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Fluvial facies models based on river planform are flawed and not fully fit for purpose. An alternative approach to classifying fluvial deposits is based on river discharge characteristics. A recent paper showed that the co‐efficient of variance of annual peak discharge (CVQp) correlates well with the characteristics of preserved alluvium for a suite of modern rivers. Here, the database of rivers is expanded and augmented, and the utility of this statistic confirmed. For modern rivers, plotting the running‐value of CVQp for a set interval (for example, 30 years) over a longer discharge record shows that the statistic varies both spatially and temporally. The CVQp can rise abruptly at a given location in response to a single flow event if that event is significantly larger than is common in that river. Such abrupt changes in CVQp are superimposed on longer‐term patterns of more gradual change stimulated by environmental factors or anthropogenic effects such as dam construction. If the period of calculation for CVQp is relatively short, 'anomalous' events appear more frequently. Sequential studies of modern rivers indicate that such anomalous events have a high probability of being preserved in the alluvial record of the river, and suggest that, over the timeframes of channel filling and abandonment, they may constitute the dominant (characteristic) portion of the record in high CVQp systems. Since flow events with strongly peaked hydrographs (flashy discharges) are more common in high CVQp systems and leave a record dominated by upper flow regime stratification styles, it follows that the alluvial record of high CVQp rivers will be dominated by upper flow regime stratification. In contrast, in lower CVQp systems the occurrence of an event that changes the running CVQp value significantly may form a distinct event deposit, and the temporarily changed CVQp is unrepresentative for the duration of the channel's life. The dominance of upper flow regime stratification, together with decreased preservation of identifiable macroform structure, increased lateral lithological heterogeneity, and in many cases increased preservation of in situ tree fossils in channel deposits of higher CVQp rivers, forms the basis for a series of new facies models for low, moderate, high and very high/ultra‐high CVQp alluvial systems and deposits. The new models can be applied to ancient successions either in combination with traditional, planform‐based models, or not. These models provide information about ancient palaeoenvironmental conditions, and changes in such conditions over time at various scales via stratigraphic investigations. [ABSTRACT FROM AUTHOR]

In this study, the shallow S-wave velocity structures beneath the Tainan area, Taiwan are investigated using microtremor array measurements at 18 sites. An F-K spectrum method was used to calculate the dispersion curves for these sites, and surface-wave inversion was used to estimate the S-wave velocity structures beneath the Tainan area. The results indicated that, at frequencies between 0.2 and 1.1 Hz, propagation is concentrated between the northwest and south quadrants, corresponding to the coast of the Taiwan Strait. CHM, a hard central site on the Tainan tableland, was found to have higher phase velocities than the soft sites do, such as site SIM, on the Anping Plain, particularly at frequencies of 0.3–5.0 Hz. Given that the tertiary basement exhibits an S-wave velocity of 1500 m/s, the depth of the Quaternary alluvium in the Tainan area ranges from 400 m at site CHM to 1350 m at site FUP on the Anping Plain. In addition, the depth of the alluvium gradually increases radially from the central CHM site (on the Tainan tableland) to the surrounding areas. These results are consistent with the geolpogy of the Tainan area. Because our shallow S-wave velocity structures are comparable to those proposed in three other studies, our inversion results are concluded to be reasonable and valid. According to the horizontal/vertical (H/V) ratios of our microtremor array data from 18 sites, the predominant frequencies range from 1.0 to 3.8 Hz. Compared with the eastern part (i.e., Dawan lowland), the central part (i.e., Tainan tableland) has higher predominant frequencies. [ABSTRACT FROM AUTHOR]

This research explores the relationship between aquifer vulnerability, water quality and agricultural and mining activities carried out in a southern portion of the Central Valleys of Oaxaca. This site is located on a shallow aquifer with an average thickness of 30 – 40 m, composed mainly of gravel, sand, clay and silt. These materials constitute the alluvial fill that is considered the main hydrogeological unit, which overlies the metamorphic basement of the Oaxacan complex, which acts as a lower limit restricting the flow of water towards deep infiltration. The study applies a comprehensive methodology, which combines several approaches: the thematic weighting of layers through the DRASTIC method, the analysis of physical–chemical parameters of 145 water samples to determine quality and contamination indices, the interpretation of geological-geophysical data obtained from 11 Transient Electromagnetic Surveys (TEM) that allowed the identification of isoresistive units associated with the geology of the area, these data were complemented with geological field work. The results show that the area dedicated to agriculture has a medium to high vulnerability, with water quality varying from slightly contaminated to highly contaminated, which translates into a moderate to high level of contamination. According to the geological-geophysical interpretation, this area is located in U2b, which presents resistivities that range between 200 and 300 Ohm.m related to alluvial deposits and conglomerates. In the mining activity area, a medium vulnerability was identified, with water quality indices varying from very contaminated to contaminated and contamination levels from moderate to high. The isoresistive unit at this site corresponds to U3, with values greater than 350 Ohm.m, associated with andesitic rocks. At the recharge sites, a low vulnerability was determined, with acceptable water quality indices and low levels of contamination. [ABSTRACT FROM AUTHOR]

Cahuachi (Nazca River Valley, South Peru) was the major ceremonial center of the Nasca civilization. According to previous studies, it was struck and destroyed by three El Niño-Southern Oscillation events, which would have occurred around 100 BCE, 600 CE and 1000 CE, respectively. At the end of the series of events, the ceremonial center would have been buried by a cap of conglomerates. Despite this hypothesis raised well-founded doubts regarding its geochronological and paleoenvironmental implications, it is uncritically used as a reference in geoarchaeological research. In the present study, optically stimulated luminescence (OSL) dating results of some samples taken from alluvial deposits at Cahuachi are reported, with the aim to evaluate the literature's hypothesis. Since the obtained ages are older than the Holocene epoch, such a hypothesis must be rejected. A number of field evidences corroborate this result. Finally, the advancement in fluvial geomorphology knowledge of the Nazca River Valley is briefly discussed. [ABSTRACT FROM AUTHOR]

Using historical topographic maps and aerospace remote sensing data since the 1930s, this study investigates the spatial and temporal evolution of Dongting Lake beach. The evolution characteristics of the beaches in different regions and the related formation mechanism were also analyzed. The results show that Dongting Lake beach expanded from 1 622.17 km2 in 1938 to 1 962.28 km2 in 2018. With the addition of 980.96 km2 of reclaimed high bay beach, the beach area increased by 1 321.07 km2. However, the change process fluctuated somewhat rather than continuously increased. Substantial expansion of the beach area occurred during 1938–1948 and 1958–1998, while slow contraction of the beach area occurred during 1948–1958 and 1998–2018. Dongting Lake beach was dominated by terrigenous debris, the sedimentary types included lacustrine deposits, river alluvial deposits, floodplain and main channel deposits, and river-lake interaction deposits. The rapid expansion occurred in the estuary delta of the east branch of the Ouchi River, which advanced 38.55 km from the estuary toward the lake over the past 90 years. The causes of the changes in the beach included beach reclamation, sediment changes, and lake sand mining. Seventy embankments (covering 2 057.77 km2) have been enclosed in the Dongting Lake area since 1930s, of which the high bay beach covered an area of 980.96 km2. The amount of sediment deposited in Dongting Lake has reached 230 857 × 104 m3 since 1950s, which is equivalent to an average deposition height of 0.85 m on the lake's bottom. The mining of lake sand caused the beach to shrink, and the proportion of the beach area decreased from 77.18% in 1998 to 72.60% in 2018. The results of this study provide objective data for protecting the lakeshore's ecosystem and biodiversity and supporting the ecological restoration and environmental protection of the Yangtze River Basin. [ABSTRACT FROM AUTHOR]

Supercritical flows and their associated upper‐flow‐regime bedforms have been increasingly recognized in several contrasting depositional environments around the world, including volcano‐sedimentary settings. In recent years, there have been significant advances in flow modelling, architecture and depositional dynamics in upper‐flow‐regime bedforms related to glacio‐volcanic interaction, however most of these works come from specific volcanic landscapes. Examples of other regions with different tectonic and volcanic settings are needed in order to gain a more global perspective regarding the generation and preservation of upper‐flow‐regime glacio‐volcanic bedforms. This study presents a detailed analysis of Pleistocene volcaniclastic deposits accumulated in alluvial to lacustrine deltaic environments in the Southern Andes within the Southern Volcanic Zone. Six facies were defined and related to distinctive bedforms by examining sedimentary features, including textural characteristics, sedimentary structures, architecture and composition. Among these facies, five are distinguished by deposition from supercritical flows and upper‐flow‐regime bedforms, such as cyclic steps, chutes and pools, and antidunes. The stratigraphic succession reveals a predominance of repeated supercritical flows, which appear to be influenced by the availability of detritus for removal along with sudden water discharges. Compositional analyses indicate that explosive volcanism was the primary source of detritus, occurring synchronously with sedimentation. Additionally, the widespread occurrence of Pleistocene glacial conditions in this region suggests that volcanic‐induced melting ice or snow may have been an important source of water supply. Regarding the Southern Andes, the presence of local depressions, such as volcano‐tectonic calderas plays an essential role in the generation and preservation of the upper‐flow‐regime bedforms related to glacio‐volcanism. Furthermore, the importance of carrying out detailed and multidisciplinary studies seems to be critical for the recognition of these deposits in the record of the Andes. [ABSTRACT FROM AUTHOR]

The Indo-Gangetic Plain (IGP) is characterized by thick sediments, predominantly comprising alluvial deposits, which can amplify seismic waves generated by earthquakes in the Himalayan region located to the north of the plain. The presence of loose sediments can indeed pose significant seismic hazards, mainly due to phenomena like soil liquefaction. These sediments pose a threat to densely populated Delhi and NCR regions, which are 200 km away from the plate boundary of India and the Eurasian plate. Scientists are concerned about people's safety in mitigating damage caused by high-rise buildings and loose sediments in the IGP region. Reliable knowledge of the sedimentary layer's thickness and velocity structure is crucial for investigating buried active faults, understanding significant destruction, and risk assessment. Sedimentary basins are also crucial for geo-resources such as hydrocarbon and geothermal energy. This research estimated the structure of the sedimentary layer beneath four stations in the Chandigarh–Ambala region in IGP using the high-frequency receiver function (PRF) technique. The study found that the sedimentary layer thickness varies significantly, with values from 2.0 to 3.0 km beneath the IGP and increasing northward. Shallow shear velocity (Sv) in the column of sediments below the Siwalik Himalaya ranges from 2.8 to 2.9 km/s, which can be utilized for assessing earthquake ground-motion sites. The study provides new perceptions of the geodynamic processes and seismotectonic structure of the Himalayan region, allowing for better identification of the earthquake hypocenter and assessment of seismic hazards. The shear wave velocity models estimated from this research can also be beneficial for assessing seismic hazards and earthquake-resistant construction. Estimates of the crustal thickness values from waveform inversion of the PRF at individual stations reveal that the Moho depth varies between 44 and 50 km in the Indo-Gangetic Plain. From Siwalik Himalaya to the higher Himalaya, it ranges from 44 to 65 km. The depth of Moho increases from the Indo-Gangetic plain towards the lesser Himalaya. [ABSTRACT FROM AUTHOR]

[Objective] Study of the Quaternary stratigraphical characteristics of the eastern Songnen Plain is of particular importance for gaining an understanding of regional climate change and the evolution of sedimentary environments. To data, however, there has been comparatively little research focusing on the Quaternary strata in this area, which has accordingly limited our comprehension of the mechanisms underlying changes in the regional climate and environment. [Methods] In this study we focused on the borehole WKZK01 in the eastern Songnen Plain. On the basis of lithological characteristic analysis, we obtained dating, sedimentary environment evolution, and climatic evolution information using optically stimulated luminescence, palynology, and laser grain size analytical methods, and based on comparisons with the results obtained from a typical Huangshan section, Harbin, we discuss the Quaternary stratigraphy of the borehole and the sedimentary environments it reflects. [Results] The Quaternary strata in Wangkui county are divided from old to new as follows: the middle Pleistocene Huangshan Formation, the middle Pleistocene Harbin Formation, and the upper Pleistocene Guxiangtun Formation, with an absence of a Holocene Tantu Formation. The Huangshan Formation is 13.05 m thick, with a median grain size (Md) ranging from 7.77 μm to 11.84 μm, and an average value of 9.62 μm. Pollen zone I-1 is dominated by xerophytic herbaceous pollen, with small amounts of mixed coniferous and broadleaf woody plant pollen, although lacks pollen derived from hydrophilic herbaceous plant. The Harbin Formation is 24.05 m thick, with a median grain size (Md) ranging from 9.67 μm to 14.98 μm, and an average value of 11.74 μm. Pollen zone I-2 is still dominated by xerophytic herbaceous pollen, with that derived from mixed coniferous and broadleaf woody plants as the secondary component, and the appearance of hydrophilic herbaceous plant pollen. The Guxiangtun Formation is 15.6 m thick, with a median grain size (Md) ranging from 11.61 μm to 19.91 μm, and an average value of 14.12 μm. Compared with the earlier stages, pollen zone II has a less abundant pollen content, although is characterized by an increase in hydrophilic herbaceous pollen, and a marked decline in the content of pollen derived from xerophytic woody and herbaceous plants. [Conclusion] The Huangshan Formation represents lacustrine deposits, with pollen zone I-1 providing evidence of a cool and dry climate during the early Middle Pleistocene. The Harbin Formation also comprises lacustrine deposits, with the pollen record in zone I-2 indicating a cool and humid climate during the late Middle Pleistocene. The Guxiangtun Formation comprises fluvial deposits, with pollen zone II recording a cold and wet climate during the Late Pleistocene. [Significance] The borehole WKZK01 provides a record of the environmental evolution of a small lake adjacent to the large Songnen paleolake, revealing a transition from the lake center to the margin and eventually disappearing with the formation of rivers. [ABSTRACT FROM AUTHOR]

This article is devoted to the study of the Quaternary aeolian sands of the boreal zone of north Asia. Using the example of the study reference sections of the Selenga Dauria (Western Transbaikalia), it was established that the activation of aeolian processes is determined by the complex interaction of natural and anthropogenic factors. Natural factors include neotectonic movements; wide distribution of alluvial and lacustrine-alluvial deposits; a sharply continental semi-arid climate; and forest-steppe and steppe vegetation. Among the anthropogenic factors, the leading ones are deforestation, plowing of land and construction of new settlements, roads and other line structures. The obtained radiocarbon dating of buried soils and coal from ancient fire pits indicates the activation of aeolian processes during the Holocene. The main sources for aeolian transport (winnowing) are sands located in the areas of river and lake beaches, floodplains and river terraces. Almost all aeolian sands of the boreal zone were formed as a result of short-range wind transport. They form mini-deserts unfixed by vegetation, with active aeolian processes, dunes, barkhans and deflationary basins. Aeolian swells and blowout basins characterize aeolian landscapes weakly fixed by vegetation. It is noted that aeolian deposits of the boreal zone of north Asia, in contrast to similar sands of the subtropical and tropic zones, consist of coarser-grained material. Medium- and fine-grained sands dominate their composition, which is polymineral and well-sorted. In subtropical and tropical deserts, they are predominantly monomineral, fine and fine-grained. At the same time, mainly minerals that are unstable to weathering (feldspars, plagioclases, pyroxenes and amphiboles) represent the mineralogical composition of the studied aeolian sands. Weathering-resistant minerals dominate the sands of classical deserts: quartz, leucoxene, ilmenite, epidote, zircon, garnets, tourmaline, rutile and others. Modern aeolian landscapes are a unique natural formation for the boreal zone of north Asia and can be successfully used for the development of ecotourism. [ABSTRACT FROM AUTHOR]

Understanding the tectonic evolution of ancient orogens relies on reconstructing the primary architecture of suture zones that may be modified by post‐subduction events. Modifications in East Junggar, southern Altaids, have led to controversial interpretations about the Paleozoic tectonic evolution. To clarify these relationships, we report the Mesozoic thrust horizon in East Junggar that has displaced the Baishanbao Klippe, which contains siltstone, sandstone, conglomerate and biogeographical Tuva‐Mongolia Tuvaella fauna. This klippe is distinct from units in the footwall that contain Ordovician‐Early Devonian accretionary complexes with dismembered basalts, cherts and deep marine tuffaceous siltstones, Carboniferous volcanic rocks and granites, Middle‐Late Jurassic sediments, and Kazakhstan biogeographic Ordovician‐Late Devonian coral‐brachiopod‐ammonoid fauna. The thrust horizon and the aforementioned units are unconformably capped by Late Jurassic‐Early Cretaceous alluvial fan deposits; it constrains the thrust to a Mesozoic age. These two biogeographic domains were separated by the Paleo‐Asian Ocean until the Late Paleozoic, as evidenced by the 478 Ma Kujibai MOR‐type ophiolite that involved into subduction zone in the Carboniferous. This Mesozoic thrust transported the Baishanbao Klippe for over 100 km southwards from its root in the Altay‐Fuyun area and crossed a cryptic suture zone of the Paleo‐Asian Ocean as an allochthonous unit in East Junggar. It extensively disrupted the primary Paleozoic orogenic architecture of East Junggar that leads to misinterpretation of the regional tectonic evolution. A lesson from disruption of this Mesozoic thrusting is that care must be taken in studies of the architecture of paleo‐suture zones. Key Points: The Tuva‐Mongolia biogeographic block containing Tuvaella sp. is distinct from blocks of the Kazakhstan domain in East JunggarThe Tuvaella sp.‐bearing Baishanbao Klippe was thrust over rock units of the Kazakhstan domain during the Late Jurassic‐Early CretaceousThe paleo‐suture zone of the Paleo‐Asian Ocean was disrupted by Mesozoic thrusts to complicate the crustal architecture of southern Altaids [ABSTRACT FROM AUTHOR]

The Early–Middle Jurassic Nazas continental rift province in Mexico has been debated as either an extensional continental arc due to eastward subduction beneath North America or an intracontinental rift linked to Pangea break-up. New petrographic and U-Pb geochronological data from the La Boca Formation near Ciudad Victoria – a key locality within this province – reveal diverse clastic sources, forming three provenance groups. Group 1 (Juan Capitán Member) crops out in the Huizachal Valley and consists of volcaniclastic fluvial deposits derived from a local volcanic centre. Group 2 (Agua de Las Minas Member), also found in the Huizachal Valley, overlies Group 1 and has mixed provenance from local volcanic and surrounding basement uplift sources. Both groups transition laterally to deposits of Group 3 (San Pedro Member) to the north, which consists of metamorphiclastic fluvial deposits from the eastern basement uplift and is not influenced by the volcanic centre. The rapid dilution of volcanic detritus within ~35 km highlights the limited extent of the volcanic centre as a source of sediment. Our results suggest that the Nazas province was more likely formed in a continental rift basin with sparse volcanic activity linked to Pangea break-up rather than as an extensive volcanic arc. [ABSTRACT FROM AUTHOR]

We investigate how luminescence signals imprinted on fluvial sediments vary depending on the depositional environment and vary through time in the same river. We collected sediment samples from four geomorphically distinct locations on the modern floodplain and modern point bar on the Buffalo River in northwest Arkansas, USA, in order to determine if different depositional environments are associated with distinct bleaching characteristics in the sediments. Our analysis revealed that all samples from different depositional environments yielded ages consistent with modern deposition. The samples collected from the floodplain and bar head contained a higher proportion of grains with residual doses, indicative of incomplete bleaching during transport, while samples from the mid‐bar and bar tail appeared well bleached. Our results are particularly intriguing for two significant reasons. First, they highlight distinct equivalent dose distributions in different depositional environments. Second, they shed light on an intriguing relationship: despite generally well‐bleached modern floodplain samples, ancient sediments from corresponding terraces displayed equivalent dose (De) distributions that suggest partial bleaching in some cases. This research contributes to the growing body of work that seeks to establish a relationship between luminescence properties and sediment transport processes and offers valuable insight into how luminescence signals vary locally in modern fluvial deposits, which can help guide the interpretation of older fluvial deposits. [ABSTRACT FROM AUTHOR]

The extraction of thin bedrock coal seams with thick alluvium poses a challenging issue in the realm of coal safety production in China. Especially for mining under aquifers, knowing the development height of water-conducting fracture zones above the goaf is crucial for coal mine safety and production. Taking the 11092 working face of lower slice mining in Zhaogu No. 1 Mine as an example, the failure transfer process of the overlying strata is analyzed first. On this basis, the development height of the water-conducting fracture zone is predicted using empirical formulas and the BP neural network. According to the empirical formula, the height of the roof caving zone ranges from 6.93 m to 27.72 m, while the height of the water-conducting fracture zone ranges from 22.17 m to 71.73 m. The BP neural network predicts that the development height of the water-conducting fracture zone in the working face after mining is 56.83 m. CDEM numerical simulation is employed to analyze the development height of two zones of overburden rock. The findings indicate that with a mining height of 2.5 m and a cumulative mining height of 6 m, the maximum caving ratio is 2.61. It is observed that for a cumulative mining thickness of less than 6 m, a bedrock thickness of not less than 30 m, and a clay layer thickness exceeding 5 m, the clay layer effectively obstructs the upward development of the water-conducting fracture zone. Finally, the prediction results of the development height of the two zones of overlying strata in the working face are verified by using the height observation method on the underground water-conducting fracture zone and the borehole peeping method. In conclusion, the height of the overlying strata after mining the lower slice working face in the first panel of the east can be used as a basis for determining the thickness of coal (rock) pillars for waterproofing and sand control safety during the mining of lower slice working faces in mines. [ABSTRACT FROM AUTHOR]

Understanding the role of open vegetation, particularly in white-sand ecosystems (WSE) and savannas, is crucial for elucidating their role in Amazonian biotic diversification. These ecosystems predominantly develop on sandy terrains, suggesting that the geological substrate significantly influences the vegetation upon it. Therefore, the interaction between landscape changes and biotic diversification is closely tied to the dynamics and resilience of these sandy substrates. Current WSE and savannas in lowland Amazonia colonized fluvial sediments deposited during the past 120 ka, with marked synchronicity over the last 23 ka, as shown by optically stimulated luminescence (OSL) and radiocarbon ages of such sandy substrates. In contrast, sandy substrates supporting open vegetation in highland areas, unsuitable for Quaternary sand accumulation, would have persisted beyond the Quaternary, as ancient sedimentary rocks in these areas are prone to developing sandy soils. The current distribution of open vegetation ecosystems in lowland Amazonia is coupled with the deposition and erosion of sandy sediments by Quaternary fluvial systems, while weathering sandy substrates in highland areas serve as long-term and resilient refugia beyond the Quaternary. The contrasting spatiotemporal dynamics of landscape changes in lowland and highland areas has implications for biodiversification or extinction events leading to current biogeography patterns in Amazonia. [ABSTRACT FROM AUTHOR]

Theory suggests that the response time of alluvial channel long profiles to perturbations in climate is related to the magnitude of the forcing and the length of the system. Shorter systems may record a higher frequency of forcing compared to longer systems. Empirical field evidence that system length plays a role in the climate periodicity preserved within the sedimentary record is, however, sparse. The Toro Basin in the Eastern Cordillera of NW Argentina provides an opportunity to test these theoretical relationships, as this single source-to-sink system contains a range of sediment deposits, located at varying distances from the source. A suite of eight alluvial fan deposits is preserved along the western flanks of the Sierra de Pascha. Farther downstream, a flight of cut-and-fill terraces has been linked to eccentricity-driven (100 kyr) climate cycles since ca. 500 ka. We applied cosmogenic radionuclide (10Be) exposure dating to the fan surfaces to explore (1) how channel responses to external perturbations may or may not propagate downstream and (2) the differences in landscape response to forcing frequency as a function of channel length. We identified two generations of fan surfaces: the first (G1) records surface activity and abandonment between ca. 800 and 500 ka , and the second (G2) does so within the last 100 kyr. G1 fans record a prolonged phase of net incision, which has been recognized throughout the central Andes and was likely triggered by enhanced 100 kyr global glacial cycles following the Mid-Pleistocene Transition (MPT). Relative fan surface stability followed, while 100 kyr cut-and-fill cycles occurred downstream, suggesting a disconnect in behavior between the two channel reaches. G2 fans record higher-frequency climate forcing, possibly the result of precessional forcing of climate (ca. 21/40 kyr timescales). The lack of a high-frequency signal farther downstream provides field support for theoretical predictions of a filtering of high-frequency climate forcing with increasing channel length. We show that multiple climate periodicities can be preserved within the sedimentary record of a single basin. Differences in the timing of alluvial fan and fluvial terrace development in the Toro Basin appear to be associated with how channel length affects fluvial response times to climate forcing and local controls on net incision, such as tectonic deformation. [ABSTRACT FROM AUTHOR]

Existing empirical relations used to predict the porosity of gravel beds are mainly derived from laboratory-generated sediment beds with random grain packing. However, such relations could not adequately describe beds with non-random grain arrangements that occur widely in fluvial deposits. In this work, the effect of grain imbrication on gravel-bed porosity has been quantified using beds with variable strengths of imbrication generated by flume experiments. Mono-sized ellipsoids with specific shapes were used in experiments to remove particle size and sorting effects on porosity. Random bed packings were generated by settling of ellipsoids in still water whilst imbricated beds generated under flowing water. Beds were frozen using liquid nitrogen before extraction. A new relatively simple and time-saving workflow was developed to measure the orientation of particles and quantify the degree of grain imbrication in frozen beds from X-ray Computed Tomography images. Beds with the strongest grain fabric display a ca. 0.03 absolute reduction of porosity value on average (8–10% relative reduction) compared to that of random packing for undisturbed beds. Further, results were obtained for beds deposited under still-water conditions subject to disturbance by shaking, to mimic the potential effect of vibrations from currents, waves or other sources in the environment. A reduction in bed porosity of ca. 0.014–0.018 (ca. 5% relative reduction) is observed between beds with the strongest grain fabric and those with random packing that had undergone shaking after deposition. Hence, a significant proportion (> 50%) of the porosity loss observed for imbricated beds may be attributable to tighter packing due to turbulence-related vibrations from the flow. The small decrease in porosity value despite the formation of strong imbrication is considered to be due to the limited improvement in grain organization, as the results show that the flat shape of the ellipsoids and the uniformity of their size promote the formation of a stacking structure under gravity, leading to a similarly highly ordered grain organization in random packings compared to the imbricated packings. [ABSTRACT FROM AUTHOR]

This study analyzes the depositional regime and textural properties of the sediments from the Shitalakshya River in Bangladesh, enabling us to comprehend how these sediments evolved in a river environment. For this investigation, 30 representative samples were taken from the Shitalakshya River, and their textures were analyzed. The cumulative frequency curve is obtained by using semilog graph paper to plot particle size (in phi scale) against cumulative percent. The statistical parameters such as median (Md), mode (Mo), mean (MZ), standard deviation (σi), skewness (SKi), and kurtosis (KG) were calculated using the percentile of phi values (1%, 5%, 16%, 25%, 50%, 75%, 84%, and 95%). The cumulative curves show that the sediments are deposited through the traction population (1.90%), saltation population (75.64%), and suspension population (22.46%). The median value varies between 0.7Ø and 4.85Ø, with an average of 2.738Ø indicating coarse sand to coarse silt. The analyzed samples have unimodal, bimodal, and polymodal distribution, which indicates the sediments are carried by different tributaries and distributaries in the Sitalakshya River system. The range of 1.46Ø–4.05Ø represented by the observed mean value suggests sand with medium to extremely fine grains. Most of the sediments indicate moderate sorting, which is shown by the standard deviation (sorting), which ranges from 0.399Ø to 1.48Ø. The skewness value ranges between −0.01Ø and 0.66Ø, suggesting near symmetrical skewed, while the kurtosis value ranges from 0.54Ø to 1.87Ø, indicating the sediments are 20% leptokurtic, 20% mesokurtic, and 60% platykurtic. According to the CM plot, the Shitalakshya River is mostly deposited in the area between the rolling and suspension fields, indicating a transportation regime of saltation. The scatter plots of skewness versus sorting and graphic mean versus sorting indicate that the sediments fall within the river sand zone. The energy process discriminant functions of the sediments show that they were deposited by a fluvial process. [ABSTRACT FROM AUTHOR]

The southwestern part of Turkey is called the 'western Anatolia Extensional Province'. Today, there is an approximately N-S-oriented extension in this area. The seismically active region is characterized by E-W and N-S-trending grabens. The tectonism and evolution of Tavşanlı Graben, one of these grabens, during the Plio-Quaternary period are the main subjects of this study. The Tavşanlı Graben, about which there is no information in the literature, has been defined for the first time in this study, and the geometrical and kinematic properties, relative ages, and interrelationships of some Neogene-aged faults, especially Quaternary-aged faults, have been presented in the manuscript. The data obtained indicate strike-slip faulting in the late Pliocene in the region. These E-W striking faults and the basin they formed are the first in western Anatolia with these features. In the Quaternary, E-W-oriented normal faults were formed in the region. The asymmetric topography of the graben area is consistent with the other E-W-oriented grabens in western Anatolia. Late Cretaceous basement rocks and Miocene-aged units are observed at the margins of the graben, which are fragmented by faults. The fill of the graben is Quaternary-aged fan deposits and alluvium. In this study, it was determined that the Tavşanlı Basin, which started to form with a transtensional mechanism at the end of the Pliocene, was transformed into the Tavşanlı Graben in the Pleistocene. The basin formation, which started with directional faulting in the late Pliocene, evolved into a graben in the Quaternary, and reached its present form by completing its development in two phases, supports the views that adopt the multi-stage deformation of western Anatolia in the late Cenozoic. In addition to contributing to the literature on this subject, the article will also serve as a basis for future paleoseismological studies. [ABSTRACT FROM AUTHOR]

The Rheic Ocean closure stratigraphic record in southern Mexico is largely exposed in the Paleozoic Acatlán Complex. One of the most distinctive characteristics of the Acatlán Complex is the presence of high-pressure rocks, interpreted as remnants of the Rheic Ocean and the adjacent continental margin of Gondwana, which were subducted and then exhumed to the surface. Despite its importance in reconstructing the dynamics of the westernmost Rheic Ocean closure, the timing and mechanisms of exhumation of these high-pressure rocks remain debated. Some authors have tentatively interpreted the late Paleozoic, fluvial to marine succession of the Patlanoaya Group in southern Mexico as the sedimentary response to the exhumation of high-pressure rocks of the Acatlán Complex. Therefore, these sedimentary rocks may be particularly helpful in understanding the timing and evolution of high-pressure rocks exhumation during the Rheic Ocean closure. In this work, the tectono-sedimentary evolution of the continental deposits of the Patlanoaya Group was reconstructed, integrating sedimentologic, petrographic, and U-Pb detrital geochronological data to test the different scenarios proposed for the exhumation of the Acatlán Complex high-pressure rocks. Our data suggest that the lower Patlanoaya Group was deposited in an Early Mississippian basin with a two-stage evolution: a phase characterized by debris flow deposits derived from small-scale reliefs composed of low-grade metamorphic rocks and a subsequent phase marked by an NNE-trending fluvial system deposits sourced from low-metamorphic grade rocks of a mylonitic zone. Therefore, the lower Patlanoaya Group deposition was controlled by a major NNE-trending mylonitic shear zone associated with the development of a supradetachment basin linked to the progressive exhumation of high-pressure rocks during an Early Mississippian major extensional event. This work highlights the importance of sedimentary deposits in reconstructing the late Paleozoic history of the Acatlán Complex during the Rheic Ocean closure and the final stage of the Pangea assembly. [ABSTRACT FROM AUTHOR]

Introduction: The Stratigraphic Pile (SP) is one of the foundation of most geological studies. It represents, in a compact and practical way, a vertical succession of depositional events over geological time. Accurate definition of the SP is crucial for geological modeling, yet challenges arise when relying on borehole data in the absence of clear biostratigraphic indicators or chronostratigraphical data. Methods: This manuscript introduces an algorithm designed to automatically determine the SP using borehole unit sequences. The algorithm also addresses the complexities associated with incomplete sedimentological records and subjective geological interpretations. The algorithm was tested on various datasets, taking into account differences in the number of boreholes and available information. Results and Discussion: The efficiency of the algorithm was demonstrated through real-world applications, providing a basis for a comprehensive discussion of its advantages, limitations, and potential applications. The proposed methodology assumes that each borehole contains a single occurrence of a stratigraphic unit, taking into account possible interpretation errors and inconsistencies. The algorithm is capable of: automatically determining one or an ensemble of plausible stratigraphic sequences, identifying potential misinterpreted wells, quantifying the vertical relationships of the stratigraphic units, and assisting in the data preprocessing step and in building the geologic concept of the modeling area. In particular, this ensemble of SPs and identified inconsistencies provide valuable insights into the geological history and concepts for a particular area. Conclusion: This research contributes to the refinement of geological modeling workflows and provides a valuable tool for automatic refinement of SP selection. [ABSTRACT FROM AUTHOR]

The whiteflies (Hemiptera: Aleyrodidae) are small sternorrhynchan insects, which have the potential to cause significant economic damage to agricultural crops. There is a paucity of knowledge regarding the diversity, disparity, and evolutionary history of these insects, with classification based on the immatures, called puparia. The fossil record of whiteflies is sparse and incomplete, with the majority of fossils representing imaginal forms preserved as inclusions in fossilized resins. In this study, we present the first inclusion in succinite associated with the layers of Lower/Middle Miocene 2nd Lusatian Lignite Seam of Wanninchen in Brandenburg, Germany. The objective of the present study is to elaborate this fossil, and as a consequence, a new fossil genus and species, Pudrica christianottoi gen. et sp. nov., is described. This fossil is a representative of the subfamily Aleyrodinae, and it is the third fossil genus of this whitefly subfamily to be described. The discovery of the fossil inclusion in the succinite from the lignite deposits of Lower Lusatia challenges the current understanding of the character and conditions of formation and deposition of central and east European Paleogene fossil resins. Succinite is a fossil resin that occurs in the Eocene deposits of the Gulf of Gdańsk, belonging to the Prussian Formation, containing a glauconite-rich horizon known as the 'Blue Earth'. Similarly, glauconite-rich deposits are present in the Lublin area of Poland, where they are associated with the occurrence of succinite. Additionally, succinite has been found in deposits in the Rovno-Zhitomir area of Ukraine, which are alluvial deposits containing glauconite and lignite layers. Succinite was also identified in Eocene strata of Spitsbergen and in Axel Heiberg Island in the Canadian Arctic. Succinite has also been discovered in early Miocene deposits in Bitterfeld, Germany, where it occurs alongside lignite deposits (the deposit actually encompasses different fossil resins, so potentially originating from different source plants). Furthermore, it has been identified in younger (Pleistocene) deposits across Europe. The autochthonous (parautochthonous) character of the lignite deposits in Lower Lusatia raises questions regarding the time range of the succinite-producing gymnosperm trees and the autochthonous or allochthonous character of the lignite layers associated fossilized resins. [ABSTRACT FROM AUTHOR]

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Late Devonian sedimentation in the southern Bonaparte Basin was controlled by, and provides a record of, contemporaneous fault movements in the Halls Creek Orogen. An important episode of Late Devonian faulting caused uplift and southward tilting of the Carr Boyd Ranges block and uplift and northward tilting of the O'Donnell Ranges block forming the Galloping Creek and Ragged Ranges sub-basins, respectively. Uplift of the Carr Boyd Ranges provided the eastern source of the Ragged Range Conglomerate, while the south-dipping Carr Boyd Ranges and the uplifted O'Donnell Ranges and Bow River blocks formed the northern and western sources of the Galloping Creek Formation. Conglomeratic facies on both the northern and southwestern margins of the Galloping Creek Sub-basin record interaction with a fault-controlled topography. The apparent lack of unconformities within the northern Galloping Creek Formation and the progressive increase in siltstone content towards the centre of the sub-basin suggest that faulting was no longer an active driver for sedimentation. While alluvial fan deposition infilled the southwestern part of the sub-basin, the remainder of the Galloping Creek Formation was deposited by fluvial systems that changed from an initial proximal braided stream character to a later distal character with more extensive floodplain deposition. Post-depositional folding and faulting of the Galloping Creek Sub-basin were confined to movement on the Halls Creek and Glenhill faults with a probable 10+ km of sinistral offset and uplift of the western block along at least the latter. KEY POINTS: Late Devonian fluvial sedimentation in fault-initiated sub-basins of the southern Bonaparte Basin, Western Australia. Faults were active during Ragged Range Conglomerate deposition, but movement ceased during Galloping Creek Formation deposition. Galloping Creek Formation shows upward fining away from the sub-basin margins. Few faults were reactivated after Frasnian deposition. [ABSTRACT FROM AUTHOR]

• The CO is one of the thickest tuff beds known for the Santa Cruz Formation. • CO tuff represents aeolian processes. • CO tuff includes a rich and diverse mammal assemblage. • The formation of the assemblage can be linked to a normal attritional model. • Biotic and abiotic processes conditioned the taphonomic history of the remains. The CO tuff is one of the volumetrically largest volcaniclastic events so far recorded in the Early-Middle Miocene Santa Cruz Formation (Patagonian Argentina). It represents aeolian processes, related with westerlies, that reworked and transported enormous quantities of volcanic ash from the Andes into the continental interior that accumulated in fluvial floodplain deposits. This volcanic event generated a major environmental change at ∼17 Ma (Burdigalian) and hostile living conditions for the biota of the area, at least during the time of deposition. We performed here a comprehensive study including taxonomic, sedimentological, and taphonomic aspects of the mammal assemblage recovered from this tuff deposit. The assemblage is constituted by representatives of Microbiotheria, Paucituberculata, Folivora, Cingulata, Rodentia, Notoungulata, and Litopterna, reflecting a wide mammalian diversity. The formation of the assemblage can be linked to a normal attritional model, in which the death of the individuals and subsequent deposition and burial of their remains would have occurred gradually over time, simultaneously with the accumulation of volcanic ash, at the place of death or very close to it. The time between the death and burial would have been relatively short, in accordance with the rapid and continuous influx of volcanic ash to the depositional environment. This multidisciplinary study allows us to interpret and reconstruct the possible taphonomic pathways of the mammal assemblage and to provide novel information on this particular preservation context linked to volcanically-influenced fluvial environments. [ABSTRACT FROM AUTHOR]

We conducted a habitat suitability assessment for two burrowing rodents, Anatolian or Nehring's blind mole rat (Nannospalax xanthodon) and Harting's vole (Microtus hartingi), on the island of Lesvos using a niche-based approach. We collected data on the presence of the two species across the island and selected several environmental variables, including land cover, geology, and habitat topography, to assess their influence on habitat suitability. We used the Maxent species distribution modelling algorithm to predict suitable habitats. The results showed that both species preferred habitats with low slopes and specific geological substrates, i.e., alluvial deposits and volcanic rocks. M. hartingi showed a preference for open habitats such as saltmarshes and non-irrigated arable land, while N. xanthodon preferred non-irrigated arable land, pastures, and discontinuous urban fabric. The model predicted a wider area of suitable habitats for Microtus hartingi compared to N. xanthodon. Interestingly, the two species are absent from the southeastern part of the island despite our model predicting high suitability; this indicates that a natural barrier of hilly terrain, extensive pine forests, and limestone rock formations may exist that impedes dispersal. Our study provides valuable insights into the habitat preferences of these two burrowing rodents on the island of Lesvos, which can inform biodiversity conservation and ecosystem management strategies. [ABSTRACT FROM AUTHOR]

The shear-wave velocity (Vs) of soils has been acknowledged among the most critical factors affecting the nature of seismic surface motions, known as seismic site effects, in the course of probable earthquakes. Together with the one-dimensional (1D) Vs profiles of soils, the lateral heterogeneity of velocity contrasts may strongly impact seismic ground motions within the surface. Such conditions seem to occur in the city of Tehran, Iran, mainly in the eastern part, Hakimiyeh Valley, wherein alluvial deposits have been settled between the Alborz and Sepayeh (the Anti-Alborz) mountain ranges. In this resepct, the significant differences observed between previous analytical and empirical studies doubles the necessity of estimating real bedrock depth and Vs structure in this area. Given that the improper analysis of seismic site effects, using unrealistic dynamic characteristics, gives rise to the low-accuracy prediction of seismic hazards as well as significant human and financial losses; this study is an attempt to extract the two- dimensional (2D) Vs structure of the subsurface layers in the form of two north-south and east-west profiles, through the single-station and array measurements of ambient noises (viz., microtremors), as the first deep alluvial models in this area. For this purpose, the ambient noises are recorded with reference to 4 and 11 array and single-station measurements, respectively. A circular layout, comprised of two concentric circles, is further considered for the array measurements with 11 three-component narrow-band seismometers, Lennartz LE-3D/20S, within each array. The recorded array seismograms are then analyzed via the spatial autocorrelation (SPAC) method and the frequency-wavenumber (F-K) analysis, and all seismograms recorded in this line are subsequently evaluated by the time-frequency analysis (TFA) of ellipticity in the Geopsy software. Afterward, the results are utilized as the objective functions (OFs) in the inversion operation for calculating the Vs profiles at the selected stations. The neighborhood algorithm is further applied for the inversion of the OFs and the extraction of the Vs profiles. The study results as it comes to the extraction of the 2D profiles and the recognition of the Vs structure in this area, along with the velocity of 2200 m/s, correspond to the seismic bedrock located in the deepest part of the sedimentary basin, 800 m. Moreover, the underground topographies, such as faults, can be identified in the Vs profiles by means ofusing the ambient noises. As a final point, the profiles indicate that the variations in the Vs and dynamic properties of the soil are significant in this area, as one with a complicated subsurface structure. The dominant frequencies of the sediments in Hakimiyeh Valley, reported in previous analytical research, are also significantly different from that those extracted in this empirical study. As an illustration, no sharp and clear peaks can be spotted in the analytical amplification functions in Hakimiyeh Valley, while there are distinct peaks below 2 Hz at most stations in the present study. Furthermore, the study results are in good agreement with the geology of this area, and pave the ground for analytical site effect studies in the future. [ABSTRACT FROM AUTHOR]

The Paleogene paleotopography of the western United States, which may grant insight into Farallon subduction dynamics and North American Cordillera orogenic processes, can be constrained by reconstructing drainage networks through sediment provenance studies. In the northern Sierra Nevada, the provenance of SW-directed, Paleogene paleochannel deposits is controversial; prior studies favor either sources proximal to the deposits or distal source areas in central Nevada. These different hypothesized source areas would have contrasting implications for the paleotopography of the Sierra Nevada and western Basin and Range. We conducted a new provenance analysis of paleochannel deposits in the Sierra Nevada and western Nevada using new and compiled detrital zircon U-Pb age data from across the preserved paleochannel network, together with compiled bedrock geochronologic ages of potential sediment source areas for the paleochannel deposits. The geochronology compilation of potential source areas reveals systematic longitudinal variations in bedrock ages within the study area. Jurassic ages are present primarily in the western Sierra Nevada batholith, Cretaceous ages are dominant in the eastern Sierra Nevada batholith, and Eocene ages are present only in north-central Nevada. The distribution of potential source ages allows confident inference of sediment provenance from detrital zircon U-Pb ages. The distributions of detrital zircon U-Pb ages in the paleochannel deposits can be categorized into three distinct types. The first type, found in the vicinity of Malakoff Diggins State Historic Park (SHP) and further northwest, is dominated by Jurassic, Paleozoic, and Precambrian ages reflecting derivation from local sources in the western Sierra Nevada, and also contains scattered Eocene ages. The lack of Late Cretaceous ages in these samples, despite the presence of Late Cretaceous plutons in close proximity to the east, suggests small sediment source areas with fluvial transport of zircon grains no farther than 50 km. The few Eocene ages in these samples likely reflect volcanic air fall, consistent with an overlying tuff at one sample site that is interpreted to have its volcanic source to the north, outside the paleochannel network. The second zircon age distribution type, from samples south of Malakoff Diggins SHP, includes Cretaceous and Jurassic ages representative of exposed bedrock across the entire width of the Sierra Nevada batholith but no Eocene ages. This combination of ages suggests a sediment source area that encompassed the entire batholith but did not include north-central Nevada. The third zircon age distribution type, from samples to the northeast of Malakoff Diggins SHP, contains Jurassic, Cretaceous, and Eocene ages consistent with fluvial derivation of sediment from the entire width of the Sierran batholith as well as from north-central Nevada. This third type only occurs in fluvial deposits interbedded with Oligocene ignimbrite tuffs, whereas samples older than the Oligocene tuffs belong to zircon age distribution types 1 or 2. Thus, prior to the emplacement of Oligocene ignimbrites, there is no evidence of fluvial transport of sand-sized sediment from north-central Nevada sources to Sierran paleochannel deposits. The lack of pre-Oligocene fluvial transport across the Sierra Nevada may reflect either a Paleogene drainage divide that separated the Sierra Nevada from north-central Nevada or a large-scale knick zone with a low-gradient upstream reach that trapped sand and larger sediment. The first arrival of fluvially transported Eocene zircon grains following Oligocene ignimbrite emplacement suggests that ignimbrite volcanism, and related hinterland uplift, established or promoted sediment transport from north-central Nevada across the Sierra Nevada by driving drainage reorganization or steepening existing channels. Our provenance analysis broadly confirms previous paleochannel network reconstructions, especially for the Ancestral Yuba River, and thus validates the use of paleochannel deposits as a datum by which to infer post-Paleogene tilting of the northern Sierra Nevada. Azimuthal trends in Ancestral Yuba River paleochannel gradient suggest ~0.6° SW-directed, post-Paleogene tilting of the northern Sierra Nevada, which would have resulted in ~1 km of uplift of the range crest. Such a magnitude is consistent with Eocene–Oligocene stable isotope paleoelevation estimates. [ABSTRACT FROM AUTHOR]

Blancan III or late early Blancan–early late Blancan (3.9–2.6 Ma, Pliocene) cervid remains are described from alluvial deposits of the locality Los Hornitos, northeastern Sonora, northwestern Mexico. These remains include antlers, teeth, a mandible fragment, and other several postcranial elements. These Sonoran Blancan fossil cervid elements constitute the second most abundant group of the mammalian assemblage after the equids in the studied area. The morphometric comparative study with Pliocene and Pleistocene cervid material from United States and Mexico together with statistical analyses (bivariate and multivariate), indicate that herein described material correspond to the species Odocoileus virginianus. This is the first record of this medium-sized deer from the Blancan of Sonora and the earliest unequivocal record to Mexico. [ABSTRACT FROM AUTHOR]

The Global Industry Standard on Tailings Management (GISTM) promotes performance-based approaches in geotechnical assessments. Hence, characterizing the spatial variability of deposited tailings is expected to be a key input for some tailings storage facilities (TSFs); however, it has seldom been investigated. In this study, we assess the spatial variability of thickened and conventional tailings, which have been deposited into the same TSF, providing a unique opportunity to investigate two tailings technologies. A dense array of 15 cone penetration tests (CPTus) with an average offset of 1.5 m has been conducted to collect data. In addition to evaluating the spatial variability, the collected information is also used to assess the potential of machine learning (ML) for detrending when deriving random fields. Using a new proposed stationarity score, we find that an ML-based detrending outperforms traditional procedures for most scenarios. In terms of correlation lengths, we find similar ranges for thickened and conventional tailings (vertical: δwv=0.2–0.6 m , horizontal δwh=1.5–4.5 m) and similar distributions, likely influenced by the depositional processes. In contrast, the variance in the conventional tailings is higher, which we attribute to its segregating nature. Finally, by inspecting previous studies on natural soils, we find that the variability of mine tailings (δwh/δwv=2–21) resembles that observed in alluvial deposits, which we attribute to the parallels in the depositional processes. [ABSTRACT FROM AUTHOR]

Sedimentation traps were used to assess the annual surface renewal dynamics of the low floodplain of the Oka River (a major tributary of the Volga River in central European Russia). Trap-mats and platforms made of crushed bricks were installed in positions near the meandering and relatively straight riverbed, in different sedimentation environments. Stationary research in 2014–2020 covered a section of the bottom of the Oka River valley with a length of more than 400 km along the main channel. The graphical-analytical processing of field data using Ferret's Triangles and sedimentation diagrams showed that transport and deposition of suspended sediment dominated in the accumulation of 87% of alluvium samples. The formation of ripples was not recorded, which was lithologically reflected in the horizontal layering of the new sediment. The determination of the granulometric composition of the removed sediment and their thickness on the traps showed the absence of statistically significant differences according to the Kruskal–Wallis test between the data samples from the trap-mats and trap-platforms. The reference to the daily calendar of synoptic mechanisms according to the classification of Dzerdzeevsky contributed to the identification of meteorological prerequisites for the variation of the hydrograph curve of the Oka River in its middle reaches. Prolonged floods caused by the premature arrival of spring lead to massive deposition of silt and clay particles even on sandbanks. On the other hand, short (15–35 d) March floods and abnormal high water in June, caused by Atlantic cyclone intrusions, can stabilize sand accumulation on the riverine floodplain. The thickest sediment layers on the traps were obtained in 2018 after a very cold March and a powerful April flood, and the overall distribution of alluvium thickness and its particle size distribution also depends on the morphology of the riverine relief. The siltation is caused by the accumulation of silts; the most finely dispersed sediment was deposited in those facies environments for which siltation was also characteristic in historical times. [ABSTRACT FROM AUTHOR]

Radiocarbon dates on charred plant remains are often used to define the chronology of archives such as lake cores and fluvial sequences. However, charcoal is often older than its depositional context because old-wood can be burnt and a range of transport and storage stages exist between the woodland and stream or lake bed ("inherited age"). In 1978, Blong and Gillespie dated four size fractions of charcoal found floating or saltating in the Macdonald River, Australia. They found larger fragments gave younger age estimates, raising the possibility that taphonomic modifications could help identify the youngest fragments. In 1978 each date required 1000s charcoal fragments. This study returns to a sample from the Macdonald River to date individual charcoal fragments and finds the inherited age may be more than 1700 years (mode 250 years) older than the collection date. Taphonomic factors, e.g., size, shape or fungal infestation cannot identify the youngest fragments. Only two fragments on short-lived materials correctly estimated the date of collection. In SE Australia, this study suggests that wood charcoal will overestimate the age of deposition, taphonomic modifications cannot be used to identify which are youngest, and multiple short-lived materials are required to accurately estimate the deposition age. [ABSTRACT FROM AUTHOR]

The final season of excavations at the archaeological park of Monte Rinaldo in 2023 focused on the southwestern area, revealing the façade of a Republican building and a pavement defining the square of the sanctuary. The earliest phases included levelling of the area during the reconstruction of the sanctuary in the second century BC, with significant finds such as black glaze pottery, metal items, and organic material. The structures of the Republican period were later reused and rebuilt using material from the previous construction, particularly architectural terracottas. Additionally, a fieldwalking survey around the sanctuary revealed rare fragments of pottery, suggesting an absence of a population in the immediate area. The research was conducted by a team from the University of Bologna in collaboration with the Soprintendenza Archeologia, Belle Arti e Paesaggio, the British School at Rome, and ARCADRIA, with support from the municipality of Monte Rinaldo. [Extracted from the article]

Bedrock rivers often alternate between relatively wide unconstrained reaches and conspicuously narrow deep incised bedrock reaches (canyons). These bedrock canyons exhibit a constriction‐pool‐widening (CPW) morphology that consists of a lateral constriction, a deeply scoured pool formed downstream of the constriction, and a channel widening at or near the pool exit. To explore how CPWs are formed in bedrock canyons, we hypothesize that the lateral constriction at the canyon entrance forces a CPW to form allogenically with subsequent CPWs propagating further downstream. Our hypothesis was tested experimentally in a flume channel with a forced lateral constriction at the canyon entrance. Our experiment shows that the forced constriction can cause a primary CPW to form allogenically because the backwater upstream of the forced constriction causes sediment deposition that creates an elevation drop, promoting flow and sediment to plunge toward the bed and carve a primary pool. Channel widening occurs at the primary pool exit because sediment deposit forms that deflects sediment into the banks, causing lateral erosion. Downstream of the primary widening, channel width declines and a new lateral constriction forms, which causes the formation of pools and widening downstream, resulting in downstream CPW propagation. In our experiment, the bedrock channel evolved until a persistent alluvial cover formed, reaching a steady state morphology without further vertical erosion until perturbed by higher discharge. Our experiment shows that discharge variation is necessary for a channel to evolve in the absence of uplift. Plain Language Summary: Mountain rivers often alternate between wide, shallow channels that are not constrained by bedrock and deep, narrow canyons that are laterally constrained by bedrock. Canyons often exhibit repeating sequences of channel narrowing that are accompanied by deep pools and channel widening near the pool exit. Here, we conducted a laboratory experiment to better understand how these morphological sequences are formed. Our experimental bed and banks were made of a type of foam board commonly used for insulation because the foam board erodes like rock, but at a much faster rate. We setup our experimental channel so that there was an initial channel narrowing, like at the entrance to a canyon, and then studied the erosion patterns created by gravel transport through the simulated canyon. We found that sediment deposition upstream of the channel narrowing creates a steep water surface slope entering the canyon, which drives sediment into the bed carving a slot at the canyon entrance. The slot gradually widens forming a pool that is elongated downstream. At the pool exit, flow slows down and sediment deposition occurs, which then deflects sediment into the channel banks, creating a channel widening. This initial constriction‐pool‐widening is propagated downstream, creating new sequences of this morphology. Key Points: Lateral constriction of bedrock canyons can cause the formation of pools through vertical erosion and the widening through lateral erosionThe constriction, pool and widening morphology can self‐propagate downstreamBedrock channel morphology can reach a steady state through a balance between uplift and lateral and vertical erosion rates [ABSTRACT FROM AUTHOR]

River meanders entrenched into bedrock are found worldwide, and they are famously well represented in the Colorado Plateau of the southwestern U.S. Meandering of bedrock streams can eventually lead to cutting off canyon loops, and these abandoned "rincons" are locations with high preservation of fluvial deposits and landforms. We document and luminescence date the fluvial terraces in and around the Jackson Hole rincon along the Colorado River downstream of Moab, Utah. Results indicate cutoff and abandonment of the rincon at ~200 ka and also record the rapid and unsteady incision in this region over the past 300 ky. A convergence of conditions contributed to the cutoff of the rincon, including alluvial‐channel conditions at the onset of MIS 6 glacial‐climate, which provided channel‐bed cover and enhanced lateral erosion of weak strata. Also, a contemporaneous rock‐avalanche partially obstructed the paleochannel just downstream of the breach, potentially creating a backwater that further enabled a flood to avulse across the neck. Although other studies show that bedrock‐channel meandering and cutoff can generate unpaired strath terraces and short‐term increases in incision rates, these are not evident in the record at the Jackson Hole rincon. This novel case study leverages the high preservation potential within abandoned bedrock meanders to illuminate the processes and controls of rincon formation during landscape evolution. [ABSTRACT FROM AUTHOR]

Coastal marine and fluvial deposits, exposed at Cerro El Divisadero near Rancho La Palma, Baja California Sur, Mexico, contain a fossil record of cetaceans (baleen whales). U-Pb zircon dating of a tuff horizon collected near the base of Cerro El Divisadero yields a 206Pb/238U age of 27.95 ± 0.16 Ma. This suggests that the marine and fluvial beds at the Rancho La Palma locality are late Rupelian in age and not lower Miocene as previously reported. Therefore, the marine deposits from the Cerro El Divisadero section can be correlated with the Oligocene El Cien Formation at San Juan de La Costa and are contemporaneous with the middle part of its San Juan Member, representing a marginal facies of this unit. Our results constrain the age of the baleen whales found at the Cerro El Divisadero section, providing clues for Oligocene cetacean evolution in the North Pacific. [ABSTRACT FROM AUTHOR]

Incision rates of major rivers may reflect the effects of drainage reorganization, hillslope processes, tectonic uplift, climate, the properties of rocks into which rivers incise, and other autogenic processes. On the Colorado Plateau, incision rates along the Colorado River have been interpreted as resulting from abrupt base-level changes produced by the integration of the Colorado River system. Specifically, the integration of the Colorado River in the location of Grand Canyon is thought to have created a knickpoint, enhanced by lithologic contrasts, which is propagating upstream. While evidence exists for a < 1 Ma acceleration of incision on parts of the Colorado River, uncertainty about the processes reflected in shorter-term incision rates muddies comparison with longer-term averages. In this work, we combine a cosmogenic radionuclide depth profile exposure age and post-infrared infrared stimulated luminescence (p-IR IRSL) to date fluvial deposits adjacent to the San Juan River, a major tributary of the Colorado River, near Mexican Hat, Utah. The deposits, resting on a 27 m strath surface, are constrained to be ∼ 28–40 ka, suggesting an incision rate of 678–968 m Myr -1 , which is a factor of 7 higher than the long-term rate of ∼ 125 m Myr -1 over the past ∼ 1.2 Myr. We observe fluvial deposits that were abandoned due to a bedrock meander cutoff, which partially explains our accelerated incision rate. We use a simple geometric model, informed by our field data, to demonstrate how planform river evolution may, in some circumstances, increase short-term incision rates relative to long-term averages. These short-term rates may reflect a combination of autocyclic and climatic processes, which limits their ability to resolve longer-term changes in incision rates that may be related to changes in base level or tectonics. [ABSTRACT FROM AUTHOR]

The McCoy Mountains Formation (McMF) in southern California–Arizona preserves an anomalously thick record of sedimentation during the Mesozoic at a critical time when western North America experienced contrasting tectonic events related to intracontinental rifting along the Mexican Border rift system and consolidation of the North American Cordilleran system. The spaciotemporal interactions among these events and the development of the McCoy basin challenge our understanding of the evolution of the southern extent of North America. At its type locality in the McCoy Mountains, the McMF consists of ~ 7 km of low‐grade metasedimentary rocks, originally interpreted as meandering fluvial to alluvial‐fan deposits. Uncertainty in the initial timing of sedimentation in the McCoy basin has resulted in multiple tectonic models. We measured ~ 7160 m of detailed stratigraphy and present new sedimentological and detrital zircon results showing that the McCoy basin was occupied by deep‐water turbidite systems. These systems deposited an upward‐coarsening succession of fine‐ to coarse‐grained detritus during the Cretaceous (ca. 137–70 Ma). Provenance data indicate that the McCoy basin received sediment from Proterozoic basement rocks and metamorphosed Palaeozoic to early Mesozoic sedimentary units. These source rocks are equivalent to the stratigraphy found in the Grand Canyon and Colorado Plateau regions and were likely shed from the southward‐advancing Maria fold‐thrust belt and possibly the southern Sevier belt in southern Nevada and California. These results, combined with subsidence curves typical of foreland basins, favour deposition within a subaqueous flexural foreland basin system. The presence of a Cretaceous foreland basin this far southwest challenges previously proposed models and suggests that the contractional tectonic regime associated with the North American Cordillera extended into the southwestern most United States during the Early–Late Cretaceous. [ABSTRACT FROM AUTHOR]

This study broadens our knowledge of the relationship between the clayey georesources available in northern Apulia and the artisanal production of ceramics. The focus is placed on a collection of 6th and 7th century A.D. pottery found in the domus excavated within the archaeological complex of Canosa San Pietro (ancient Canusium) in Italy. The integration of the results obtained from this study with those already available made it possible to outline conscious technological choices in terms of raw materials' exploitation, based on which the alluvial deposits were selected for the production of coarse cooking ware and the marine Subapennine clays for the production of fine common ware. This selective choice undoubtedly had a practical implication since it supplied raw materials that required little processing, being already suitable for the type of ceramic to be produced. Moreover, the compositional comparison of investigated pottery with products distributed along the Carapelle valley, rather than those from Canusium previously studied, provides new perspectives for reconstructing the microcirculation of ceramics in northern Apulia. Lastly, the imports of Classe‐type pottery, probably from the northern Adriatic area, are worth mentioning since they represent the most consistent distribution of this type of ceramic in southern Italy and may reflect the assiduous pilgrimage of the monastery after the death of Bishop Savinus. [ABSTRACT FROM AUTHOR]

The large number of rural Roman settlements known from the Low Countries is generally characterised by a poor preservation of ecological proxies due to the absence of waterlogged contexts. The riverside site of Wijmeers (Wichelen, Belgium), a small rural settlement located in the Lower Scheldt basin, represents a rare exception to this pattern. Due to the presence of a waterlogged sequence with Roman (late 1st–3rd centuries AD) waste layers, located only a few metres from a main building structure, and the covering of the site with alluvial sediments shortly after its abandonment, the preservation condition of charred and uncharred organic materials was exceptional. The combined study of these proxies (pollen, seeds, charcoal, mollusc shells and animal bones) presents unique insights into the subsistence economy of a Roman rural household in the Lower Scheldt valley in general, and especially its exploitation of the valley and river environments. Besides this cultural–economical perspective, the site provides key information for understanding the chronology of fluvial and alluvial processes in the Lower Scheldt Basin for a large part of the Subatlantic period (Iron Age to Early Middle Ages, ca 800 BC–900 AD). [ABSTRACT FROM AUTHOR]

Most of the oil reservoirs in China are fluvial deposits with firm reservoir heterogeneity, where differences in fluid flow capacity in individual directions should not be ignored; however, the available commercial reservoir simulation software cannot consider the anisotropy of the relative permeability. To handle this challenge, this paper takes full advantage of the parallelism of the multi-scale finite volume (MsFV) method and establishes a multi-scale numerical simulation approach that incorporates the effects of reservoir anisotropy. The methodology is initiated by constructing an oil–water black-oil model considering the anisotropic relative permeability. Subsequently, the base model undergoes decoupling through a sequential solution, formulating the pressure and transport equations. Following this, a multi-scale grid system is configured, within which the pressure and transport equations are progressively developed in the fine-scale grid domain. Ultimately, the improved multi-scale finite volume (IMsFV) method is applied to mitigate low-frequency error in the coarse-scale grid, thereby enhancing computational efficiency. This paper introduces two primary innovations. The first is the development of a multi-scale solution method for the pressure equation incorporating anisotropic relative permeability. Validated using the Egg model, a comparative analysis with traditional numerical simulations demonstrates a significant improvement in computational speed without sacrificing accuracy. The second innovation involves applying the multi-scale framework to investigate the impact of anisotropy relative permeability on waterflooding performance, uncovering distinct mechanisms by which absolute and relative permeability anisotropy influence waterflooding outcomes. Therefore, the IMsFV method can be used as an effective tool for high-resolution simulation and precise residual oil prediction in anisotropic reservoirs. [ABSTRACT FROM AUTHOR]

The morphometric indices (MI) have been calculated along the Gavilgarh/Salbardi Fault (G/SF) to investigate active deformation, tectonic uplift, and basin tilt to find out its impact on the late Quaternary landscape. To explore the tectonic intensity, we computed MI such as stream-length gradient index (SL), hypsometric integral (HI), transverse topographic symmetry factor (T), asymmetry factor (Af), basin elongation ratio (Re), mountain front sinuosity (Smf) and valley floor width to valley height ratio (Vf). The necessary field investigations were carried out on the evolution of the Quaternary landscape to ascertain the various morphometric indices. The evaluated values of SL, HI, Re, Smf, and Vf show the high uplift of the northern block exists as opposed to the southern block, and the tilt and asymmetric character of the basins are shown by T and Af values. The presence of sedimentary landscapes like Quaternary alluvium, triangular facets, natural levees, and boulder-pebbly beds, indicates that the area has recently experienced tectonic activity. The assessed values of MI with supporting field evidence proposed that the northern block is uplifted and the basins are tilted because of the effect of G/SF. [ABSTRACT FROM AUTHOR]

An integrated analysis of the surface geology with geotechnical parameters of soils within the Kashmir Basin has been presented in this study. Spatial distribution maps of soil properties were prepared using an extensive database of Standard Penetration Test (SPT) reports at ~ 700 sites collected from geotechnical consultancies. The SPT N is high (~ 10–50) in the stiff, dry Pleistocene Karewas and low (< 20) in saturated Recent Alluvial deposits of the Jhelum River. These sedimentary deposits show a low plasticity index (< 17%) as well as the presence of stable clay minerals. The compression index is lower for Karewas (0.08–0.27) than for alluvium (0.16–0.36) indicating higher settlement hazard in the latter. Geological-cum-geotechnical cross-sections along seven transverse and five longitudinal transects were also developed. As an application of this study, the bearing capacity estimates, along with the liquefaction susceptibility map of the soils in the urban area of Greater Srinagar are presented. The alluvial floodplains are revealed to be critical in terms of low ultimate bearing capacity (< 300 kPa) as well as high liquefaction susceptibility (LS > 0.8). On the other hand, Karewas show good bearing capacity (> 300 kPa) and medium liquefaction susceptibility (LS 0.5–0.8). Based on these geotechnical aspects, Karewa highlands were found to be the most suitable for the expansion of the city and its future urbanisation. The results of this study are aimed to assist civil engineers in the proper design of structures, especially foundations, as well as to support urban planners in creating policies for town planning and expansion strategies in Kashmir. [ABSTRACT FROM AUTHOR]

The environment of the Marseille basin in the Early Pleistocene was reconstructed through a multiproxy study of fluvial tufa deposits. Palaeomagnetic measurements revealed the Jaramillo subchron and dated the tufa to within the 0.8–1.5 Ma interval, probably between 0.9 and1.2 Ma. Sedimentological studies show varied depositional environments comprising natural dams formed by accumulations of plants promoting the development of upstream water bodies. The very negative δ13C values indicate that the Marseille tufa is not travertine sensu stricto but tufa deposited by local cold-water rivers. Palynological analyses indicate a semi-forested, diverse, mosaic vegetation landscape dominated by a Mediterranean pine and oak forest. Along the streams, the riparian forest was diverse and included Juglans, Castanea, Platanus and Vitis. The potential diet reconstructed from pollen was varied. The most surprising discovery was the presence of proto-cereals, which could potentially enrich the diet with carbohydrates. The identification of spores of coprophilous fungi seems to indicate the presence in situ of large herbivore herds. It is possible that, as in Anatolia, the disturbance of ecosystems by large herbivores was responsible for the genetic mutation of Poaceae and the appearance of proto-cereals. Climatic reconstructions indicate a slightly cooler and wetter climate than the present. [ABSTRACT FROM AUTHOR]

The White Hills Gravel is the coarsest fluvial gravel within Victoria, southeastern Australia, and outcrops discontinuously across a substantial part (>35 000 km2) of this region. It overlies a major regional unconformity representing >300 Ma, and is dominated by conglomerate (61% of beds), with less abundant sandy lithofacies (36% of beds) and rare mudstones (3% of beds). The sedimentary characteristics of the basal conglomerates (e.g. thick bedding, common boulders, very poor sorting and in places chaotic appearance) indicate deposition by significant paleofloods, including debris floods, within braided streams that had similar flow directions to the modern drainage. Paleohydraulic calculations estimate that the paleofloods had discharges exceeding >7200 m3 s−1, over 25 times the largest recorded floods in the same valleys. These paleofloods were probably caused by exceptionally severe storm systems, consisting of many individual thunderstorms. Deposition of the White Hills Gravel has previously been attributed to the mid-Cretaceous uplift that affected southeastern Australia, but the maximum possible age of the formation (early Paleocene) is too young for this to be a viable explanation. Instead, the White Hills Gravel may have been deposited during a period of increased precipitation at the Paleocene–Eocene Thermal Maximum (ca 56 Ma), when an intensification of the hydrological system generated significant sediment responses within fluvial systems around the world. Modelling indicates that this climatic event had a substantial impact in Victoria, where increases in mean annual precipitation (50–60%) and the most extreme rainfall rates achieved by the strongest storms (60–70%) were some of the largest globally, and frequent and intense Atmospheric Rivers were an important part of the hydrological system. These factors, together with a period of disturbed vegetation cover, resulted in major paleofloods that could have deposited the coarse-grained conglomerates of the White Hills Gravel. KEY POINTS: The White Hills Gravel in central Victoria is dominated by conglomerate (∼61% of beds), with lesser sandstone (∼36% of beds) and rare mudstone (∼3% of beds). In valleys across the central Victorian Highlands, White Hills Gravel outcrops are characteristically elevated above the Calivil Formation, and in the Campaspe and Loddon valleys, the long profiles of both formations cross over downstream. There is no evidence of a tectonic origin for the formation; instead, the White Hills Gravel was most likely deposited in response to a sharp rise in precipitation. The very-coarse-grained base of the formation was deposited by major thunderstorm-generated paleofloods with discharges up to and exceeding 7200 m3 s−1 in small catchments. The White Hills Gravel may denote a significant fluvial response to climate modification across the Paleocene–Eocene Thermal Maximum. [ABSTRACT FROM AUTHOR]

The article presents the discussion on career and academic achievements of Professor Tomasz Zieliński, born on October 3, 1952, in Starachowice, who specialized in Quaternary geology and held prominent positions at the University of Silesia and Adam Mickiewicz University. Topics include his educational background, significant research contributions leading to his habilitation degree; and his roles in administrative and scientific functions.

A quarter of a century ago, during cartographic works using then-known field methods for measuring structural features, on the boundary of the Sudetic and Fore-Sudetic blocks, new phenomena were recognised; these were interpreted to be tectonic in nature and the result of left-lateral strike-slip movement in the subsurface. Grabens, half-grabens, shear zones and seismites in the gold-bearing sands and gravels that form the slopes of the valley of the River Kaczawa, are estimated to be of Pliocene and early Pleistocene age, having been interpreted as deposits of the pre-Kaczawa alluvial fan system. The natural exposures documented 25 years age have now all disappeared. In 2022, these levels became exposed again as a result of renewed gravel exploitation and phenomena described in the past reappeared. Field measurements were made again, this time using modern data-recording techniques, such as photogrammetry and terrestrial laser scanning. This work has enabled a comparison of field measurement methods with those obtained from the point clouds data. The results were found to be highly consistent. At the same time, precise reconstructions of the structures and their connection to the geodetic reference system make it possible to supplement previous geokinematic interpretations for this segment of the Sudetic Marginal Fault Zone (SMFZ). A formerly postulated left-lateral strike-slip regime in this zone was confirmed during the period of formation of the pre-Kaczawa alluvial fan deposits, but also probable is a kinematic inversion that must have occurred during, or just after, the early Pleistocene. [ABSTRACT FROM AUTHOR]

Allowing the transitory attainment of bearing capacity of caisson foundations supporting bridge piers during strong seismic events can lead to substantial optimisation in their design and major cost savings. If the approach of capacity design is applied to geotechnical systems, the temporary triggering of plastic mechanisms may be permitted if the resulting permanent displacements are smaller than given threshold values. To validate this design approach, the seismic performance of caisson foundations was assessed through dynamic centrifuge testing on reduced-scale models. This paper presents the results of two tests in which a caisson–pier–deck system was embedded in a typical alluvial deposit and subjected to a series of earthquakes of different intensities. The caissons were founded on soft and very soft clay, to either avoid or induce the attainment of plastic soil behaviour under the same seismic inputs. It is shown that both yielding and failure of the layer of very soft clay limit inertial forces transmitted to the superstructure, validating the design approach and some useful empirical relations available in the literature. In contrast, inelastic soil behaviour implies accumulation of permanent rotation and settlement of the system, which must be carefully evaluated to check for fulfilment of performance requirements. [ABSTRACT FROM AUTHOR]

Comprehensive research has been implemented to raise the efficiency of the geochemical survey of stream sediments (SSs) that formed under the cryolithogenesis conditions. The authors analysed the composition, structure and specific features of the formation of exogenous anomalous geochemical fields (AGFs) identified through SSs of large river valleys of IV order. In our case, these were the valleys of Maly Ken, Ken and Tap Rivers. These rivers are located in the central and southern parts of the Balygychan–Sugoy trough enclosed in the Magadan region, North–East of Russia. The authors proposed a new technique to sample loose alluvium of SSs in the large river valleys along the profiles. The profiles were located across the valleys. The AGFs of Au, Ag, Pb, Zn, Sn, Bi, Mo and W were studied. Correlations between elements have been established. These elements are the main indicator elements of Au–Ag, Ag–Pb, Sn–Ag, Mo–W and Sn–W mineralization occurring on the sites under study. The results obtained were compared with the results of geochemical surveys of SSs. It is concluded that the AGFs recognized along the profiles reflect the composition and structure of eroded and drained ore zones, uncover completely and precisely the pattern of element distribution in loose sediments of large water flows. The alluvium fraction < 0.25 mm seems to be most significant in a practical sense, as it concentrated numerous ore elements. Sampling of this fraction in the river valleys of IV order does not cause any difficulty, for this kind of material is plentiful. The developed technique of alluvium sampling within large river valleys is efficient in searching for diverse mineralization at all stages of prognostic prospecting. It is applicable for geochemical survey of SSs performed at different scales both in the North–East of Russia, as well as other regions with similar climatic conditions, where the SSs are formed under the cryolithogenesis conditions. [ABSTRACT FROM AUTHOR]

Lisbon's historical seismicity, socioeconomic importance and population density contribute to a moderate to high seismic risk. The geological setting of the city includes cases of inclined layers, interbedding sedimentary rock layers in soil deposits, sand and clay layers in the same geological unit, leading to cases of shear wave velocity inversion and a large scatter of geotechnical properties within each geological unit. The morphological setting of the city is characterised by the existence of several hills and relatively shallow, stream-carved valleys filled with alluvial deposits. The seismic site effects in Lisbon were assessed through numerical simulation using the linear equivalent method and adopting the two types of seismic action defined in the Portuguese National Annex of Eurocode 8: (i) one-dimensional subsoil models covering the city, at sites where borehole data and geophysical data were available; (ii) two-dimensional subsoil models along three cross-sections representative of the geological settings and morphology. The distribution of amplification factors in the city revealed a pattern related to ground characteristics that impact seismic soil response, such as the presence of high-thickness cover deposits, significant shear-wave variations, alluvial valleys, a crest or significant slope variations and inclined layers. The 2D/1D spectral ratio highlighted the areas were 2D seismic effects are more important. The soil factor determined in the numerical analyses was consistently greater than the soil factor values indicated in Eurocode 8. [ABSTRACT FROM AUTHOR]