...
Cooling rate effects on paleointensity estimates in submarine basaltic glass and implications for dating young flows
(2005-07-12)
Cooling rate effects on the intensity of thermoremanent magnetization (TRM) have been well documented in ceramics. In that case, laboratory cooling is generally more rapid than the initial cooling, leading to an overestimate ...