The conventional rules, derived from empirical and theoretical considerations, for the interpretation of anisotropy magnetic susceptibility (AMS) in terms microstructure deformation are subject to numerous exceptions as a result particular rock effects. Unusual relationships between structural axes (so‐called inverse or intermediate fabrics) can occur because presence certain minerals, either single domain magnetite various paramagnetic minerals. When more than one mineral is responsible...

Temperature dependence of magnetic susceptibility (χ−T) has been widely used to determine changes in mineralogy natural samples during heat treatment. We carried out integrated rock experiments interpret the χ−T curves Chinese loess/palaeosols argon. both raw materials and heated samples. In addition, we also investigated properties extracts residues quantify contributions from each fraction bulk properties. For heating curves, loss (∼30 per cent) between ∼300–400 °C is caused by inversion...

Abstract For 40 years magnetic anisotropy has provided successful geological interpretations of ellipsoid orientations; in contrast the interpretation magnitudes is far more convoluted. This due to complexities at various levels within rocks, including different physical responses minerals, grain-scale anisotropy, interacting ensembles, mineralogical constitution rocks and processes mechanisms that align minerals nature. The chief factors determining fabrics tectonized include:...

A new method for determining magnetic anisotropy using anhysteric remanence susceptibility is described. The fabric of a collection Trenton Limestone specimens has been determined this method, as well by conventional susceptibility. results demonstrate the usefulness finding rock units such in which bulk susceptibilities are low. model proposed to explain observed foliated and lineated consequence overburden compaction regional horizontal stresses. original inferred have isotropic; resides...

Hysteresis measurements, Lowrie‐Fuller tests, Cisowski and low‐temperature demagnetization experiments on samples of the Knox Dolomite, Trenton Limestone, Onondaga Limestone indicate that remanence in these remagnetized carbonate units resides principally single‐domain magnetite, contrast to previous interpretations. Volumetrically, however, a significant fraction magnetite is coarser grained, as scanning electron microscopic work magnetic extracts has shown. These conclusions are based...

The distribution of remanence coercivities in a rock sample can be obtained by differentiating alternating field (AF) demagnetization curves anhysteretic remanent magnetization (ARM); however, significant errors introduced grain interactions and the noise inherent differentiation. We have found that 1) this error significantly reduced measuring partial ARM's (pARM's) 2) pARM patterns show strong empirical correlation with grain‐size. pARM's are imparted exposing to small direct magnetic...

Abstract Magnetic hysteresis loops are important in theoretical and applied rock magnetism with applications to paleointensities, paleoenvironmental analysis, tectonic studies, among many others. Information derived from these data is the most ubiquitous magnetic used by Earth science community. Despite their prevalence, there no general guidelines aid scientists obtaining best possible widely available software allow efficient analysis of loop using advanced appropriate methods. Here we...

Chinese loess/paleosol sequences have been regarded as excellent continental archives for encoding continuous paleoclimatic variations over the past 2.5 Myr. However, mechanism magnetic enhancements (especially low‐field mass‐specific susceptibility, χ) of paleosols is still not completely resolved. This study quantifies contributions aeolian and pedogenic particles to bulk properties loess/paleosols by using a extraction technique. Magnetic separates (extractable) corresponding residues...

We suggest that inclination errors in detrital remanent magnetization (DRM) may be recognized and corrected by measurement of the anisotropy anhysteretic (ARM). ARM reflects directional variations remanence capacity relatively fine-grained magnetic particles rocks or sediments, generally same carry stable component DRM. Relative vertical horizontal DRM magnitudes are controlled this capacity, as well alignment efficiency particle moments, which turn is governed relative intensities...

Surface recombination is an important characteristic of optoelectronic material. Although surface a limiting factor for very small devices it has not been studied intensively. We have investigated velocity on the exposed surfaces AlGaN, InGaAs, and InGaAlP material systems by using absolute photoluminescence quantum efficiency measurements. Two these three low enough to be usable in nanoscale photonic crystal light-emitting diodes.

Yucca Mountain Tuff contains small titanomagnetite grains with narrow size distributions in the superparamagnetic range [ Schlinger et al. , 1988]. Magnetic measurements on three samples (comprising hysteresis loops at low and ambient temperatures, acquisition demagnetization of isothermal remanent magnetization, thermal saturation remanence a low‐temperature thermoremanence, frequency‐ temperature‐dependent susceptibilities) allow evaluation magnetic properties terms Néel's [1949]...

New stratigraphic, geochemical and palaeomagnetic data from the Peters Creek Volcanics are used to revise correlations of part Palaeoproterozoic northern Australia. The revised geological history for these cover rocks Murphy Inlier is extrapolated into 1800–1700 Ma successions McArthur Basin Mt Isa regions. stratigraphic subdivisions relationships contrasted with established lithostratigraphic schemes also conflicting published tectono‐stratigraphic interpretations. For first time, a...

Magnetic hysteresis data are centrally important in pure and applied rock magnetism, but to date, no objective quantitative methods have been developed for assessment of quality the uncertainty parameters calculated from imperfect data. We propose several initial steps toward such assessment, using loop symmetry as an key. With a few notable exceptions (e.g., related field cooling exchange bias), magnetic loops possess high degree inversion ( M H ) = − (− )). This property enables us treat...

Abstract Authigenic formation of fine-grained magnetite is responsible for widespread chemical remagnetization many carbonate rocks. grains, dominantly in the superparamagnetic and stable single-domain size range, also give rise to distinctive rock-magnetic properties, now commonly used as a ‘fingerprint’ remagnetization. We re-examine basis this association terms magnetic mineralogy particle-size distribution remagnetized carbonates having these characteristic including ‘wasp-waisted’...

Abstract Field experiments were performed in artificial ponds to evaluate how the density of predatory diving beetles (Dytiscidae) would affect population levels mosquito larvae (Culicidae). Mosquitoes colonizing predominantly species genus Culex . In 2000, most dytiscids small ( Hydroporus spp.), and these predators had no impact on size larval populations, not even with added dytiscids. 2001, larger Ilybius, Rhantus , Agabus spp.) more common, there significantly fewer highest numbers...