Rock Magnetics
Our Rock Magnetics Service provides chronostratigraphic correlations using palaeomagnetism, magnetic mineralogy (including provenance) and magnetic susceptibility data that can be used for correlation or for rock fabric analysis.
Palaeomagnetism
Palaeomagnetism periods of reversed and normal polarity in sediments to define chronostratigraphic correlations. The big advantage of palaeomagnetism is that it provides irrefutable chronostratigraphic correlations that can then be linked to the Global Magnetic Polarity Time Scale (GMPTS), thereby allowing absolute ages to be assigned to surfaces. The disadvantage is that it requires conventional core (although there is NO need for either oriented core or for specialised non magnetic core plugging devises). It can be done on rocks of any age from almost any depositional environment.
Magnetic Mineralogy
Magnetic mineralogy is a method to determine the composition of the grains that are contributing to the magnetic signatures. It provides important information on the redox state of Fe-,minerals, something lacking from our elemental services. As such, it can provide important information on reducing versus oxidising depositional conditions.
Magnetic Mineral Inclusion Provenance Analysis (MMIPA) is a provenance tool that potentially provides highly sensitive indications of provenance. Chemostrat in association with Mark Hounslow at Lancaster University are currently continued research in developing this service.
Magnetic Susceptibility
Magnetic susceptibility measures how susceptible a sediment is to accepting a magnetic field. It falls into two categories, isotropic magnetic susceptibility (normally referred to as MS) and anisotropic magnetic susceptibility (AMS).
MS is a cost effective and rapid tool that can be carried out in a lab or as part of our portable analytical solutions (LINK) services. It provides stratigraphic correlations that reflect changes terrigenous content and redox conditions and commonly allows determination of Transgressive – regressive cycles.
By measuring AMS information on palaeocurrent direction in fluvial sediments and turbidites can be acquired. It can also be used to determine flow direction in mudrock, a service the Chemostrat and Mark Hounslow are currently working on as an additional tool for shale resource studies.
