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Describes the use of a new pedagogic approach to geology used to create a sequence of investigative activities enabling students to speculate, hypothesize, observe, test, reason, and infer about the characteristics of rocks. The approach is framed by two questions: (1) What are the key characteristics of different rock groups?; and (2) How did the rocks acquire these different characteristics? (Author/MM)

Describes the Proffit Mountain project, part of a senior-level class in applied geophysics that provides students with hands-on experience in applying principles and techniques learned in class. Students conduct magnetic, gravity, and radiometric studies over a diabase body which intrudes rhyolite at Proffitt Mountain in southeast Missouri. Contains 22 references. (Author/PVD)

Measurement of the compositions and temperatures of H2O-NaCl brines in equilibrium with ice can be used as an easy in-class experimental determination of a liquidus. This experiment emphasizes the symmetry of the behavior of brines with regard to the minerals ice and halite and helps to free students from the conceptual tethers of one-component ice melting. (Author/PVD)

This annotated subject guide to Web sites for grades K-8 focuses on the American Revolution, fitness, U.S. Presidents, rocks and minerals, spelling, vocabulary, and calendar connections for Women's History Month and other March observations. Specific grade levels are indicated for each annotation. (LRW)

The processes responsible for the isotopic compositions and abundances of volatile elements in the early solar system remain highly debated. Orders of magnitude variation of (highly) volatile elements exist between different magmatic iron meteorite groups, but it is unclear to what extent their depletions can be explained by evaporation from metal melts during parent body accretion and/or subsequent break up. To this end, we present 86 new evaporation experiments with the aim of constraining the volatility of most volatile metals from metallic melts. The results confirm the previously proposed important effects of S in metal melt on the volatility of the elements of interest governed by their S-loving or S-phobic behavior. Nominally S-loving elements In, Sn, Te, Pb and Bi are significantly more volatile in Fe melt relative to FeS liquid, whereas nominally S-avoiding elements Ga and Sb are more volatile in FeS liquid relative to Fe melt, at a given pressure and temperature. The newly derived volatility sequences for S-free/poor and S-rich metallic melts were also compared with commonly used volatility models based on condensation temperatures. The results indicate significant differences between the latter, including the much more volatile behavior of Te, relative to Se, in both explored bulk compositions, which are traditionally assumed to be equally volatile. The (minimum) degree of volatile element depletion due to evaporation was quantified using the new experimental results and models. A comparison between the volatile element depletions in magmatic iron meteorites and the predicted depletions appropriate for evaporation from Fe melts shows that the latter depletions can be easily reconciled with (an) evaporation event(s). Altogether, the new data and models will provide an important framework when more accurate and precise estimates of magmatic iron meteorite bulk volatile element contents are available. [ABSTRACT FROM AUTHOR]

This study marks the first detailed depositional, diagenetic and organic geochemical investigation of Jurassic Isha Formation in North Waziristan, Khyber Pukhtunkhuwa, Pakistan. Detailed systematic sampling was carried out from exposed outcrop along the Mirali road in North Waziristan for microfacies analysis and diagenetic studies to unravel the depositional environment and diagenetic alterations. The oraganic maturity and hydrocarbon generation potential were assessed by total organic content and Rock-Eval pyrolysis. Outcrop analogue revealed that the formation predominantly comprises of thick to thin bedded oolitic fractured limestone, bioclastic and dolomitic limestone. In the petrography, a total of eight microfacies (MF1–MF8) were constructed and were directed different depositional enviroments. Based on the integrated field data and microfacies analyses, the Isha Formation is interpreted to be deposited on a homoclinal ramp particularly in peritidal, lagoon, and carbonate shoals. Sequences stratigraphic setup shows intervallic Transgressive and Regressive Systems Tracts. The TSTs are mostly grainstone and packstone facies whereas the RSTs are wackestone and mudstone microfacies which demonstrates a single 2nd order cycle and then multiple 3rd order transgressive and regressive cycles for the deposition of Isha Formation. The total organic content and Rock-Eval pyrolysis results were ploted on VanKerevlen diagram which indicate that the source rock potential fall within the type III kerogen. The HI versus Tmax and PI versus Tmax cross plots indicate that the formation lies within the zone of maturation, generation potentiality indicate that the formation has fair to poor potential and hydrocarbons are indigenous. [ABSTRACT FROM AUTHOR]

Summary: The focus of this paper is the Middle and Late Roman (third–seventh centuries AD) cooking pottery recovered during the excavations at the Agora in Nea Paphos. Macroscopic investigation suggested that a part of this assemblage was imported from north‐western Cyprus. To verify this assumption, selected samples were analysed with thin section petrography and wavelength dispersive X‐ray fluorescence spectrometry. The results of an integrated macroscopic and laboratory analysis indicated the presence of two typologically distinguishable groups characterized by the same fabric. Comparative studies suggest that they were likely produced in the area of Dhiorios located in north‐western Cyprus. It was also noted that the cooking pottery vessels characterized by the same fabric were being imported to Nea Paphos already in the first century AD. The continuity of the production and exportation of the Dhiorios pottery suggests the economic importance of north‐western Cyprus throughout the entire Roman period. [ABSTRACT FROM AUTHOR]

This research presents the findings of a petrographic analysis conducted on pre‐colonial Ceramics from Aruba, focusing on understanding ceramic mineral resources and production. The study compared ceramics from nine sites with a selection of clay sources from the island. Petrographic analysis identified the existence of three different mineralogical compositions. Two groups of undecorated vessels were likely manufactured using locally sourced clay materials. Group 1 ceramics show a connection with the weathering of quartz‐diorite intrusions in the northwest part of the island and suggest the exploitation of multiple, geographically close sources with similar compositions. Group 2 ceramics are related to clay sources found in the southeast of Aruba, with a mixed geological composition, including limestone, volcanic tuff and quartz‐diorite. In contrast, Group 3 ceramics are mostly decorated and belong to the Early Urumaco Period. They display a distinct composition characterized by a calcareous matrix with clay pellets, clay streaks and the presence of shell fragments added as temper. The extensive clay preparation practice leaves uncertainties concerning the origin of ceramics from Group 3. The study also highlights clay selection and use patterns, indicating that different clay sources were interchangeably utilized by communities across Aruba. [ABSTRACT FROM AUTHOR]

A study of a 2nd century AD assemblage of handmade/slow wheel-made cooking wares, found at the Roman settlement of Tamuda (Tetouan, Morocco) is presented. Such ceramics are rare in Early-Middle Roman Imperial contexts of the western Mediterranean. A combined typological and archaeometric approach – including petrographic, mineralogical, and chemical analyses – was carried out to study this assemblage, aiming to examine the hypothesis of a local or regional provenance and to shed light on its production technology. The results indicate the existence of a diversity of products, including a fabric that was likely locally manufactured, as well as other imported fabrics that point to micro-regional distribution or trade of some of these wares. This research is a significant contribution towards a better understanding of the handmade/slow wheel-made pottery that was produced and consumed in the northern Moroccan Rif in the Roman period. [ABSTRACT FROM AUTHOR]

ABSTRACT This research focuses on the field observations, petrography, mineral chemistry and geochemistry of the serpentinised peridotite of Al‐Barramiya ophiolitic sequence to place constraints on their magmatic history and their geodynamic evolution. Al‐Barramiya ophiolitic rocks are a dismembered ophiolite which was strongly deformed and metamorphosed under greenschist to lower amphibolite facies. They comprise a mantle section dominated by highly serpentinised peridotite with less metapyroxenite and chromitite, as well as a crustal portion represented by metagabbros. Along shear zones, the ophiolite sequence was affected by several types of alteration. Extensive carbonate alteration is common in the ultramafic section, resulted in talc carbonates, listvenites and magnesite, while rodingitisation is common in the metagabbro resulted in rodingite. Despite the extensive serpentinisation, some fresh relics of primary mantle minerals such as Cr‐spinel, olivine and pyroxenes are preserved sporadically in the serpentinised peridotite. Few Cr‐spinel crystals are sometimes surrounded by subhedral flakes of Cr‐chlorite (kämmererite) that was formed due to replacement of Cr‐spinel during later alteration or regional metamorphism. The serpentinite samples are depleted in the total REE (0.56–1.19 ppm) with slightly negative to slightly positive Eu anomalies (0.89–1.28). The fresh cores of Cr‐spinel have Cr# mostly > 60, and the relics of pyroxenes and olivine are Mg‐rich suggesting that the Al‐Barramiya serpentinites are residual to high degrees of melt extraction. The estimated degrees of partial melting range between 18.2% and 20.7%. All the mineralogical and geochemical characteristics of the ultramafic section of the Al‐Barramiya ophiolites are most consistent with its formation in a fore‐arc setting. [ABSTRACT FROM AUTHOR]

Lithology classification is a fundamental aspect of reservoir classification. Due to the limited availability of core samples, computational modelling methods for lithology classification based on indirect measurements are required. The main challenge for standard clustering methods is the complex vertical dependency of sedimentological sequences as well as the spatial coupling of well logs. Machine learning methods, such as recurrent neural networks, long short‐term memory and bidirectional long short‐term memory, can account for the spatial correlation of the measured data and the predicted model. Based on these developments, we propose a novel approach using two distinct models: a self‐attention‐assisted bidirectional long short‐term memory model and a multi‐head attention‐based bidirectional long short‐term memory model. These models consider spatial continuity and adaptively adjust the weight in each step to improve the classification using the attention mechanism. The proposed method is tested on a set of real well logs with limited training data obtained from core samples. The prediction results from the proposed models and the benchmark one are compared in terms of the accuracy of lithology classification. Additionally, the weight matrices from both attention mechanisms are visualized to elucidate the correlations between depth steps and to help analyse how these mechanisms contribute to improved prediction accuracy. The study shows that the proposed multi‐head attention‐based bidirectional long short‐term memory model improves classification, especially for thin layers. [ABSTRACT FROM AUTHOR]

Landslide hazards affect the security of human life and property. Landslide hazard maps are essential for landslide prevention and mitigation. In this study, the success of machine learning and statistical methods in predicting landslide hazards in and around the district center of Maden, Elazığ province, within the borders of Turkey, was analyzed, and their performances were compared. The Random Forest method correctly predicted 1.398 of the 1.425 landslide points in the training dataset, but was incorrect on 27 points. The same method predicted 1942 of the 2075 landslide-free points in the training dataset, but incorrectly predicted 133 points as landslide-exposed. As a result of the study, it is evident that the Random Forest and M5P Rule Tree methods yield more successful results than the Frequency Ratio method. In the study area, the landslide hazard is concentrated in areas close to the East Anatolian Fault and in areas with steep slopes. Lithology, slope, and seismicity have been identified as important triggering factors for landslides in the region. It is expected that machine learning methods, which operate with high levels of accuracy, will make a significant contribution to the prediction of landslide hazards. [ABSTRACT FROM AUTHOR]

ABSTRACT The Northwest Himalayan region has a record of several phases of mafic magmatic activity spanning from Precambrian to Cenozoic in a dynamic tectonic setting. Here, we studied detailed petrography and new whole‐rock geochemistry of mafic volcanic and dykes from the Nagrota–Kathindi Section (NKS), Himachal region of the NW Himalaya, to understand the petrogenesis and possible tectonic setting. Both rock types have comparable mineralogical compositions (clinopyroxene + plagioclase + actinolite‐tremolite + chlorite + iron oxides ± hornblende ± epidote ± quartz ± carbonates) overprinted by greenschist to lower amphibolite facies metamorphism. The mafic volcanic and dykes of NKS exhibit subalkaline basalts to basaltic andesites and a typical tholeiite compositional character. The chondrite‐normalized rare earth element pattern exhibits similar LREE‐enrichment and strong HREE‐fractionation, whereas primitive mantle‐normalized multi‐element patterns show pronounced LILE‐enrichment of Rb, Ba, Th, LREE, and HFSE depletion of Nb, K, P, and Ti. The Zr–Y–Nb–Th relationships indicate that both rock types were derived from the plume source, whereas low Nb/La (< 1), similar high large‐ion lithophile element concentrations, and pronounced negative Nb, Zr, P, and Ti anomalies suggest that components other than mantle plume must have been involved in the generation and evolution of both rock types, that is, most likely plume and subcontinental lithosphere mantle (SCLM) interaction. The genesis of parent magma for the NKS volcanic and dykes was derived by 4%–6% and 10%–20% partial melting from the spinel + garnet lherzolite stability field. The majority of the studied samples correspond to spinel + garnet peridotite melting on (Gd/Yb)N versus CaO/Al2O3 diagram, thereby corroborating residual garnet in the mantle restite. All the basalts and dykes from the NK section did erupt/intrude in an intracontinental rift setting based on geochemical discrimination. The key petro‐tectonic processes attributed to the formation of these rocks are as follows: (i) the melting of the ascending plume by adiabatic decompression; (ii) the partial melting of this plume–SCLM source in the melting regime, which produces basaltic magma with a tholeiitic composition; and (iii) the release of heat that provides the thermal condition for melting of SCLM and interaction between upwelling mantle plume and subduction metasomatized SCLM. [ABSTRACT FROM AUTHOR]

The Neoproterozoic Bou Azzer Ophiolite, located in the Pan-African orogen of the Anti-Atlas, Morocco, exposes a well-preserved mantle section of the ophiolitic sequence. Although ultramafic rocks are the most common rock types in the sequence, they have received less attention in previous studies. In this work, we investigate the petrogenesis of these ultramafic rocks in detail, including their petrology, mineralogy, and whole rock geochemistry. The mineral assemblages are mainly formed by antigorite with minor lizardite, chlorite, and accessory Cr-spinel. The only preserved primary mantle mineral is Cr-spinel, which shows unaltered cores with Cr# between 0.61 and 0.71 and alteration rims to ferrian chromite and magnetite. Whole rock analyses indicate almost total serpentinization and, locally, strong carbonation (mass loss of ignition between 11.94 and 22.20 wt%). The non-carbonated samples preserve protolith signatures, with decreased MgO/SiO2 suggesting metasomatic processes related to serpentinization. Immobile trace elements compare well with fore-arc peridotites, while melting modelling indicates intense and polyphasic melting events. We propose polyphase melting in a subduction-initiation setting, with a first stage of 14–23% anhydrous melting, forming fore-arc basalts, and a second stage of 15–25% melting with 1 wt% H2O, forming boninites. The Bou Azzer ultramafic rocks represent the fore-arc region of a supra-subduction zone, challenging previous interpretations that suggested a back-arc position. [ABSTRACT FROM AUTHOR]

Lower Miocene plutons exposed in the Western Cordillera of Colombia record the reinitiation of continental arc magmatism in the Northern Andes after a period of magmatic quiescence between the Late Eocene and Early Miocene. Petrography, U-Pb zircon geochronology, whole-rock geochemistry, mineral chemistry, and zircon Hf isotope data from these plutons are used to reconstruct the Miocene magmatic evolution in the Colombian Andes and understand its relation with the major plate-tectonic reorganization experienced by the NW South American continental margin during the Lower Miocene. We examined a suite of gabbros, granodiorites and tonalites from Danubio, Pance and Tatamá plutons, formed between 21 Ma and 15 Ma. Gabbros present highly positive εHf values (+13.5 and + 11.5) with low Th/La and La/Yb ratios, and granodiorites and tonalites present lower εHf values (+14.3 to + 6.4). The results of this contribution show a major asthenospheric source with absent or minor melting of subducted sediments, and contribution of oxidized aqueous fluids. The compositional diversification of these magmas was controlled by fractional crystallization and, in the Tatamá pluton, also by local assimilation of continental crust at lower crustal levels of the upper plate. Subsequently, these magmas were emplaced in the Cretaceous to Palaeogene volcanic and sedimentary rocks in the uppermost crust. The renewed magmatic activity recorded by the studied plutons suggests a normal to step subduction of the elder Farallon Plate during the Neogene subduction re-organization in the Colombian Andes, as well as the local presence of continental crust fragments in the lower crust of the Western Cordillera of Colombia. [ABSTRACT FROM AUTHOR]

The Enriquillo-Plantain Garden fault (EPGF), the southern branch of the northern Caribbean left-lateral transpressional plate boundary, has ruptured in two devastating earthquakes along the Haiti southern peninsula: the Mw 7.0, 2010 Haiti and the Mw 7.2, 2021 Nippes earthquakes. In Jamaica, the 1692 Port Royal and 1907 Great Kingston earthquakes caused widespread damage and loss of life. No large earthquakes are known from the 200-km-long Jamaica Passage segment of this plate boundary. To address these hazards, a National Science Foundation Rapid Response survey was conducted to map the EPGF in the Jamaica Passage south of Kingston, Jamaica, and east of the island of Jamaica. From the R/V Pelican we collected >50 high-resolution seismic profiles and 47 gravity cores. Event deposits (EDs) were identified from lithology, physical properties, and geochemistry and were dated in 13 cores. A robust 14C chronology was obtained for the Holocene. A Bayesian age model using OxCal 4.4 calibration was applied. Out of 58 EDs that were recognized, 50 have ages that overlap within their 95% confidence ranges. This allowed for their grouping in multiple basins located as much as 150 km apart. The significant age overlap suggests that EDs along the Enriquillo-Plantain Garden plate boundary resulted from large and potentially dangerous earthquakes. Most of these earthquakes may derive from the EPGF but also from thrust faulting at this strain-partitioned transpressional boundary. The recent increase in Coulomb stress on the EPGF from the Mw 7.2 Nippes earthquake in southwestern Haiti and the discoveries reported here enhance the significance for hazard in the Jamaica Passage. [ABSTRACT FROM AUTHOR]

Karapınar region (Konya, Türkiye) is one of the important regions of the world in terms of sinkhole formations. The research aimed to map the sinkholes in detail, to determine their spatial distribution and geometrical parameters. For this purpose, the long axes, short axes, depths and the proximity to settlements of the sinkholes were measured and their circumferences and areas were calculated. During the studies, the relationship of the sinkholes with lithology, their cross sections, shapes and the related structures were determined and the sinkholes were divided into five main groups as following: Basement rock sinkholes, Obruk Plateau sinkholes, Seyithacı sinkholes, Siyeklik sinkholes and Basin sinkholes. The d/l ratios of each sinkhole group were separately determined and interpreted. Accordingly, most of the d/l ratios are smaller than 0.2. Namely, the long axes are higher than the depth and it indicates that the shallow and wide sinkholes are common in the region. It has been determined that the fracture systems in the region, as well as the lithology and groundwater factors, are quite effective in the formation and distribution of the sinkholes in the Karapınar region. Considering the distance of the sinkholes to the settlements, Seyithacı sinkholes are the most risky group in the region because they are deep and close to the settlements. [ABSTRACT FROM AUTHOR]