scholarly journals Emplacement of Lamproites in and around Ramadugu, Nalgonda District- ground Magnetic evidence

2016 ◽  
Vol 3 (2) ◽  
Author(s):  
Ramadass G ◽  
Sri Ramulu G ◽  
Udaya Laxmi
Keyword(s):  
Granite Gneiss ◽  
Analytical Signal ◽  
Magnetic Data ◽  
Intensity Data ◽  
Banded Iron Formations ◽  
Study Region ◽  
Ground Magnetic ◽  
Iron Formations ◽  
Averaged Power Spectrum ◽  
Nalgonda District

<p>The total magnetic intensity data has been collected in and around Ramadugu Village in Eastern DharwarCraton to understand the magnetic evidence over the known Lamproites zones in conjunction with geology and geomorphology. Based on the magnetic, geological and geomorphological signatures observed from the known lamproites potential zones, new probable locations are identified in the study area. Nine magnetic lows and fourteen magnetic highs are traced, lows are representing the presence of Lamproites within the granite gneiss, and highs are observed over the presence of banded iron formations. The generated analytical (Horizontal, Vertical, Tilt, Analytical signal) maps from the total magnetic anomaly show the trends of the magnetic lineaments and trending in NW-SE, NE-SW &amp;E-W direction. The coefficient of variation (CV) of the magnetic data clearly identified four tectonic disturbed (A.B,C,D) zones, various faults and other lineaments/dykes and the intersection of lineaments, geological, morpho structural, tectonic aspects of reported occurrence of lamproites near Ramadugu and Vattikodu areas were found to be localized at surrounding of the domal peripherals. Using this criterion eight potential lamproites zones were delineated(2,3,4,5,8,9,10,11 and 13) in the study region. The long normalized radial averaged power spectrum of the study area indicated that the depth to the granite gneiss basement is around 2 Km.The dyke configurations in the region was obtained via the inversion of magnetic profiles.</p>

Inversion and magnetization homogeneity testing for 2D magnetic sources

Geophysics ◽  
2021 ◽  
Vol 86 (1) ◽  
pp. J13-J19
Author(s):  
William Pareschi Soares ◽  
Carlos Alberto Mendonça
Keyword(s):  
Binary Solution ◽  
Analytical Signal ◽  
Data Interpretation ◽  
Magnetic Data ◽  
Magnetization Direction ◽  
Data Inversion ◽  
Uniform Magnetization ◽  
Real Value ◽  
Ground Magnetic ◽  
Magnetic Profile

Many approaches to magnetic data inversion are based on assumptions that source magnetization is homogeneous in direction and intensity. Such assumptions rarely can be verified with independent geologic information and are usually incorporated without further inquiry in the next steps of data interpretation. The use of magnetization direction invariants, such as the gradient intensity of the total field anomaly (equivalent to the amplitude of the analytical signal [ASA]) and the intensity of the anomalous vector field (IAVF), is effective for modeling sources with strong remanent magnetization, usually with unknown direction. Even in such cases, however, the assumption of uniform magnetization is understood but unchecked when seeking smooth or compact solutions from data inversion. We have developed a procedure to test the assumption of uniform magnetization for 2D sources. For true 2D homogeneous sources, the ratio of ASA to IAVF can be modeled with a binary solution (0 and 1) regardless of the real value of the magnetization. A procedure to provide convergence was applied, and its output solution was submitted to a binary test to verify the uniformity hypothesis. This technique was illustrated with numerical simulations and then used to reinterpret a ground magnetic profile across an intrusive diabase body in sediments of the Paraná Basin, Brazil, revealing the existence of two adjacent bodies that are homogeneous with different magnetization intensities.

Interpretation of ground magnetic data in Suyoc, Mankayan Mineral District, Philippines

2021 ◽  
Author(s):  
Creszyl Joy J. Arellano ◽  
Leo T. Armada ◽  
Carla B. Dimalanta ◽  
Karlo L. Queaño ◽  
Eric S. Andal ◽  
...  
Keyword(s):  
Magnetic Data ◽  
Ground Magnetic ◽  
Mineral District

Optical filtering of airborne and ground magnetic data

1976 ◽  
Vol 114 (4) ◽  
pp. 663-683 ◽  
Author(s):  
M. K. Seguin ◽  
H. H. Arsenault
Keyword(s):  
Magnetic Data ◽  
Optical Filtering ◽  
Ground Magnetic

scholarly journals Iron and Carbon Isotope Constraints on the Formation Pathway of Iron-Rich Carbonates within the Dagushan Iron Formation, North China Craton

Minerals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 94
Author(s):  
Xiaoxue Tong ◽  
Kaarel Mänd ◽  
Yuhao Li ◽  
Lianchang Zhang ◽  
Zidong Peng ◽  
...  
Keyword(s):  
Iron Reduction ◽  
Isotope Composition ◽  
Iron Formation ◽  
Banded Iron Formations ◽  
Organic C ◽  
Formation Pathway ◽  
Wide Range ◽  
Dissimilatory Iron Reduction ◽  
O Isotope ◽  
Iron Formations

Banded iron formations (BIFs) are enigmatic chemical sedimentary rocks that chronicle the geochemical and microbial cycling of iron and carbon in the Precambrian. However, the formation pathways of Fe carbonate, namely siderite, remain disputed. Here, we provide photomicrographs, Fe, C and O isotope of siderite, and organic C isotope of the whole rock from the ~2.52 Ga Dagushan BIF in the Anshan area, China, to discuss the origin of siderite. There are small magnetite grains that occur as inclusions within siderite, suggesting a diagenetic origin of the siderite. Moreover, the siderites have a wide range of iron isotope compositions (δ56FeSd) from −0.180‰ to +0.463‰, and a relatively negative C isotope composition (δ13CSd = −6.20‰ to −1.57‰). These results are compatible with the reduction of an Fe(III)-oxyhydroxide precursor to dissolved Fe(II) through microbial dissimilatory iron reduction (DIR) during early diagenesis. Partial reduction of the precursor and possible mixing with seawater Fe(II) could explain the presence of siderite with negative δ56Fe, while sustained reaction of residual Fe(III)-oxyhydroxide could have produced siderite with positive δ56Fe values. Bicarbonate derived from both DIR and seawater may have provided a C source for siderite formation. Our results suggest that microbial respiration played an important role in the formation of siderite in the late Archean Dagushan BIF.

ESTIMATION OF SOURCE PARAMETERS IN IBADAN, SOUTH – WESTERN NIGERIA USING DIGITIZED AEROMAGNETIC DATA

2018 ◽  
Vol 14 (2) ◽  
pp. 15-28
Author(s):  
A A ALABI ◽  
O OLOWOFELA
Keyword(s):  
Magnetic Susceptibility ◽  
Source Parameters ◽  
Granite Gneiss ◽  
Geological Structure ◽  
Magnetic Data ◽  
Susceptibility Map ◽  
Rock Types ◽  
Upward Continuation ◽  
Magnetic Basement ◽  
Local Wavenumber

Airborne magnetic data covering geographical latitudes of 7000‟N to 7030‟N and longitudes of 3 30′E to 4 00′E within Ibadan area were obtained from Nigeria Geology Survey Agency. The data were ana-lyzed to map the sub surface structure and the source parameters were deduced from the quantitative and qualitative interpretation of magnetic data. The upward continuation technique was used to de-emphasize short – wavelength anomaly while the depth to magnetic sources in the area was deter-mined using local wavenumber technique, the analytic signal was also employed to obtain the depths of the magnetic basement. Analysis involving the local wavenumber, upward continuation and appar-ent magnetic susceptibility techniques significantly improves the interpretation of magnetic data in terms of delineating the geological structure, source parameter and magnetic susceptibility within Iba-dan area.. These depth ranges from 0.607km to 2.48km. The apparent susceptibility map at the cut-off wavelength of 50 m ranges from -0.00012 to 0.00079 which agree with the susceptibility value of some rock types; granite gneiss, migmatite biotite gneiss, biotite muscovite granite, hornblende granite, quartz and schists. The result of the local wavenumber suggests variation along the profiles in the surface of magnetic basement across the study area.

scholarly journals Spectral characteristics of banded iron formations in Singhbhum craton, eastern India: Implications for hematite deposits on Mars

2016 ◽  
Vol 7 (6) ◽  
pp. 927-936 ◽  
Author(s):  
Mahima Singh ◽  
Jayant Singhal ◽  
K. Arun Prasad ◽  
V.J. Rajesh ◽  
Dwijesh Ray ◽  
...  
Keyword(s):  
Spectral Characteristics ◽  
Eastern India ◽  
Banded Iron Formations ◽  
Singhbhum Craton ◽  
Iron Formations
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