Academia.eduAcademia.edu

Figure 10 – uploaded by Lev V Eppelbaum

See full PDFdownloadDownload figure
Greater and Lesser Caucasus, an accumulation of thick (up to several kilometers) Cenozoic terrigenous sediments is recognized. In Figure 10: (la) Magmatic formations of orogenic uplifts of the late collisional stage, (1b) nolasse deposits of different origins, (2a) formations of collisional rifting of volcano-plutonic belts. 2b) terrigenous carbonate flyschoid, (3a) magmatic formations of continental margins, (3b) errigenous flysch, (4a) differentiated volcanic and intrusive series, (4b) formations of deep-sea uboceanic basins, (5) subplatform deposits.

Figure 10 Greater and Lesser Caucasus, an accumulation of thick (up to several kilometers) Cenozoic terrigenous sediments is recognized. In Figure 10: (la) Magmatic formations of orogenic uplifts of the late collisional stage, (1b) nolasse deposits of different origins, (2a) formations of collisional rifting of volcano-plutonic belts. 2b) terrigenous carbonate flyschoid, (3a) magmatic formations of continental margins, (3b) errigenous flysch, (4a) differentiated volcanic and intrusive series, (4b) formations of deep-sea uboceanic basins, (5) subplatform deposits.

Related Figures (22)

3. Petrophysical support The data sources for petrophysical support are primarily the rock magnetic map and rock magnetic sections (if available). Rock magnetic data from core samples and deep mine workings are critical since regular surface changes do not distort them. The most excellent weight should be given to determining magnetic properties based on materials comparing the observed magnetic field with an available geological section.
3. Petrophysical support The data sources for petrophysical support are primarily the rock magnetic map and rock magnetic sections (if available). Rock magnetic data from core samples and deep mine workings are critical since regular surface changes do not distort them. The most excellent weight should be given to determining magnetic properties based on materials comparing the observed magnetic field with an available geological section.
When observing a magnetic field under conditions of inclined magnetization, determining t irection of magnetization is of particular importance since both the intensity and the shape of t lagnetic anomaly significantly depend on the inclination of the excess magnetization of the object [4 nly induc ssidual magnetization /, is relatively tiny. In this case, data on the values of y of rocks and or¢ ; sufficien ive magnetization J; is often assumed when analyzing magnetic properties, and th . However, contrary to previously held beliefs, remanent magnetization is more t 4 4 4 ule than the exception [7], especially in volcanic and intrusive rocks, where it can be characterize ues and directions that differ from the direction of the modern magnetic field of th y large va arth’s region under study. mpcutiie: iat he information must satisfy the recognized section’s petro- and paleomagnetic data. After this, a mode ased on rock-magnetic characteristics is generated. The weighted average magnetization values fo. pecific rock complexes are obtained and combined with the magnitude of magnetic properties o1 nagnetization direction (within one paleomagnetic zone). When calculating the weighted average values of the igneous rocks’s magnetization, it may be helpful to use the explosiveness coefficient (th« atio in the context of the volumes of lavas and pyroclasts) since lower values of magnetic usceptibility y and natural remanent magnetization of rocks Jn usually characterize the latter.
When observing a magnetic field under conditions of inclined magnetization, determining t irection of magnetization is of particular importance since both the intensity and the shape of t lagnetic anomaly significantly depend on the inclination of the excess magnetization of the object [4 nly induc ssidual magnetization /, is relatively tiny. In this case, data on the values of y of rocks and or¢ ; sufficien ive magnetization J; is often assumed when analyzing magnetic properties, and th . However, contrary to previously held beliefs, remanent magnetization is more t 4 4 4 ule than the exception [7], especially in volcanic and intrusive rocks, where it can be characterize ues and directions that differ from the direction of the modern magnetic field of th y large va arth’s region under study. mpcutiie: iat he information must satisfy the recognized section’s petro- and paleomagnetic data. After this, a mode ased on rock-magnetic characteristics is generated. The weighted average magnetization values fo. pecific rock complexes are obtained and combined with the magnitude of magnetic properties o1 nagnetization direction (within one paleomagnetic zone). When calculating the weighted average values of the igneous rocks’s magnetization, it may be helpful to use the explosiveness coefficient (th« atio in the context of the volumes of lavas and pyroclasts) since lower values of magnetic usceptibility y and natural remanent magnetization of rocks Jn usually characterize the latter.
Table 2. Common principles to interpret magnetic maps for the case of oblique magnetization (modified after [4]). Note: Inverse magnetization is assumed to be included in the “magnetic properties”.
Table 2. Common principles to interpret magnetic maps for the case of oblique magnetization (modified after [4]). Note: Inverse magnetization is assumed to be included in the “magnetic properties”.
Figure 2. Scheme of estimating magnetization of the upper geological section. Since solving geophysical problems almost always requires integrating various methods, expressing the obtained data using common measurement units is desirable. This allows for determining the recognition efficiency of individual geophysical methods and calculating various where J is the magnetization of the upper portion of the geological section (in mA/m), o is the acute angle between the average slope and the horizon (in degrees), R is the length of the inclined scarp along strike (in meters), and the coefficient b has the dimension nT/m.
Figure 2. Scheme of estimating magnetization of the upper geological section. Since solving geophysical problems almost always requires integrating various methods, expressing the obtained data using common measurement units is desirable. This allows for determining the recognition efficiency of individual geophysical methods and calculating various where J is the magnetization of the upper portion of the geological section (in mA/m), o is the acute angle between the average slope and the horizon (in degrees), R is the length of the inclined scarp along strike (in meters), and the coefficient b has the dimension nT/m.
Figure 3. Typical interpreting models that are used in magnetic prospecting.
Figure 3. Typical interpreting models that are used in magnetic prospecting.
The parameters of the magnetic moment M., the position of the epicenter xo, and the normal background level A7packgr are determined from the values of @u h obtained by the characteristic point method using the formulas from Table 3. Figure 4. The position of tangents, characteristic points, and other interpretation parameters are used to interpret magnetic anomalies from a thin bed model quantitatively.
The parameters of the magnetic moment M., the position of the epicenter xo, and the normal background level A7packgr are determined from the values of @u h obtained by the characteristic point method using the formulas from Table 3. Figure 4. The position of tangents, characteristic points, and other interpretation parameters are used to interpret magnetic anomalies from a thin bed model quantitatively.
Figure 6. Position of tangents, characteristic points, and other interpretation parameters used in the quantitative interpretation of magnetic anomalies from a thick bed model. (1) Inflection points of the 47 anomaly plot, (2) position of the magnetization vector, (3) position of left and right angular points of the thick bed, (4) position of the middle of the thick bed upper edge. Tangents | and 2 are the left-hand and right-hand inclined ones, respectively, and 3 and 4 are the upper and lower horizontal ones, respectively. The locations of intervals di—ds are explained in the text. Figure 6. Position of tangents, characteristic points, and other interpretation parameters
Figure 6. Position of tangents, characteristic points, and other interpretation parameters used in the quantitative interpretation of magnetic anomalies from a thick bed model. (1) Inflection points of the 47 anomaly plot, (2) position of the magnetization vector, (3) position of left and right angular points of the thick bed, (4) position of the middle of the thick bed upper edge. Tangents | and 2 are the left-hand and right-hand inclined ones, respectively, and 3 and 4 are the upper and lower horizontal ones, respectively. The locations of intervals di—ds are explained in the text. Figure 6. Position of tangents, characteristic points, and other interpretation parameters
Figure 8. An example of quantitative magnetic field analysis from an object occupying an intermediate position between a thin horizontal plate model and a thick bed.
Figure 8. An example of quantitative magnetic field analysis from an object occupying an intermediate position between a thin horizontal plate model and a thick bed.
For an approximate estimate of h and M. vaues. the average values gq, = 1.8 and gu = 1.4 can be used (without calculating the parameter Q2). Then h = 1801p and M, = 1.3Q?/T,. The parameters of the magnetic moment M. and the normal background level A7packgr are determined using the values of Q and / as in the characteristic point method using the formulas in Table 3. Table 5. Formulas for quantitative interpretation of magnetic anomalies over TIB and HCC using an improved characteristic areal method (after [36]).
For an approximate estimate of h and M. vaues. the average values gq, = 1.8 and gu = 1.4 can be used (without calculating the parameter Q2). Then h = 1801p and M, = 1.3Q?/T,. The parameters of the magnetic moment M. and the normal background level A7packgr are determined using the values of Q and / as in the characteristic point method using the formulas in Table 3. Table 5. Formulas for quantitative interpretation of magnetic anomalies over TIB and HCC using an improved characteristic areal method (after [36]).
In Figure 12: (1) Yalakhkam suite J2aal2, (2) Zainkam suite J2aal;, (3) Nagab suite Jitoas, (4) Iseilakhan suite Jjtoa3, (5) the Lower and Middle Toarcian suite Jitoa\-2, (6) dikes of the gabbro- Jiabasic association;, (7) the Major Caucasian Ridge (upthrust-overthrust), (8) ore controlling (a) and ore distributing (b) upthrust-overthrusts, (9) Reford’s point [29], (10) inflection points on AT plots, (11) position of the anomalous body obtained from quantitative interpretation; (12) obtained direction of the magnetization vector projection.
In Figure 12: (1) Yalakhkam suite J2aal2, (2) Zainkam suite J2aal;, (3) Nagab suite Jitoas, (4) Iseilakhan suite Jjtoa3, (5) the Lower and Middle Toarcian suite Jitoa\-2, (6) dikes of the gabbro- Jiabasic association;, (7) the Major Caucasian Ridge (upthrust-overthrust), (8) ore controlling (a) and ore distributing (b) upthrust-overthrusts, (9) Reford’s point [29], (10) inflection points on AT plots, (11) position of the anomalous body obtained from quantitative interpretation; (12) obtained direction of the magnetization vector projection.
(12) Mesozoic, (13) G complex (velocity analogue of the “granitic” layer), (14) Bu and B subcomplexes of B complex (velocity analogue of the “basaltic” layer), (15) B; complex (basite anc high-density ultramafites), (16) M complex (presumed peridotite composition), (17) Cenozoic complex: mainly terrigenous deposits, Mesozoic complex: (18) terrigenous-carbonaceous formations. (19) mainly effusive associations of basic and intermediate composition, (20) mainly Baikalian complex (Pt2-Pz): metamorphic (primarily terrigenous) associations (the presence of younger deposits in the upper part is possible), (21) Pre-Baikalian complex (Ar2-Pr): mainly gneisses and marbles, (22) ancient complex (471): gneisses and amphibolites, (23) root of the basic magmatism, (24) undividec effusive-intrusive complex, (25) low density rock complex (serpentinization zone ?), (26) complex ot magmatic associations corresponding to the crust-to-mantle transition (ultramafic-mafic complexes ?). (27) upper mantle roof position, (28) large fault zones. (27) upper mantle roof position, (28) large fault zones.
(12) Mesozoic, (13) G complex (velocity analogue of the “granitic” layer), (14) Bu and B subcomplexes of B complex (velocity analogue of the “basaltic” layer), (15) B; complex (basite anc high-density ultramafites), (16) M complex (presumed peridotite composition), (17) Cenozoic complex: mainly terrigenous deposits, Mesozoic complex: (18) terrigenous-carbonaceous formations. (19) mainly effusive associations of basic and intermediate composition, (20) mainly Baikalian complex (Pt2-Pz): metamorphic (primarily terrigenous) associations (the presence of younger deposits in the upper part is possible), (21) Pre-Baikalian complex (Ar2-Pr): mainly gneisses and marbles, (22) ancient complex (471): gneisses and amphibolites, (23) root of the basic magmatism, (24) undividec effusive-intrusive complex, (25) low density rock complex (serpentinization zone ?), (26) complex ot magmatic associations corresponding to the crust-to-mantle transition (ultramafic-mafic complexes ?). (27) upper mantle roof position, (28) large fault zones. (27) upper mantle roof position, (28) large fault zones.
Mud volcanism is a natural phenomenon based on the fluid-geodynamic and thermobaric processes at the depth. In Azerbaijan territory, about 35% of all available mud volcanoes on the Earth are disposed of [47,50]. The compiled map (Figure 17) first indicates the relationship between the averaged negative magnetic anomaly and the location of most of the Azerbaijani mud volcanoes. Considering the average character of the magnetic field, this map is unsuitable for quantitative analysis. At the same time, it is evident that the sources of this magnetic anomaly occur at a significant depth. Combined geological-geophysical analysis of the obtained phenomenon may shed light on the nature of the formation of many mud volcanoes in a given area.
Mud volcanism is a natural phenomenon based on the fluid-geodynamic and thermobaric processes at the depth. In Azerbaijan territory, about 35% of all available mud volcanoes on the Earth are disposed of [47,50]. The compiled map (Figure 17) first indicates the relationship between the averaged negative magnetic anomaly and the location of most of the Azerbaijani mud volcanoes. Considering the average character of the magnetic field, this map is unsuitable for quantitative analysis. At the same time, it is evident that the sources of this magnetic anomaly occur at a significant depth. Combined geological-geophysical analysis of the obtained phenomenon may shed light on the nature of the formation of many mud volcanoes in a given area.
Figure 17. Map of the magnetic field AZ recalculated to one common level of 2.5 km over the mean sea level (initial data from https://geomag.colorado.edu/magnetic-field-model- mf7.html) with the location of the mud volcanoes (Baku Bay, adjacent areas of the South Caspian Basin, and Absheron Archipelago).
Figure 17. Map of the magnetic field AZ recalculated to one common level of 2.5 km over the mean sea level (initial data from https://geomag.colorado.edu/magnetic-field-model- mf7.html) with the location of the mud volcanoes (Baku Bay, adjacent areas of the South Caspian Basin, and Absheron Archipelago).
Related topics:
Deterministic MethodProbabilistic Approach
580 California St., Suite 400
San Francisco, CA, 94104
© 2025 Academia. All rights reserved