Natural remanent magnetization studies of a layered Breccia Boulder from the lunar highland region

The Moon ◽  
1975 ◽  
Vol 14 (3-4) ◽  
pp. 473-481 ◽  
Author(s):  
S. K. Banerjee ◽  
G. Swits
Keyword(s):  
Remanent Magnetization ◽  
Natural Remanent Magnetization ◽  
Highland Region

Contributions of Cretaceous Quiet Zone natural remanent magnetization to Magsat anomalies in the Southwest Indian Ocean

1994 ◽  
Vol 99 (B6) ◽  
pp. 11923-11936 ◽  
Author(s):  
Lawrence G. Fullerton ◽  
Herbert V. Frey ◽  
James H. Roark ◽  
Herman H. Thomas
Keyword(s):  
Indian Ocean ◽  
Remanent Magnetization ◽  
Natural Remanent Magnetization ◽  
Southwest Indian Ocean

scholarly journals Acquisition of Natural Remanent Magnetization for Dirt-Snow Containing Rock Dust.

1991 ◽  
Vol 43 (10) ◽  
pp. 803-811 ◽  
Author(s):  
Minoru FUNAKI ◽  
Hideo SAKAI
Keyword(s):  
Remanent Magnetization ◽  
Natural Remanent Magnetization ◽  
Rock Dust

scholarly journals Paleomagnetic secular variation for a 21,000-year sediment sequence from Cascade Lake, north-central Brooks Range, Arctic Alaska

2021 ◽  
Author(s):  
Douglas P. Steen ◽  
Joseph S. Stoner ◽  
Jason P. Briner ◽  
Darrell S. Kaufman
Keyword(s):  
Secular Variation ◽  
Remanent Magnetization ◽  
Sediment Cores ◽  
Natural Remanent Magnetization ◽  
Companion Paper ◽  
Angular Deviation ◽  
Arctic Alaska ◽  
Geomagnetic Field Models ◽  
Paleomagnetic Secular Variation ◽  
Radiometric Ages

Abstract. Two > 5-m-long sediment cores from Cascade Lake (68.38° N, 154.60° W), Arctic Alaska, were analyzed to quantify their paleomagnetic properties over the past 21,000 years. Alternating-field demagnetization of the natural remanent magnetization, anhysteretic remanent magnetization, isothermal remanent magnetization, and hysteresis experiments reveal a strong, well-defined characteristic remanent magnetization carried by a low coercivity magnetic component that increases up core. Maximum angular deviation values average < 2°, and average inclination values are within 4° of the geocentric axial dipole prediction. Radiometric ages based on 210Pb and 14C were used to correlate the major inclination features of the resulting paleomagnetic secular variation (PSV) record with those of other regional PSV records, including two geomagnetic field models and the longer series from Burial Lake, located 200 km to the west. Following around 6 ka (cal BP), the ages of PSV fluctuations in Cascade Lake begin to diverge from those of the regional records, reaching a maximum offset of about 2000 years at around 4 ka. Several correlated cryptotephra ages from this section (reported in a companion paper by Davies et al., this volume) support the regional PSV-based chronology and indicate that some of the 14C ages at Cascade Lake are variably too old.

Multi-proxy study of the Cretaceous-Paleogene (K-Pg) boundary in deep-sea turbiditic sediments in the Uzgruň section (Outer Flysch Carpathians, Czech Republic)

2021 ◽  
Author(s):  
Šimon Kdýr ◽  
Tiiu Elbra ◽  
Miroslav Bubík ◽  
Petr Schnabl ◽  
Lilian Švábenická
Keyword(s):  
Magnetic Susceptibility ◽  
Czech Republic ◽  
Detection Limit ◽  
Remanent Magnetization ◽  
Magnetic Particles ◽  
Principal Component ◽  
Natural Remanent Magnetization ◽  
Ongoing Research ◽  
Small Stream ◽  
Magnetic Methods

&lt;p&gt;The composite profile, with 4 studied sections, is located near the Uzgru&amp;#328; village (Czech Republic) next to a small stream. The profile is composed of Late Maastrichtian to Palaeocene flysch sediments and the K-Pg boundary is set in claystones within this turbiditic setting. Ongoing research of local paleoenvironment and stratigraphy is based on paleo- and rock-magnetic methods, micropaleontology and geochemistry to obtain more detailed view of the local situation during the K-Pg extinction event. Based on biostratigraphy, two dinocyst zones (Bub&amp;#237;k et al., 2002): Palynodium grallator and Carpatella cornuta (first occurrence in the Danian), two calcareous nannofossil zones in the Upper Maastrichtian, and the agglutinated foraminifer zone Rzehakina fissistomata in the Paleogene were distinguished. Biostratigraphic data support the K-Pg boundary interval. The uppermost Maastrichtian is indicated by nannofossil species Micula prinsii, UC26d&lt;sup&gt;TP&lt;/sup&gt; zone. Basal Paleogene non-calcareous strata contain dinocyst Carpatella cornuta and agglutinated foraminifers of Rzehakina fissistomata zone. The presence of low-latitude nannofossil taxa M. prinsii and Ceratolithoides kamptneri show input of warm waters during the uppermost Maastrichtian. Several rock-magnetic methods, such as acquisition of Isothermal remanent magnetization (IRM), acquisition of Anhysteretic remanent magnetization (ARM), Anisotropy of magnetic susceptibility (AMS), Field dependence of magnetic susceptibility (HD) and Frequency dependence of magnetic susceptibility (FD), were applied to estimate behaviour and origin of magnetic particles. Natural remanent magnetization (NRM) values of samples range from 0.09 to 2.48 mA/m. Volume normalized magnetic susceptibility (MS) show values from 130 up to 1197 SI*10-6. There is no increase observed in MS across stratigraphic boundary due to turbiditic evolution of sediment. Due to character of sediments, we applied alternating field (AF) demagnetization and used principal component analysis (PCA; Kirschvink, 1980) for estimation of characteristic remanent component. Most of the K/Pg sections worldwide have well documented Iridium anomaly. In Uzgru&amp;#328;, the preliminary results show that although the values are not as pronounced, the Ir at K-Pg boundary is still higher than in surrounding sediments. For tracing of Deccan traps effect we plan to apply mercury (Hg)/total organic carbon (TOC) stratigraphy. TOC content of 20 pilot samples is low, but not under detection limit of the instrumentation (mean value 0.92 wt%). One sample reached value 4.41 wt% of TOC. Sulphur contents are reaching 1 wt%, but several samples were under detection limit of the instrumentation. Sulphur concentrations suggest more reduction conditions of burial.&lt;/p&gt;&lt;p&gt;Current research is supported by Czech Science Foundation project no. 19-07516S and is in accordance with research plan no. RVO67985831.&lt;/p&gt;&lt;p&gt;Bub&amp;#237;k, M., Adamov&amp;#225;, M., B&amp;#261;k, M., Franc&amp;#367;, J., Gedl, P., Mikul&amp;#225;&amp;#353;, R., &amp;#352;v&amp;#225;benick&amp;#225;, L., &amp; Uchman, A. (2002). V&amp;#253;sledky v&amp;#253;zkumu hranice k&amp;#345;&amp;#237;da/terci&amp;#233;r v magursk&amp;#233;m fly&amp;#353;i u Uzgrun&amp;#283;. Geologick&amp;#233; v&amp;#253;zkumy na Morav&amp;#283; a ve Slezsku, 9, 18&amp;#8211;22&lt;/p&gt;&lt;p&gt;L. Kirschvink (1980), The least-squares line and plane and the analysis of palaeomagnetic data,&amp;#160;Geophysical Journal International, 62(3), 699&amp;#8211;718,&amp;#160;https://doi.org/10.1111/j.1365-246X.1980.tb02601.x&lt;/p&gt;

scholarly journals Post-Depositional Fluid Flow in Jurassic Sandstones of the Uncompahgre Uplift: Insights From Magnetic Fabrics

2020 ◽  
Vol 8 ◽  
Author(s):  
John I. Ejembi ◽  
Eric C. Ferré ◽  
Sara Satolli ◽  
Sarah A. Friedman
Keyword(s):  
Fluid Flow ◽  
Remanent Magnetization ◽  
Magnetic Hysteresis ◽  
Natural Remanent Magnetization ◽  
Upper Jurassic ◽  
Hydrocarbon Exploration ◽  
Reservoir Rock ◽  
Magnetic Fabrics ◽  
Deformation Processes ◽  
Carbonate Formations

The anisotropy of magnetic susceptibility (AMS) in sedimentary rocks results from depositional, diagenetic, syn- and post-sedimentary processes that affect magnetic grains. Some studies have also shown the potential role played by post-depositional fluid flow in detrital and carbonate formations. Here we present a new case study of Middle-Upper Jurassic sandstones where secondary iron oxides, precipitated from fluids that migrated through pores, give rise to the AMS. These sandstones are well exposed in the Uncompahgre Uplift region of the Central Colorado Trough, Colorado. The magnetic foliation of these undeformed, subhorizontal strata consistently strike NE-SW over a large distance with an average 45° dip to the SE. This steep AMS fabric is oblique with respect to the regional subhorizontal bedding and therefore does not reflect the primary sedimentary fabric. Also, outcrop-scale and microscopic observations show a lack of post-depositional plastic (undulose extinction) or pressure-solution (stylolites) deformation microstructures in these sandstones, hence precluding a tectonic origin. The combination of magnetic hysteresis, isothermal remanent magnetization, and thermal demagnetization of the natural remanent magnetization indicate that these rocks carry a chemical remanent magnetization born primarily by hematite and goethite. High-field magnetic hysteresis and electron microscopy indicate that detrital magnetite and authigenic hematite are the main contributors to the AMS. These results show that post-depositional iron remobilization through these porous sandstones took place due to the action of percolating fluids which may have started as early as Late Cretaceous along with the Uncompahgre Uplift. The AMS fabric of porous sandstones does not systematically represent depositional or deformation processes, and caution is urged in the interpretation of magnetic fabrics in these types of reservoir rock. Conversely, understanding these fabrics may advance our knowledge of fluid flow in porous sandstones and may have applications in hydrocarbon exploration.

scholarly journals A survey of the natural remanent magnetization and magnetic susceptibility of Apollo whole rocks

2019 ◽  
Vol 290 ◽  
pp. 36-43 ◽  
Author(s):  
Camille Lepaulard ◽  
Jérôme Gattacceca ◽  
Minoru Uehara ◽  
Pierre Rochette ◽  
Yoann Quesnel ◽  
...  
Keyword(s):  
Magnetic Susceptibility ◽  
Remanent Magnetization ◽  
Natural Remanent Magnetization

Evidence of Single-Domain Magnetite in the Michikamau Anorthosite

1971 ◽  
Vol 8 (3) ◽  
pp. 361-370 ◽  
Author(s):  
G. S. Murthy ◽  
M. E. Evans ◽  
D. I. Gough
Keyword(s):  
Remanent Magnetization ◽  
Theoretical Models ◽  
Natural Remanent Magnetization ◽  
Single Domain ◽  
Isothermal Remanent Magnetization ◽  
Mineral Separation ◽  
Domain Configuration ◽  
Plagioclase Felspar ◽  
Magnetite Particles ◽  
Theoretical Evidence

The Michikamau anorthosite possesses very stable natural remanent magnetization, some of which resists alternating fields up to 1800 Oe. The rock contains two types of opaque grains, fine opaque needles of order 10 × 0.5 μ in the plagioclase felspar, and large equidimensional magnetite particles. Ore microscope studies suggest, but do not establish, that the needles are composed of magnetite. Saturation isothermal remanence and thermal demagnetization studies indicate magnetite as the carrier of remanent magnetization. In order to distinguish the effects of the large grains from those of the needles, mineral separation was used to show that an artificial specimen of essentially pure plagioclase had very similar isothermal remanent magnetization properties to the whole rock. Both indicated magnetite as the magnetic mineral. Thermoremanent properties of the separated mineral fractions indicated magnetite as the dominant magnetic constituent but showed some evidence of laboratory-produced hematite. Theoretical models of grains elongated along [111] and [110] axes are used to show that magnetite needles can exist in stable single-domain configuration in the size and shape ranges of the needles observed in the Michikamau anorthosite. There is thus considerable experimental and theoretical evidence for the conclusion that the stable remanent magnetization of the Michikamau anorthosite is carried by fine single–domain needles of magnetite in the plagioclase felspar.

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