Bedrock Geologic Map of the Northern Half of the Bedford 30- X 60-Minute Quadrangle, Indiana

The Bedrock Geologic Map of the Northern Half of the Bedford 30- X 60-Minute Quadrangle is an Esri File Geodatabase that contains six feature data sets, five geodatabase tables, and two raster data sets detailing the bedrock geology of the northern half of the Bedford 30- X 60-minute quadrangle in Indiana. This data set conforms to "GeMS (Geologic Map Schema)--a standard format for the digital publication of geologic maps." For more information on GeMS please refer to the supplemental information within this metadata.

Hydrogeochemical Characteristics of Uranium and Radon in Groundwater from the Goesan Area of the Ogcheon Metamorphic Belt (OMB), Korea

Uranium and radon concentrations in groundwater from the Goesan area of the Ogcheon Metamorphic Belt (OMB), central Korea, whose bedrock is known to contain the highest uranium levels in Korea, were analyzed from 200 wells. We also measured the uranium concentrations in the bedrock near the investigated wells to infer a relationship between the bedrock geology and the groundwater. The five geologic bedrock units in the Goesan area consist of Cretaceous granite (Kgr), Jurassic granite (Jgr) and three types of metasedimentary rocks (og1, og2, and og3). The percentages of the groundwater samples over 30 μg/L (maximum contaminant level, MCL of US EPA) were 2.0% of the 200 groundwater samples; 12% of Kgr and 1.8% of Jgr exceeded the MCL, respectively. Overall, 16.5% of the 200 groundwater samples exceeded 148 Bq/L (alternative maximum contaminant level, AMCL of US EPA); 60.0% of Kgr and 25.0% of Jgr exceeded the AMCL, but only 0% of og1, 7.9% of og2, and 2.6% of og3 exceeded the value, respectively. No direct correlation was found between uranium concentration and radon concentration in water samples. Radon has a slightly linear correlation with Na (0.31), Mg (−0.30), and F (0.36). However, uranium behavior in groundwater was independent of other components. Based on thermodynamic calculation, uranium chemical speciation was dominated by carbonate complexes, namely the Ca2UO2(CO3)3(aq) and CaUO2(CO3)32− species. Although uraniferous mineral phases designated as saturation indices were greatly undersaturated, uranium hydroxides such as schoepite, UO2(OH)2 and U(OH)3 became possible phases. Uranium-containing bedrock in OMB did not significantly affect radioactive levels in the groundwater, possibly due to adsorption effects related to organic matter and geochemical reduction. Nevertheless, oxidation prevention of uranium-containing bedrock needs to be systematically managed for monitoring the possible migration of uranium into groundwater.

Diversity of Groundwater Crustaceans in Wells in Various Geologic Formations of Southern Poland

Data on Crustacea from underground waters accessed through wells are limited in Poland. A recent study was undertaken to determine diversity and factors influencing the crustacean communities inhabiting wells drilled in three bedrocks, Jurassic limestone, Cretaceous marls and flysch. A total of 23 crustacean species and subspecies were recorded belonging to Copepoda, Ostracoda, Amphipoda and Bathynellacea. Only four species of low abundance, however, were stygobionts. Our studies showed that abundance and species number of Copepoda and Ostracoda were affected by bedrock geology (with higher abundances and species richness in wells of Cretaceous marls), and in the case of copepods, also by sampling season. Furthermore, this paper lists all species of Crustacea recorded from inland groundwater habitats of Poland based published over the last 133 years. The most species-rich group was Copepoda with 43 representatives (four stygobites), followed by Ostracoda and Amphipoda with a total of 37 and 12 species, respectively (each with nine stygobites). In addition, two species of Isopoda (one stygobite) and one Bathynellid appear in the checklist. The checklist identifies geographical (and environmental) gaps which require further research.

Páramo Lakes of Colombia: An Overview of Their Geographical Distribution and Physicochemical Characteristics

The páramo lakes, Colombia, situated in the neotropical region, are of great value both as natural heritage and as water source to the most populated areas of the Andes, but are threatened by expanding agriculture, livestock, mining, and landscape fragmentation. Nonetheless, a general assessment of the lakes’ distribution and biogeochemical characteristics was lacking. We made a complete inventory of the Colombian páramo lakes and characterized their morphometry and water chemistry based on a survey of 51 lakes in the Eastern Cordillera. There are 3250 lakes distributed across 28 páramo complexes in Colombia, mainly located between 3600 and 4400 m a.s.l. The lakes are usually small (<10 ha) and shallow (<10 m). Most of them are slightly acidic (average pH~6), with high nutrient (total phosphorus ~0.6 mg/L, total nitrogen ~1 mg/L) and total organic carbon (~6 mg/L) concentrations and low oxygen (~3.5 mg/L) at the bottom. Water chemistry varies according to two main independent gradients related to watershed bedrock geology and trophic state. Global change pressures may be challenging the preservation of these unique ecosystems. Increasing the protection of more lake watersheds should reduce these potential impacts by mitigating negative synergies with local pressures.

Bedrock Geology of the Southern Half of the Knox 30- x 60-Minute Quadrangle, Indiana

This is a map. It has an introduction, but no abstract.

3D overdeepened trough morphology revealed as a product of bedrock geology (northern Switzerland)

&lt;p&gt;Subglacial overdeepenings are a common element of once glaciated mountain forelands and have considerable implications for society, e.g. in construction projects, water production and radioactive waste disposal. Yet the processes of overdeepening erosion, especially the influence of bedrock lithology and structure, are poorly understood. We present a case study of the Gebenstorf-Stilli Trough in northern Switzerland, a unique overdeepening with complex underlying geology: In contrast to the Molasse-hosted majority of the Alpine foreland overdeepenings, it is to a large part incised into Upper Jurassic limestones and marls. In order to constrain its morphology in 3D, it was targeted with scientific boreholes as well as a seismic campaign based on analysis of surface waves. The results reveal unexpected trough morphology with two nested sub-basins that appear to be closely related to the bedrock geology. We suggest that this morphology is a product of low erosional efficiency in Jurassic limestones in comparison with both underlying marls and overlying Molasse deposits as well as secondary paleoglaciological effects. We further infer that the glacier&amp;#8217;s basal drainage system was the main driver of subglacial erosion of the Gebenstorf-Stilli Trough.&lt;/p&gt;

Improved Automated Mapping of Sinkholes Using High-Resolution DEMs

ABSTRACT Sinkholes are common surface manifestations of the presence of networks of subsurface caverns in areas where the bedrock geology is dominated by soluble rocks such as limestones. Accurate mapping of sinkholes is crucial as they are hazardous to transportation infrastructure and may serve as conduits of contaminants to the groundwater. The use of high-resolution digital elevation models extracted from LiDAR and tools in ArcGIS have made it a simple task to automate the process of identification of closed depressions. However, these automated methods do not differentiate between sinkholes and other man-made depressions. Multivariate statistical methods such as linear discriminant analysis, quadratic discriminant analysis, and logistic regression were used to produce predictive models based on selected shape factor values such as circularity, sphericity, and curvature. Curvature values, especially when combined with circularity, were found to be the most powerful variables in separating closed depressions into sinkholes and other artificial depressions.