Rocks In Area Research Articles

Artificial-Intelligence-Based Investigation on Land Use and Land Cover (LULC) Changes in Response to Population Growth in South Punjab, Pakistan

Land use and land cover (LULC) changes are significantly impacting the natural environment. Human activities and population growth are negatively impacting the natural environment. This negative impact directly relates to climate change, sustainable agriculture, inflation, and food security at local and global levels. Remote sensing and GIS tools can provide valuable information about change detection. This study examines the correlation between population growth rate and LULC dynamics in three districts of South Punjab, Pakistan—Multan, Bahawalpur, and Dera Ghazi Khan—over a 30-year period from 2003 to 2033. Landsat 7, Landsat 8, and Sentinel-2 satellite imagery within the Google Earth Engine (GEE) cloud platform was utilized to create 2003, 2013, and 2023 LULC maps via supervised classification with a random forest (RF) classifier, which is a subset of artificial intelligence (AI). This study achieved over 90% overall accuracy and a kappa value of 0.9 for the classified LULC maps. LULC was classified into built-up, vegetation, water, and barren classes in Multan and Bahawalpur, with an additional “rock” class included for Dera Ghazi Khan due to its unique topography. LULC maps (2003, 2013, and 2023) were prepared and validated using Google Earth Engine. Future predictions for 2033 were generated using the MOLUSCE model in QGIS. The results for Multan indicated substantial urban expansion as built-up areas increased from 8.36% in 2003 to 25.56% in 2033, with vegetation and barren areas displaying decreasing trends from 82.96% to 70% and 7.95% to 3.5%, respectively. Moreover, areas containing water fluctuated and ultimately changed from 0.73% in 2003 to 0.9% in 2033. In Bahawalpur, built-up areas grew from 1.33% in 2003 to 5.80% in 2033, while barren areas decreased from 79.13% to 74.31%. Dera Ghazi Khan expressed significant increases in built-up and vegetation areas from 2003 to 2033 as 2.29% to 12.21% and 22.53% to 44.72%, respectively, alongside reductions in barren and rock areas from 32.82% to 10.83% and 41.23% to 31.2%, respectively. Population projections using a compound growth model for each district emphasize the demographic impact on LULC changes. These results and findings focus on the need for policies to manage unplanned urban sprawl and focus on environmentally sustainable practices. This study provides critical awareness to policy makers and urban planners aiming to balance urban growth with environmental sustainability.

Provenance characteristics from the Mesozoic to the Cenozoic era and their implications for basin-mountain system evolution in the southwestern Junggar Basin: Insights from field outcrop observations in the Tostai area

The Mesozoic-Cenozoic formations in the southwestern Junggar Basin are a key target for oil and gas exploration. However, complex provenance conditions hinder a comprehensive understanding of sedimentary reservoirs. Based on the petrology and elemental geochemistry analysis of field outcrops in the Tostai area, research is conducted on the tectonic background, sediment transport distances, compositions of parent rocks, and evolutionary characteristics of provenance conditions in the provenance areas. It is generally believed that there have been three notable shifts in basin-mountain relationships during this period. Initially, from the Triassic to the Jurassic, the Northern Tianshan magmatic rock area predominated as the primary provenance, with decreasing basin-mountain proximity and predominantly magmatic rock sediment composition indicating near provenance. Subsequently, heightened Cretaceous tectonic activity in the Tianshan Mountains leads to significant uplift of metamorphic rock regions in the Middle Tianshan Mountains, gradually becoming the provenance for the study area. This increased distance between the provenance and sedimentary areas is marked by a substantial presence of metamorphic rocks in sediments, indicating a far provenance. Finally, the Cenozoic Himalayan movement resulted in the vigorous uplift of the magmatic rock area in the northern Tianshan Mountains, re-establishing it as the primary provenance. This minimized the basin-mountain distance, leading to the deposition of the near-provenance transported alluvial fans, braided rivers, and predominantly magmatic rock sediments.

Assessment of groundwater potential zones for hard rock area of sabi river basin using an integrated approach of remote sensing, GIS and AHP techniques

The study was conducted to assess groundwater potential zones (GWPZs) for hard rock area of Sabi river basin for the sustainable development. Remote Sensing (RS) and Geographic Information System (GIS) have emerged as crucial methods in retrieval, monitoring and conserving groundwater resources were used along with Analytical Hierarchy Process (AHP) to demarcate the GWPZs. In order to assess GWP in the study area, eight thematic maps: drainage density, geomorphology, geology, rainfall, land use/land cover, lineament density, slope and soil were prepared using RS and conventional data. The AHP was applied to assign the weightages for each thematic map and its sub classes. Then, the thematic layers were overlaid using the weighted overlay analysis means of ArcGIS 10.4 to assess the GWPZ map of Sabi basin. The Sabi basin was categorized into five classes of GWPZ as very good (0.01%), good (24.72%), moderate (56.54%), poor (10.45%) and very poor (8.28%). The accuracy of produced GWPZ map was assessed with well yield data by agreement scheme using ground water prospects map and by using ROC curve analysis through R-studio software which indicates the satisfactory GWPZ map prediction accuracy. This study provides valuable database in planning and development of groundwater recharging and to delineate locations of potential artificial recharge sites in the hard rock regions and semi -arid areas so that appropriate structures could be planned and constructed to manage aquifer recharge for sustainable groundwater management in the future.

The Gas Generation Process and Modeling of the Source Rock from the Yacheng Formation in the Yanan Depression, South China Sea

The research on deepwater oil and gas exploration areas is relatively limited, and sample collection is difficult. A drilled coal sample from Yanan Depression was used to investigate the hydrocarbon generation process, and the potential, by a gold tube thermal simulation experiment. The results show that the total gas yield was much higher than the oil yield. According to an analysis of the gas pyrolysis data, as represented by ln(C1/C2) and ln(C2/C3), the gas generation process consisted of two forms, namely, primary gas with ~1.33% Ro and secondary gas that occurred at levels greater than 1.33% Ro. The primary gas from kerogen was generated at ~1.33% Ro, which coincided with the %Ro value of the maximum oil yield. The activation energy distribution of the C1–C5 generation processes ranged from 54 to 72 kcal/mol, with a frequency factor of 6.686 × 1014 s−1 for the coal sample. We constructed the history of gas generation on the basis of the process and kinetic parameters, combined with data on the sedimentary burial and thermal history. The extrapolation of the gas history revealed that the gas has been generated from 5 Ma to the present, with a maximum yield of 178.5 mg/gTOC. This history suggests that the coal has good primary gas generation potential and provides favorable gas source conditions for the formation of gas fields. This study provides a favorable basis for expanding the effective source rock areas.

Enhancement of the geological mapping in weathered plutonic and metamorphic rocks areas using village water supply wells data (lithology and hydrochemistry)

In weathered plutonic and metamorphic rocks areas, because rock outcrops are rare due to the extensive regolith cover, geological mapping is largely based on the interpretation of airborne data and imagery (aerial photographs, satellite images, airborne geophysics when available, etc.). In the sub-Saharan Africa, numerous village water supply campaigns were performed during the last 40 years. Most hydrogeological and geological data from these campaigns are stored and safeguard in country scale databases. In this study, we develop a methodology to improve the existing geological maps in a such geological context with lithological data from the existing databases. These data were not used during past geological mapping; yet they provide a complementary access to the lithology, notably in areas where outcrops are very scarce. We propose a coherent methodology to use and validate such geological data, complementary to field observations on the scarce outcrops, to cope with their uncertainties. We also show that groundwater hydrochemistry, namely the silica content, can be of use to complete the geological mapping. Using data from 735 boreholes drilled in the Koudougou and Léo square study area of Burkina Faso, we validate this new methodological approach and locally propose a more accurate 1:200,000 geological map.

Impacts of Bedrocks on Vegetation Carbons in Typical Karst Areas: A Case Study in Puding County, Southwest China

An accurate estimation of vegetation carbon pools and their carbon sequestration potential is significant in global carbon cycle research but the existing estimations are still insufficient and largely uncertain. Here, we estimated the vegetation carbon density, carbon stocks, and carbon sequestration potential under three main bedrock types (limestone, dolomite, and non-carbonate) in Puding County, Guizhou Province, Southwestern China. The data used here included high-resolution vegetation maps of Puding, data from 274 sample plots, and the carbon contents measured previously in adjacent areas. The land area ratio of natural vegetation at an early stage (namely, grassland and shrub, excluding artificial forests and cultivated land) in carbonate rock areas is significantly larger than that in non-carbonate areas. The average existing carbon densities of vegetation in the non-carbonate, limestone, and dolomite areas were 31.59 ± 7.43, 16.75 ± 4.12, and 8.26 ± 2.45 Mg·ha−1, respectively, while their existing carbon stocks were 752.37 ± 172.85, 855.69 ± 210.65, and 208.49 ± 61.82 Gg, respectively. The maximum vegetation carbon densities of mature forests in the three bedrock types were 156.49 ± 12.92, 130.27 ± 6.05, and 117.41 ± 30.03 Mg·ha−1, respectively. Then, their average vegetation carbon sequestration potentials were 56.07 ± 23.06, 70.13 ± 11.39, and 59.11 ± 33.00 Mg·ha−1, respectively. In other words, vegetation carbon stocks in the non-carbonate, limestone, and dolomite areas increased by 1.34 ± 0.42, 3.58 ± 0.48, and 1.49 ± 0.51 Tg, respectively, after continuous evolution to mature forests. In conclusion, the potential growth of carbon density for karst vegetation is slightly higher than that of non-karst vegetation, despite its lower existing carbon density. Additionally, natural vegetation has a greater potential for carbon sequestration than plantations on all three bedrock types.

A Quantitative Study of Axial Performance of Rockbolts with an Elastic–Debonding Model

Full-length anchorage rockbolts are widely used in roadway reinforcement and rock controlling in underground mining. This article proposes using an elastic–debonding (ED) model to analyse the axial performance of rockbolts. The advantage of this ED model was that the full force–deformation curve of rockbolts comprised only three phases, which was relatively simpler to calculate. Its effectiveness was compared with experiment tests. Based on the ED model, a series of parameter studies was conducted. Results showed that for cross-section area of rock, there was a critical range. Once the cross-section area of rock was beyond that critical range, external rock had a mild impact on the axial performance of rockbolts. Rockbolt diameter significantly affected the axial performance of rockbolts. When rock diameter increased, the peak force of rockbolts increased linearly, while deformation at the peak force decreased non-linearly. The corresponding calculation equation between the peak force, deformation at the peak force, and rockbolt diameter was obtained. Borehole diameter had a mild impact on the axial performance of rockbolts. Increasing rockbolt length benefits improving the peak force of rockbolts. Rockbolt modulus of elasticity had a more apparent impact on the deformation at peak force. Mechanical properties of the bolt/grout (b/g) face affected the axial performance of rockbolts. Increasing the b/g face strength improved the peak force of rockbolts. Slippage at the ultimate load had a more apparent impact on the turning point between the elastic phase and the elastic–softening phase.

A method for velocity modeling in a volcanic rock zone that integrates the amplitude envelope attribute and grid tomography: application to data from the North Jiangsu Basin

Abstract The complexity of volcanic rocks presents challenges in seismic data quality and fine characterization of structural morphology, making velocity modeling difficult. In this study, we propose a velocity modeling method for volcanic rock areas that combines the use of amplitude envelope attribute and grid tomography inversion. By exploiting the strong reflection characteristics of volcanic rocks, the amplitude envelope attribute is employed to identify volcanic rock structures, eliminating the need for labor-intensive manual interpretation. The grid tomography inversion technique is then used to derive background velocity fields for all strata. These are further refined by incorporating the residual velocity fields of volcanic rocks through fusion and superposition. This integrated approach significantly improves the efficiency and accuracy of velocity modeling in complex volcanic rock areas, overcoming the limitations associated with conventional volcanic rock structural models and resulting in more accurate velocity inversion. The effectiveness and feasibility of the proposed method for velocity modeling in volcanic rock zone are demonstrated through the application of seismic data from an oilfield in eastern China. The results highlight the method's strong industrial application value.

Manajemen Pengelolaan Situs Geologi Batu Angus dalam Mendukung Pulau Ternate Menuju Geopark Island di Indonesia

Batu Angus Geological Site is one of the tourist attractions that can support Ternate Island towards Geopark Island in Indonesia. Although the attraction of this tourist attraction is very potential, it is not yet popular and the visit of foreign and domestic tourists to the location of these attractions is also still not optimal. The objectives of this study are (1) to determine the existence of angus geological sites on Ternate Island, (2) to describe the management of angus geological sites on Ternate Island, and (3) to develop a management strategy for angus geological sites. The method used in this research is descriptive qualitative method where data is obtained through interviews, field observations, documentation, and literature studies. Sampling in this study was carried out using purposive sampling method. The results of this study, namely (1) The Angus Rock Area of Ternate Island has been identified and catalogued by IAGI (Indonesian Geologists Association) North Maluku together with the Ternate City Bappelitbangda Office and the Ternate City Tourism Office, (2) The Angus Rock geological site is very good, but still lacks facilities and infrastructure and lacks Human Resources (HR), the government and the surrounding community need to work together to make the Angus rock geological site into one of the tourist attractions that can support Ternate Island towards a geopark island in Indonesia. (3) The strategy used to improve the management of angus stone geological site in supporting Ternate Island towards Geopark Island in Indonesia by using strength-opportunity strategy, weakness-opportunity strategy, strength-threat strategy, and weakness-threat strategy. The four strategies can make the angus stone geological site better. By applying the right strategies, it can improve the management of Batu Angus geological site on Ternate Island.

Brown bear habitat use patterns across 19 years of population expansion in the Cantabrian Mountains

ContextLarge carnivores have faced severe extinction pressures throughout Europe during the last centuries, where human-induced disturbances reached unprecedented levels. In the late twentieth century, the Cantabrian brown bear population was on the verge of extinction, due to poaching. Yet, the end of the last century was a turning point for this population. Presence data on the western Cantabrian subpopulation was collected since the beginning of the century and insights provided by this long-term monitoring may be useful for brown bear conservation.ObjectivesHere, we aim to: (i) identify the landscape features relevant to bears’ recovery; and (ii) understand if and how the landscape use patterns by bears changed over time.MethodsWe tested the influence of landscape structure (i.e., composition and configuration) on bear occurrence patterns using MAXENT in three periods representative of land cover change.ResultsDespite variation across the 19-year monitoring period, brown bears were more often detected near broad-leaf forests and bare rock areas and at lower to intermediate altitudes, but avoided arable lands, permanent crops, and burnt areas. Human population density or distance to roads—often used for modelling habitat suitability for Cantabrian brown bears—were not identified as relevant variables for this brown bear subpopulation. Artificial areas were identified as relevant landscape features, but not as disturbance.ConclusionsThese findings reinforce the importance of preserving bears’ native habitats and provide new insights, namely on the use of humanized landscapes.

Contribution of groundwater-borne nutrients to eutrophication potential and the share of benthic algae in a large lowland river

Groundwater inflow can be a significant source of nutrients for riverine ecosystems, which can affect eutrophication i.e., the elevated primary production and the corresponding accumulation of algal biomass. Experimental and modelling work has shown that benthic algae (autotrophic biofilms) in particular benefit, as they have direct access to the inflowing groundwater-borne nutrients. Primarily the supply of phosphorus (P) enhances pelagic algal biomass, as it is the limiting nutrient for primary production in most freshwater systems. In this study, we estimate the effect of groundwater inflow on overall eutrophication of a large, European lowland river and tested its seasonal effect on biofilms in particular. We calculated the effects on overall eutrophication during summer according to the estimated input of groundwater-borne P and the C:P stoichiometry of planktonic algae in the Elbe River. Our model indicated that these diffuse P inputs have the potential to significantly increase eutrophication. Groundwater-P can contribute up to 1.5 t/d PO4 over the investigated 450 km stretch of the Elbe River under low flow conditions. This would result in an additional planktonic load of about 46 t/d of particulate organic carbon, thereby contributing to eutrophication at the regional scale in this river. In contrast, at the local scale, biofilms were collected seasonally from artificial substrata exposed in the river either in hydrogeologically active areas with groundwater inflow, or in areas of varying hydraulic connectivity. Analyses of biofilm macronutrients, structural components and biofilm community composition show distinct effects of season, hydrogeology and groundwater inflow. The dominant predictors were season and the interaction between hydrogeology and groundwater. Benthic eutrophication is most likely to occur in autumn in areas of loose rock with high groundwater inflow. The strong interaction of environmental factors in determining benthic eutrophication highlights the need to assess these factors in combination rather than in isolation.

Soil Quality Assessment and Influencing Factors of Different Land Use Types in Red Bed Desertification Regions: A Case Study of Nanxiong, China

Soil environmental issues in the red bed region are increasingly conspicuous, underscoring the critical importance of assessing soil quality for the region’s sustainable development and ecosystem security. This study examines six distinct land use types of soils—agricultural land (AL), woodland (WL), shrubland (SL), grassland (GL), bare rock land (BRL), and red bed erosion land (REL)—in the Nanxiong Basin of northern Guangdong Province. This area typifies red bed desertification in South China. Principal component analysis (PCA) was employed to establish a minimum data set (MDS) for calculating the soil quality index (SQI), evaluating soil quality, analyzing influencing factors, and providing suggestions for ecological restoration in desertification areas. The study findings indicate that a minimal data set comprising soil organic matter (SOM), pH, available phosphorus (AP), exchangeable calcium (Ca2+), and available copper (A-Cu) is most suitable for evaluating soil quality in the red bed desertification areas of the humid region in South China. Additionally, we emphasize that exchangeable salt ions and available trace elements should be pivotal considerations in assessing soil quality within desertification areas. Regarding comprehensive soil quality indicators across various land use types, the red bed erosion soils exhibited the lowest quality, followed by those in bare rock areas and forest land. Within the minimal data set, Ca2+ and pH contributed the most to overall soil quality, underscoring the significance of parent rock mineral composition in the red bed desertification areas. Moreover, the combined effects of SOM, A-Cu, and AP on soil quality indicate that anthropogenic land management and use, including fertilization methods and vegetation types, are crucial factors influencing soil quality. Our research holds significant implications for the scientific assessment, application, and enhancement of soil quality in desertification areas.

The Volcanic Rocks and Hydrocarbon Accumulation in the Offshore Indus Basin, Pakistan

To analyze the impact of volcanic rocks in the Offshore Indus Basin on hydrocarbon reservoir formation, seismic data interpretation, seismic data inversion, and sea–land correlation analysis were carried out. The results show that, longitudinally, volcanic rocks are mainly distributed at the top of the Cretaceous system or at the bottom of the Paleocene, and carbonate rock platforms or reefs of the Paleocene–Eocene are usually developed on them. On the plane, volcanic rocks are mainly distributed on the Saurashtra High in the southeastern part of the basin. In terms of thickness, the volcanic rocks revealed by drilling in Karachi nearshore are about 70 m thick. We conducted sparse spike inversion for acoustic impedance in the volcanic rock area. The results show that the thickness of the Deccan volcanic rocks in the study area is between 250 and 750 m which is thinning from southeast to northwest. Based on sea–land comparison and comprehensive research, the distribution of volcanic rocks in the Indian Fan Offshore Basin played a constructive role in the Mesozoic oil and gas accumulation in the Indus offshore. Therefore, in the Indian Fan Offshore Basin, attention should be paid to finding Mesozoic self-generated and self-stored hydrocarbon reservoirs and Cenozoic lower-generated and upper-stored hydrocarbon reservoirs.

Sea level controls on Ediacaran-Cambrian animal radiations.

The drivers of Ediacaran-Cambrian metazoan radiations remain unclear, as does the fidelity of the record. We use a global age framework [580-510 million years (Ma) ago] to estimate changes in marine sedimentary rock volume and area, reconstructed biodiversity (mean genus richness), and sampling intensity, integrated with carbonate carbon isotopes (δ13Ccarb) and global redox data [carbonate Uranium isotopes (δ238Ucarb)]. Sampling intensity correlates with overall mean reconstructed biodiversity >535 Ma ago, while second-order (~10-80 Ma) global transgressive-regressive cycles controlled the distribution of different marine sedimentary rocks. The temporal distribution of the Avalon assemblage is partly controlled by the temporally and spatially limited record of deep-marine siliciclastic rocks. Each successive rise of metazoan morphogroups that define the Avalon, White Sea, and Cambrian assemblages appears to coincide with global shallow marine oxygenation events at δ13Ccarb maxima, which precede major sea level transgressions. While the record of biodiversity is biased, early metazoan radiations and oxygenation events are linked to major sea level cycles.

Carbonate rocks and karst water resources in the Mediterranean region

Carbonate rocks in the Mediterranean region form karst landscapes with a variety of morphological and hydrological features, and are of particular interest from a water management perspective as they represent major karst aquifers. The Mediterranean Karst Aquifer Map and Database (MEDKAM) provides a 1:5,000,000 scale map showing the distribution of carbonate and evaporite rocks that can host karst groundwater resources, with additional information on other hydrogeological settings, selected terrestrial and submarine karst springs, caves and karst groundwater-dependent ecosystems. A statistical evaluation shows that carbonate rocks cover ~39.5% of the Mediterranean region within a 250-km focus area from the coastline. North Africa has the largest continuous area of carbonate rocks, while smaller countries in the Middle East and the Dinarides have the largest proportion of carbonate rocks in relation to their total area. Carbonate rocks are also widespread in coastal areas, occurring along ~33.6% (14,000 km) of the total Mediterranean coastline, including large islands such as Crete and Mallorca, and ~25.9% (6,400 km) of the continental coastline. Two additional maps display (1) groundwater recharge, showing a climatic gradient from north to south, and (2) groundwater storage trends, indicating a mean annual karst groundwater loss from 2003 to 2020 of 436 million m3 in the 250-km area. This study quantifies the carbonate rocks in the Mediterranean region and shows their importance for groundwater resources. MEDKAM will serve as a basis for further research and improved international cooperation in karst groundwater management.

Hydrocarbon-generating potential of the Middle Permian Lucaogou source rock in the eastern Junggar Basin, China

The Middle Permian Lucaogou Formation is the most significant source rock in the eastern Junggar Basin. Previous studies have confirmed its excellent hydrocarbon-generating potential in the Jimsar Sag. However, its potential in other areas of the eastern Junggar Basin remains uncertain. Based on total organic carbon and pyrolysis, organic petrology, hydrocarbon simulation experiments, basin simulation, and combined well-seismic coupling interpretation, this study systematically compares the hydrocarbon-generating potential of the Lucaogou source rock in the Jimsar Sag with other areas of the eastern Junggar Basin. It discusses the sedimentary environment of high-quality source rocks and depicts the distribution of practical source kitchens. The Lucaogou source rocks in the eastern Junggar Basin are oil-prone, dominated by type I–II kerogen, and generally classified as good to excellent source rocks. Nowadays, the area of the Lucaogou source rocks that have entered the main oil-generating window is approximately 11 × 103 km2. Except for the bulge area, the Lucaogou source rocks in the eastern Junggar Basin successively entered the hydrocarbon-generating threshold during the Jurassic and the main oil-generating window in the Cretaceous. The Lucaogou source rocks in the Jimsar Sag and other parts of the eastern Junggar Basin share similar biomarker fingerprints, characterized by relatively low ratios of Pr/Ph, Pr/n-C17, Tm/C30 hopane, C19/C20 tricyclic terpene, and C24 tetracyclic terpene/C26 tricyclic terpene, and high β-carotene content, gammacerane index, and Ts/Tm ratios. These characteristics reflect deposition in a strongly reducing brackish lacustrine environment with parental sources dominated by lower organisms such as algae and bacteria. Generally, the Lucaogou source rocks in the eastern Junggar Basin have an oil-generating intensity of more than 3 × 106 t/km2. Several oil-generating centers with an intensity of more than 5 × 106 t/km2 have developed in the front of the Bogda Mountain, Jimsar Sag, Dongdaohaizi Sag, Wucaiwan Sag, and Shazhang Fault Zone, covering a total area of approximately 12,500 km2. These characteristics of the Lucaogou source rocks promise favorable potential for forming large and medium oil fields. The results further consolidated the oil and gas resources in the eastern Junggar Basin and provided valuable references for exploring future oil and gas fields.

Evaluation of pore characteristics evolution and damage mechanism of granite under thermal-cooling cycle based on nuclear magnetic resonance technology

During the development process of deep geothermal energy (Hot dry rock, HDR), the high-temperature granite matrix in the wellbore needs to withstand thermal-cooling cycles, easily leading to wellbore instability and collapse. Considering the actual drilling engineering using different types of drilling fluid, thermal-cooling cycle experiments (cycles of 1, 2, 4, 8, 12 times) of granite were conducted using natural, water, and liquid nitrogen (LN2) cooling methods. Based on the low-field nuclear magnetic resonance measurement, the development and evolution of pore size, quantity, and distribution under different cooling ways and thermal cycles were studied, and the changes in rock mechanical parameters under different cooling methods and thermal cycling conditions were quantified. Then, the rock damage coefficients based on the variation patterns of different types of pores were calculated, and a quantitative relationship was established among T2 spectrum, pore, and mechanical damage. Finally, the proton weighting method was used to analyze the changes in the internal bearing area of rocks, revealing the deterioration mechanism of rock mechanical properties under different cooling ways and thermal cycling conditions. The results showed that the porosity increased with thermal cycles during the thermal-cooling cycle treatment, and the growth rate was first fast and then slow. Under the same number of thermal cycles, the groundwater cooling porosity was the highest, followed by LN2 and natural cooling. The relationship between T2 spectral area and rock damage was established on this basis, and the rock damage value increased with thermal cycles in an exponential function, and the proportion of large pores significantly affected the pore damage. A relationship (positively proportional linear) between pore damage and the mechanical degradation coefficient of high-temperature cooling cycle granite and a method for predicting rock degradation through pore damage were established, the deterioration mechanism of rock mechanical properties under thermal cycle treatment was revealed.

Genesis of the Ke’eryin Two-Mica Monzogranite in the Ke’eryin Pegmatite-Type Lithium Ore Field, Songpan–Garze Orogenic Belt: Evidence from Lithium Isotopes

Previous studies on the Ke’eryin pegmatite-type lithium ore field in the Songpan–Ganzi Orogenic Belt have explored the characteristics of the parent rock but have not precisely determined its magma source area. This uncertainty limits our understanding of the regularity of lithium ore formation in this region. In this study, to address the issue of the precise source area of the parent rock of lithium mineralization, a detailed analysis of the Li isotope composition of the ore-forming parent rock (Ke’eryin two-mica monzogranite) and its potential source rocks (Triassic Xikang Group metamorphic rocks) was conducted. The δ7Li values of the Ke’eryin two-mica monzogranite, Xikang Group metasandstone, and Xikang Group mica schist are −3.3–−0.7‰ (average: −1.43‰), +0.1–+6.9‰ (average: +3.83‰), and −9.1–0‰ (average: −5.00‰), respectively. The Li isotopic composition of the Ke’eryin two-mica monzogranite is notably different from the metasandstone and aligns more closely with the mica schist, suggesting that the mica schist is its primary source rock. The heavy Li isotopic composition of the two-mica monzogranite compared to the mica schist may have resulted from the separation of the peritectic garnet into the residual phase during the biotite dehydration melting process. Moreover, the low-temperature weathering of the source rocks may have been the main factor leading to the lighter lithium isotope composition of the Xikang Group mica schist compared to the metasandstone. Further analysis suggests that continental crust weathering and crustal folding and thickening play crucial roles in the enrichment of lithium during multi-cycle orogenies.

Development of Machine Learning Techniques for the Multiclass Semantic Segmentation of Underwater Images

The Neptune grass (NG) is an endemic plant of the Mediterranean Sea. Successive studies carried out show a significant decrease in their presence in this sea. Concern for the conservation of NG implies being able to monitor its evolution and thus be able to determine if its presence is increasing or decreasing in seabeds. Nowadays, expensive and limited methods are used to carry out this follow-up, which often also involves manual intervention. The work carried out aims to automatically determine the type of seabed from underwater images, performing semantic segmentation using deep neural networks. In this work, a deep neural network has been implemented to carry out a semantic segmentation of images of the seabed, offering improvements with respect to the techniques currently used to obtain this information. The developed neural network allows for distinguishing in the images of the seabed the areas of NG, rock, and sand. The possibility of identifying other elements present, such as dead NG, both the plant itself and its loose leaves scattered on the bottom, has also been explored in this work.

Urban oasis? Abundant dice snake (Natrix tessellata) populations along artificial lakeside habitats in urban landscapes

ContextHuman-induced landscape modification, such as urbanization, creates new environments that can have adverse effects on flora and fauna, posing threats to biodiversity. Understanding how reptiles respond to urbanization is crucial, especially in light of their ongoing population declines.ObjectivesWe examined the influence of landscape-scale and local-scale urbanization features on the abundance of an aquatic snake species. Our investigation focused on dice snakes (Natrix tessellata) inhabiting a lake with a heavily urbanized shoreline.MethodsWe conducted visual encounter surveys at 25 study sites during the activity period of dice snakes around Lake Balaton in Hungary. We measured both landscape-scale and local-scale variables, including urban land use cover, vegetation cover, road cover, distance of main roads and city size, emergent vegetation cover and the area of artificial rock and concrete shoreline protection structures. We analysed snake survey data using N-mixture models to estimate abundance and examine relationships with landscape-scale and local-scale variables.ResultsUrban land use cover, road cover, the proximity of main roads and the extent of artificial rock and concrete shoreline protection structures positively affected the abundance of snakes. These findings imply that urban habitats may offer new ecological opportunities for dice snakes.ConclusionsThe findings of this study indicate that both landscape-scale and local-scale human-induced landscape modifications may have a positive impact on the abundance of urban snakes. Taken together, our findings suggest that urbanization is a complex phenomenon, affecting species at different levels and with subtle effects.