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Geological structural sketch map of Sicily (compiled and modified from Catalano et al., 2000a, b, 2008; Accaino et al., 2011). The position of the main mud volcanoes (sampled: red circle; not sampled: blue circle) and the Fuoco di Censo dry methane seep (violet circle) is also indicated (after Etiope et al., 2002; Grassa et al., 2004). Acronyms of mud volcanoes (sampled: red circle; not sampled: blue circle) are: Ma, Maccalube di Aragona; Si, Simeto; St, Stadio; Fo, Fondachello; MS, Monte Sara; SB, Santa Barbara; VS, Vallone Salato. Acronym of the sampled dry methane seep (violet circle): FdC, Fuoco di Censo. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)
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This paper presents new chemical data of hydrocarbon-rich gases discharged from mud volcanoes and CH4-rich emissions located in different areas of Italy (Northern Apennines and Sicily). The determination of C5–C10 alkanes, cyclics and aromatics was carried out by GC–MS, while the main gas species and C1–C4 hydrocarbons were analyzed by GC-TDC and G...
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... blocks: i) the Panormide block on the hanging-wall, whose leading edge is manifested by a major E-W-trending crustal oblique thrust (i.e., the Mount Kumeta- Alcantara Fault; Ghisetti and Vezzani, 1984), and ii) the Pelagian block made of African crust on the thrust belt footwall ( Roure et al., 1990;Finetti et al., 2005;Catalano et al., 2011; Fig. 2). South of the Mount Kumeta-Alcantara fault the Apennine-Maghrebian fold-and- trust belt consists of a thick clastic sequence of Miocene-Pliocene sedi- ments deposited in a system of amalgamated thrust-top basins (e.g., Butler et al, 1992;Catalano et al., 2000a, b). The Siculo-Calabrian Rift Zone delimits the Apennine-Maghrebian ...
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... thrust-top basins (e.g., Butler et al, 1992;Catalano et al., 2000a, b). The Siculo-Calabrian Rift Zone delimits the Apennine-Maghrebian collision belt to the east, deforming the Ionian offshore area and the easternmost sector of Sicily, including the eastern flank of the Mount Etna volcano (Monaco and Tortorici, 2000;Catalano et al., 2008; Fig. ...
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... of Sicily are associated with both the (1) Neogene Apennine-Maghrebian fold-and-thrust belt and its (2) Pelagian foreland, where oil and thermogenic gases are related to Late Triassic-Early Jurassic source rocks and similarly aged traps ( Granath and Casero, 2004;Bertello et al., 2008). Mud volcanoes occur in eastern and south-western Sicily (Fig. 2) essentially over the thick clastic sequences filling the system of Miocene to Pleistocene foredeep and piggy-back basins (Caltanissetta Basin). Mud volcanoes and other seeps of Sicily release either thermogenic methane or gases with isotope signatures that were interpreted as produced by mixing of thermogenic and microbial gases ( ...
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... fold-and-thrust belt, consisting of thermo-and biogenic gas-charged Tertiary reservoirs ( Granath and Casero, 2004;Bertello et al., 2008). However, it is also possible that part of the thermo- genic gas could be released from the deeper petroleum system through deeply rooted faults, such as for the normal faults around the Mount Etna volcano (Fig. ...
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... chemical composition of the main gas compounds (in mmol/ mol) of the 21 gas discharges (13 mud volcanoes (Fig. 3a), 2 dry gas vents (Fig. 3b), 1 well from Emilia-Romagna (Fig. 1b), and 4 mud vol- canoes and 1 bubbling gas from Sicily, southern Italy (Fig. 2)), ana- lyzed in the present study, is reported in Table 1. These gases are dominated by CH 4 that ranges from 931 to 988 mmol/mol, with the only exception of the Vallone Salato (VS), Simeto (Si) and Stadio (St) gases (Fig. 2), which have relatively high CO 2 concentrations (from 582 to 935 mmol/mol). Significant contents of N 2 , CO 2 ...
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... (Fig. 3b), 1 well from Emilia-Romagna (Fig. 1b), and 4 mud vol- canoes and 1 bubbling gas from Sicily, southern Italy (Fig. 2)), ana- lyzed in the present study, is reported in Table 1. These gases are dominated by CH 4 that ranges from 931 to 988 mmol/mol, with the only exception of the Vallone Salato (VS), Simeto (Si) and Stadio (St) gases (Fig. 2), which have relatively high CO 2 concentrations (from 582 to 935 mmol/mol). Significant contents of N 2 , CO 2 , O 2 and Ar (up to 41.5, 17.9, 2.85 and 1.05 mmol/mol, respectively) char- acterize the CH 4 -dominated gases, whereas He does not exceed 0.026 mmol/mol. VS, Si and St gases have significant CH 4 (up to 390 mmol/mol) ...
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... of gases: 1) "MVA", including the CH 4 -dominated gases from the Emilia Apennines, i.e. Rivalta (Ri), Torre (To), Casola-Querzola (C-Q), Macognano (Ma), Regnano (Re), Canalina (Ca), Puianello (Pu), Nirano (Ni), Montegibbio (Mg), Ospita- letto (Os), Portico di Romagna (PdR1 and PdR2) (Fig. 1b), and the Maccalube di Aragona (Ma) gas from Sicily (Fig. 2), display propor- tionally high concentrations of cyclic compounds; 2) "MVB", consist- ing of the three CO 2 -rich gases (VS, Si and St; Fig. 2) and the CH 4 -rich gas from Fondachello (Fo) (Fig. 2), is dominated by aromatics; 3) "MVC", which has relatively low concentrations of both cyclic and ar- omatic compounds and includes the DdS, ...
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... (Ma), Regnano (Re), Canalina (Ca), Puianello (Pu), Nirano (Ni), Montegibbio (Mg), Ospita- letto (Os), Portico di Romagna (PdR1 and PdR2) (Fig. 1b), and the Maccalube di Aragona (Ma) gas from Sicily (Fig. 2), display propor- tionally high concentrations of cyclic compounds; 2) "MVB", consist- ing of the three CO 2 -rich gases (VS, Si and St; Fig. 2) and the CH 4 -rich gas from Fondachello (Fo) (Fig. 2), is dominated by aromatics; 3) "MVC", which has relatively low concentrations of both cyclic and ar- omatic compounds and includes the DdS, Be and CR mud volcanoes and the BdR well (Fig. ...
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... Nirano (Ni), Montegibbio (Mg), Ospita- letto (Os), Portico di Romagna (PdR1 and PdR2) (Fig. 1b), and the Maccalube di Aragona (Ma) gas from Sicily (Fig. 2), display propor- tionally high concentrations of cyclic compounds; 2) "MVB", consist- ing of the three CO 2 -rich gases (VS, Si and St; Fig. 2) and the CH 4 -rich gas from Fondachello (Fo) (Fig. 2), is dominated by aromatics; 3) "MVC", which has relatively low concentrations of both cyclic and ar- omatic compounds and includes the DdS, Be and CR mud volcanoes and the BdR well (Fig. ...
Citations
... Quantitative analysis implied the use of a proper external standard calibration procedure. This was based on calibration curves constructed by measuring Accustandard® standard liquid mixtures in methanol or, alternatively, hexane solvents at increasing concentrations as described by Tassi et al. (2012a). The relative standard deviation computed by five replicate analyses of the standard mixture was <5 %. ...
... Relevant similarities and interesting differences were observed among the chemical composition of VOCs in the geogenic gases from different sites, indicating the action of local site-specific constraints (Fig. 3). The composition of VOCs in all geogenic gases was dominated by alkanes (Fig. 3), consistently with other natural gaseous exhalations worldwide (e.g., Tassi et al., 2012aTassi et al., , 2012cTassi et al., , 2010Whelan and Hunt, 1983). The alkane series invariably exhibited a general decreasing trend of concentrations with increasing carbon numbers (Tables S.1 and S.2; Tassi et al., 2015aTassi et al., , 2015bVenturi et al., 2024). ...
... Cyclic compounds in volcanic/hydrothermal gases (LFCgas and BdLgas) did not occur or were found in low concentrations (Fig. 3), in agreement with previous findings (Tassi et al., 2010), whilst these VOCs are generally enriched in oil and biogenic gases (Guzmán et al., 2022;Hu et al., 2010;Polyakov and Horita, 2021). In volcanic-hydrothermal fluids, i.e., at relatively high temperatures and oxidising conditions, the catalytic dehydrogenation and aromatisation of cyclics are favoured (Konn et al., 2015;Tassi et al., 2012a;Venturi et al., 2017), whilst this process is not efficient in gases from systems at decreasing enthalpy (MZgas, NPgas, PdUgas, SFgas, and TCMgas) that showed, consequently, increasing concentrations of cyclics (Fig. 3). Aromatics were detected in significant amounts in the volcanic and hydrothermal exhalations, whilst they were found in subordinate amounts in TCMgas (Fig. 3). ...
... The brackish waters making up the mud are likely to be connate pore marine entrapped in the Plio-Pleistocene sediments as supported by the isotopic signatures of δD and δ 18 O (Conti et al., 2000;Heller et al., 2011;Martinelli and Judd, 2004;Minissale et al., 2000;Oppo et al., 2013;Sciarra et al., 2019). Geochemical studies on gas and water samples have also revealed that the gas consists of a mixture of primary and secondary thermogenic gases due to thermal cracking of oil, biogenic CH 4 due to biodegradation of oils, with minor condensates and oil (Oppo et al., 2017;Tassi et al., 2012). ...
... Geochemical and isotopic investigations by Sciarra et al. (2019) on the gases exiting the vents confirm a thermogenic origin for the methane originating from organic material at temperatures higher than 100 • C (Whiticar and Suess, 1990). Sciarra et al. (2019) also analyze the CO 2 isotopes and suggest that the strongly positive δ 13 C-CO 2 indicates that the CO 2 is caused by anaerobic oxidation of heavy hydrocarbons (Pallasser, 2000), followed by secondary methanogenesis (Tassi et al., 2012). This process depends on the reservoir microbial communities, as well as its pressure-temperature conditions, and can strongly enrich the residual CO 2 in 13 C (Etiope et al., 2009;Wang et al., 2005). ...
... Furthermore, the lack of direct correlation between rainfall and gas discharge rate variations at the three sampled vents suggests that this eruptive system may be not simply controlled by shallow meteoric water dynamics (i.e., increase in fluxes after recent rainfall and consequent recharge of the shallow water reservoir). More specifically, this system may be associated with more complex mudfluid-water reservoirs localized at greater depth below the superficial aquifers, and controlled by the input of deep gases from the larger CR (Bicocchi et al., 2013), in a similar fashion to other wellknown mud volcano systems located along the Apennine foothills (e.g., the Salse di Nirano in Emilia Romagna, and the Monteleone di Fermo mud volcanoes, Marche; e.g., Etiope et al., 2007;Capozzi and Picotti, 2010;Tassi et al., 2012;Maestrelli et al., 2017Maestrelli et al., , 2019. ...
The CO2-(N2)-rich pressurised Caprese Reservoir (Northern Apennines, central Italy) is a structural system controlled by a subsurface fold anticline. Mud volcano-like structures and cold gas seeps lie along steep, ~NE-trending faults, which are intimately connected to the deep fluid reservoir. In August 2010, five vents erupted mud flows after a local, small magnitude seismic sequence (MLmax 3.2). Although the exact dates of such paroxysmal episodes are unknown, they occurred within 55 days after the main shocks. These eruptions are evidence of triggered responses of mud volcano-like vents induced by earthquakes with small magnitude (ML3.0–3.2). Static stresses at the erupted vents are negligible, thereby dynamic strain is inferred to be the sole triggering mechanism. The main earthquakes produced a near-vent peak ground velocity (PGV) of ~0.5 cm s−1 (ML3.2)
and ~ 0.2 cm s−1 (ML3.0). Although small, they are similar to other PGV values that triggered eruptive events in similar systems worldwide. A potential triggering mechanism can be searched in the enhanced permeability of fluid pathways produced by the passage of seismic waves. Fluid pressurization within the antiformal-shaped Caprese Reservoir by seismic wave focusing can also have played a significant role. This implies that seismic waves carrying even small perturbing stresses have the ability to stimulate hydrogeological systems to produce eruptions. Furthermore, our investigations allowed to assess the relationship between distance and earthquake magnitude for an M ~ 3 event, and corroborate the validity of some existing empirical triggering thresholds of mud volcano-like systems even in the case of small earthquake magnitudes.
... The brackish waters making up the mud are likely to be connate pore marine entrapped in the Plio-Pleistocene sediments as supported by the isotopic signatures of δD and δ 18 O (Conti et al., 2000;Heller et al., 2011;Martinelli and Judd, 2004;Minissale et al., 2000;Oppo et al., 2013;Sciarra et al., 2019). Geochemical studies on gas and water samples have also revealed that the gas consists of a mixture of primary and secondary thermogenic gases due to thermal cracking of oil, biogenic CH 4 due to biodegradation of oils, with minor condensates and oil (Oppo et al., 2017;Tassi et al., 2012). ...
... Geochemical and isotopic investigations by Sciarra et al. (2019) on the gases exiting the vents confirm a thermogenic origin for the methane originating from organic material at temperatures higher than 100 • C (Whiticar and Suess, 1990). Sciarra et al. (2019) also analyze the CO 2 isotopes and suggest that the strongly positive δ 13 C-CO 2 indicates that the CO 2 is caused by anaerobic oxidation of heavy hydrocarbons (Pallasser, 2000), followed by secondary methanogenesis (Tassi et al., 2012). This process depends on the reservoir microbial communities, as well as its pressure-temperature conditions, and can strongly enrich the residual CO 2 in 13 C (Etiope et al., 2009;Wang et al., 2005). ...
... Recent investigations (Tassi et al., 2012;Bonini et al., 2013) found the C 4 -C 10 fraction of thermogenic gases discharged by mud volcanoes and seeps located in the Emilia Apennines enriched in cyclic compounds with respect to alkanes and aromatics. This feature was attributed to the incomplete aromatization of organic matter during thermal maturation at temperatures not exceeding 120-150 • C at >3000 m depth. ...
... Furthermore, based on the relative concentration of cyclic compounds with respect to the total cyclic abundance (Fig. 9), three main patterns can be distinguished: (i) enrichment in C 6 cyclic compounds (cyclohexane and methycyclopentane) in the Cavone gases; (ii) enrichment in mono-and di-methylated cyclohexane and cyclopentane in the Spilamberto and San Martino gases and (iii) enrichment in dimethylcyclopentane and trimethylcyclohexane in Sillaro and Dosso Angeli gases. The paucity of methylated species and the high contents of aromatic compounds in the Cavone gases may be ascribed to the progressive expulsion of methyl groups from the cyclic rings and the consequent aromatization of the source organic matter as the maturity increases (Tassi et al., 2012). ...
... Cyclic compounds at Spilamberto and San Martino display a pattern approaching those observed for the thermogenic gases discharged from mud volcanoes and seeps at the Emilia Apennines, suggesting a common source rock of a predominant terrigenous origin (likely the Marnoso Arenacea; Lindquist, 1999;Tassi et al., 2012). Degradation of carotenoids during the early stage of organic matter transformation into kerogen could instead be responsible for the high relative concentrations of trimethylcyclohexane in the Sillaro and Dosso Angeli gases. ...
This paper presents new chemical and isotopic data on gases from deep oil and gas fields, bubbling gases, dissolved gases in groundwaters and dry seeps of the Southern Po River Basin (Emilia-Romagna, Italy), aiming to (i) characterize and differentiate the various types of deep natural gases; (ii) identify the source(s) of methane and light hydrocarbons in shallow aquifers and surface gas-rich emissions; (iii) propose a conceptual model of natural fluid migration pathways in the sedimentary prism of the Southern Po River Basin. Based on the isotopic composition of CH4 and C2–C4 n-alkanes, CH4/(C2H6+C3H8) ratio, relative proportion of the C7 hydrocarbons and relative concentration of cyclic compounds with respect to the total cyclic abundance, three main deep reservoirs of hydrocarbons are identified in the subsurface of the Southern Po River Basin: (1) microbial gas hosted in Pliocene-Pleistocene marine sediments, (2) thermogenic gas hosted in Miocene deposits and (3) thermogenic gas produced in Triassic carbonates. Helium isotopes of these deep fluids indicate an almost pure crustal origin (Rc/Ra values = 0.014–0.04), with negligible contributions from mantle-derived helium. A variable contribution of atmosphere-derived fluids is highlighted by low ⁴He/²⁰Ne (down to 5.42) and ⁴⁰Ar/³⁶Ar (≤319.5) values. Comparison of chemical and isotopic signatures of deep and surficial hydrocarbon occurrences suggests that methane in shallow groundwaters or gas seeps is sourced by microbial gas migrating upward from deep Plio-Pleistocene reservoirs, with no detectable contributions of Triassic or Miocene thermogenic hydrocarbons. At shallow depths (roughly around 20–50 m.b.g.l.), Plio-Pleistocene microbial methane appears to be mainly stored in anoxic aquifers. However, where CH4 further migrates upwards and reaches aerobic environments (e.g., aquifers or soils), it readily undergoes a process of exothermic microbial oxidation mediated by methanotrophic bacteria. Instead, where the structural architecture of the sedimentary sequence favors the upward migration of fluids, the methanotrophic biofilter is bypassed and CH4 is discharged through soil diffuse degassing or gas bubbling at water wells. We argue that microbial consumption might be able to bio-sequester significant amounts of Plio-Pleistocene deep-sourced methane in the form of CO2 and biomass. Such process might be widespread in the subsurface of the Southern Po River Basin and, possibly, in other foreland basins worldwide.
... The saline composition, δD and δ 18 O signatures indicate that part of the waters originates from marine connate pore waters entrapped in the Miocene and Plio-Pleistocene sediments during marine deposition, with no contamination from recent meteoric water (Conti et al. 2000;Minissale et al. 2000;Martinelli and Judd 2004;Heller et al. 2011;Oppo et al. 2013). Geochemical analyses, of both water and gas samples, show that the gas contained in these reservoirs is mainly a mixture of primary and secondary thermogenic gases (due to thermal cracking of oil), and secondary biogenic methane (due to biodegradation of oils), with minor condensates and oil (Tassi et al. 2012;Oppo et al. 2017). Several authors (Mattavelli et al. 1983(Mattavelli et al. , 1993Riva et al. 1986;Martinelli et al. 2012) recognize that in this region of the Northern Apennines, the hydrocarbons (gas and oil) originate in the turbiditic sequences of the Tertiary Marnosa-Arenacea Fm. ...
The Nirano Salse, known since the Roman Times, are one of the most beautiful and scenic mud volcanoes areas of Italy with thousands of visitors every year. In this work, we apply novel (for the context) hydrogeological techniques to characterize mud levels in the Salse by means of GPS-RTK positioning and continuous level logging within mud conduits. This is important to quantify the gas–liquid ratio in the conduits and evaluate the potential for dangerous abrupt mud eruptions. The results presented suggest that different mud levels in mud volcanoes clusters are due to the different gas–liquid ratio in the conduits and not necessarily exclude interconnection at depth, a hypothesis, on the other hand, that seems strengthened by mud level time series correlations. The presence of shallow aquifers at a depth of 5 to 30 m is also supported by our field data and allows us to delineate the boundaries of the shallow mud reservoir—pipes system and its overall shape. The shallow aquifers may provide a temporary storage for the ascending gas and when fluid pressure in these aquifers exceeds the tensional strength of the sedimentary rock, leakage of fluids to the surface would occur. In this case, if the gas–liquid ratio is high, mud volcanoes develop into tall gryphons and tend to have a discontinuous activity with sudden eruptions of mud after long periods of quiescence. This, together with the knowledge of shallow conduits localization has an important implication for site safety in proximity to the mud volcanoes. Our inferences based on mud level relationships to mud extrusion dynamics can be applied to lower risk in other mud volcanoes areas of the world with high geo-tourist visits, such as those of Trinidad, Azerbaijan, and Colombia.
... hydrocarbons (LHs) associated with gas contain abundant geochemical information, so they have been widely used to determine the genetic type and origin of natural gas (Hu et al., 1990;Dai, 1993;Mango, 1997;Tassi et al., 2012;Hu et al., 2018). In particular, the iso/normal alkane ratio, normal heptane (nC 7 ), methylcyclohexane (MCH), and total dimethylcyclopentane (DMCP) ternary diagram are usually utilized to identify the type of organic source. ...
To understand the effect of thermochemical sulphate reduction (TSR) on the stable carbon isotopes of light hydrocarbons (LHs) associated with natural gas, 15 gases with varying H2S content from Ordovician reservoir of the Tazhong gas field (TZ-I) in Tarim Basin and Triassic Leikoupo reservoir of the Zhongba gas field (ZB) in Sichuan Basin were collected. Based on the data from molecular components and stable carbon isotope ratios of the C1-C4 alongside the individual LHs (C6-C7) in these gases, the origin of natural gas and the effect of TSR on the stable carbon isotope ratio of individual LHs were studied. The δ¹³C in ethane (<−28‰), LHs (<−26‰) and the composition distribution characteristic of C6-C7 indicated that the gases were oil-associated gases. Moreover, the gas sourness index, defined as H2S/(H2S+∑Cn) demonstrated that the gases from the TZ-I and ZB gas fields were in the early liquid-hydrocarbon-involved and heavy-hydrocarbon-gas-dominated TSR stages, respectively. The comparison of stable carbon isotope ratios of the LHs between the two gas fields revealed that TSR exhibited a complex effect on the carbon isotope values of LHs, but only little effect on 2-methylpentane (2-MP) and 3-methylpentane (3-MP). The δ¹³C values of benzene (BEN) and toluene (TOL) were -28.3‰ and -29.4‰ in the TZ-I and -27.7‰ and -28.1‰ in the ZB gas field. The stable carbon isotope ratios of BEN and TOL in ZB gas field exhibited more enriched ¹³C than those in TZ-I gas field, likely driven by TSR. Meanwhile, cycloalkanes, such as methyl cyclopentane (MCP), cyclohexane (CH), and methylcyclohexane (MCH), enriched ¹³C with TSR process and displayed a greater trend than aromatic compounds, about 2‰. Therefore, the influence of TSR on the carbon isotopes of individual LHs should be considered while using the stable carbon isotope ratio of cycloalkanes, BEN, and TOL to identify the genetic type and source of marine natural gas, especially at the cross plot (δ¹³C = −24‰) of coal-derived gas and oil-associated gas.
... The mud extrusion is driven by the adiabatic expansion of methane during the ascent and the consequent decrease in the uid density compared to the surrounding rocks(Martinelli et al., 2012;Mattavelli et al., 1983;Mattavelli and Novelli, 1988), and the increase in overpressure where gas accumulates (bottlenecks in the conduits and reservoirs).The saline composition, δD and δ 18 O signatures indicate that part of the waters originates from marine connate pore waters entrapped in the Miocene and Plio-Pleistocene sediments during marine deposition, with no contamination from recent meteoric water (Conti et al., 2000; Heller et al., 2011; Martinelli and Judd, 2004; Minissale et al., 2000; Oppo et al., 2013). Geochemical analyses, both on water and gas samples, show that the gas contained in these reservoirs is mainly a mixture of primary and secondary thermogenic gases (due to thermal cracking of oil), and secondary biogenic methane (due to biodegradation of oils), with minor condensates and oil(Oppo et al., 2017;Tassi et al., 2012). Several authors(Martinelli et al., 2012;Mattavelli et al., 1983Mattavelli et al., , 1993Riva et al., 1986) recognize that in this region of the Northern Apennines, the hydrocarbons (gas and oil) originate in the turbiditic sequences of the Tertiary Marnosa Arenacea Fm. ...
The Nirano Salse , known since the Roman Times, are one of the most beautiful and scenic mud volcanoes areas of Italy with thousands of visitors every year. In this work, we apply hydrogeological techniques to characterize mud levels in the Salse by means of GPS-RTK positioning and continuous level logging within mud conduits. Our results suggest that different mud levels in mud volcanoes clusters are due to the different gas-liquid ratio in the conduits and not necessarily exclude interconnection at depth, a hypothesis, on the other hand, that seems strengthened by mud level time series correlations. The presence of shallow aquifers at a depth of 5 to 30 m is also supported by our field data. These shallow aquifers may provide a temporary storage for the ascending gas and when fluid pressure in these aquifers exceeds the tensional strength of the sedimentary rock, leakage of fluids to the surface would occur.
... Feizi et al. (2015) mentioned Mud Volcano in the coastal Iranian side (the Napag) has been controlled by tensional tectonic forces, that have been considerable during the roll-back of oceanic lithosphere in the Makran subduction zone (beneath of Oman Sea). Organic gas compounds associated with mud volcanism are typically dominated by CH4 (Dia et al., 1999;Dimitrov, 2002;Etiope et al., 2004), with significant concentrations of heavier hydrocarbons, CO2, H2S, N2, and noble gases (Blinova et al., 2003;Tassi et al., 2012). Mud volcanoes emitting CO2-rich fluids were occasionally recognized close to volcanic areas (Chiodini et al., 1996;Giammanco et al., 2007;Tassi et al., 2012;Yang et al., 2004), though, Schlüter et al. (2002) argued presence of higher hydrocarbon illustrate thermally more mature source rock. ...
... Organic gas compounds associated with mud volcanism are typically dominated by CH4 (Dia et al., 1999;Dimitrov, 2002;Etiope et al., 2004), with significant concentrations of heavier hydrocarbons, CO2, H2S, N2, and noble gases (Blinova et al., 2003;Tassi et al., 2012). Mud volcanoes emitting CO2-rich fluids were occasionally recognized close to volcanic areas (Chiodini et al., 1996;Giammanco et al., 2007;Tassi et al., 2012;Yang et al., 2004), though, Schlüter et al. (2002) argued presence of higher hydrocarbon illustrate thermally more mature source rock. ...
Makran has a largely unconstrained seismogenic potential although GPS data indicate the subduction is accumulating some strain to be released during future earthquakes. I first build a structural map along the Iranian part of the Oman Sea which indicates three segments. Then, I retrieve the pore fluid pressure and the frictional properties of the wedge with the critical taper theory and the limit analysis. The results show that along the eastern and western profiles, a transition from very low to extremely low friction is required to activate the large coastal normal fault. To propagate the deformation to the front, an increase of friction along the imbricated zone is necessary.The Makran Models are calibrated the thermal parameters and boundary conditions of the numerical simulations using seafloor and bottom sea reflector depth and few available well data. Considering two décollements, the results show that, -underplating is associated to viscous deformation -dewatering and smectite/illite transition permit to produce three slope segments observed in accretionary prisms but this friction drop is not sufficient for formation of normal faults. - the subduction of a large seamount is accompanied by large normal faults, while their location migrates through time. If the brittle décollements have a seismogenic behavior, the down-dip limit of the seismogenic zone will correspond to the onset of underplating. By assuming that the up-dip limit of seismic asperities correlates with smectite-illite transition, then a seismic asperity may extend from this transition, down to the onset of underplating, and correlate with a relatively flat topography.
... Gaz ve su çıkışları ile sıkı ilişkili olan bu volkanlar, genellikle antiklinal doruklarına veya kıvrımlanma sonucu oluşan kırıklara yakın yerlerde oluşurlar [114]. Çamur volkanları ve petrol sistemleri arasındaki yakın ilişki, birçok çalışmada kanıtlanmıştır [115][116][117][118][119][120][121][122][123][124][125][126][127][128][129]. Dolayısıyla, Erdoğan [53] ve Festa ve diğ. ...
Literatürde, hidrokarbon birikimleri ve altın cevherleşmeleri arasındaki bağlantılar incelenmiştir. Bu çalışmalardan elde edilen sonuçlara göre, altın ve hidrokarbonların aynı hidrotermal akışkanlar tarafından taşındığı ve çökeltildiği tespit edilmiştir. Seferihisar Yükselimi’nde, Türkiye’nin kanıtlanmış en büyük altın cevheri rezervine sahip Efemçukuru Altın İşletmesi bulunmaktadır. Bu nedenle, Seferihisar Yükselimi’nin petrol ve doğalgaz potansiyelinin soğuksu kaynaklarından alınan örnekler üzerinde Toplam Petrol Hidrokarbonları (TPH) analizleri yapılarak araştırılması amaçlanmıştır. Yapılan analizler sonucunda, su numunelerinin tamamında hidrokarbonlar tespit edilmiştir. Sularda tespit edilen hidrokarbonların kaynağının belirlenmesi için organik jeokimyasal yöntemler kullanılmıştır. Su numunelerinde belirlenen n-alkan hidrokarbonlar, olgun petrol hidrokarbonlarıdır. Bu olgun petrol hidrokarbonları, çalışma alanında çalışan bir petrol sisteminin varlığı için jeokimyasal bir kanıttır. Dolayısıyla, gravite ve manyetik verilere göre çalışma alanında belirlenen maksimum 765 m derinliğindeki yapının bir petrol ve/veya doğalgaz rezervuarı olma potansiyeli oldukça yüksek olarak değerlendirilmiştir.
Anahtar Kelimeler: rezervuar hedefli petrol ve doğalgaz arama, suda TPH analizi, hidrokarbonca zengin su, Bornova Filiş Zonu, altın yatağı
