DOI: 10.5061/dryad.2fqz612xf
title: Anisotropy of magnetic susceptibility (AMS) and rock magnetic data for Pachmarhi dyke swarm of Deccan

description: The Pachmarhi dyke swarms, situated in the Eastern part of the
 Narmada-Satpura-Tapi (N-S-T) dykes of the Deccan Continental Flood Basalt
 (DCFB), are studied using the Anisotropy of Magnetic Susceptibility (AMS)
 technique. Here, we determine the direction and sense of magma flow within
 the dykes to gain insights into the depth, number, and location of magma
 chambers, as well as the geodynamics of their plumbing system. Petrography
 and rock magnetism analyses revealed high-titanium magnetite particles,
 predominantly of Pseudo-Single Domain (PSD) nature, with a smaller
 proportion of Multi-Domain (MD) grains. We identified four distinct
 magnetic fabric types (I-IV) within the Pachmarhi dykes. The imbrication
 of magnetic foliation (for oblate fabric) and magnetic lineation (for
 prolate fabric) has been employed to discern the direction of magma flow
 which revealed multiple trends of magma flow, ranging from
 vertical/sub-vertical to inclined, with one particular dyke exhibiting
 lateral flow. The intersection of imbrication within the dyke margins
 provided valuable information about the presence of multiple shallow
 sub-crustal magma chambers which are supported by independent geophysical
 evidence and are similar to those of the Nandurbar-Dhule dyke swarms in
 the western region of the N-S-T dykes. Consequently, it can be inferred
 that the emplacement of dykes in the Pachmarhi region of the NSL, which
 were possible feeders to the late-stage Deccan volcanism, was primarily
 facilitated by a "polycentric flow" mechanism, wherein magma was
 injected vertically through shallow crustal fissures, potentially feeding
 into the late-stage Deccan flow units like Ambenali or Mahabaleshwar
 formation.
description: The Anisotropy of Magnetic Susceptibility (AMS) data were
 acquired from AGICO-made MFK2-FA Kappabridge instrument and data was
 analysed from Anisoft software (version 5.1.08.) by AGICO, Inc, Brno,
 Czech Republic (https://agico.cz/text/software/anisoft/anisoft.php ). The AMS data contains orientation of principal susceptibility axes (k1,k2,k3) along with shape parameter (T) and degree of anisotropy (p') etc. The research is motivated to decipher the magma flow pattern in these dykes, whether they were directly related to Reunion hotspot or fed by the fissures. The Rock Magnetic data were acquired from SQUID-VSM at IISER Bhopal and analysed from RockMag Analyzer 1.1 software by Leonhardt, 2006 (http://earthref.org/tools/rockmaganalyzer/ ).
description: # Anisotropy of magnetic susceptibility (AMS) and rock magnetic data for
 Pachmarhi dyke swarm of Deccan
 [https://doi.org/10.5061/dryad.2fqz612xf](https://doi.org/10.5061/dryad.2fqz612xf) ## Description of the data and file structure Anisotropy of Magnetic Susceptibility (AMS) data and Rock magnetic data (i.e. including coercivity and remanence) of the Pachmarhi dyke samples of the Deccan Trap: * The table with AMS data of Pachmarhi dykes has the following parameters: Km = Mean Susceptibility, T= Shape Parameter, P'= Degree of Anisotropy, D= Declination, I= Inclination, JCE = Jelinek Confidence ellipse parameters. * The rock magnetic data has magnetic remanence and coercivity values for the dyke samples. The hysteresis magnetic parameters includes saturation remanence magnetization (Mrs), saturation magnetization (Ms), coercivity remanence (Hcr), and coercive force (Hc). ## Sharing/Access information Data was derived from the following sources: * The AMS of core samples of dyke have been subjected to the instrument named MFK2-FA Multifunction Kappabridge * Data acquisition software `Safyr `controls all particular functions of the Kappabridges, calculate results of individual measurements as well as advanced statistics on measured data. Standard visualisation of the results is also incorporated (Source: Agico). * Anisoft is the advanced software for treatment of Magnetic Anisotropy data. This software supports data files from all AGICO Kappabridges and is helpful in making the Stereoplots of the Magnetic Susceptibilities data. ## Software We used open-source software Anisoft (version 5.1.08.) by AGICO, Inc, Brno, Czech Republic ([https://agico.cz/text/software/anisoft/anisoft.php](https://agico.cz/text/software/anisoft/anisoft.php) ) for AMS data analysis and visualization. To determine the rock magnetic properties, we used RockMag Analyzer 1.1 software by Leonhardt, 2006 ([http://earthref.org/tools/rockmaganalyzer/](http://earthref.org/tools/rockmaganalyzer/) ). **RockMag Analyzer 1.1** is a software tool crafted for the precise determination of rock magnetic characteristics derived from a diverse range of rock magnetic tests. Its primary purpose is to interpret and assess data gathered from isothermal remnant magnetization acquisition, coercivity curves, hysteresis loops, and/or thermomagnetic curves. By processing these curves, the software swiftly computes a wide array of both standard and non-standard rock magnetic parameters. This streamlines and expedites the quantitative analysis of the collected data. (Source: earthref.org).