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Research Project CGL2016-75679-P (Spanish Ministry of Education and Science); Research Groups, Projects of the Generalitat Valenciana, Alicante University (CTMA-IGA); Grants from the University of Urbino Carlo Bo (M. Tramontana).

The investigation of tectonic controls on CH4 and CO2 emissions was conducted by measuring the fluxes of the gases in the different tectonic units along the northwestern margin of the Ordos Block in China, a region renowned for its intricate tectonic configuration. The mean fluxes of CH4 ranged from −1.5 to 1.1 mg m−2 d−1, while CO2 fluxes spanned from 2.0 to 29.2 g m−2 d−1. Notably, the Minqin, Ordos, and Haiyuan blocks primarily exhibited absorption characteristics for CH4. In contrast, within the Hetao and Yinchuan grabens, both degassing and absorption processes coexist. A striking observation was that blocks with high internal deformation exhibited significantly higher CH4 and CO2 fluxes compared to those in the stable blocks. Additionally, regions experiencing extensional deformation demonstrated greater gas emission than those undergoing compressional deformation. The spatial distribution of CH4 and CO2 fluxes at the study points exhibited a similar trend to faults in the Yinchuan Graben. Our findings revealed that CH4 and CO2 are mainly of biogenic origin, accompanied by abiotic emissions from underground. And the gas source, migration pathway, and tectonic stress were the primary factors influencing gas emission, with tectonic stress playing a pivotal role. This stress controlled the formation of tectonic structures, changed the degassing pathway, and served as the driving force for gas migration. The results of this study offer valuable insights into the mechanisms governing CH4 and CO2 emission in faulted regions. Furthermore, our results may contribute to future assessments aimed at quantifying the contribution of geological sources to greenhouse gas emissions. Key Points Tectonic controls on CH4 and CO2 emissions were investigated along the western margin of the Ordos Block in China Extensional deformation regions demonstrated greater gas degassing than compressional deformation regions Spatial distribution of gas fluxes mirrored fault patterns in the Yinchuan Graben

The presence of a set of well-known turbidite successions, deposited in progressively E-migrating foredeep basins and subsequently piled up with east vergence, makes the Northern Apennines of Italy paradigmatic of the evolution of deepwater fold-and-thrust belts. This study focuses on the early Apenninic collisional stage, early Miocene in age, which led to the accretion of the turbidites of the Trasimeno Tectonic Wedge (TTW), in the central part of the Northern Apennines. Based on the interpretation of previously unpublished seismic reflection profiles with new surface geology data and tectonic balancing, we present a detailed tectonic reconstruction of the TTW. In the study area, the TTW is characterized by a W-dipping shaly basal décollement located at a depth of 1-5 km. The tectonic wedge is c. 5 km thick at its central-western part and tapers progressively eastwards to c. 1 km. The total shortening, balanced along a 33 km long cross-section, is c. 60 km, including 20 km (40%) of internal imbrication, c. 23 km of horizontal ENE-wards translation along the basal décollement and c. 17 km of passive translation caused by the later shortening of footwall units. Deformation balancing, constrained through upper Aquitanian - upper Burdigalian (c. 21-16 Ma) biostratigraphy, provides an average shortening rate of c. 8.6 mm a-1. Internal shortening of the TTW shows an average shortening rate of c. 4 mm a-1 for this period.

Heat flow patterns variability related to the age of the consolidated, and differences in, sedimentary thickness of the sedimentary succession are important constraints upon the thermal state of the sedimentary fill and its geothermal energy potential. Heat flow in the Permian basin of central Europe varies from a low of 40 mWm−2 in the Precambrian Platform to 80 mWm−2 in the Paleozoic basement platform influencing temperature for geothermal potential drilling depth. Continuity of thermal patterns and compatibility of heat flow Q across the Permian basin across the Polish–German basin was known from heat flow data ever since the first heat flow map of Europe in 1979. Both Polish and German heat flow determinations used lab-measured thermal conductivity on cores. This is not the case for the recent heat flow map of Poland published in 2009 widely referenced in Polish geological literature. Significant differences in heat flow magnitude exist between many historical heat flow maps of Poland over the 1970s–1990s and recent 21st century patterns. We find that the differences in heat flow values of some 20–30 mWm−2 in Western Poland exist between heat flow maps using thermal conductivity models using well log interpreted mineral and porosity content and assigned world averages of rock and fluid thermal conductivity versus those measured on cores. These differences in heat flow are discussed in the context of resulting mantle heat flow and the Lithosphere-Asthenosphere Boundary depth modelled differences and possible overestimates of deep thermal conditions for enhanced geothermal energy prospects in Poland.

Identifying distinct tectonic units is key to understanding the geotectonic framework and distribution law of oil and gas resources. The South China Sea and its adjacent areas have undergone complex tectonic evolution processes, and the division of tectonic units is controversial. Guided by block tectonics theory, this study divide the South China Sea and its adjacent areas into several distinguished tectonic units relying on known boundary markers such as sutures (ophiolite belts), subduction-collision zones, orogenic belts, and deep faults. This work suggests that the study area is occupied by nine stable blocks (West Burma Block, Sibumasu Block, Lanping-Simao Block, Indochina Block, Yangtze Block, Cathaysian Block, Qiongnan Block, Nansha Block, and Northwest Sulu Block), two suture zones (Majiang suture zone and Southeast Yangtze suture zone), two accretionary zones (Sarawak-Sulu accretionary zone and East Sulawesi accretionary zone), one subduction-collision zone (Rakhine-Java-Timor subduction-collision zone), one ramp zone (Philippine islands ramp zone), and six small oceanic marginal sea basins (South China Sea Basin, Sulu Sea Basin, Sulawesi Sea Basin, Banda Sea Basin, Makassar Basin, and Andaman Sea Basin). This division reflects the tectonic activities, crustal structural properties, and evolutionary records of each evaluated tectonic unit. It is of great theoretical and practical importance to understand the tectonic framework to support the exploration of oil and gas resources in the South China Sea and its adjacent areas.

High-resolution 3D seismic P-wave velocity model of Poland (Grad et al., Tectonophysics 666:188–210, 2016) and corrected for paleoclimate heat flow map (Majorowicz and Wybraniec, Int J Earth Sci 100(4):881–887, 2011) gridded to a common mesh are used together with four independent thermal models of the crust and upper mantle to calculate heat flow variation with depth and geotherms. Heat flow at Moho depth are calculated and mapped and both confirm large variability with an elevated mantle heat flow (circa 30–40 mW/m2) in the Paleozoic Platform which is some 10–20 mW/m2 higher than Moho heat flow in the north-eastern and south-eastern Poland which belong to a variety of tectonic terranes (the oldest Precambrian Craton, younger Cadomian, Trans-European Suture Zone, Carpathians). Temperatures calculated for the crust show consistent pattern: higher temperatures beneath the Paleozoic Platform and lower temperatures beneath the Precambrian and Cadomian units. At 10 km depth this difference is about 150 °C, about 300 °C at 20 km depth, and about 400 °C at 50–60 km. Assuming the calculated isotherm 580 °C as Curie temperature the magnetic crust thickness was determined as 5–10 km only beneath the Polish Basin, circa 20 km in Carpathians, circa 30 km in Sudetes, and 35–40 km beneath the Precambrian and Cadomian units. Such a thick magnetic crust results from a great depth of Curie temperature, thick crystalline crust, and thin sediments. Mantle heat flow variability is mainly correlating with measured surface heat flow and influences geotherms. Calculated thermal LAB depth follows patterns of heat flow and Moho heat flow variability through Poland with thinnest lithosphere in the high surface heat flow and high mantle heat flow areas. Comparison of this thermal LAB depth estimates with seismic data based LAB depth shows general coincidences when Precambrian Craton vs Paleozoic Platform are considered along the P4 seismic experiment data model (circa 190 km depth vs some 90 km depth, respectively). However, significant differences exist in many areas and especially for the SE Poland when compared with map for the whole of Poland compiled from other seismic reported data.

The İstanbul-Zonguldak Tectonic Unit is an Amazonia-derived continental fragment added to Baltica during the middle Paleozoic, and represents Far East Avalonia. The soft-docking time of two continental blocks, thus the consumption of the Teisseyre-Tornquist Ocean, is poorly known. This paper reports biotite-bearing dacite and pyroxene-bearing basaltic andesite and dacite dykes of Ordovician igneous crystallization ages in the İstanbul-Zonguldak Tectonic Unit (NW Turkey). They have porphyritic to spherulitic textures. U–Pb dating on igneous zircons from arc- and syncollisional-related dykes yielded Ordovician ages of ca. 484.1 ± 2.5 Ma (2σ) and 444.4 ± 3.7 to 443.0 ± 2.1 Ma (2σ). They display calc-alkaline signatures and are noteworthy with subduction components, as deduced by the presence of marked negative Nb anomalies. Biotite-bearing dykes intruded to it in an arc setting whereas pyroxene-bearing dykes emplaced into it in a syncollisional setting. Besides, Middle-Late Ordovician granites (c. 464–446 Ma) intruding the high-grade metamorphic rocks, known as rift-related intrusions in previous studies, show calc-alkaline affinities and contain subduction components, and they formed in a volcanic arc. I suggest that Early-Late Ordovician magmatism is related to the Teisseyre-Tornquist Ocean subducting under Far East Avalonia, and Late Ordovician magmatism is associated with soft-docking between two continental blocks, thus the destruction of the Teisseyre-Tornquist Ocean. Overall, its suture in Far East Avalonia overlaps with the Vardar suture in Balkans, and it can be traced from İzmir to Söğüt in Anatolia and represents the missing part in Far East Avalonia.

We studied some exposures of the Roccacaramanico Conglomerate (RCC), a calcareous-clastic mega-bed intercalated within the Late Messinian–Early Pliocene pelitic succession of the La Queglia and Maiella tectonic units (central Apennines). The outcrops, localized in the overturned limb of a kilometric-scale syncline, show a complex array of fractures, including multiple systems of closely spaced cleavages, joints, and mesoscopic faults, which record the progressive deformation associated with the Late Pliocene thrusting. Due to the extent of the investigated sites and a large amount of data to collect, we applied a multi-methodology survey technique integrating unmanned aerial vehicle (UAV) technologies and digital mapping in the field. We reconstructed the 3D digital outcrop model of the RCC in the type area and defined the 3D pattern of fractures and their time–space relationships. The field survey played a pivotal role in determining the various sets of structures, their kinematics, the associated displacements, and relative chronology. The results unveiled the investigated area’s tectonic evolution and provide a deformation model that could be generalized in similar tectonic contexts. Furthermore, the methodology allows for evaluating the reliability of the applied remote survey techniques (i.e., using UAV) compared to those based on the direct measurements of structures using classic devices. Our purpose was to demonstrate that our multi-methodology approach can describe the tectonic evolution of the study area, providing consistent 3D data and using a few ground control points. Finally, we propose two alternative working methods and discuss their different fields of application.

In northern Calabria (Italy), the metasedimentary succession of the Lungro-Verbicaro tectonic unit preserves mineral assemblages suggesting underthrusting to depths in excess of 40 km. Internal deformation of these rocks occurred continuously during the following decompression. Index mineral composition associated with progressively younger tectonic fabrics indicates that a substantial part of the structural evolution took place within the blueschist-facies P-T field. Despite their tectonic and metamorphic history, the rocks of the Lungro-Verbicaro Unit preserve significant sedimentary and palaeontological features allowing correlations with successions included in adjacent thrust sheets and the reconstruction of the Mesozoic continental margin architecture. The subduction-exhumation cycle recorded by the Lungro-Verbicaro Unit is entirely of Miocene age. This portion of the Apulia continental palaeomargin was involved in convergence-related deformation not earlier than the Aquitanian. The integration of our results with available constraints on the tectonic evolution of the Apennine-Calabrian Arc system suggests that subduction and most of the subsequent exhumation of the Lungro-Verbicaro Unit occurred, up to Langhian time, at maximum vertical rates in excess of 15 mm a-1. The exhumation process was then completed, at much slower rates (<2 mm a-1) in Late Miocene time, as indicated by both apatite fission-track data and stratigraphic information.

In order to explore the rules between gravity anomalies and oil-gas distribution characteristics in central and western Sichuan Basin, we divided the tectonic unit in central and western Sichuan basin on the base of the analysis of gravity anomaly characteristics, and studied the correlation between the oil–gas distribution and the local gravity anomaly in the study area. The results show that the variation in the range of the Bouguer gravity field in the interior of the basin is relatively small, and the southern part shows a clear gravity high zone, with gradual gravity gradient zones all around the basin periphery. The abnormal value of the residual gravity field in the basin is an obvious high–value gravity belt in the north and west, and the interior is arranged alternately with local high gravity and low gravity in the north–east direction. The tectonic units of the central and western Sichuan Basin can be divided into five regions, based on the characteristics of the Bouguer gravity field, namely, the Central Sichuan uplift zone, the West Sichuan depressional zone, the East Sichuan high steep zone, the South Sichuan low steep zone, and the North Sichuan low slow zone. Combined with geological data and Bouguer gravity anomaly processing results, the distribution of oil and gas fields in the central and western Sichuan Basin is certain correlated with the local gravity high zone and the transition zone between the local gravity high zone and the local gravity low zone. They are the major areas of oil and gas.