Mineral Potential Mapping Via TOPSIS with Hybrid AHP–Shannon Entropy Weighting of Evidence: A Case Study for Porphyry-Cu,Farmahin Area,Markazi Province,Iran

This paper presents an AHP–Shannon Entropy weighting approach as a new hybrid method for assigning evidential weights in mineral potential mapping. For demonstrating the proposed method, a case study was selected for porphyry-Cu potential mapping in Markazi Province, Iran. Then, geo-datasets were gathered, and evidence layers were generated for integration by TOPSIS method (via combination of AHP–Shannon Entropy weighting). Finally, the output mineral potential map was evaluated by field checking and chemical analysis of samples. Two outcrops with evidence of a porphyry system were encountered in areas with high potential values. In addition, there was good correlation between high potential values and Cu content of samples taken from the field. Hence, the usefulness of the AHP–Shannon Entropy weighting of evidence for MPM was demonstrated.     

Application of Artificial Neural Network for Gold–Silver Deposits Potential Mapping: A Case Study of Korea

The aim of this study is to analyze hydrothermal gold–silver mineral deposits potential in the Taebaeksan mineralized district, Korea, using an artificial neural network (ANN) and a geographic information system (GIS) environment. A spatial database considering 46 Au and Ag deposits, geophysical, geological, and geochemical data was constructed for the study area using the GIS. The geospatial factors were used with the ANN to analyze mineral potential. The Au and Ag mineral deposits were randomly divided into a training set (70%) to analyze mineral potential using ANN and a test set (30%) to validate predicted potential map. Four different training datasets determined from likelihood ratio and weight of evidence models were applied to analyze and validate the effect of training. Then, the mineral potential index (MPI) was calculated using the trained back-propagation weights, and mineral potential maps (MPMs) were constructed from GIS data for the four training cases. The MPMs were then validated by comparison with the test mineral occurrences. The validation results gave respective accuracies of 73.06, 73.52, 70.11, and 73.10% for the training cases. The comparison results of some training cases showed less sensitive to training data from likelihood ratio than weight of evidence. Overall, the training cases selected from 10% area with low and high index value of MPM_L and MPM_W gave higher accuracy (73.52 and 73.10%) for MPMs than those (73.06 and 70.11%, respectively) from known deposits and 10% area with low index value of MPI_L and MPI_W.     

Practical Implementation of Random Forest-Based Mineral Potential Mapping for Porphyry Cu–Au Mineralization in the Eastern Lachlan Orogen,NSW, Australia

Natural Resources Research - With the increasing use of machine learning for big data analytics, several methods have been implemented for the purpose of exploration targeting using mineral...     

Extraction of Mineralization-Related Anomalies from Gravity and Magnetic Potential Fields for Mineral Exploration Targeting: Tongling Cu(–Au) District,China

Natural Resources Research - Extraction of mineralization-related anomalies for mineral exploration targeting lies in the interpretation of geological anomalies that indicate favorable ore-forming...     

Predictive Mapping of Prospectivity in the Gurupi Orogenic Gold Belt,North–Northeast Brazil: An Example of District-Scale Mineral System Approach to Exploration Targeting

The Gurupi Belt hosts a Paleoproterozoic gold province located in north–northeastern Brazil, at the borders of Pará and Maranhão states. It is considered to be an extension of the prolific West African Craton’s Birimian gold province into South America. Additionally, the belt has been the object of recent mineral exploration programs with significant resource discoveries. This study presents the results of predictive mapping using up-to-date mineral system concepts and recently finished regional-scale geological mapping, stream sediment and airborne geophysical surveys conducted by the Geological Survey of Brazil. We relate gold mineralization to an initially enriched crust, metamorphism, deep fluid pathways, structurally controlled damage zones and hydrothermal alteration. Prospective targets were generated using only regional public datasets and knowledge-driven targeting technique. This work did not incorporate any known gold deposits, yet it predicted the largest known deposits and their satellite targets. Besides, high prospective targets mapped almost 40% of known primary gold occurrences within 7% of the project area. This work allowed considerable search area reduction and identification of new target areas, thus collaborating on reducing costs, time and risk of mineral exploration. Results indicate that we achieved an efficient understanding of the geological processes related to the Gurupi Belt mineral system.     

Нigh-Quality Development Path of the Enclave Economy from the Perspective of Symbiosis: A Case Study of Guangqing Economic Cooperation Zone (Guangde Park)

The enclave economy is an important governance tool for promoting regional integration. Guangdong Province occupies the leading position in exploring the enclave economy model in China, which has effectively promoted the development of the east and northwest of Guangdong Province through the point to area approach. However, certain problems that are associated with the enclave economy concept, including a weak level of industrial relatedness, disconnection with the development of the local urban system, and inadequate interest driving mechanisms, need to be urgently addressed. The article aims to explore the high-quality development path of the enclave economy in the new era, taking advantage of the symbiosis theory. Based on field research and semi-structured interview methods, the present study attempts to not only probe into the cooperative relationship and mutually beneficial symbiosis mechanism among different actors in the enclave economy but also explore a more sustainable and mutually beneficial development enclave economy model. With respect to theoretical contribution, based on the symbiosis theory and the characteristics of the enclave economy, this study facilitates a better understanding of the high-quality development logic of the enclave economy from the perspective of symbiosis in particular and establishes a theoretical framework comprising the industrial symbiosis network-industrial symbiosis unit-interest symbiosis mechanism components. Empirically, this study takes the Guangqing Economic Cooperation Zone (Guangde Park) as the case study; reveals the development process and problems of the enclave economy, including the isolation of industry transplantation, fragmentation of industry-city units, and locking of interests and mismatch between rights and responsibilities; and proposes high-quality development strategies, such as establishing a cross-regional enclave economic circle, a resource-linking platform between industry and city, and a community of interests in industrial parks and towns, to form a more sustainable symmetric and mutually beneficial symbiotic mechanism. The key contribution of this study lies in the theoretical framework for the high-quality development of the enclave economy through the lens of symbiosis, which enriches the ways of analysis and cognitive logic of the enclave economy and advances cross-regional cooperation and enclave economy research. It enhances the cross-territorial geographic thinking of regional cooperation and enclave economy research, holding the potential to provide decision-making references for the promotion of regional coordinated development in Guangdong Province in the new period. It also has practical application value for relieving the pressure of unbalanced and insufficient regional development in China by promoting cross-municipal and cross-provincial cooperation. © 2023 Environmental Sanitation Engineering. All rights reserved.     

GIS-based Mineral Prospectivity Mapping of Seafloor Massive Sulfide on Ultraslow-spreading Ridges: A Case Study of Southwest Indian Ridge 48.7°–50.5° E

With the depletion of mineral resources on land, seafloor massive sulfide deposits have the potential to become as important for exploration, development and mining as those on land. However, it is difficult to investigate the ocean environment where seafloor massive sulfide deposits are located. Thus, improving prospecting efficiency by reducing the exploration search space through mineral prospectivity mapping (MPM) is desirable. MPM has been used in the exploration for seafloor deposits on regional scales, e.g., the Mid-Atlantic Ridge and Arctic Ridge. However, studies of MPM on ultraslow-spreading ridges on segment scales to aid exploration for seafloor massive sulfide have not been carried out to date. Here, data of water depth, geology and hydrothermal plume anomalies were analyzed and the weights-of-evidence method was used to study the metallogenic regularity and to predict the potential area for seafloor massive sulfide exploration in 48.7°–50.5° E segments on the ultraslow spreading Southwest Indian Ridge. Based on spatial analysis, 11 predictive maps were selected to establish a mineral potential model. Weight values indicate that the location of seafloor massive sulfide deposits is correlated mainly with mode-E faults and oceanic crust thickness in the study area, which correspond with documented ore-controlling factors on other studied ultraslow-spreading ridges. In addition, the detachment fault and ridge axis, which reflect the deep hydrothermal circulation channel and magmatic activities, also play an important role. Based on the posterior probability values, 3 level A, 2 level B and 2 level C areas were identified as targets for further study. The MPM results were helpful for narrowing the search space and have implications for investigating and evaluating seafloor massive sulfide resources in the study area and on other ultraslow-spreading ridges.

     

An Improved Data-Driven Multiple Criteria Decision-Making Procedure for Spatial Modeling of Mineral Prospectivity: Adaption of Prediction–Area Plot and Logistic Functions

Natural Resources Research - Assigning realistic weights to targeting criteria in order to synthesize various geo-spatial datasets is one of the most important challenging tasks for mineral...     

An analysis of intra-event precipitation variability for the United States (1980–2010)

Hourly precipitation data were collected from 143 first-order US weather stations during the period from 1980 to 2009 to assess the internal distribution of precipitation events lasting at least three hours. A total of 46,595 individual precipitation events were identified and evaluated using the mean, standard deviation, skewness, kurtosis, and the number of peaks occurring within an event. Mean event duration is longest along the West and Northwest coasts, the Mid-South, the Mid-Atlantic, and the Northeast; while shorter-duration events are more frequent in the Rocky Mountains, the Southwest, and the Great Plains. Mean event precipitation and standard deviation are greatest along the Gulf Coast and decrease inland. Precipitation events are positively skewed, indicating that more precipitation tends to occur earlier in the event. The most positively-skewed events are also located in regions flanking the Gulf of Mexico, while less-skewed events are common in the Northwest and Rocky Mountain regions. Event kurtosis is negative throughout the entire USA, with the highest negative values generally west of the Front Range, where cyclonic development and transition produce more evenly distributed precipitation within storms. Intra-event precipitation maxima were also evaluated, with western Florida and the desert Southwest having the greatest number per event.     

Analysis of Spatial–Temporal Evolution of Mining-Induced Fracture Field: A Case Study Using Image Processing in the Shaqu Coal Mine,China

Natural Resources Research - Mining-induced fracture plays a key role in gas drainage for gas burst-prone underground coal mines, especially for closely multilayered coal seams. The layout and...     

Multivariate Mapping of Heavy Metals Spatial Contamination in a Cu–Ni Exploration Field (Botswana) Using Turning Bands Co-simulation Algorithm

Natural Resources Research - With a mining-driven economy, Botswana has experienced increased geochemical exploration of minerals around existing mining towns. The mining and smelting of copper and...     

Application of AdaBoost Algorithms in Fe Mineral Prospectivity Prediction: A Case Study in Hongyuntan–Chilongfeng Mineral District,Xinjiang Province,China

Natural Resources Research - Continuous resource supply is one of the key points to improve comprehensive national strength. Resource prediction models supportive of target delineation for...     

Evidence for temporally coherent increases in the abundance of small Discostella (Bacillariophyceae) species over the past 200 years among boreal lakes from the Experimental Lakes Area (Canada)

Journal of Paleolimnology - Increased relative abundances and accumulation rates of the small, centric diatom Discostella have been recorded in numerous paleolimnological investigations of north...     

Can One-Run-Fixed-Arrhenius Kerogen Analysis Provide Comparable Organofacies Results to Detailed Palynological Analysis? A Case Study from a Prospective Mississippian Source Rock Reservoir (Bowland Shale,UK)

Natural Resources Research - Organofacies analysis, a fundamental component within source rock appraisal based on the study of kerogen within a source rock, is typically produced from microscopy...     

Late Quaternary (30.7–9.0 cal ka BP) vegetation history in Central Asia inferred from pollen records of Lake Balikun, northwest China

Surface and fossil pollen samples were collected to reconstruct the vegetation and environment since 30.7 cal ka BP in the Lake Balikun Basin, northwest China. This record demonstrates that the region was occupied by four vegetation communities during the interval 30.7–9.0 cal ka BP, including desert steppe (30.7–25.1 cal ka BP), Amaranthaceae-Asteraceae desert (25.1–17.7 cal ka BP), Amaranthaceae-Artemisia-Asteraceae desert (17.7–12.8 cal ka BP) and Amaranthaceae desert (12.8–9.0 cal ka BP), corresponding to relatively humid, the coldest and driest, cold and dry, and colder and drier conditions, respectively. The reconstructions of vegetation and environmental changes around Lake Balikun do not support the interpretation of an extremely humid LGM in Central Asia, challenging the cold-moist (glacial), warm-dry (interglacial) pattern of late Quaternary environmental change in Central Asia. The Last Glacial Maximum was cold and dry, and similarly harsh conditions continued into the early Holocene.     

The role of fire as a long-term landscape modifier: Evidence from long-term fire observations (1922–2000) in Greece

The objective of this paper is to document the role of fire in shaping the landscape by identifying links between historical fire records and the current landscape indicating that fire favors certain land use/land cover (LULC) types. We geo-referenced fire records taken from 1922 to 2000 in Aitoloakarnania, the largest prefecture -in terms of surface area- of Greece and compared the past LULC classes where fires burned to the present landscape. The outputs indicated a shift of the historic fire ignition points from natural to agricultural-related LULC classes since a significant proportion of fire incidents that, according to the fire records, burnt natural vegetation units is currently located in agricultural landscape units. Additionally, a significant proportion of the fire-affected land cover classes retain their character thus supporting the argument that these classes, especially fire-prone or fire-resistant, have developed mechanisms to cope with fire. In such ecosystems the role of fire is to maintain rather than transform land cover classes.The findings of this research lead us to conclude that fire can be perceived as a long-term landscape modifier in the Mediterranean, although its effects may vary from region to region because of differences in regeneration patterns among the main land cover types, topographic constraints and local fire histories. Historical fire records extending back to the early 20th century proved to provide valuable information that can reveal interesting patterns of fire burning history and explain present land cover and use patterns. This knowledge, documented from historical records, can be used to develop fire management and land cover/land use management planning.     

Existing Territories and Formalization of Territorial Use Rights for Moored Fish Aggregating Devices: The Case of Small-Scale Fisheries in the La Désirade Island (France)

Moored fish aggregating devices (MFADs) are used by small-scale fishers to access fish species difficult to harvest in large numbers. In the case of Guadeloupe (Caribbean area), the use of MFADs has increased considerably and this is causing congestion in these fishing areas and creating conflict between fishers. The aim of this article is to understand how informal fishing territories around the La Desirade Island were established and examine these territories through the lens of economic defendability theory. Results of semistructured interviews show that MFAD fishers display territoriality along MFAD tract lines forming quasi-privatized areas. Territoriality in this article is based on the following factors: the type of targeted resources, the cost of harvesting, the defending of territories, and the acknowledgment of territories by the fishing community. Conflicts and utilization of MFADs (overcapacity) have raised an opportunity to create co-managed legalized territorial use rights for fisheries.     

A new climatology of maximum and minimum temperature (1951–2010) in the Spanish mainland: a comparison between three different interpolation methods

This study presents a new climatology of monthly temperature for mainland Spain (1951–2010), performed with the highest quality and spatially dense, up-to-date monthly temperature dataset available in the study area (MOTEDAS).

Three different interpolation techniques were evaluated: the Local Weighted Linear Regression (LWLR), the Regression-Kriging (RK) and the Regression-Kriging with stepwise selection (RKS), a modification of RK. The performances of the different models were evaluated by the leave-one-out validation procedure, comparing the results from the models with the original data and calculating different error measurements.

The three techniques performed better for T_max than for T_min, and for the cold, rather than warmer months, also at lower altitude than highland areas. The best results were achieved with LWLR applied for the first time on temperatures in the Spanish mainland. This method improved the accuracy of the temperature reconstruction with respect to RK and RKS.

We present a collection of T_max and T_min monthly charts, using the same temperature legend to prevent any visual bias in the interpretation of the results. The dataset is available upon request.