Southwestern Slope Research Articles

Prospects for discovery large amber-succinite deposits of in Ukraine

Amber and the deposits are represented by Eocene-Oligocene placers of the coastal-sea and lagoon delta genesis. as practice has shown, they have low industrial grade from 5-10 to 250 g/m3. Few studies have been carried out on the amber of the Dnieper basin. These are the eastern and south-western slopes of the Ukrainian Shield at the juncture of the Dnieper-Donetsk and Black Sea basin.The aim of this work, its scientific and practical significance, is to substantiate the forecast of industrial amber-succinitis placers in Ukraine, which are as good as the Baltic placers, where the concentration of gem per cubic metre is calculated not in grams but in kilograms (up to 2 kg/m3). To carry out this task, the authors conducted expedition work in a number of regions of Ukraine and described sections of boreholes, pits, pits, etc. The authors have processed a large amount of scientific information on the alluvial geology, described and analysed the well sections presented in reports on geological surveys of medium and large scale.The article substantiates the identification and conditions for the accumulation of primary biogenic-sedimentary deposits of the protoamber (primary sources of amber-succinitis placers), age and genesis of placers in the first intermediate reservoirs. The article provides a geological and paleographic analysis of the natural conditions of the Tractor Station and the shallow seas in the Eocene-Early Oligocene. At that time there was an accumulation of tar secretions and their transformation into fossil tars and brand-succinite. The forecast for detection of a new type of buried amber-succinitis placers in Ukraine, which are associated with the remote part of the shelf, fully determines the practical and scientific value of the research conducted by the authors, which is ultimately aimed at improving the quality of amber prospecting and exploration works.Keywords: amber-succinite, prognosis, deposits, fossil resins, placers

Altitudinal and Seasonal Variation in the Structure of Nocturnal Primate Assemblages on Mount Cameroon

Mountain ecosystems cover a large proportion of Earth and represent important environments for a range of different taxa, including nocturnal primates. This group of primates is generally understudied because of their small size and their cryptic and nocturnal nature. Thus, much of their ecology and distribution still remains unknown, especially in mountain ecosystems. We investigated the effects of altitude and seasonality (wet vs. dry season) on observed species richness and relative abundance of nocturnal primates across the diverse forest types of Mount Cameroon. Using standardized line and recce transect methodologies, we surveyed nocturnal primates at four altitudes (650 m.a.s.l., 1100 m.a.s.l., 1450 m.a.s.l., and 2200 m.a.s.l.) on the southwestern slope of the mountain. We recorded six species (four from the Galagidae family and two from the Lorisidae family). Our results indicate a decrease in primate abundance as altitude increases. We also found that primate species composition changes with altitude. However, species diversity (Shannon diversity) drops drastically only at the highest altitude and species richness (number of species) does not differ between sites at lower to mid-altitudes. There was no seasonality effect on primate diversity. Habitat features, such as temperature, resource availability, and vegetation structure likely play a relevant role in the distribution and diversity patterns of primates on Mount Cameroon.

PETROLEUM POTENTIAL OF THE EDIACARAN SUCCESSION RELATED TO GEOLOGICAL AND GEOCHEMICAL CONDITIONS IN THE VOLYN-PODILIAN

This work is concerned with the studying of Ediacaran petroleum potential within Volyn-Podyllian. For the first time ever, the lithostratigraphycal, geological, geothermal, geochemical and paleohistorical analysis was provided for the whole Ediacaran section to determine its petroleum potential.The description of Precambrian succession in the world with its hydrocarbon occurrence was included. In addition to that, this work contains methodology and methods of the basin analysis study, which was perfomed. The potential source rocks, reservoirs and seals within the study area were defined and described.Based on the computer-integrated instruments, for the Neoproterozoic deposits were created: third-dimensional model of its succession, depth map, schematic map of katagenetic zones and concentration model of organic carbon. The paleoconditions of deposition and maturation processes of organic matter were reconstructed. Key words: Ediacaran deposits, Volyn-Podillian, oil-and-gas potential, computer modelling, basin analysis, sedimentary

Runoff‐generated debris flows: Observation of initiation conditions and erosion–deposition dynamics along the channel at Cancia (eastern Italian Alps)

AbstractIn the Dolomitic region, abundant coarse hillslope sediment is commonly found at the toe of rocky cliffs. Ephemeral channels originate where lower permeability bedrock surfaces concentrate surface runoff. Debris flows initiate along such channels following intense rainfall and determine the progressive erosion and deepening of the channels. Sediment recharge mechanisms include rock fall, dry ravel processes and channel‐bank failures. Here we document debris flow activity that took place in an active debris flow basin during the year 2015. The Cancia basin is located on the southwestern slope of Mount Antelao (3264 m a.s.l.) in the dolomitic region of the eastern Italian Alps. The 2.5 km2 basin is incised in dolomitic limestone rocks. The data consist of repeated topographic surveys, distributed rainfall measurements, time‐lapse (2 s) videos of two events and pore pressure measurements in the channel bed. During July and August 2015, two debris flow events occurred, following similarly intense rainstorms. We compared rainfall data to existing rainfall triggering thresholds and simulated the hydrological response of the headwater catchment with a distributed model in order to estimate the total and peak water discharge. Our data clearly illustrate how debris entrainment along the channel is the main contributor to the overall mobilized volume and that erosion is dominant when the channel slope exceeds 16°. Further downstream, sediment accumulation and depletion occurred alternately for the two successive events, indicating that sediment availability along the channel also influences the flow behaviour along the prevailing‐transport reach. The comparison between monitoring data, topographical analysis and hydrological simulation allows the estimation of the average solid concentration of the two events and suggests that debris availability has a significant influence on the debris flow volume. © 2020 John Wiley & Sons, Ltd.

Differences in Fungal Disease Dynamics in Co-occurring Terrestrial and Aquatic Amphibians.

The fungal pathogen, Batrachochytrium dendrobatidis (Bd), has devastated biodiversity and ecosystem health and is implicated as a driver of mass amphibian extinctions. This 100-year study investigates which environmental factors contribute to Bd prevalence in a fully terrestrial species, and determines whether infection patterns differ between a fully terrestrial amphibian and more aquatic host species. We performed a historical survey to quantify Bd prevalence in 1127 Batrachoseps gregarius museum specimens collected from 1920 to 2000, and recent data from 16 contemporary (live-caught) B. gregarius populations from the southwestern slopes of the Sierra Nevada mountains in California, USA. We compared these results to Bd detection rates in 1395 historical and 1033 contemporary specimens from 10 species of anurans and 427 historical Taricha salamander specimens collected throughout the Sierra Nevada mountains. Our results indicate that Bd dynamics in the entirely terrestrial species, B. gregarius, differ from aquatic species in the same region in terms of both seasonal patterns of Bd abundance and in the possible timing of Bd epizootics.

A study of kudurs used by wild animals located on the water sources high in REE content in the Caucasus Nature Reserve

One of the theories explaining the reasons for geophagy, which was proposed earlier by the authors of the article, consists in the assumption that animals need rare-earth elements (REE). In order to test this hypothesis, we studied the chemical composition of spring waters in the territory of the Caucasus Nature Reserve at three kudurs along the Achipsta River, as well as at the Mamaevsky kudur (southwestern slope of the Pshekish mountain). At the Mamaevsky kudur, we also studied the chemical composition of earth consumed by animals, and the species, age and gender composition, seasonal and daily activity of ungulate animals-visitors of the kudur. It was determined that the most active visitors of the Mamaevsky kudur were European bison (Bison bonasus) with one activity peak during the rut, in July. The frequency of visits to the kudur by red deer (Cervus elaphus) was 4 times lower with the highest peak activity in April and a lower peak in August. Only in one of four water sources at the Mamaevsky kudur there was an elevated concentration of Na (by 7 times). In the other three the concentration was comparable to the local river water. The waters of two "sodium-free" springs had increased concentrations of REE (by 5-8 times). Geophagic earths near the Mamaevsky springs are decomposition products of siltstone and sandstone shale rocks of the Jurassic age consisting of clay minerals (illite mixed with smectite, and chlorites)-from 42 to 45%, and quartz and feldspar (in total up to 50%) mixed with Fe and Ca carbonates. The chemical composition of acid extracts (0.1N HCl, pH = 1.0) from consumed earth showed the highest extractability of Ca and Fe. In trace elements, Sr, Ba, Zn, Cu, Ni, Co, V, light lanthanides, and Y are most actively extracted. Na is extracted at 0.03-0.1g/kg. The sodium bicarbonate spring water consumed by animals at kudurs on the Achipsta River had Na contents 70-300 times, and REE contents 25-40 times higher than that in the river water. The revealed facts do not contradict the hypothesis that the desire for geophagy in animals in the Caucasus (in addition to the long-known "urge" for Na) can be also related to the properties of lanthanides group elements exchange in the body.

Scientific substantiation of overcoming of existing ecological problems caused by separate impacts and recreational loads on landscape complexes on the south-western slopes of Azerbaijan (On the example of Sheki-Zakatala zone)

Scientific substantiation of overcoming of existing ecological problems caused by separate impacts and recreational loads on landscape complexes on the south-western slopes of Azerbaijan (On the example of Sheki-Zakatala zone)

Correlation analysis of land surface temperature and topographic elements in Hangzhou, China

In addition to human activities, this study found that topography is also an important factor affecting land surface temperature (LST). In this paper, based on Landsat 8 OLI/TIRS remote sensing images, a radiative transfer model was adopted to retrieve the LST, and a maximum likelihood method was used to remove artificial environmental interference factors, such as water bodies and built-up lands. This paper aims to analyze the influence of topographic factors, such as elevation, slope, aspect and shaded relief, on the LST of Hangzhou. By means of a statistical analysis, we obtained the quantitative relationship between these factors and constructed a multiple linear regression model of terrain factors and LST. The research revealed the following findings: (1) in the study area, elevation and slope are negatively correlated with LST, and all the factors have linear relationships with LST. (2) The relationship between aspect and LST is not significant, and high values of LST are found on the southern, southeastern and southwestern slopes; the lowest values are found on the northern slopes. (3) There is a significant linear relationship between the values of the shaded relief map and LST, and the more shadows there are, the lower the LST value will be. (4) After comprehensive analysis of the influence of the abovementioned topographic factors on the LST, it is found that shaded relief has the greatest contribution and is positively correlated with LST. The influence of shaded relief on surface thermal environment should be paid more attention in the process of surface thermal environment work. The assessment of the influence degree of shaded relief and surface thermal environment should be the premise and basis for many other studies.

Habitat preference and spatial distribution model of threatened species Saurauia microphylla in Mt. Slamet, Central Java, Indonesia

Abstract. Helmanto H, Nisyawati, Robiansyah I, Zulkarnaen RN, Fikriyya N. 2020. Habitat preference and spatial distribution model of threatened species Saurauia microphylla in Mt. Slamet, Central Java, Indonesia. Biodiversitas 21: 2946-2954. Saurauia microphylla de Vriese has the potentials for medicinal uses, yet it is listed in the IUCN Red List under Vulnerable status. The natural population of this species is only found in highlands one of which is in Mount Slamet, Central Java, Indonesia. This study aims to determine the population structure, habitat preference and predicted spatial distribution of S. microphylla in the Mount Slamet area. The method used was purposive sampling by establishing 103 observation plots with size of 20x20 m2 for each plot. The research parameters recorded were abiotic variables and biotic associations. Data were analyzed using Principal Component Analysis (PCA) to determine the most influencing environmental factors on the presence of S. microphylla. Species association of S. microphylla was analyzed using the Jaccard index equation. Spatial distribution model was analyzed using Maxent (Maximum Entropy) software. The results showed that S. microphylla populations were found in highland forest areas with elevations of 1689-2265 m above sea level, slope of 3-40°, temperature of 16°-26°C, air humidity of 49.3-90%, soil pH 5.8-7, soil moisture 5-70% and canopy cover of 0-92%. Our analyses revealed that elevation is the most influential factor in the presence of S. microphylla. There are 20 tree species which found around S. microphylla habitat with 4 species have significant association with the species. The spatial distribution model showed that S. microphylla spread across all the slopes of Mount Slamet with the southwestern slope was predicted had the most extensive habitat suitability for the species and become smaller to the north, east, and south slopes.

Occurrence of active gas hydrate mounds in the southwestern slope of the Chukchi Plateau, Arctic Ocean

Occurrence of active gas hydrate mounds in the southwestern slope of the Chukchi Plateau, Arctic Ocean

A new species of Mathania Oberthür, 1890 from Peru (Lepidoptera, Pieridae).

A new species of the genus Mathania Oberthür, 1890, M. hughesi Lamas, Farfán Cerdeña, sp. n. is described from the southwestern slopes of the Andes of Peru, associated with xerophytic environments, between 2300 and 3500 m elevation. This new species is distinguishable from its congeners by the following external character: a black band on forewing dorsal surface at the end of the discal cell, extending from the costal margin to the base of cell M3-CuA1. Adults and male and female genitalia are illustrated and compared to other species of Mathania. In addition, we report Ligaria cuneifolia (R. et P.) Tiegh. (Loranthaceae) as host plant of M. hughesi.

Scientific Substantiation of Overcoming of Existing Ecological Problems Caused By Separate Impacts and Recreational Loads on Landscape Complexes on the South-Western Slopes of Azerbaijan(on the Example of Sheki-Zakatala Zone)

Scientific Substantiation of Overcoming of Existing Ecological Problems Caused By Separate Impacts and Recreational Loads on Landscape Complexes on the South-Western Slopes of Azerbaijan(on the Example of Sheki-Zakatala Zone)

Topographic Rainfall of Tropical Cyclones past a Mountain Range as Categorized by Idealized Simulations

Abstract Topographic rainfall induced by westbound tropical cyclones past an island mountain is investigated using an idealized Weather Research and Forecasting (WRF) Model. Idealized simulations with varying vortex core size R (100–250 km), vortex intensity Vmax (20–35 m s−1), and steering wind speed U (4–10 m s−1) are conducted. The results show that the geometric distributions of major rainfall over the island are not greatly sensitive to cloud microphysics schemes using either single momentum or double momentum. Major rainfall is produced over northeastern and southwestern slopes of the mountain for smaller U. As U is doubled, the rainfall, however, is considerably weakened or is present only over southwestern slopes. For smaller U, a bifurcation of island rainfall with a sudden change in intensity or geometric shifting exists within a tiny range of R or Vmax. When the bifurcation occurs with small track deviations, geometric distributions of major rainfall are also more sensitive to cloud microphysics schemes. Such formation of bifurcation or double-peak rainfall, however, is significantly reduced when the terrain size is doubled. Systematic experiments are conducted to relate the topographical rainfalls over the northern half, southern half, and the whole of the mountain slopes to varying R, Vmax, and U. Larger U tends to produce much larger southern rainfall than northern rainfall. The average and maximum rainfalls generally increase with increased Vmax, except for large R. The decrease of average rainfall and maximum rainfall with increased U is more evident for smaller R, while not necessarily true for larger R.

Reassessing Initial Village Period Settlements in the Upper Khuzestan Plain

Reassessing Initial Village Period Settlements in the Upper Khuzestan Plain

Deforestation Processes in the Polish Mountains in the Context of Terrain Topography

In the 1980s, the Western Sudety Mountains were affected by a forest dieback process, resulting in large-scale deforestation covering an area of about 15,000 ha. A similar phenomenon is presently being observed in the Western Beskidy and Eastern Sudety Mountains, where the course of the process and the final effects are similar. The presented study analyzed the relationships between forest dieback processes today and in the past. Among others, the impact of the following factors was examined: exposure, slope, altitude, and topographic index, which was generated based on the airborne LIDAR (also airborne laser scanning abbreviated as ALS) data. The identification of forest dieback areas in the past was carried out based on the archived Landsat satellite imagery, as well as data obtained from the Polish State Forests. The identification of forest dieback areas at present was carried out based on the ALS data (single-tree detection approach) and color infrared aerial images. In the study, inter-dependencies between forest dieback today and in the past were compared. The performed analyses show significant differences between forests’ dieback specifics in all three areas. The process first occurred at 800–900 m a.s.l., and afterwards at over 900 m. Mortality was especially intensive on the western and southwestern slopes. Below 700 m a.s.l., forests survived quite well. In the 1980s, significantly higher concentrations of hazardous chemical compounds were noted, which resulted in respectively greater deforestations on aspects open to the operation of prevailing winds (mainly west). Nowadays, a proportionately higher number of trees die on the southern aspects, which is particularly visible in the Western Sudety Mountains.

Does caching strategy vary with microclimate in endangered Mt. Graham red squirrels?

Food hoarding is a common behavior used by a variety of animals to cope with periods of low food availability. At the retreating edge of species' distribution, the stressful environment and unfavourable climate conditions may impose severe costs on hoarding behavior. Since relict populations are hotspots for evolution and adaptation, and considering that food hoarding behavior has a strong evolutionary basis, we decided to evaluate the occurrence of behavioral variability in the amount of food cached by the endangered Mount Graham red squirrel (Tamiasciurus fremonti grahamensis). We tested the variation in cache size in response to microclimate, soil relief, vegetation, food availability and squirrel sex. The number of pits excavated by squirrels to cache cones was used as a proxy of cache size and was affected by mountain slope aspect and density of trees. More pits were excavated in the northeast facing slopes. The density of trees negatively affects the cache volume on southwest slopes, but not on northeast slopes. The sex of the resident squirrel also affects the number of pits in the squirrel midden, with males excavating 47% more pits than females. Males and females also presented different responses to the mountain slope aspect, with females excavating more pits on northeastern slopes than on southwestern slopes, whereas male cache size did not vary with the slope aspect. Finally, the squirrel's caching behavior did not vary in response to midden microclimate variation, a result with possible implications for the survival of the Mt Graham red squirrels, given the predicted temperature increases in the region due to climate change.

Assessing spatial and temporal patterns of canopy decline across a diverse montane landscape in the Klamath Mountains, CA, USA using a 30-year Landsat time series

Tree mortality is of considerable concern, but the magnitude and extent of forest canopy decline are relatively unknown in landscapes with high levels of topographic complexity, spatial heterogeneity, and species diversity. We assessed 30 years of canopy decline, including a 5-year period characterized by extreme drought, in one of North America’s most diverse landscapes in the Klamath Mountains of northern California, USA. (1) Characterize tree mortality by species, (2) Quantify temporal and spatial patterns of remotely-sensed canopy decline in relation to climate, (3) Compare canopy decline among vegetation types, topographic settings, and stand structural classes during drought. We characterized tree mortality by species with field data and quantified the role of climate on canopy decline with a 30-year Landsat time series. We assessed and compared the role of topography and stand structure on canopy decline during drought. Most tree mortality and canopy decline occurred at higher elevations in Shasta red fir (Abies magnifica var. shastensis) and subalpine forests. Annual area of canopy decline was positively correlated with summer temperature and minimum vapor pressure deficit but not precipitation. The area of canopy decline was three times greater during the drought. The magnitude of decline was greatest at higher elevations, on more exposed, southwestern slopes, and in stands with old-growth structure. Stands in valleys and low slopes experienced relatively little decline. Our study demonstrates the vulnerability of high elevation, old-growth forests to increasing temperature and suggests the potential for refugia from drought in diverse, heterogeneous landscapes.

Synchronous Changes in Sediment Transport and Provenance at the Iceland‐Faroe Ridge Linked to Millennial Climate Variability From 55 to 6 ka BP

AbstractUnique marine sediment cores retrieved from the southwestern slope of the Iceland‐Faroe Ridge (IFR), close to the main axis of the Iceland‐Scotland Overflow Water (ISOW), revealed prominent sedimentary cycles reflecting near‐bottom current dynamics, sediment transport, and deposition, coincident with Dansgaard‐Oeschger cycles and deglacial perturbations of the Atlantic Meridional Overturning Circulation. The transition between Greenland Stadials (GSs) and Greenland Interstadials (GIs) follows a distinct, recurring sedimentation pattern. Basaltic (Ti‐rich) silts were transported from local volcanic sources by strong bottom currents and deposited during GIs comparable to modern ocean circulation. Finer‐grained felsic (K‐rich) sediments were deposited during GSs, when Iceland‐Scotland Overflow was weak. Possible felsic source areas include British‐Ireland and/or Fennoscandian shelf areas. A cyclic sawtooth pattern of bottom current strength is characterized by gradual intensification during GIs followed by a sharp decline toward GSs as is documented at core sites along the flank of Reykjanes Ridge. The cores north of the Faroe Channel instead document the opposite pattern. This suggests that the near‐bottom currents along the Reykjanes Ridge are strongly controlled by the flow cascading over the IFR. Heinrich‐(like) HS‐1 and HS‐2, are characterized by the deposition of very fine felsic sediments pointing to weakened bottom currents. Distinct coarse‐grained intervals of ice‐rafted debris are absent from the sediment records, although pebble‐ and gravel‐sized ice‐rafted debris is irregularly distributed throughout the fine sediment matrix. Near‐bottom currents are considered to have a major control on the lithogenic sediment deposition southwest of the IFR and further downstream.

Morphometric Features of the Submarine Slope of the Southwestern Part of Valaam Island

A digital bathymetric model with a 10 × 10 m spatial resolution was created on the basis of the depth sounding on the southwestern slope of Valaam Island with the use of an echo sounder combined with a side-scanning sonar and satellite navigation system. Bottom slopes with 60-degree value, where there are rock structures barely overlapped by recent bottom deposits, were registered. Large boulders and slide rocks, which can cause underwater noise in sliding down along steep slopes, were revealed.

Sequence architecture and depositional evolution of the late Palaeogene in southwestern slope of Lufeng Depression, Pearl River Mouth Basin: Responses to tectonic processes and base‐level changes

The southwestern slope of Lufeng Depression, which is located in the central part of Zhu I Depression is a significant geomorphic unit due to its petroliferous discoveries and tectonic evolutions since early Palaeogene. Based on the comprehensive analysis of cores, wireline logs, seismic volumes, and other related geological and geophysical information, the sequence architecture and depositional evolution was analysed, and their responses to regional tectonic processes and base‐level changes were revealed. The results indicated that two second‐order sequences and six third‐order sequences defined by different types of sequence boundaries are recognized. The second‐order and third‐order sequences were bounded by regional erosional unconformities on the depression margin or slope and unconformities in the central depression with the assist of stacking patterns of wireline logs and depositional characteristics of cores. The second‐order sequence generally consists of two regional transgressive–regressive cycles which can be further subdivided into several local sub‐cycles equivalent to corresponding third‐order sequences which can be identified from wireline logs and cores. The palaeogeomorphology resulted from compound and complex tectonic events in the early Palaeogene plays an important and main role in controlling sequence architecture. In contrast, the base‐level changes largely controls the sequence architecture in the late Palaeogene. The depositional systems within the sequence stratigraphic framework are mainly composed of braided delta deposits and shore deposits, which respectively includes braided channel, subaqueous distributary channel, lacustrine shale, beach bar, maximum flooding surface, shoreface, and foreshore. The base‐level changes, which apparently originated from tectonic uplift and subsidence and sediment supply, controlled the regional transgressions and regressions in sedimentary facies distributions. The development of subsequence (what we call it sand units or sections) from 2,980 to 2,880 in Enping Formation in the Early Palaeogene is obviously influenced by a decrease in tectonic subsidence (rifting stage) and an increase in accommodation space (base‐level rising), while the case is opposite in subsequence 2,850 of Enping Formation. However, the subsequence in Zhuhai Formation in the late Palaeogene from 2,760 to 2,600 was formed in stable tectonic settings (transition stage), and thereby, it was mainly dominated by base‐level changes which were caused by sediment supply and accommodation space changes.