All ICDP Publications with Abstracts
From parent-sysfolder "Publications" + 2 folder-levels deep
2769.
Early Diagenesis in the Lacustrine Ostracods from the Songliao Basin 91.35 Million Years Ago and Its Geological Implications
Minerals,
13
(1)
2023
2768.
An astronomical time scale for the Early Cretaceous continental strata in the Songliao Basin, Northeastern China (in Chinese with English abstract); [松辽盆地松科2井早白垩世沙河子组天文年代标尺]
Quaternary Sciences,
43
(6)
1573-1583
2023
2767.
Effect of Pressure Perturbations on CO2 Degassing in a Mofette System: The Case of Hartoušov, Czech Republic
Geosciences (Switzerland),
13
(1)
2023
ISSN: 20763263
Publisher: MDPI
Abstract: ▾ Mofettes are gas emission sites where high concentrations of CO2 ascend through conduits from as deep as the mantle to the Earth’s surface and as such provide direct windows to processes at depth. The Hartoušov mofette, located at the western margin of the Eger Graben, is a key site to study interactions between fluids and swarm earthquakes. The mofette field (10 mofettes within an area of 100 m × 500 m and three wells of 28, 108, and 239 m depth) is characterized by high CO2 emission rates (up to 100 t/d) and helium signatures with (3He/4He)c up to 5.8 Ra, indicating mantle origin. We compiled geological, geophysical, geochemical, and isotopic data to describe the mofette system. Fluids in the Cheb basin are mixtures between shallow groundwater and brine (>40 g/L at a depth of 235 m) located at the deepest parts of the basin fillings. Overpressured CO2-rich mineral waters are trapped below the mudstones and clays of the sealing Cypris formation. Drilling through this sealing layer led to blow-outs in different compartments of the basin. Pressure transients were observed related to natural disturbances as well as human activities. External (rain) and internal (earthquakes) events can cause pressure transients in the fluid system within hours or several days, lasting from days to years and leading to changes in gas flux rates. The 2014 earthquake swarm triggered an estimated excess release of 175,000 tons of CO2 during the following four years. Pressure oscillations were observed at a wellhead lasting 24 h with increasing amplitudes (from 10 to 40 kPa) and increasing frequencies reaching five cycles per hour. These oscillations are described for the first time as a potential natural analog to a two-phase pipe–relief valve system known from industrial applications. © 2022 by the authors.
2766.
In-situ physical and elastic properties of Archaean basement granitoids
in the Koyna seismogenic zone, western India from 3 km downhole
geophysical well logs: Implications for water percolation at depth
TECTONOPHYSICS,
848
2023
Keywords:▾
Fault zone; Downhole geophysical logs; Recurrent earthquakes; Scientific
drilling; Koyna; India
2765.
Milankovitch cycle identification of Denglouku Formation
in Songliao Basin and its paleoclimate significance (in Chinese with English abstract); [松科3井下白垩统登娄库组米兰科维奇旋回识别及其古气候意义]
Sedimentary Geology and Tethyan Geology
2023
2764.
Enrichment of rare methanogenic Archaea shows their important ecological role in natural high-CO2 terrestrial subsurface environments
Frontiers in Microbiology,
14
2023
2763.
Magmatism during the continent - ocean transition
EARTH AND PLANETARY SCIENCE LETTERS,
614
2023
Keywords:▾
rifting; East Africa; Afar Stratoid Series; magmatism
2762.
Joint passive seismic imaging based on surface wave inversion and reflection wavefield retrieval: A case study in the sedimentary basin areas adjacent to Well Songke-2
Journal of Applied Geophysics,
208
2023
ISSN: 09269851
Publisher: Elsevier B.V.
Keywords:▾
China; Songliao Basin; Acoustic noise; Cost effectiveness; Sedimentology; Seismic prospecting; Seismic response; Shear waves; Signal to noise ratio; Surface waves; Underground structures; Wave energy conversion; Wave propagation; Ambient noise; Ambient noise seismic interferometry; Geological interpretation; High-mode surface wave inversion; Higher mode; Sedimentary basin; Sedimentary basin geological interpretation; Seismic interferometries; Songliao basin; Surface wave inversion; Well songke-2; ambient noise; sedimentary basin; seismic reflection; seismic wave; surface wave; wave field; Seismic waves
Abstract: ▾ Owing to their cost-effectiveness, environmental friendliness, and high-efficiency, passive seismic methods are widely used in geophysical exploration. However, field passive seismic data suffer from low signal-to-noise ratio, as well as the fact that different types of seismic waves are naturally mixed together, which can affect the accuracy of subsurface imaging results and the subsequent geological interpretation. In this paper, we demonstrate that these problems can be addressed and present a case study on passive seismic detection in sedimentary basin areas adjacent to Well Songke-2 in Songliao Basin. To obtain accurate and reliable imaging results of the sedimentary strata, a detailed practical scheme is proposed, where fundamental and higher mode surface wave dispersion curves are inverted for obtaining the near-surface S-wave velocity profile, and the body wave component of ambient noise is utilized to retrieve the reflection wavefield information. The obtained profiles from surface wave inversion and reflection wavefield retrieval illustrate similar underground structures. The marker boundaries T2 (1.5 s) and T4 (2.1 s) are well demonstrated, and a low velocity stratum (0.4 s) is detected at a shallow depth of around 400–600 m. Further, the results are highly consistent with the data obtained from borehole logging of Well Songke-2 and the deep reflection seismic profile adjacent to this area, which indicates that the surface wave and body wave in passive seismic data can be utilized together to contribute to a detailed and accurate subsurface imaging and interpretation. Overall, this study investigated and validated the reliability and accuracy of the combination use of passive seismic methods for geological structure exploration, which can further boost their applications for geological interpretation in sedimentary basin areas. © 2022 Elsevier B.V.
2761.
Iron-mediated anaerobic ammonium oxidation recorded in the early Archean
ferruginous ocean
GEOBIOLOGY,
21
(3)
277-289
2023
Keywords:▾
ammonium oxidation; biogeochemistry; Buck Reef Chert; Feammox;
ferruginous ocean; nitrogen isotopes; Paleoarchean
Abstract: ▾ The nitrogen isotopic composition of organic matter is controlled by metabolic activity and redox speciation and has therefore largely been used to uncover the early evolution of life and ocean oxygenation. Specifically, positive delta N-15 values found in well-preserved sedimentary rocks are often interpreted as reflecting the stability of a nitrate pool sustained by water column partial oxygenation. This study adds much-needed data to the sparse Paleoarchean record, providing carbon and nitrogen concentrations and isotopic compositions for more than fifty samples from the 3.4 Ga Buck Reef Chert sedimentary deposit (BRC, Barberton Greenstone Belt). In the overall anoxic and ferruginous conditions of the BRC depositional environment, these samples yield positive delta N-15 values up to +6.1% . We argue that without a stable pool of nitrates, these values are best explained by non-quantitative oxidation of ammonium via the Feammox pathway, a metabolic co-cycling between iron and nitrogen through the oxidation of ammonium in the presence of iron oxides. Our data contribute to the understanding of how the nitrogen cycle operated under reducing, anoxic, and ferruginous conditions, which are relevant to most of the Archean. Most importantly, they invite to carefully consider the meaning of positive delta N-15 signatures in Archean sediments.
2760.
Insights into organic metagenesis using Raman spectroscopy and high resolution mass spectrometry: A case study of the Shahezi formation, deep Songliao basin, China
International Journal of Coal Geology,
265
2023
ISSN: 01665162
Publisher: Elsevier B.V.
Keywords:▾
China; Songliao Basin; Aromatic compounds; Energy resources; Mass spectrometry; Organic lasers; Petroleum deposits; Raman spectroscopy; Reflection; Fourier transform ion cyclotron resonance mass spectrometry; Fourier-transform ion cyclotron resonance mass spectrometry; Laser Raman; Laser Raman spectroscopy; Maturity parameters; Raman parameters; Shahezi formations; Songliao basin; Source rocks; Vitrinite reflectance; Fourier transform; hydrocarbon resource; lithostratigraphy; mass spectrometry; organic compound; organic matter; Raman spectroscopy; source rock; vitrinite reflectance; Thermodynamic stability
Abstract: ▾ The maturity of sedimentary organic matter is a key parameter for evaluating oil and gas resources. Existing maturity indicators have different evaluation principles and application scopes. This study investigated samples of high to overmature lacustrine source rocks (Ro = 1.33%–4.24%) from the deep Shahezi formation in the Songliao basin, including the zone of catagenesis and metagenesis. Various methods, including vitrinite reflectance, Tmax, laser Raman spectroscopy, and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) were used to evaluate the samples' maturity. Through laser Raman analysis of representative samples from the Shahezi formation, most laser Raman parameters showed an inflection point or reversal when the thermal evolution of deep source rocks in the Shahezi formation reaches a certain stage. The variation trend of some Raman parameters and Ro has strong regularity (1.33% < Ro < 3.52%). Based on FT-ICR MS, this research analyzed the relative content and molecular composition of polycyclic and heterocyclic aromatic compounds in soluble organic matter of lake source rock samples and comparison samples (marine shale). Quantitative maturity evaluation of organic matter was performed by converting the signal intensity of each compound. The fitting results of maturity parameter based on FT-ICR MS and Tmax indicated that the maturity parameter of the samples have high coefficient of correlations with maturity in the vitrinite reflectance (Ro) range of 1.33%–2.5% and the Tmax range of 420 °C–600 °C. The maturity parameter values decreased as Ro exceeded 2.5% and Tmax exceeded 600 °C. These findings are attributed to the thermal stability of organic compounds and the formation of pyrobitumen and graphite. The parameters of laser Raman spectroscopy also confirmed the growth of aromatic rings reflected by the maturity parameters of FT-ICR MS. These two methods revealed the structural changes of organic matter in the thermal evolution process from multiple perspectives and provided insights for the maturity evaluation of deep source rocks. © 2022
2759.
Initial results of coring at Prees, Cheshire Basin, UK (ICDP JET project): towards an integrated stratigraphy, timescale, and Earth system
understanding for the Early Jurassic
Scientific Drilling,
321--25
2023
2758.
Incompatibility between serpentinization and epidote formation in the
lower oceanic crust: Evidence from the Oman Drilling Project
JOURNAL OF METAMORPHIC GEOLOGY,
41
(5)
2023
Keywords:▾
epidote; lower oceanic crust; olivine gabbro; Oman ophiolite; prehnite;
serpentinization
2757.
Machine-learning-based morphological analyses of leaf epidermal cells in
modern and fossil ginkgo and their implications for palaeoclimate
studies
PALAEONTOLOGY,
66
2023
Keywords:▾
Ginkgo; epidermal cell; micro-character; machine learning; palaeoclimate
parameter
2756.
Implications of a short carbon pulse on biofilm formation on mica schist in microcosms with deep crystalline bedrock groundwater
Frontiers in Microbiology,
14
2023
ISSN: 1664302X
Publisher: Frontiers Media S.A.
Keywords:▾
acetic acid; carbon; ground water; methane; methanol; mica; RNA 16S; Actinobacteria; archaeon; Article; Ascomycetes; Basidiomycetes; bedrock; biofilm; Desulfobulbus; DNA extraction; Escherichia coli; Firmicutes; fungal community; gene sequence; microbial community; microbial diversity; microcosm; nonhuman; Proteobacteria; real time polymerase chain reaction
Abstract: ▾ Microbial life in the deep subsurface occupies rock surfaces as attached communities and biofilms. Previously, epilithic Fennoscandian deep subsurface bacterial communities were shown to host genetic potential, especially for heterotrophy and sulfur cycling. Acetate, methane, and methanol link multiple biogeochemical pathways and thus represent an important carbon and energy source for microorganisms in the deep subsurface. In this study, we examined further how a short pulse of low-molecular-weight carbon compounds impacts the formation and structure of sessile microbial communities on mica schist surfaces over an incubation period of ∼3.5 years in microcosms containing deep subsurface groundwater from the depth of 500 m, from Outokumpu, Finland. The marker gene copy counts in the water and rock phases were estimated with qPCR, which showed that bacteria dominated the mica schist communities with a relatively high proportion of epilithic sulfate-reducing bacteria in all microcosms. The dominant bacterial phyla in the microcosms were Proteobacteria, Firmicutes, and Actinobacteria, whereas most fungal genera belonged to Ascomycota and Basidiomycota. Dissimilarities between planktic and sessile rock surface microbial communities were observed, and the supplied carbon substrates led to variations in the bacterial community composition. Copyright © 2023 Nuppunen-Puputti, Kietäväinen, Kukkonen and Bomberg.
2755.
Evaluating geophysical logs as proxies for cyclostratigraphy in lacustrine deposits using power ratio accumulation
Palaeogeography, Palaeoclimatology, Palaeoecology,
614
2023
2754.
Hydrogeochemical and isotopic signatures elucidate deep subsurface hypersaline brine formation through radiolysis driven water-rock interaction
Geochimica et Cosmochimica Acta,
34065-84
2023
ISSN: 0016-7037Keywords:▾
Groundwater, Brine, Radiolysis, Isotope geochemistry, Deep biosphere
Abstract: ▾ Geochemical and isotopic fluid signatures from a 2.9–3.2 km deep, 45–55 °C temperature, hypersaline brine from Moab Khotsong gold and uranium mine in the Witwatersrand Basin of South Africa were combined with radiolytic and water–rock isotopic exchange models to delineate brine evolution over geologic time, and to explore brine conditions for habitability. The Moab Khotsong brines were hypersaline (Ca-Na-Cl) with 215–246 g/L TDS, and Cl− concentrations up to 4 mol/L suggesting their position as a hypersaline end-member significantly more saline than any previously sampled Witwatersrand Basin fluids. The brines revealed low DIC (∼0.266–∼1.07 mmol/L) with high (∼8.49–∼23.6 mmol/L) DOC pools, and several reduced gaseous species (up to 46 % by volume H2) despite microoxic conditions (Eh = 135–161 mV). Alpha particle radiolysis of water to H2, H2O2, and O2 along with anhydrous-silicate-to-clay alteration reactions predicted 4 mol/L Cl− brine concentration and deuterium enrichment in the fracture waters over a period > 1.00 Ga, consistent with previously reported 40Ar noble gas-derived residence times of 1.20 Ga for this system. In addition, radiolytic production of 7–26 nmol/(L × yr) H2, 3–11 nmol/(L × yr) O2, and 1–8 nmol/(L × yr) H2O2 was predicted for 1–100μ g/g 238U dosage scenarios, supporting radiolysis as a significant source of H2 and oxidant species to deep brines over time that are available to a low biomass system (102–103 cells/mL). The host rock lithology was predominately Archaean quartzite, with minerals exposed on fracture surfaces that included calcite, pyrite, and chlorite. Signatures of δ18Ocalcite, δ13Ccalcite, Δ33Spyrite, δ34Spyrite and 87Sr/86Sr obtained from secondary ion mass spectrometry (SIMS) microanalyses suggest several discrete fluid events as the basin cooled from peak greenschist conditions to equilibrium with present-day brine temperatures. The brine physiochemistry, geochemistry, and cellular abundances were significantly different from those of a younger, shallower, low salinity dolomitic fluid in the same mine, and both were different from the mine service water. These results indicate the discovery of one of few long-isolated systems that supports subsurface brine formation via extended water–rock interaction, and an example of a subsurface brine system where abiotic geochemistry may support a low biomass microbial community.
2753.
Holocene variations in Lake Titicaca water level and their implications for sociopolitical developments in the central Andes
Proceedings of the National Academy of Sciences of the United States of America,
120
(2)
2023
Keywords:▾
Climate; Lakes; Water; biological marker; organic carbon; water; Andes; archeology; Article; cultural anthropology; environmental parameters; geochemical analysis; geographic and geological phenomena; geographic elevation; Holocene; human; lake; lake basin; lake sediment; lake water level; Late Holocene; Middle Holocene; paleoecology; paleoeshoreline; politics; population migration; scientist; shoreline; social evolution; stable isotope labeling; chemistry; climate
Abstract: ▾ Holocene climate in the high tropical Andes was characterized by both gradual and abrupt changes, which disrupted the hydrological cycle and impacted landscapes and societies. High-resolution paleoenvironmental records are essential to contextualize archaeological data and to evaluate the sociopolitical response of ancient societies to environmental variability. Middle-to-Late Holocene water levels in Lake Titicaca were reevaluated through a transfer function model based on measurements of organic carbon stable isotopes, combined with high-resolution profiles of other geochemical variables and paleoshoreline indicators. Our reconstruction indicates that following a prolonged low stand during the Middle Holocene (4000 to 2400 BCE), lake level rose rapidly ~15 m by 1800 BCE, and then increased another 3 to 6 m in a series of steps, attaining the highest values after ~1600 CE. The largest lake-level increases coincided with major sociopolitical changes reported by archaeologists. In particular, at the end of the Formative Period (500 CE), a major lake-level rise inundated large shoreline areas and forced populations to migrate to higher elevation, likely contributing to the emergence of the Tiwanaku culture. Copyright © 2023 the Author(s).
2752.
Hierarchical Milankovitch and sub-Milankovitch cycles in the environmental magnetism of the lower Shahezi Formation, Lower Cretaceous, Songliao Basin, northeastern China
Frontiers in Earth Science,
11
2023
ISSN: 22966463
Publisher: Frontiers Media S.A.
Keywords:▾
China; Songliao Basin; Cretaceous; cyclostratigraphy; geomagnetism; hierarchical system; lacustrine deposit; Milankovitch cycle; paleoclimate; paleoenvironment
Abstract: ▾ SK-2 borehole in Songliao Basin provides unprecedented geological materials for investigating the Early Cretaceous continental paleoenvironment and paleoclimate in northeastern China. The lacustrine successions of the lower Shahezi (K1sh) Formation at the depth from 4,542 to 5,695 m was systematically studied using environmental magnetism and cyclostratigraphy in this study. Magnetic analysis reveals an inverse correlation between magnetic susceptibility (MS) and lithological ranks in fine clastic sediments, with the highest values in mudstones and the lowest in sandstones. The main magnetism carriers in the lower K1sh are pseudo-single-domain (PSD) and/or multi-domain (MD) magnetite with minor presence of hematite. MS was used to further explore the genesis of the environmental and climatic variations through cyclostratigraphic analysis. Sedimentary cycles of 113 m, 34 m, 13 m and 6 m can be identified in the power spectrum, which were interpreted as long and short eccentricity, obliquity, and precession cycles, demonstrating the impact of astronomical cyclicity on sedimentary rhythmicity. Floating astronomical time scale (FATS) of 4,090 kyr and 4,148 kyr were established by tuning the inferred long and short eccentricity cycles to the artificial 405-kyr and 105-kyr orbital eccentricity curves respectively. The estimated sediment accumulation rate around 28 cm/kyr confirms the rapid deposition process within the faulted lacustrine basin. Based on this study, the lake level oscillations in Songliao Basin are assumed to be shaped by long and short eccentricity, precession and semi-precession cycles during Early Cretaceous. This study also indicates that the sand-mudstone alternations deposition in K1sh is most likely driven by the seasonal discrepancies of summer insolation during semi-precession periods. Copyright © 2023 Zhang, Wu, Zhang, Yang, Li, Fang and Shi.
2751.
Environmental changes during the onset of the Late Pliensbachian Event (Early Jurassic) in the Cardigan Bay Basin, Wales
Climate of the Past,
19
(5)
979 – 997
2023
Keywords:▾
Cardigan Bay; United Kingdom; Wales; carbon cycle; chemical weathering; climate forcing; environmental change; orbital forcing; organic matter; paleoenvironment; palynology; Pliensbachian; thermohaline circulation
Abstract: ▾ The Late Pliensbachian Event (LPE), in the Early Jurassic, is associated with a perturbation in the global carbon cycle (positive carbon isotope excursion (CIE) of ∼2‰), cooling of ∼5C, and the deposition of widespread regressive facies. Cooling during the late Pliensbachian has been linked to enhanced organic matter burial and/or disruption of thermohaline ocean circulation due to a sea level lowstand of at least regional extent. Orbital forcing had a strong influence on the Pliensbachian environments and recent studies show that the terrestrial realm and the marine realm in and around the Cardigan Bay Basin, UK, were strongly influenced by orbital climate forcing. In the present study we build on the previously published data for long eccentricity cycle E459±1 and extend the palaeoenvironmental record to include E458±1. We explore the environmental and depositional changes on orbital timescales for the Llanbedr (Mochras Farm) core during the onset of the LPE. Clay mineralogy, X-ray fluorescence (XRF) elemental analysis, isotope ratio mass spectrometry, and palynology are combined to resolve systematic changes in erosion, weathering, fire, grain size, and riverine influx. Our results indicate distinctively different environments before and after the onset of the LPE positive CIE and show increased physical erosion relative to chemical weathering. We also identify five swings in the climate, in tandem with the 405kyr eccentricity minima and maxima. Eccentricity maxima are linked to precessionally repeated occurrences of a semi-arid monsoonal climate with high fire activity and relatively coarser sediment from terrestrial runoff. In contrast, 405kyr minima in the Mochras core are linked to a more persistent, annually wet climate, low fire activity, and relatively finer-grained deposits across multiple precession cycles. The onset of the LPE positive CIE did not impact the expression of the 405kyr cycle in the proxy records; however, during the second pulse of heavier carbon (13C) enrichment, the clay minerals record a change from dominant chemical weathering to dominant physical erosion. © 2023 Teuntje P. Hollaar et al.
2750.
Ground Surface Temperature History Since the Last Glacial Maximum in Northeast Asia: Reconstructions From the Borehole Geotherms of the International Continental Scientific Drilling Program
Geophysical Research Letters,
50
(8)
2023
2749.
Experimental study on nonlinear mechanical behavior and sampling damage characteristics of rocks from depths of 4900–6830 m in Well Songke-2; [松科二井4900~6830 m不同深度岩石非线性力学行为和取样损伤特性试验研究]
Journal of Central South University,
30
(4)
1296 – 1310
2023
ISSN: 20952899
Publisher: Central South University of Technology
Keywords:▾
Minerals; Sedimentary rocks; Sedimentology; Burial depths; Characteristic stress; Deep rocks; Deformation and failures; Different depth; Magmatic rock; Mechanical behavior; Sampling damage; Uni-axial compression tests; Well songke-2; Compression testing
Abstract: ▾ Based on the deep cores of Well Songke-2 (SK-2), uniaxial compression tests of deep rock from 8 different depths in the 4900–6830 m range were carried out, and deformation and failure characteristics were analyzed in detail. It was found that in the range of 4900–6830 m, the mechanical parameters of uniaxial compression tests of rocks changed nonlinearly with depth, and the strength was positively correlated with the hard mineral content. Comparing the rock failure of these samples with the 4500–7000 m core disc segment in SK-2, it was found that the failure of magmatic rock samples in both cases was smoother than that of sedimentary rock, indicating that deep magmatic rocks more easily released energy during the failure process. From depths of 4900–6000 m, prepeak characteristic stresses increased with increasing depth, while from depths of 6000–6830 m, they decreased with increasing depth. Fracture closure stress was used to characterize rock sampling damage at depths of 1000–6830 m, and it was found that sampling damage varied linearly with burial depth in sedimentary strata, while in igneous strata, sampling damage remained stable with increasing burial depth. © 2023, Central South University.
2748.
Hyperspectral core scanner: An effective mineral mapping tool for apatite in the Upper Zone, northern limb, Bushveld Complex
Journal of the Southern African Institute of Mining and Metallurgy,
123
(2)
81--92
2023
2747.
New Rock Magnetic Analysis of Ultramafic Cores From the Oman Drilling Project and Its Implications for Alteration of Lower Crust and Upper Mantle
Journal of Geophysical Research: Solid Earth,
127
(7)
e2022JB024379
2022
2746.
No evidence of multiple impact scenario across the Cretaceous/Paleogene boundary based on planktic foraminiferal biochronology
Special Paper of the Geological Society of America,
557415 – 448
2022
2745.
Numerical Simulation of Coastal Sub-Permafrost Gas Hydrate Formation in the Mackenzie Delta, Canadian Arctic
Energies,
15
(14)
2022
ISSN: 19961073
Publisher: MDPI
Keywords:▾
Flow of fluids; Gas hydrates; Hydration; Methane; Numerical models; Permafrost; Proven reserves, Canadian Arctic; CH 4; Conventional hydrocarbons; Dissolved CH; Fault; Fault system; Gas hydrates formation; Hydrate accumulations; Mallik; Thermogenic methane, Climate change
Abstract: ▾ The Mackenzie Delta (MD) is a permafrost-bearing region along the coasts of the Canadian Arctic which exhibits high sub-permafrost gas hydrate (GH) reserves. The GH occurring at the Mallik site in the MD is dominated by thermogenic methane (CH4), which migrated from deep conventional hydrocarbon reservoirs, very likely through the present fault systems. Therefore, it is assumed that fluid flow transports dissolved CH4 upward and out of the deeper overpressurized reservoirs via the existing polygonal fault system and then forms the GH accumulations in the Kugmallit–Mackenzie Bay Sequences. We investigate the feasibility of this mechanism with a thermo– hydraulic–chemical numerical model, representing a cross section of the Mallik site. We present the first simulations that consider permafrost formation and thawing, as well as the formation of GH accumulations sourced from the upward migrating CH4-rich formation fluid. The simulation results show that temperature distribution, as well as the thickness and base of the ice-bearing permafrost are consistent with corresponding field observations. The primary driver for the spatial GH distribution is the permeability of the host sediments. Thus, the hypothesis on GH formation by dissolved CH4 originating from deeper geological reservoirs is successfully validated. Furthermore, our results demonstrate that the permafrost has been substantially heated to 0.8–1.3 °C, triggered by the global temperature increase of about 0.44 °C and further enhanced by the Arctic Amplification effect at the Mallik site from the early 1970s to the mid-2000s. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.