scholarly journals Interpretation of Oil Seepage of Source Rock Based Magnetic Survey in Cipari Cilacap District

2015 ◽  
Vol 5 (02) ◽  
pp. 80 ◽  
Author(s):  
Sukmaji Anom Raharjo ◽  
Sehah S

<p class="AbstractText">The magnetic survey had been conducted in Village of Cipari, District of Cipari, Region of  Cilacap to interpret to the location of the oil seepage source rock. Boundary of the research area is 108.75675°E – 108.77611°E and 7.42319°S – 7.43761°S. The observed total magnetic data is corrected and reducted to obtain the local magnetic anomaly data. The local magnetic anomaly data is applied to model the subsurface bodies anomalies based on the Mag2DC for Windows software. With be supported the geological information, the some bodies anomalies are interpreted as the basaltic igneous rock (c = 0.0051), the alternately of sandstone and claystone and insert of marl from Halang Formation (c = 0.0014), the breccia from Kumbang Formation (c = 0.0035), the alternately of sandstones and claystone with insert of marl and breccia from Halang Formation (c = 0.0036), the claystone from Tapak Formation (c = 0.0015), the alternately of sandstones and claystone with insert of marl and compacted breccia from Halang Formation (c = 0.0030), and the alternately of sandstone and claystone from   Halang Formation (c = 0.0020). The plantonic foraminifer fossils as resources of oil seepage are estimated in the sedimentaries rocks, where the oil flows from those rocks into the         reservoir (source rock). Based on the interpretation results, the source rock is above basaltic igneous rock with the approximate position is 108.76164°W and 7.43089°S; and the depth is 132.09 meters below the average topographic.</p>

2017 ◽  
Vol 7 (2) ◽  
pp. 71 ◽  
Author(s):  
Sehah Allasimy ◽  
Sukmaji Anom Raharjo ◽  
Iska Andriyanto

<p class="AbstractText">Exploration of the spread of iron sand on the eastern coastal of Binangun District in Cilacap Regency has been conducted using the magnetic surveys. The magnetic data acquisition was conducted in April 2017. The total magnetic field data obtained is processed, so that can be obtained the local magnetic anomaly data. The modeling of the local magnetic anomaly data is performed on the trajectory of AB that extending from the position point of 109,274698° E and 7.686620° S to 109.2296195° E and 7.689099° S so that obtained various model of the subsurface anomalous objects. Interpretation on the subsurface anomalous objects is done to estimate the types of rocks and their formations based on the magnetic susceptibility value of each object which supported by the geological information of the research area. Based on the interpretation results to be obtained two layers of subsurface rocks that can be estimated as the iron sand that coexists with silt dan clay derived from the alluvium formation. The first rock has a length of 1238.2 meters, a depth of 1.709 – 20.513 meters, and a magnetic susceptibility value of 0.0183 cgs unit. The second rock has a length of 643.055 meters, a depth of 16.524 – 34.188 meters, and a magnetic susceptibility value of 0.0174 cgs unit. The results of this research are also supported by the results of geoelectric data interpretation, where the iron sand that coexists with silt and clay is found at a depth of 9.42 – 19.48 meters with a resistivity value of 52.99 Ωm at Geo-1 point; and a depth of 10.56 – 22.20 meters with resistivity value of 49,03 Ωm at Geo-2 point. Based on the results of of this research, the eastern coastal area of Binangun District is estimated to contain potentially iron ore and economically is a prospect for exploitation.</p>


2017 ◽  
Vol 4 (02) ◽  
pp. 171
Author(s):  
Sehah S ◽  
Sukmaji Anom Raharjo ◽  
Adi Chandra

<p>The Estimation of coal bituminous depth in Village of Banjaran, District of Salem, Regency of Brebes based on magnetic anomaly data has been done. The Village of Banjaran is located in the geology basin which called as Bentarsari Basin. The activities stages that carried out in this research include of magnetic data acquisition in the field, data processing, and interpretation. The interpretation of the anomalies data is done through the modeling using the Mag2DC for Window software on the local magnetic anomalies data. Based on this modeling results, then obtained six anomalous objects that can be interpreted as the subsurface rocks in the research area, which consists of sediments of gravel, sand, clay, and silt ( = 0.0020 cgs units); tuff and tuffaceous sandstone ( = 0.0069cgs units); andesite breccia, tuff, and tuffaceous sandstone ( = 0.0085cgs units); solid andesite breccia which not layered ( = 0.0115 cgs units); coarse sandstones, limestones, and sandy marl ( = 0.0109cgs units); andesite sandstone that layered with claystone and thin insertions of new coal bituminous alternately ( = 0.0008cgs units). Based on the modeling results and the geological information of this research area, it can be estimated that the coal bituminous found in the Kaliglagah formation, with its depths ranging between 104.48 m – 505.97m, and the value of the magnetic susceptibility is 0.0008 cgs units.</p>


Geophysics ◽  
1979 ◽  
Vol 44 (8) ◽  
pp. 1395-1416 ◽  
Author(s):  
James C. Macnae

This paper discusses geophysical prospecting techniques for kimberlite pipes, a major source of diamonds. A simple geologic model based on descriptions by Hawthorne (1975) and Nixon (1973) is given, and the varied geophysical responses obtained over kimberlite pipes are interpreted in terms of this model. The three main factors controlling these responses are the original size and inhomogeneity of the pipe, the depth of erosion, and the degree of weathering. Kimberlite pipes are roughly elliptical in surface exposure in most cases, with a “carrot shaped” extension at depth. The unweathered portion of the pipe generally contains a few percent magnetite, and this in most cases produces a clearly detectable magnetic anomaly. The presence of deep weathering may alter the magnetite in the top of the pipe to nonmagnetic oxides of iron, thus resulting in an increased depth to the magnetic source. If this depth is large, the magnetic response may not be large enough to detect the kimberlite in the presence of noise and the effect of other structures. In addition, if little erosion has taken place since emplacement, kimberlitic sediments known as epiclastic kimberlite will be present to considerable depths in the pipe, and this may also lead to the absence of a clear magnetic anomaly. In one large survey in South Africa, electromagnetic (EM) techniques have proven to be remarkably effective in detecting the presence of weathered clays or epiclastic kimberlite contained within the pipes. All pipes discovered during this survey had unmistakable EM signatures, while five out of eight had very small magnetic anomalies which would not likely have been selected as potential targets on the basis of magnetic data alone. These examples would indicate that in any area where deep weathering is expected, an EM survey is essential in combination with a magnetic survey if reconnaissance is to be based on airborne geophysical techniques. Due to the emplacement mechanism of kimberlite, considerable inhomogeneity within a pipe may be present, leading to significant variation in the response of any geophysical technique to one pipe, with resultant interpretation difficulties. Although this is not a limitation in the discovery of new pipes, it does make their geophysical delimitation difficult.


2017 ◽  
Vol 7 (2) ◽  
pp. 79 ◽  
Author(s):  
S Sehah ◽  
Sukmaji Anom Raharjo

The research aiming to explore the iron ore deposits in the Nusawungu coastal Regency of Cilacap has been conducted using the magnetic survey. The acquisition of magnetic data was conducted in April – Mei 2017, covering the area in the ranges of 109.314° – 109.345°E and 7.691° – 7.709°S. The obtained magnetic field strength data were corrected, reduced, and mapped to obtain the contour map of local magnetic anomaly. The modeling process was carried out along the path extending over the map from the positions of 109.314°E and 7.695°S to 109.335°E and 7.699°S, so that some subsurface anomalous objects are obtained. The lithological interpretation was performed to identify the types of subsurface rocks and their formations based on the magnetic susceptibility value of each anomalous objects and supported by the geological information of the research area. Based on the interpretation results, three rocks deposits of alluvium formations were obtained, which are estimated to contain iron ore. The first deposit has a length of 164.85 m, a depth of 0.57 – 8.43 m, and a magnetic susceptibility value of 0.0097 cgs. The second deposit has a length of 376.28 m, a depth of 2.56 – 19.66 m, and a magnetic susceptibility value of 0.0108 cgs. The third deposit has a length of 1,306.26 m, a depth of 3.70 – 58.69 m, and a magnetic susceptibility value of 0.0235 cgs. Out of the whole rocks deposits, the third rock deposit is interpreted to have the most prospective iron ore. This interpretation based on its high magnetic susceptibility value, which indicates the presence of many magnetic minerals (i.e. iron ores) in the rock.


2016 ◽  
Vol 16 (2) ◽  
pp. 69
Author(s):  
Yudhistira Adi Nugraha ◽  
Puguh Hiskiawan ◽  
Supriyadi Supriyadi

Magnetic method is a geophysics method to determine the kind of subsurface material in certain depth by identifying the magnetic characteristics of rock based on the value of magnetic suspetibility. The data analysis described the subsurface anomaly using upward continuation filter. It separated local anomaly and regional anomaly by lifting research area in certain elevation. The raw data research was the total of magnetics data around Bedadung watershed, Jember. It was proceeded to obtaine magnetic anomaly curve on 5 line in contour map. It was digitalized and use as data input of magpick and upward continuation filter program. Upward continuation program was conducted using variation of area elevation in each track from 1 m up to 30 m. magnetic anomaly from this program is compared to magpick result showed that the magnetic anomaly curve on each line have good suitability with the accuracy 0,93%. Therefore, the continuation program become the alternative in magnetic data processing.


Author(s):  
Thorkild M. Rasmussen ◽  
Leif Thorning

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Rasmussen, T. M., & Thorning, L. (1999). Airborne geophysical surveys in Greenland in 1998. Geology of Greenland Survey Bulletin, 183, 34-38. https://doi.org/10.34194/ggub.v183.5202 _______________ Airborne geophysical surveying in Greenland during 1998 consisted of a magnetic project referred to as ‘Aeromag 1998’ and a combined electromagnetic and magnetic project referred to as ‘AEM Greenland 1998’. The Government of Greenland financed both with administration managed by the Geological Survey of Denmark and Greenland (GEUS). With the completion of the two projects, approximately 305 000 line km of regional high-resolution magnetic data and approximately 75 000 line km of detailed multiparameter data (electromagnetic, magnetic and partly radiometric) are now available from government financed projects. Figure 1 shows the location of the surveyed areas with highresolution geophysical data together with the area selected for a magnetic survey in 1999. Completion of the two projects was marked by the release of data on 1 March, 1999. The data are included in the geoscientific databases at the Survey for public use; digital data and maps may be purchased from the Survey.


Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1092
Author(s):  
Brian R. Page ◽  
Reeve Lambert ◽  
Nina Mahmoudian ◽  
David H. Newby ◽  
Elizabeth L. Foley ◽  
...  

This paper presents results from the integration of a compact quantum magnetometer system and an agile underwater glider for magnetic survey. A highly maneuverable underwater glider, ROUGHIE, was customized to carry an increased payload and reduce the vehicle’s magnetic signature. A sensor suite composed of a vector and scalar magnetometer was mounted in an external boom at the rear of the vehicle. The combined system was deployed in a constrained pool environment to detect seeded magnetic targets and create a magnetic map of the test area. Presented is a systematic magnetic disturbance reduction process, test procedure for anomaly mapping, and results from constrained operation featuring underwater motion capture system for ground truth localization. Validation in the noisy and constrained pool environment creates a trajectory towards affordable littoral magnetic anomaly mapping infrastructure. Such a marine sensor technology will be capable of extended operation in challenging areas while providing high-resolution, timely magnetic data to operators for automated detection and classification of marine objects.


Entropy ◽  
2021 ◽  
Vol 23 (10) ◽  
pp. 1309
Author(s):  
Yaoxin Zheng ◽  
Shiyan Li ◽  
Kang Xing ◽  
Xiaojuan Zhang

Despite the increased attention that has been given to the unmanned aerial vehicle (UAV)-based magnetic survey systems in the past decade, the processing of UAV magnetic data is still a tough task. In this paper, we propose a novel noise reduction method of UAV magnetic data based on complete ensemble empirical mode decomposition with adaptive noise (CEEMDAN), permutation entropy (PE), correlation coefficient and wavelet threshold denoising. The original signal is first decomposed into several intrinsic mode functions (IMFs) by CEEMDAN, and the PE of each IMF is calculated. Second, IMFs are divided into four categories according to the quartiles of PE, namely, noise IMFs, noise-dominant IMFs, signal-dominant IMFs, and signal IMFs. Then the noise IMFs are removed, and correlation coefficients are used to identify the real signal-dominant IMFs. Finally, the wavelet threshold denoising is applied to the real signal-dominant IMFs, the denoised signal can be obtained by combining the signal IMFs and the denoised IMFs. Both synthetic and field experiments are conducted to verify the effectiveness of the proposed method. The results show that the proposed method can eliminate the interference to a great extent, which lays a foundation for the further interpretation of UAV magnetic data.


2018 ◽  
Vol 36 (3) ◽  
pp. 1 ◽  
Author(s):  
Luizemara Soares Alves Szameitat ◽  
Francisco José Fonseca Ferreira ◽  
Gianreto Manatschal ◽  
Monica da Costa Pereira Lavalle Helbron

ABSTRACT. Inheritance on continental lithosphere is considered as an important aspect on passive margins, since they may control magmatic budget and strain evolution during rifting and lithospheric breakup. On the distal Western Iberian margin, the transition to a steady state oceanic crust was little sampled and less investigated, in comparison to the more proximal parts near to the continental edge. In this work, we use marine magnetic data to analyze some aspects of the transition between the zone of exhumed continental mantle (ZECM) and the unequivocal oceanic crust, using transformed magnetic data. We observe that the end of the ZECM presents some straight magnetic features, especially at the eastern limit of the J anomaly. These magnetic lineaments are consistent with Early Cretaceous flow lines of the Iberian Plate. Straight structures are not expected in a newly formed oceanic lithosphere. Instead, it seems to be controlled by mantle inheritance. These straight magnetic features may indicate basement inheritance controlling magmatic insertions at the beginning of the oceanic crust formation.Keywords: Iberia, Magnetometry, Ocean-Continent Transition, Inherited Structures, Magma-Poor Margin. RESUMO. Estruturas herdadas na litosfera continental são um aspecto importante em margens passivas, pois poderão condicionar a entrada de magma e a evolução da deformação durante o rifteamento e quebra litosférica. Na porção distal da Margem Ibérica Ocidental, a transição da crosta continental até a crosta oceânica bem estabelecida possui menos dados e é menos investigada em comparação com a porção junto do limite de crosta continental. Neste trabalho, usamos dados magnéticos marinhos para analisar alguns aspectos entre a zona de exumação mantélica e a crosta oceânica inequívoca, através de dados magnéticos transformados. Observa-se que o final da zona de exumação mantélica apresenta algumas feições retilíneas, especialmente no limite leste da Anomalia J. Estes lineamentos magnéticos estão em conformidade com linhas de fluxo mesozoicas da Placa Ibérica. Feições retilíneas não são esperadas em uma litosfera oceânica neoformada. Ao contrário, estas aparentam ser um controle dado por estruturas pretéritas do manto. Portanto, estas feições magnéticas retilíneas sugerem uma herança do embasamento continental controlando as intrusões magmáticas no início da formação da crosta oceânica.Palavras-chave: Ibéria, Magnetometria, Transição Continente-Oceano, Estruturas Herdadas, Margem Pobre em Magma. 


2020 ◽  
Author(s):  
Carlos Ribeiro ◽  
Pedro Terrinha ◽  
Marcos Rosa ◽  
Marta Neres ◽  
João Noiva ◽  
...  

&lt;p&gt;The Tagus River ebb-delta is located near an important city center off Lisbon, Portugal. The Tagus delta hosts various kilometer scale landslides, the most important of which has been mapped and described with a presumable age of ~11 ky and 10 km in length, 4 km wide and 20 m of maximum thickness. An equivalent area of gas trapped in the sediments has also been reported (Terrinha et al., 2019).&lt;/p&gt;&lt;p&gt;The TAGUSGAS project aims at characterizing the nature and source of the gas. A multibeam and backscatter survey was carried out recently covering an area of 44 km&lt;sup&gt;2&lt;/sup&gt;. Several morphologic artifacts were found. The magnetic survey carried out simultaneously allows at discriminating the anthropogenic origin of some of these artifacts. It also allows at distinguishing gas and igneous rock sources of acoustic blanking in the seismic reflection record.&lt;/p&gt;&lt;p&gt;The multibeam and backscatter basemap also serves as a tool to decide targets for seafloor sites for sample collection.&lt;/p&gt;&lt;p&gt;The authors would like to acknowledge the FCT financial support through project UIDB/50019/2020 &amp;#8211; IDL and TAGUSGAS project (PTDC/CTA-GEO/31885/2017).&lt;/p&gt;


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