Types Of Karst Research Articles

Terrestrial Invertebrates Strike Back: Aerial and Ground‐Based Colonisation of a Dry Riverbed

ABSTRACT Dispersal, either active or passive, plays a key role in community assembly during the colonisation of newly available habitats such as the dry riverbeds of intermittent rivers. These unstable environments are exposed to an ongoing colonisation process, often from adjacent riparian habitats that are local biodiversity hot spots. We aimed to identify the diversity, origin and colonisation pathways of terrestrial invertebrates in the dry bed of an intermittent Mediterranean river. We sampled aerial and ground‐dwelling invertebrates during the colonisation of dry riverbeds using cross‐vane window traps and pitfall traps. Invertebrate communities were sampled in three habitat types of the intermittent karst Krčić River in Croatia: dry riverbed, riparian and upland habitat. For aerial invertebrates, we differentiated between diurnal and nocturnal colonists and between lateral and longitudinal colonists. All invertebrates were identified to order level, Carabidae, Araneae and Orthoptera to species. Environmental parameters were measured in each habitat. Colonisation of the dry riverbed was primarily diurnal. Aerial invertebrates colonised both laterally, from the adjacent riparian habitat, and longitudinally, along the riverbed. Invertebrate catch was positively correlated with wind speed and direction, indicating the importance of passive dispersal by aerial plankton. The ground‐dwelling invertebrate community exhibited rapid dry riverbed colonisation, with riparian habitats supporting the highest diversity and unique taxa. Taxonomic metrics showed different patterns for ground‐dwelling invertebrates and each studied taxonomic group. The observed patterns suggest that ground‐dwelling Araneae and Carabidae colonised dry riverbed mostly through spillover from the riparian habitat. In contrast, Orthoptera probably colonised the dry riverbed from the upland habitat. Concurrent sampling of aerial and ground‐dwelling colonists characterised responses that could not have been detected using a single method. Our study demonstrates that multiple dispersal modes and source habitats are involved in the colonisation of the dry riverbed. Our results underline the importance to conserve riparian and upland areas along intermittent rivers as source habitats during the dry phase. Given the increase in stream intermittency due to climate change, the conservation and restoration of appropriate river landscapes could become more widely relevant in the future.

New insight into the controlling factors of differences in carbonate buried-hills driven by tectonic activity: a case study of the Weixinan Sag, Beibuwan Basin, China

As the main field for crude oil exploration in the western of the South China Sea, the Weixinan Sag, Beibuwan Basin, has discovered multiple hydrocarbon-bearing structures. Carboniferous carbonate buried-hills in the Weixinan Sag, as a new field for increasing oil reserves and production, have enormous potential for exploration. Due to the influence of karstification, carbonate buried-hill reservoirs exhibit strong heterogeneity and rapid changes in physical properties, making the exploration of effective reservoirs more difficult. In this study, drilling cores and resistivity imaging logging data were employed to investigate the petrological characteristics and fracture development patterns of buried-hill reservoirs. By processing and calculating well logging curves, the development characteristics and vertical distribution patterns of karst in buried-hill reservoirs can be effectively displayed. Based on this, divide karst facies zones, measure karst thickness, and analyze their distribution patterns. The results indicate that tectonic activity is the main controlling factor for the karst differences in carbonate buried-hills in the Weixinan sag. the carbonate buried-hills karst in the No. 1 and No. 2 fault zones has characteristics of vertical zoning, plane partitions, and multiple phases. The buried-hills in the No. 1 fault zone have more karst stages and effective karst storage space than the buried-hills in the No. 2 fault zone. We propose four karst types under the control of tectonic activities, and establish a development model for the karst in the Weixinan Sag buried-hills. This study provides significant guidance for the development and reservoir prediction for similarly carbonate buried karst hills.

Assessing and explaining rising global carbon sink capacity in karst ecosystems

Global karst vegetation is crucial for carbon sequestration and biodiversity conservation. However, research on the carbon sink capacity of vegetation and its potential driving mechanisms across different geographic types of global karst remains scant. This research delineates the trend characteristics and differences of net primary productivity (NPP), heterotrophic respiration (Rh), and net ecosystem productivity (NEP) across various bedrock and climatic zones within global karst landscapes. Extreme Gradient Boosting (XGBoost), Shapley Additive Explanations (SHAP), Neural Network fitting, and Partial Least Squares Structural Equation Modeling were utilized to investigate the nonlinear impacts and underlying mechanisms exerted by the explanatory variables on NPP, Rh, and NEP. The findings indicate that from 1981 to 2019, the rates of increase in NPP (2.02 gC·m⁻2 yr⁻1), Rh (1.47 gC·m⁻2 yr⁻1), and NEP (0.54 gC·m⁻2 yr⁻1) were marginally higher in global karst regions compared to non-karst areas. Additionally, when contrasted with various bedrock types, the differences in mean values and trends of these three indicators were more pronounced across different climatic zones of karst areas. XGBoost effectively captures the nonlinear relationship between NEP and its explanatory variables, while SHAP provides a detailed explanation of the contribution and interaction of these variables. The leaf area index (LAI) was the major contributor to NEP. Additionally, the nonlinear effects of individual critical drivers on NEP varied across different aridity gradients. The cascade effect of explanatory variables on NEP follows a pathway where geography affects climate, climate change subsequently alters vegetation characteristics, and these changes in vegetation directly drive NPP and Rh, ultimately leading to an indirect impact on NEP. This impact pathway exhibits minimal difference across different bedrock and climate types. This study enhances our comprehension of the role of vegetation carbon sinks and their underlying mechanisms across various bedrock and climate types in global karst regions.

Vertical Distribution Patterns of Nitrogen and Phosphorus in Soil Solution: Insights from a Wetland Trial Site in the Li River Basin

Agricultural activities contribute significantly to the pollution of groundwater through the incomplete absorption of nitrogen (N) and phosphorus (P). Understanding the vertical migration patterns of N and P in soil solution is crucial for controlling groundwater quality. This study is based on monitoring data of soil solution nitrogen and phosphorus at different depths (30 cm, 60 cm, 100 cm) in the Huixian Wetland Experimental Area in the Li River Basin from March to December 2021. The vertical distribution patterns of nitrogen and phosphorus in soil solution in the study area are elucidated from three aspects: seasonal variations, karst types, and land use. The results indicate that the following: (1) NO3−-N is the predominant form of nitrogen, generally decreasing with increasing soil depth, while NH4+-N concentrations show slight increases and TP concentrations remain relatively stable. Overall, NO3−-N and TN concentrations tend to accumulate at 30 cm and 60 cm depths during both irrigation and non-irrigation seasons, with no distinct distribution patterns observed for NH4+-N and TP. (2) During the irrigation season, the migration distance of NO3−-N in non-karst landforms is mainly at 60 cm, while in peak forest plains, it is mainly at 100 cm, with no clear trend observed in NO3−-N concentrations in peak cluster depressions. In non-irrigation seasons, the distribution of NO3−-N content in non-karst landforms and peak cluster depressions is mainly 30 cm > 60 cm > 100 cm. The downward migration distance of NH4+-N generally follows the order of peak cluster depressions > peak forest plains > non-karst landforms. (3) During the irrigation season, NO3−-N concentrations in paddy fields remain relatively high at 100 cm, while in drylands, NO3−-N concentrations generally follow the pattern of 30 cm > 60 cm > 100 cm but may exhibit anomalous increases or decreases at 60 cm and 100 cm depths during heavy rainfall.

Forest cover change and its carbon dynamic of the karst area in Bulusaraung, South Sulawesi, Indonesia

Information on land forest cover changes and carbon stocks in karst areas is vital for management planning. Therefore, an analysis of the dynamics of land forest cover, carbon stocks of secondary karst forests, and their future projections is necessary. This study aimed to analyze the carbon stocks of secondary forests, forest cover change, and their projections in karst areas. We used 43 sample plots of 20 m x 20 m to measure Above Ground Biomass (AGB) and soil organic carbon stocks. Forest cover data were collected using remote sensing and GIS tools. Data analysis of the ABG of the secondary forest for the karst plain and karst tower was conducted using the Chave equation. Land-cover change was analyzed by delineating the 2011, 2016, and 2021 land-cover data from satellite imagery and testing the accuracy using survey data fields and high-resolution images. Land-cover projections for 2026 and 2031 were obtained using Cellular Automata Markov (CA-Markov) analysis. The results revealed ten land cover types in the karst area of the Bulusaraung Forest Management Unit (FMU). Secondary dryland karst forests (tower and plain karst) were the dominant forest types (60%) in the Maros-Pangkep essential karst ecosystem area. Both karst types of secondary forests are relatively high carbon stores. Data projection shows that the mining area will grow extensively by 2031. Secondary dryland karst forests will be degraded by 15.5% in 20 years due to increased mining activities, conversion to paddy fields, dryland agriculture, and mixed dryland agriculture. Karst ecosystems are vital for carbon and water storage. Therefore, some strategies are required for the sustainable management of Maros-Pangkep Karst are as follows: (i) controlling the opening of mining areas according to sustainable environmental principles, (ii) encouraging the implementation of post-mining land rehabilitation, (iii) increasing public awareness of the importance of preserving karst areas, and (iv) implementing soil conservation rules by prioritizing agroforestry systems in dryland farming.

Gold in phosphorites: Accumulation forms and practical significance

Research subject. The gold-bearing potential of modern (oceanic) and ancient industrial types of phosphorite ores, including aphanitic, microgranular, granular, nodular, shell and karst. Aim. To assess the ability of phosphorites to accumulate gold to industrial concentrations. This issue has been actively discussed in the geological community in recent years due to the advent of high-precision methods for studying matter. Methods. Russian and foreign publications, unpublished geological data, as well as the authors’ data collected over a 30-year period of studying phosphorites. Results and discussion. In the section, 14 packs of rocks were identified, which are represented by 6 lithological types of secondary dolomites. Their distribution along the section, along with the presence of characteristic faunal remains, made it possible to establish three members in the section, which can be correlated with the Katian, Hirnantian, and Ruddanian stages of the General Stratigraphic Scale. Conclusion. Conditions for the possible joint accumulation of phosphates and gold are manifested in black shale basins, as well as in shelf shallow waters with glauconite-sand sediments. However, due to significant differences in the natural features of gold and phosphates, their industrial clusters are formed separately from each other. This is evidenced by the insignificant accumulation of phosphorus in the ores of gold deposits of black shale formations,as well as its low-quality concentrations in industrial phosphorite beds of phosphorite-bearing basins. For gold, phosphorites are only temporary collectors, the productivity of which depends on the combination of many, frequently random and slightly related factors.

The mineralogy and geochemistry of the Pirashkaft bauxite, Zagros belt, Iran: New inferences on the paleo-climate at the time of formation and on the nature of the parent rock

The Pirashkaft karst type bauxite is located in north of the Paskuhak anticline, Pirashkaft region, in the Fars province (Iran). The deposit is composed of six bauxite horizons, occurring between upper Cretaceous Sarvak and Gurpy Formations, and formed in the late Turonian. Mineralogical composition includes boehmite, hematite, diaspore, kaolinite, goethite, anatase and minor minerals like, gibbsite, spinel, rutile, and kaolinite. The major oxides in the bauxite horizons mainly comprise Al2O3 (46.93–61.34 wt%), SiO2 (5.78–14.60 wt%), Fe2O3 (11.22–28.00 wt%), and TiO2 (1.66–3.03 wt%). The bauxite has a pisolitic–oolitic texture. Pisoids are mainly composed of large Al-bearing hematite cores, surrounded by layers of gibbsite or boehmite. This structure suggests that bauxite formed under a humid climatic regime, punctuated by periodic arid periods. In the Pirashkaft deposit, LREEs vary between 136.49 ppm and 928.56 ppm, whilst HREEs range from 16.48 ppm to 59.5 ppm. Positive anomalies of Ce (Ce/Ce* between 1.08 and 2.36) indicate dominant oxidizing conditions during the bauxitization process. The Eu/Eu* anomalies of the bauxite samples vary between 0.44 and 0.92, this suggesting that parent material likely derived from two geochemically distinct source rocks. Stratigraphical, mineralogical, and geochemical evidences, such as the REE distribution between the bauxitic horizons and the Sarvak marly limestone, suggest that the underlying marly carbonates were one of the sources of the Pirashkaft bauxite.

ГЕНЕЗИС ОЗЕРА ТУГАР-САЛГАН В ЗАПАДНЫХ ПРЕДГОРЬЯХ ЮЖНОГО УРАЛА

Lake Tugar-Salgan is located on the territory of the Ishimbay Municipal District of the Republic of Bashkortostan,10 km southeast of the city of Sterlitamak, at the foot of Shikhan Toratau (Turataw). Despite the morphometric parameters of the lakeestablished a long time ago, its origin is not fully clear. The genesis of the lake is considered to be karstic, but the formation mechanismand even its belonging to the type of karst based on the composition of the karst rocks have not been established. The purpose of theresearch is to determine the conditions and factors of the formation of Lake Tugar-Salgan, which is a complex natural monument ofrepublican importance. Data from a state hydrogeologic survey, a survey of exogenous geologic processes, and the author's 2022 fieldsurvey served as source data for this article. Research methods employed in the study include morphological and morphometric surveysof the lake bed and of the nearest landforms in its vicinity. It has been established that the lake formation was connected with thedevelopment of karst process in the gypsum of the Kungurian Stage of the Early Permian and the lake is located in the rear part of the third supra-flood terrace of the Belaya River valley. The distribution of surface manifestations of sulfate karst in the lake area is directlydependent on the age of relief elements on which they have been formed and inversely dependent on the thickness of non-karst sediments covering karst gypsum. Along with these, the main factor of the lake formation is the course of relief formation in the NeogeneQuaternary time. The karst basin with the lake is located at the mouth of the modern semi-blind erosion-karst ravine, and in the EarlyPliocene its mouth opened 89 km to the west in the paleovalley of the Belaya River. After the paleovalley had been filled with Plioceneand then Pleistocene sediments, the middle and mouth parts of the ravine and the karst landforms were buried under Quaternary alluvium. It was in the rear part of the third supra-floodplain terrace of the Belaya River valley, in the karst basin only partially filled withclayey Middle Pleistocene sediments, where Lake Tugar-Salgan was formed.

Karst of Sterlitamak (BASHKIR) Shikhans and Their Surroundings in Southern Pre-Ural Area

Abstract—Shikhans, or lone mountains, is the local name for island mountains in the flat foothills of the Southern Urals. The shikhans are denudation remnants, sometimes with preserved residuals of Miocene-Pliocene planation surface on their tops, which allows estimating the total time of development of karst processes at least 5 million years. Despite more than 200 years of research on the shikhans, karst and its manifestations have received little attention to date. A map of karst in the shikhan territory was drawn up according to the standard methodology of karstological survey. Widespread and quite rare forms of carbonate karst of the shikhans and sulphate karst of their close vicinities were characterised. It was established that along with widespread and known in temperate latitudes karstic features, very rare corrosion wells are developed in the gypsum of the Kungurian Stage in the study area, forming karst fields with the highest density of karst forms known in the East European Plain. Gypsum caves at various stages of formation, as well as semi-blind karst-erosion gullies not typical for the lowland sulphate karst of the region were recorded. For the carbonate karst of the Shikhans in the limestones of the Sakmarian Stage, the highest location of karst caves in the foothills of the Southern Urals and the oldest (earky Middle Pleistocene) age of their foundation were established. The main peculiarity of distribution of both surface and underground karst-holes is a clearly expressed dependence of forms and frequency of their occurrence on the course of formation of relief elements in the Neogene-Quaternary time. The presence in a small area of two types of karst by composition of karst rocks with very rare karst forms predetermines the high scientific, practical and educational significance of the shikhans and their surroundings.

Geochemical features of lithium–rich bauxite from the Benxi Formation in Qinyuan County, Shanxi, China: Insights into their depositional environment and lithium enrichment

Most bauxites in China are the karst type, which usually enriches lithium (Li) resources. Therefore, Li mineralization theory must be further developed to realize the comprehensive utilization of bauxite resources. The Qinyuan Li–rich bauxite is formed in the Benxi Epoch of the Late Carboniferous and its parent rock is the underlying Ordovician limestone. In this study, the methods of stepwise extraction and element geochemical are utilized to discuss the occurrence state and sedimentary environment of Li in Qinyuan bauxite, respectively. Based on the differences in element composition, the Qinyuan Li–rich bauxite sequence can be divided into clay rocks, bauxitic clays, iron–rich clays, and bauxite from the bottom to the top. The Li content of the Qinyuan bauxite samples is highest in clay rocks (averaging 431 µg/g), followed by bauxitic clays (averaging 288 µg/g), bauxite (averaging 252 µg/g), and iron–rich clays (averaging 202 µg/g). The main mineral compositions of these samples are diaspore, calcite, anatase, pyrite, siderite, kaolinite, and illite. Among them, the Li content is positively correlated with clay mineral contents (R2 = 0.71), indicating that clay minerals are the main Li–rich minerals. More specifically, the clay mineral in bauxitic clays, bauxite, and iron–rich clays are kaolinite, and the positive correlation between Li and kaolinite (R2 = 0.46) indicates that kaolinite is the main Li–rich mineral. Nevertheless, the clay minerals in clay rocks are kaolinite and illite, and the correlation between Li and illite (R2 = 0.54) is higher than kaolinite (R2 = 0.10), indicating that Li is preferentially enriched in illite when kaolinite and illite coexist. It was found that the majority (higher than 99 %) of Li is hosted in the vacant sites of Si–O tetrahedral layers and the Al–O dioctahedral layers of illite and kaolinite to compensate the positive charge deficit caused by replacement of Si4+ and Al3+ in the tetrahedral and dioctahedral layers of clay minerals, respectively. Furthermore, the content ratios between typical elements with varied migration–deposition properties can indicate the depositional environment of Li–rich bauxite. Among them, MgO/Al2O3 and Rb/K (range from1.3 × 10-3 to 7.36 × 10-2 and 3 × 10-4 to 3.44 × 10-2 in samples, respectively) can indicate sedimentary environment. Th/U, V/Cr, and V/(V + Ni) (range from 0.45 to 3.73, 0.85 to 3.54, and 0.27 to 0.89 in samples, respectively) can indicate the paleo–redox conditions. Sr/Cu, CIA, and Cvalue (range from3.53 to 48.2, 93.8 to 99.9, and 0.43 to 7.29 in samples, respectively) can indicate paleoclimate. The results show that the Qinyuan bauxite possibly formed in the hot, humid (Sr/Cu > 5, CIA = 85–100, and Cvalue > 0.8), and dysoxic–anoxic (Th/U = 2–7, V/Cr = 2–4.25, and V/(V + Ni) = 0.46–0.84) marine–continental transitional (MgO/Al2O3 = 0.01–0.1 and Rb/K = 4 × 10-3–6 × 10-3) environment.

How diverse are the mountain karst forests of Mexico?

Tropical forests on karstic relief (tropical karst forest) are among the most species-rich biomes. These forests play pivotal roles as global climate regulators and for human wellbeing. Their long-term conservation could be central to global climate mitigation and biodiversity conservation. In Mexico, karst landscapes occupy 20% of the total land surface and are distributed mainly in the southeast of the country, along the eastern slope, and in the Yucatan Peninsula. Within each of these areas, the following types of karst occur: coastal karst, plain karst, hill karst, and mountain karst (low, medium, high). Mountain karst cover 2.07% of Mexico's land surface and are covered by tropical rainforests, montane cloud forests, and tropical deciduous forests. These are probably one of the most diverse biomes in Mexico. However, the mountain karst forests of Mexico have received little attention, and very little is known about their diversity. Here, we evaluated the vascular plant species richness within the mountain karst forests of Mexico. We assembled the first, largest, and most comprehensive datasets of Mexican mountain karst forest species, from different public databases (CONABIO, GBIF, IBdata-UNAM), which included a critical review of all data. We compiled a list of the families, genera, and species present within the mountain karst forests of Mexico. Taxa that best characterize these forests were identified based on their spatial correlation with this biome. We explored biodiversity patterns, identifying areas with the highest species richness, endemism centers, and areas of relatively low sampling intensity. We found that within the mountain karst forests of Mexico there are representatives of 11,771 vascular plant species (253 families and 2,254 genera), ca. 50% of the Mexican flora. We identified 372 species endemic to these forests. According to preliminary IUCN red list criteria, 2,477 species are under some category of conservation risk, of which 456 (3.8%) are endangered. Most of the Mexican mountain karst forests have been extensively explored and six allopatric, species-rich areas were identified. Compared to other regions in the world, the mountain karst forests of Mexico are one of the most diverse biomes. They contain more species than some entire montane systems in Mexico such as Sierra Madre Oriental, and Sierra Madre del Sur. Also, the mountain karst forests of Mexico are most diverse than similar forests of South America and Asia, even if considering the effect of different sampling areas. The fact that mountain karst forests are embedded in areas of high biotic diversity, probably contributes to their great floristic diversity. Thus, the mountain karst forests of Mexico are an important source of diversity and shelters a large percentage of the Mexican flora.

Genesis, Distribution, and Characterization of a Paleokarst Subsurface River System in the Tahe Area, Tarim Basin, Western China

Summary Subsurface river systems constitute one of three major paleokarst types that make up Ordovician reservoirs in the Tahe area of the Tarim Basin. The total length of the river system is approximately 400 km, and the reserves associated with this karst type are more than 200 million tons. However, it is manifested that 47% of drilled wells have not encountered river paleokarst, while 50% of wells that have encountered river paleokarst are fully filled due to the poor understanding of the paleokarst of this region, resulting in a significant variation of production capacities. In this study, we propose a detailed data integration approach with outcrops, drilling, logging, seismic profiles, and dynamic data to delineate the complex paleokarst river system in the Tahe area. The karst geological theory with reservoir characterization is combined in particular. The workflow of clarifying the main controlling factors, architecture types, and development distribution modes of the subsurface river system is established. Fill material type, sequence of fill structure, and fill controlling factors are also revealed. A quantitative characterization method of the subsurface rivers is established adopting predictions based on seismic data and high-resolution geostatistical and geological modeling. The Ordovician reservoirs in the Tahe area comprise three paleokarst river systems with different characteristics. Karst paleogeomorphology is the main control over the overall flow direction and plane distribution of the subsurface rivers. Changes in the surface of the phreatic zone are crucial in controlling the vertical layers and scale of the rivers. The combined action of faults plays a decisive role in controlling the anastomosing pattern of the rivers. Single-branch channels, reticulated channels, and structural corridors in single-layer or multilayer styles are the main subsurface river types. Trunk channels, branch channels, hall caves, and inlets/outlets are dominant structures in the architecture of the river system. Sand-mud, breccia, and chemically precipitated materials are the most common fill types. Three typical sequences of fill structure and four spatial combination modes exist in the subsurface river system. The morphology and fill characteristics of rivers are predictable using seismic attributes, such as frequency division energy, frequency division inversion, and coherent energy gradient. 3D models are constructed by multivariate control multipoint geostatistical method, which can characterize the strong heterogeneity characteristics of subsurface river systems. This complex paleokarst system enables remarkable results for the adjustment of the reservoir development plan through quantitative characterization.

NON-TRADITIONAL KARST TYPES IN THE SOUTHERN URALS AND CISURALS

Despite the wide distribution of sulfate and carbonate karst in the study area, the nontraditional, rarely encountered karst types are also registered. These are clastokarst, karst of calcareous tuffs, sulfide karst, salt karst and marble karst. For each of these nontraditional types of karst, the conditions and factors of development were determined according to the karstic rock composition. Calcareous tuff karst is the least common in the study area, meanwhile clastokarst is widespread. Calcareous tuff karst is spread in the westernmost part of the Southern CisUrals, in the eastern outskirts of the Volga-Ural anteclise; and clastokarst is found in the western margin of the Yuryuzan-Sylva depression of the CisUrals marginal foredeep. Sulfide karst is developed in the plains of the Southern TransUrals within the Magnitogorsk megazone of the Ural folded system, and salt karst occurs in the flat foothills of the Southern Urals within the Belaya Megadepression and the Shikhan-Ishimbai saddle of the CisUrals marginal foredeep. It has been established that the previously identified areas of clastokarst distribution in the west of the area under consideration are not confirmed by modern and Pleistocene forms of its manifestation. The negative impact of clastokarst on economic facilities and humans is comparable to the impact of the most common and dangerous sulfate karst, and this must be taken into account when designing and constructing new buildings and engineering structures. Salt karst is manifested in artificial leaching of rock salt at a depth, such salt is necessary for the production of soda ash (JSC “Soda”); the formed voids are used as underground storage facilities for oil products (OJSC Podzemneftegaz). Calcareous tuff karst is a rare type of karst in the region under consideration, it can be observed at the complex natural monument “Shumilovsky waterfall”. Surface manifestations of sulfide karst can be a search feature of new copper-sulfide deposits. Non-traditional types of karst have both positive and negative practical implications. Karst in marble complicates the development of mineral deposits, and clastokarst complicates the economic development of the territory. Calcareous tuff karst creates unique local landforms, and sulfide karst is of practical importance in the search for new mineral deposits. On the one hand, salt karst determines the extraction of minerals deposits and contributes to the creation of useful underground storage facilities, on the other hand, it destroys them.

Emerging organic contaminants in springs of the highly karstified Dinaric region

Emerging organic contaminants (EOCs) have become of increasing interest due to concerns about their impact on humans and the wider environment. Karst aquifers are globally widespread, providing critical water supplies and sustaining rivers and ecosystems, and are particularly susceptible to pollution. However, EOC distributions in karst remain quite poorly understood. This study looks at the occurrence of EOCs in the Croatian karst, which is an example of the “classical” karst, a highly developed type of karst that occurs throughout the Dinaric region of Europe. Samples were collected from 17 karst springs and one karst lake used for water supply in Croatia during two sampling campaigns. From a screen of 740 compounds, a total of 65 compounds were detected. EOC compounds from the pharmaceutical (n = 26) and agrochemical groups (n = 26) were the most frequently detected, while industrials and artificial sweeteners had the highest concentrations (range 8–440 ng/L). The number of detected compounds and the frequency of detection demonstrate the vulnerability of karst to EOC pollution. Concentrations of 5 compounds (acesulfame, sucralose, perfluorobutane sulfonate, emamectin B1b, and triphenyl phosphate) exceeded EU standards and occurred at concentrations that are likely to be harmful to ecosystems. Overall, most detections were at low concentrations (50 % <1 ng/L). This may be due to high dilution within the exceptionally large springs of the Classical karst, or due to relatively few pollution sources within the catchments. Nevertheless, EOC fluxes are considerable (10 to 106 ng/s) due to the high discharge of the springs. Temporal differences were observed, but without a clear pattern, reflecting the highly variable nature of karst springs that occurs over both seasonal and short-term timescales. This research is one of a handful of regional EOC investigations in karst groundwater, and the first regional study in the Dinaric karst. It demonstrates the need for more frequent and extensive sampling of EOCs in karst to protect human health and the environment.

Monitoring of water cycle in karst geosystems and its integration into ecosystem assessment framework

Karst is a widely spread natural phenomenon which provides essential benefits to human society, such as drinking water. The water cycle in the karst geosystems is the main factor for their formation and at the same time one of the main drivers for ecosystem services (ES) provision. The monitoring of the water cycle can provide valuable information regarding its functioning and ensure data for ES assessment. This paper aims to present an overview of the monitoring of the water cycle in the karst geosystems and the opportunities to integrate the monitoring data into the water regulation ES assessment. The monitoring of the water cycle is based on the methodological framework ProKARSTerra. It is applied in model karst geosystems, which are representative of the main karst types in Bulgaria. One of them is the Brestnitsa karst geosystem, which is the case study of this work. The monitoring ensures data for analyses of the water cycle which can be used in the assessment of water-related ecosystem services. The results from the analyses of the data requirements and availability show that some services such as water flow regulation and regulation of chemical condition of freshwaters can be easily provided through data for quantification, while for others further studies are needed. The results of the long-term integrated monitoring in Brestnitsa karst geosystem provide the foundation for important conclusions and models for the karst genesis and function under global changes and active anthropogenic pressure. Their integration into the assessment framework and mapping of ecosystem services is an essential step towards the development of models for sustainable use of natural resources in the karst areas.

Hydrological Characteristics of the Bakony Region (Hungary)

In this study, the karst systems (karst types) of the Bakony Region are classified and described. The karst features and the groundwater (karstwater) flow, their horst (block) types and the hydrological cycle of horst types were taken into consideration. In the mountains, regional flow with a hypogene branch (hypogene karst system) and epigene karsts systems of local flow were distinguished. Among local epigene systems, epigene karst system, mixed epigene karst system, complex mixed epigene karst system, incomplete epigene karst system and semi-closed epigene karst system were distinguished. Local epigene systems are only temporarily (but not all of them) separated from the regional system that developed below and around them. During their development, separated local systems are more and more becoming the descending branches of regional systems.

Reducing Drilling Hazard Risk in a Carbonate Environment Using Seismic Processing, Diffraction Imaging and Interpretation

Buried structural anomalies within carbonate depositional environments, such as karst sinkholes, impose significant dangers for borehole integrity and drilling equipment due to rapid changes in rock properties (from tight to the porous) potentially resulting in extensive mud loss, drill bit jamming and other complications. This often leads to delays in the well construction planning and sometimes to subsequent sidetrack drilling and a dramatic increase in costs. Thus, Paleo-karst localization, prior to well planning and construction, becomes a critical task for economic optimization. However, this is a non-trivial exercise due to the relatively small scale and size of karst type features and anomalies, which are at the limit of lateral resolution of most standard surface geophysical methods. In this paper, we introduce a methodology of karst prediction based on a combination of targeted 3D seismic processing and integration of the diffracted wavefield anomalies in addition to use of conventional seismic attributes. The presented approach has been proven to be efficient to detect karsts in a real oil field and can be deployed in other regions.

Comparison of the Manifestations of Western Region-Iraq Karst and Some Typical Karst Areas in the World

Karst is one of the geological manifestations that form different earth shapes and scenic landscapes. Which are generally divided into surface landscapes that are important its sinkhole and the sub-surface landscapes. The research aims to compare the manifestations of karst for the study area and the typical karst (holocaust) areas in the world. The most important of which are the caves, which result from the process of dissolution the rocks of all kinds, But the most important rocks formed for karst carbon rocks, especially limestone rock, due to its abundant and moderate solubility. add to evaporated rocks, especially gypsum, come second in the form of karst manifestations. There are several surface landscapes karst forms in the Western Desert such as a Solution and Collapse Sinkhole and subsurface landscapes karst such as cavities formed from carbonate and gypsum rocks. Landscapes karst distribution in variable shapes and dimensions on surfaces of the plateaus on Zor Hauran, Ubaid, Hussainiyat, Amij, Dammam, Umm Er Radhuma, Russ, and Ms`ad within Euphrates Fatha and Zahra formations, which belongs to Mesozoic and Cenozoic eras times. The meaning of the non-typical karst is that the surface karst forms such as (Sinkholes) and the subsurface karst forms such as (cavities) are few in number in addition to the size, depth and dimensions of these phenomena are small compared to the typical karst forms, which are characterized by the abundance of their numbers in addition to the huge size of these karst phenomena. There are a number of reasons and observations that make this phenomenon unclear and not typical for the study area because of Lithology, geomorphology, tectonic, and climatic reasons. In addition to the time factor, which has a main role in the development of karst. The type of karst in Iraq belongs to the arid and semi-arid karst group depending on classification of karst assemblages according to climate.

A General Description of Karst Types

This study includes a general description of the Earth’s karst types based on literary data and field observations. An improved classification of karst types distinguishes the main group, group, and subgroup; and, a division of karst types involves a main karst type, karst type, subtype, variety, and non-individual karst type. The relation between karst type and karst area is described. The role of various characteristics of karsts in the development of primary, secondary, and tertiary karst types is analyzed. Their structure is studied, which includes a geomorphic agent, process, feature, feature assemblage, karst system and the characteristics of the bearing karst area. Dominant, tributary, and accessory features are distinguished. The conditions of the stability and the development of types are studied, transformation ways are classified, and the effect of climate on types is described.

Karst relief of the Mali me Gropa Massif, central Albania

The mid-altitude mountain massif of Mali me Gropa is located in the central part of Albania, rises to an altitude of 1500–1800 m a.s.l., is composed mostly of Mesozoic limestone, and is characterized by extensive surface karst development. The karst relief is dominated by “doline” morphology including “polygonal” karst. Detailed geomorphological analysis of the western part of the Mali me Gropa massif (so-called Western Massif) by means of GIS methods is used to determine and explain the morphometric and morphological diversity of the area’s topography. Based on a homogeneity criterion, a number of geomorphological units with specific kinds of karst relief have been distinguished within the massif. The differences in karst sculpture concern the size (diameter) of dolines and depressions, their depth, shape and symmetry, orientation, density of occurrence and spatial pattern, which provide the basis for distinguishing geomorphological units. The spatial differentiation of the karst relief is explained by the influence of factors which are evolutionary (geological and geomorphological evolution of the massif), hypsometric (altitude difference of terrains) and geomorphologic-structural (inclination of the slopes and layers). The relatively poor expression of open karst conduits (i.e. caves and vertical shafts) on the surface of the massif may result from the relative immaturity of the epikarst zone, the widespread occurrence of residual cover on the plateau, and the accumulation of large amounts of clay material in dolines and depressions. Detailed hydrogeological studies show, however, high karst permeability and dominance of conduit flow. Considering the high geomorphological landscape and ecological value of the area, it should be granted the status of a nature reserve or national park. Geomorphological and karstological research within the massif should be continued as it represents a type of karst found also in other parts of Albania. This type of karst area is of great economic (groundwater reserves) and natural protection (environmental) importance.