Open AccessAutomated paleomagnetic and rock magnetic data acquisition with an in‐line horizontal “2 G ” system
Author(s) -
Mullender Tom A. T.,
Frederichs Thomas,
Hilgenfeldt Christian,
de Groot Lennart V.,
Fabian Karl,
Dekkers Mark J.
Publication year - 2016
Publication title -
geochemistry, geophysics, geosystems
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.928
H-Index - 136
ISSN - 1525-2027
DOI - 10.1002/2016gc006436
Subject(s) - magnetometer , paleomagnetism , demagnetizing field , geology , remanence , electromagnetic coil , rock magnetism , geophysics , search coil , magnetic field , magnetization , geodesy , seismology , nuclear magnetic resonance , electrical engineering , physics , magnetic flux , engineering , quantum mechanics
Today's paleomagnetic and magnetic proxy studies involve processing of large sample collections while simultaneously demanding high quality data and high reproducibility. Here we describe a fully automated interface based on a commercial horizontal pass‐through “2G” DC‐SQUID magnetometer. This system is operational at the universities of Bremen (Germany) and Utrecht (Netherlands) since 1998 and 2006, respectively, while a system is currently being built at NGU Trondheim (Norway). The magnetometers are equipped with “in‐line” alternating field (AF) demagnetization, a direct‐current bias field coil along the coaxial AF demagnetization coil for the acquisition of anhysteretic remanent magnetization (ARM) and a long pulse‐field coil for the acquisition of isothermal remanent magnetization (IRM). Samples are contained in dedicated low magnetization perspex holders that are manipulated by a pneumatic pick‐and‐place‐unit. Upon desire samples can be measured in several positions considerably enhancing data quality in particular for magnetically weak samples. In the Bremen system, the peak of the IRM pulse fields is actively measured which reduces the discrepancy between the set field and the field that is actually applied. Techniques for quantifying and removing gyroremanent overprints and for measuring the viscosity of IRM further extend the range of applications of the system. Typically c. 300 paleomagnetic samples can be AF demagnetized per week (15 levels) in the three‐position protocol. The versatility of the system is illustrated by several examples of paleomagnetic and rock magnetic data processing.