Papers by Saurodeep Chatterjee
Arabian Journal of Geosciences
Journal of Asian Earth Sciences
Physics of the Earth and Planetary Interiors
Journal of Earth System Science
Journal of the Geological Society of India, 2021
Petrography and rock magnetic properties of the Dalma volcanics (DV) and associated meta-sediment... more Petrography and rock magnetic properties of the Dalma volcanics (DV) and associated meta-sediments of Singhbhum mobile belt (SMB) are presented to describe magnetic grain size and Fe-Ti oxide mineralogy of the volcano-sedimentary sequence. Petrography revealed the presence of Ti-magnetite, hematite, ilmenite and pyrite in quartz-biotite-sericite-muscovite schists, quartzites, and volcanic rocks. The average value of magnetic susceptibility (χ) is 5.6 × 10−7 m3/kg, anhysteretic remanent magnetization (ARM) is 2.25 × 10−5 Am2/kg, saturating isothermal remanent magnetization (SIRM) is 403.33 × 10−5 Am2/kg, soft IRM is 240.2 × 10−5 Am2/kg, hard IRM is 77.56 × 10−5 Am2/kg, and natural remanent magnetization (NRM) is 54.1 mA/m. The central tendency of the inter-parametric ratio ARM/χ is 0.06 kAm−1, SIRM/χ is 111.04 kAm−1 and S-ratio is 0.8. Based on results, magnetic mineralogy indicated that the bulk magnetic carrier is stable single domain (SSD) or pseudo single domain (PSD) grains of Fe-Ti oxides with minor iron sulphides such as pyrite, greigite and pyrrhotite. Petrography and rock magnetic studies suggest that the magnetic carriers are chiefly secondary in origin and the NRM is modified over time.
Physics of the Earth and Planetary Interiors, 2022
Current Science, 2017
Anisotropy of magnetic susceptibility (AMS) data for a single basaltic lava flow, herein named th... more Anisotropy of magnetic susceptibility (AMS) data for a single basaltic lava flow, herein named the Gowripatnam lava flow from the Rajahmundry Traps, are evaluated for determining precisely the mechanism of lava flow. At Rajahmundry, lava flows are found on both banks of the Godavari River and sandwich intertrappean sedimentary layers in between. The ones on the west bank of the river are studied here. This study has an implication as the mechanism of lava flow or nature of lava flow patterns of Rajamundry Trap basalt is still a debatable issue. AMS directions is a powerful tool for investigating the source and direction of lava. Its application to single lava flow from Rajahmundry indicates maximum direction of susceptibility axes in almost all possible directions, indicating radial flowage from radial vent source(s). Two AMS directions (towards northwest -14%, and north-7%), however, have the maximum number of petals. This indicates that at least there were palaeoflowage patterns towards these directions. Incidentally the Godavari lineament strikes NW-SE and the flow dip is due south. However, the two dominant magnetic lineation directions are due north. Hence, the possibility of the earlier suggested river piracy model for lava flow can be ruled out. The fissure eruption near Rajahmundry is pointed out as the then prevailing lava flow mechanism. This is further supported by an overall random distribution of maximum susceptibility axes apart from two dominant flow directions.
JOURNAL OF SCIENTIFIC RESEARCH, 2022
The present study concentrates on the petrography, generation of Fe-Ti oxides and magnetic parame... more The present study concentrates on the petrography, generation of Fe-Ti oxides and magnetic parameters like magnetic susceptibility and Saturating Isothermal Remanence Magnetization (SIRM) to determine the carriers of magnetic remanence, their textural relations with the silicate minerals and to determine the feasibility of the varied rock types in recording magnetic remanence based on a comparative study of the magnetic susceptibility (serving as a proxy for the induced magnetization) and SIRM (as a representative of remanent magnetization). Studies revealed that although the magnetic susceptibility of the mafic granulites are lesser than the other rocks, they are the most feasible rocks in the terrain for recording remanence. Moreover, the Fe-Ti oxides observed in the reflected light study also bears good correlation with the magnetic parameters which is being explained here.
Earth Science India, 2016
The present study is an integrated approach consisting of field observations, petrography, rock m... more The present study is an integrated approach consisting of field observations, petrography, rock magnetism and Anisotropy of Magnetic Susceptibility (AMS) measurements which are used to determine the magneto-mineralogical characteristics and the nature of the magnetic fabrics of the high grade rocks from the Chilka Lake Area, Eastern Ghats Belts, India. Petrographic study reveals the textural relationship of the magnetic minerals with that of the silicates. The study of the thin-polished sections under reflected light microscope depicted the presence of magnetite, titano-magnetite and ilmenite as the dominant magnetic minerals. More than one generation of these minerals was found in these sections corresponding to different conditions of temperature that prevailed during their oxidation. The different generations of the magnetic minerals have significant tectonic results and points towards crustal upliftment. IRM and hysteresis curves were obtained which show the presence of both the ferromagnetic and paramagnetic minerals. Further, the determination of the Curie temperature confirmed the presence of magnetite and haematite. However, haematite was not observed in the petrographic/ore-petrographic studies. AMS studies unravelled the overall nature of the magnetic fabrics in the region. The susceptibility ellipsoids were dominantly oblate in the region as evident from the F-L and the P j-T j plots. The magnetic foliation plane has a highly variable strike varying from NE-SW to NW-SE with a moderate amount of dip. The magnetic lineation, i.e. the maximum susceptibility axes (K 1) showed clusters in the NE, SW and the NW quadrants having close accordance with that of the F 3 and F 4 fold axes pointing towards the structural controls of the magnetic fabrics.
Current Science, 2018
The present study aims to unravel the mineralogical, chemical and anisotropy of magnetic suscepti... more The present study aims to unravel the mineralogical, chemical and anisotropy of magnetic susceptibility (AMS) from gneissic rocks and associated pegmatitic bodies from Bankura-Purulia region, West Bengal (India). Petrographic studies were done to detect the textural relationship of minerals that contribute susceptibility with that of the silicates. The study of polished thin-sections under reflected light microscope showed the presence of titano-magnetite and magnetite as dominant magnetic minerals. More than one generation of magnetic minerals were found which are linked to different conditions of temperature and tectonics that prevailed during their oxidation. AMS studies depicted the overall nature of magnetic fabrics (and other related parameters like mean susceptibility, magnetic foliation, magnetic lineation, corrected degree of anisotropy, shape parameter) in the region. The susceptibility ellipsoids were dominantly oblate in the region as evident from the P j-T j plots. The absence of linear relationship between mean susceptibility and degrees of anisotropy proves that the fabrics are independent of bulk ferromagnetic susceptibility and controlled by deformational features. The equal area plots of the principal susceptibility axes and representation of maximum susceptibility axes in the rose diagram revealed parity between the field and magnetic fabrics thus pointing to a tectonic control of fabrics. Moreover, the pegmatitic bodies based on AMS parameters are found to have emplace syn-tectonic to basement deformation which impinged a linear feature (both in mesoscopic fabric and magnetic fabric) to the otherwise undeformed intrusive bodies.
Arabian Journal of Geosciences, 2018
Oriented cylindrical cores of rock samples were collected from the Talchir and Barakar formations... more Oriented cylindrical cores of rock samples were collected from the Talchir and Barakar formations of the Lower Gondwana Supergroup of the Raniganj Basin exposed in and around Kalyaneshwari and Maithon areas. The cores (2.54 cm diameter and 2.2 cm height) were studied in the low field anisotropy of magnetic susceptibility (AMS) measurement to determine the nature of magnetic fabrics, to correlate it with the sedimentological characteristics and to determine the palaeocurrent patterns. The results derived from the statistical parameters (especially the q-factor), the shapes of the susceptibility ellipsoids and directional data of the AMS indicate that the magnetic fabrics within the studied units are primary (depositional) and are correlatable form the palaeoenvironmental features. The orientation of the maximum (K 1), intermediate (K 2) and minimum (K 3) susceptibility axes is dispersed on the lower hemisphere equal area diagram rather than strong clusters which is not because of secondary (tectonic) influence but due to the moderate to high-energy environment of deposition of the sediments in the studied units. Based on the qfactor (which is 0.581 for Barakar Formation and 0.565 for Talchir Formation which are both < 0.7), it is suggested the AMS indicates that the imbrication of the K 1 axis is the indicator of palaeocurrent. Also, the magnetic foliation (average value = 1.255) exceeds the magnetic lineation (average value = 1.107) and the shape parameter exceeds 0 in most cases pointing towards an oblate fabric. The palaeocurrent in the present study as indicated by the K 1 axis imbrication is very similar in both the units under study and is due SW. However, apart from this precise palaeocurrent direction, there exists a certain degree of randomness of the susceptibility axes which are very clear indication of corresponding depositional environments.
Current Science, 2017
This study aims at tracing the distribution and concentration of contaminants in fly ash along ro... more This study aims at tracing the distribution and concentration of contaminants in fly ash along roads and highways with appreciable traffic by using magnetic proxies. Magnetic susceptibility is used for pollution mapping in the field. The distribution of susceptibility values represents polluted areas strongly influenced by traffic frequency, roadside topography, meteorological conditions (e.g. wind direction) and other factors. A magnetic phase was found to be responsible for the enhancement of magnetic signal in roadside ash. Magnetic methods provide effective tools for delineation of industrial pollution such as fly ash. In the area studied, magnetic susceptibility proved to be an excellent proxy for analysis of intensity of pollution yielding interesting results.
Arabian Journal of Geosciences
Exploration of geoheritage sites is a new venture in tourism studies. The objective of the study ... more Exploration of geoheritage sites is a new venture in tourism studies. The objective of the study is centredaround the Geoheritage site conservation for geological and geomorphological interpretation and introduction of Geotourism involving the local people in Puruliya district. The main litho-unit of Puruliya district belongs to Chhotanagpur Granite Gneissic Complex of Archean era. Nine geological/geomorphological important sites are chosen for assessing their geoheritage values and analysing the Geotourism potential. A modified model of Kubalikova (2013) is adopted for the evaluation of the selected nine important sites, where five important criteria i.e. scientific (intrinsic) values, educational values, economical values, conservation values and added (cultural, ecological and aesthetic) values are considered. The result reveals that sites like Durgabera dam, Bhanratongri hill, Garpanchakot and Jaychandi hill can be assumed as top potential Geotourism site occupying highest geohe...
Journal of Earth System Science
The present work deals with the generations of Fe-Ti oxides and the variation in magnetic fabrics... more The present work deals with the generations of Fe-Ti oxides and the variation in magnetic fabrics of the Dalma lavas and associated meta-sediments of the Singhbhum Mobile Belt (SMB) in relation to tectonics. Generations of the Fe-Ti oxides are different in meta-sediments and volcanics, the former preserving upliftment related oxidised grains, whereas the latter contains fresh grains prompting towards their upliftment due to plume upwelling before the volcanic eruption. In the meta-sediments, the magnetic fabric has close accordance with D 2 /F 2 event revealing synchronous development with D 2. The Dalma thrust developed a sudden break in the homogeneity of the magnetic fabrics of the rocks where the magnetic foliations are all parallel to the Dalma thrust. This also causes P j to be highest in this sector. The magnetic fabrics of volcanic rocks are different from the meta-sediments and record no signature of deformation. The pattern of distribution of susceptibility axes are in accordance with the subaerial lava flows. However, their K 1 and K 2 dispersed throughout the periphery with K 3 clustering at the centre. This infers towards the fact that although the volcanism took place in a subaerial environment, calm aqueous environment was locally present where the oblate grains settled on the eruption surface with their K 3 vertical.
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Papers by Saurodeep Chatterjee