The relationship between Fe mineralization and the magnetic basement structures using multifractal modeling in the Esfordi and Behabad Areas (BMD), central Iran

Author(s):  
Masoumeh NABILOU ◽  
Peyman AFZAL ◽  
Mehran ARIAN ◽  
Ahmad ADIB ◽  
Hassan KHEYROLLAHI ◽  
...  
Author(s):  
Azadeh Hosseini ◽  
Mohammad Hossein Saberi ◽  
Bahman ZareNezhad

AbstractHydrocarbon exploration has long been based on such costly and time-intensive methods as geophysical surveys, geological studies, and drilling. In recent years, however, researchers have started to consider such inexpensive alternatives as surface geochemistry for hydrocarbon exploration. Some 100 years ago, the leakage of hydrocarbons onto the surface in the form of micro- and macro-seepages motivated researchers toward drilling a well in the Khourian Desert in the south of Semnan Province, Iran. Upon drilling the well, researchers found evidences of non-released (free) hydrocarbons. These findings drove further study of the area using surface geochemistry while considering the nearby hydrocarbon accumulation in Qom Formation. Conventional and indirect surface geochemical methods provide an insight into the relationship between surface and subsurface hydrocarbons. In the present work, the results of the Rock–Eval pyrolysis showed total organic carbon (TOC) values in the range of 0.31–4.13 wt.% and S1 peaks between 0.07 and 27.35. Sulfur isotope analysis showed a sulfur isotopic value of −0.4. The study of hydrocarbon-oxidizing bacteria showed the presence of bacterial colonies in MSM at 1.22 × 106 cfu/g of soil sample. We further investigated surface changes due to the presence of free hydrocarbons and pH variations (4.9–8) resulted from the changes in the concentrations of calcium carbonate and iron. According to the results and given the presence of organic sulfur in the samples, the occurrence of Gach-i-turush and alike phenomena was proposed in this area. The results of geo-microbial prospecting method, surface secondary changes, and sulfur isotope studies were well in agreement with the characteristics of the existing hydrocarbon reserves in this area. Surface geochemical surveys can precede other geochemical and geophysical surveys to identify surface anomalies and hence focus on more probable locales of hydrocarbon accumulation in the Khourian Desert, central Iran.


2010 ◽  
Vol 104 (1-2) ◽  
pp. 34-46 ◽  
Author(s):  
Peyman Afzal ◽  
Ahmad Khakzad ◽  
Parviz Moarefvand ◽  
N. Rashidnejad Omran ◽  
Bijan Esfandiari ◽  
...  

2018 ◽  
Vol 18 (3) ◽  
pp. 312-322
Author(s):  
Nguyen Thi Thu Hang ◽  
Pham Thanh Luan ◽  
Do Duc Thanh ◽  
Le Huy Minh

In this paper, we present an improved algorithm based on Murthy and Rao’s algorithm to invert magnetic anomalies of two-dimensional basement structures. Here, the magnetic basement interface is approximated by a 2N-sided polygon with assumption that the bottom of the basement is the Curie surface. The algorithm is built in Matlab environment. The model testing shows that the proposed method can perform computations with fast and stable convergence rate. The obtained result also coincide well with the actual model depth. The practical applicability of the method is also demonstrated by interpreting three magnetic profiles in the southeast part of the continental shelf of Vietnam.


Geophysics ◽  
1980 ◽  
Vol 45 (12) ◽  
pp. 1813-1846 ◽  
Author(s):  
John C. Behrendt ◽  
Kim D. Klitgord

The U.S. Geological Survey contracted a high‐sensitivity, digital aeromagnetic survey that was flown over the U.S. Atlantic continental margin over a period of 15 months between 1974 and 1976. The 185,000 km of profile data have a relative accuracy approaching a few tenths of a nanotesla, which allowed compilation into maps at a scale of 1:250,000, with a contour interval of 2 nT. Automatic data processing using the Werner method allowed calculations of apparent depth to sources of the magnetic anomalies on all of the profiles, assuming a dike or interface as a source. Comparison of the computed depths to magnetic basement with multichannel seismic profiles across the survey area helped to reduce ambiguities in magnetic depth estimates and enabled interpolation of basement structures between seismic profiles. The resulting map showing depth to basement of the Atlantic continental margin is compatible with available multichannel seismic data, and we consider it a reasonable representation of the base of the sedimentary column.


2019 ◽  
Vol 107 ◽  
pp. 172-185 ◽  
Author(s):  
Mirko Ahmadfaraj ◽  
Mirsaleh Mirmohammadi ◽  
Peyman Afzal ◽  
Amir Bijan Yasrebi ◽  
Emanuel John Carranza

GeoArabia ◽  
1996 ◽  
Vol 1 (1) ◽  
pp. 52-63
Author(s):  
Ian C.F. Stewart ◽  
Thomas C. Connally ◽  
Jeffrey H. Copley

ABSTRACT The pre-Khuff interval of the Paleozoic sediments in central Arabia is poorly defined by conventional seismic techniques, although this layer has significant potential for hydrocarbon exploration. Model studies indicated that magnetotelluric methods could outline the regional changes expected in the pre-Khuff in the area, which are largely dependent on the topography of the Precambrian basement. The Hercynian orogenic event created an extensive block-faulted terrane of half-grabens and horsts. The Hercynian structural relief was infilled in the Permo-Carboniferous and faulting reactivated in Triassic and later time, but the relationship between pre-Khuff and post-Khuff structure was impossible to understand using seismic data alone. In this survey of almost 500 magnetotelluric (MT) stations, essential control on the shallower section was provided by seismic interpretations, in addition to well log data for depths and resistivities. The MT method was very successful in confirming the presence of significant pre-Khuff section over some basement structures, as well as defining areas where the section is thin or absent which may be suitable for further exploration for stratigraphic traps.


2019 ◽  
Vol 41 (1) ◽  
pp. 69-80
Author(s):  
Nguyen Thi Thu Hang ◽  
Erdinc Oksum ◽  
Le Huy Minh ◽  
Do Duc Thanh

The paper presents an improved algorithm based on Bhaskara Rao and Ramesh Babu’s algorithm to invert magnetic anomalies of three-dimensional basement structures. The magnetic basement is approximated by an ensemble of juxtaposed vertical prisms whose bottom surface coincides with Curie surface with the known depth. The computer program operating with the proposed algorithm is built in Matlab environment. Test applications show that the proposed method can perform computations with fast and stable convergence rate where the results also coincide well with the actual model structure. The effectiveness of the method is demonstrated by inverting magnetic anomalies of the southeast part of Vietnam continental shelf. The calculated magnetic basement relief of the study area provides useful additional information for studies in the aim of dealing with the geological structure of the area.References Beiki M., 2010. Analytic signals of gravity gradient tensor and their application to estimate source location, Geophysics, 75(6), i59–i74.Bui C.Q. (chief author), Le T., Tran T. D., Nguyen T. H., Phi T.T., 2007. Map of deep structure of the Earth’s crust, Atlas of the characteristics of natural conditions and environment in Vietnam’s waters and adjacent region. Publisher of Science and Technology, Ha Noi. Do D.T., Nguyen T.T.H., 2011. Atempt the improvement of inversion of magnetic anomalies of two dimensional polygonal cross sections to determine the depth of magnetic basement in some data profile of middle off shelf of Vietnam. Journal of Science and Technology, Vietnam Academy of Science and Technology, 49(2), 125–132.Do D.T., 2013. Study for application of 3D magnetic and gravity method to determine density contribution of basement rock and depth of magnetic basement on Vietnam’s shelf for oil research and prospecting Vietnam National University, Hanoi, Project code QG-11-04. Keating P. and Pilkington M., 2000, Euler deconvolution of the analytic signal, 62nd Annual International Meeting, EAGE, Session P0193.Keating P., Zerbo L., 1996. An improved technique for reduction to the pole at low latitudes, Geophysics, 61, 131–137.Le H.M., Luu V.H., 2003. Preliminary interpretation of the magnetic anomalies of the Eastern Vietnam sea and adiacent regions. J.  Sci. of the Earth, 25(2), 173–181. Mai T.T., Pham V.T., Dang V.B., Le D.B., Nguyen B., Le V.D., 2011. Characteristics of Pliocene - Quaternary geology and Geoengineering in the Center and Southeast parts of Continental Shelf of Vietnam. J.  Sci.  of the Earth, 33(2), 109-118.Mushayandebvu M.F., Lesur V., Reid A.B., Fairhead J.D., 2004. Grid Euler deconvolution with constraints for 2D structures, Geophysics, 69, 489–496.Nguyen N.T., Bui V.N., Nguyen T.T.H., Than D.L., 2014a. Application of power density spectrum of magnetic anomaly to estimate the structure of magnetic layer of the earth crust in the Bac Bo gulf. Journal of Marine Science and Technology, 14(4A), 137–148.Nguyen N.T., Bui V.N., Nguyen T.T.H., 2014b. Determining the depth to the magnetic basementand fault systems in Tu Chinh - Vung May area  by magnetic data interpretation. Journal of Marine Science and Technology, 14(4A), 16–25.Nguyen T.T.H., Pham T.L., Do D.T., Le H.M., 2018. Improving algorithm of determining the coordinates of the vertices of the polygon to invert magnetic anomalies of two-dimensional basement structures in space domain, Journal of Marine Science and Technology (preparing to print).Parker R.L., 1973. The rapid calculation of potential anomalies, Geophys. J. Roy. Astron. Soc, 31, 447–455. Pilkington M., Gregotski M.E., Todoeschuck J.P., 1994. Using fractal crustal magnetization models in magnetic interpretation, Geophysical Prospecting, 42, 677–692.Pilkington M., 2006. Joint inversion of gravity and magnetic data for two-layer models, Geophysics, 71, L35–L42.Rao D.B., Babu N.R., 1993. A fortran 77 computer program for three dimensional inversion of magnetic anomalies resulting from multiple prismatic bodies, Computer & Geosciences, 19(8), 781–801.Tanaka A., Okubo Y., Matsubayashi O., 1999. Curie point depth based on spectrum analysis of the magnetic anomaly data in East and Southeast Asia, Tectonic Pphysics, 306, 461–470.Thompson D.T., 1982. EULDTH – A new technique for marking computer-assisted depth estimates from magnetic data, Geophysics, 47, 31–37.Vo T.S., Le H.M., Luu V.H., 2005. Determining the horizontal position and depth of the density discontinuties in Red River Delta by using the vertical derivative and Euler deconvolution for the gravity anomaly data, Vietnam. Journal of Geology, Series A, 287(3–4), 39–52.  Werner S., 1955. Interpretation of magnetic anomalies of sheet-like bodies, Sveriges Geologiska Undersokning, Series C, Arsbok, 43, 6.Xu S.Z., 2006. The integral-iteration method for continuation of potential fields, Chinese journal of geophysics (in Chinese), 49(4), 1176–1182.Zhang C., Huang D.N., Zhang K., Pu Y.T., Yu P., 2016. Magnetic interface forward and inversion method based on Padé approximation, Applied Geophysics, 13(4), 712–720.CCOP, 1996. Magnetic anomaly map of East Asia, scale 1:4.000.000, Geological survey of Japan and Committee for co-ordination of joint prospecting for mineral resources in asian offshore areas.


GEODYNAMICS ◽  
2011 ◽  
Vol 2(11)2011 (2(11)) ◽  
pp. 89-91
Author(s):  
G. Ivanchenko ◽  
◽  
E. M. Horbunova ◽  

The relationship between the structures of the crystalline basement, structures of the sedimentary cover and relief of the day surface was traced on the basis of the geological and geophysical data and the results of visual and automated interpretation of the satellite images of the central part of East European Platform. Completed research allowed to determine the extent of the neotectonic activity of morphostructures influencing at the formation of the geophysical fields.


Sign in / Sign up

Export Citation Format

Share Document