Western Side Research Articles

L’hospitalité langagière, point critique de la philosophie comparée entre la Chine et l’Europe

The history of the philosophical exchanges between China and the West is the history of the translations between the two traditions. On the western side, after the Jesuits, the range of translators became gradually broader. On the Chinese side, many intellectuals introduced Western classics in their language in the twentieth century. This led several historians to argue that Chinese philosophy took off with the translation-comparison of both traditions. However, not all comparisons are of equal value. Thus, translation in philosophy implies comparing concepts or arguments and considering all the cultural references involved. This means taking a risk and accepting a limit. A risk is to be taken because translating interprets a “foreign thought” according to one’s context. This implies disclosing one’s presuppositions. There is a limit because transitioning from one set of references to another implies welcoming a part of “untranslatable” that always remains. According to Ricoeur’s words, “linguistic hospitality” is required here. This article first presents two interpretations of the translation-comparison processes. In the last part, it describes the necessity of linguistic hospitality in the context of Comparative Philosophy.

Sequence stratigraphy and reservoir characterization of the lower Eocene rocks (Thebes Formation) along the Tethyan Ocean's southern margin: biostratigraphy and petrophysical parameter applications

The Egyptian lower Eocene carbonate rocks (Thebes Formation) are part of an extensive carbonate platform formed during an eustatic regression along the Tethyan Ocean's southern margin. These rocks are essential in developing Egypt's petroleum system because they can operate as vertical seals in specific basins or as source-reservoir rocks. However, few in-depth studies have been conducted to explore the diagenetic history, pore system, petrophysical characteristics, and sequence stratigraphic framework of these rocks and its relationship to the global sequences. Multiple datasets (foraminiferal assemblages, petrographic, and petrophysical data) from the lower Eocene strata exposed in Wadi El-Dakhl and El-Sheikh Fadl sections on the western side of the Gulf of Suez were integrated. The biostratigraphic examination of the planktic foraminifera shows that three Eocene biozones (E5–E7) were identified in the studied successions. The reservoir quality index and the flow zone indicator show that reservoir quality ranges from poor to fair and good. The primary reservoir porosity was resulted from diagenetic processes, including dissolution, fracturing, and meteoric diagenesis, which enhanced reservoir quality. The inferred benthic foraminifera and petrographic studies indicate a shallowing upward trend and deposition in fluctuating settings ranging from upper slope to middle shelf. This progressive reduction in the relative sea level corresponds to a gradual eustatic decline and demonstrates the enhanced control of tectonic activity and eustasy. Consequently, the Thebes Formation was deposited due to Tethyan sea-level changes, and its pore system was influenced by tectonics associated with the Syrian Arc system and Gulf of Suez rifting.

Time-varying solar radiation-induced non-uniform temperature distribution of steel-concrete composite box girder-ballastless track system

Aiming to investigate the non-uniform temperature distribution of the steel-concrete composite box girder-ballastless track system induced by the time-varying solar radiation, the ray-tracing algorithm was used to calculate the environmental parameters. The segment finite element model (SFEM) for spatial interaction between the bridge and the ballastless track was used to perform several numerical simulations. The temperature variation induced by solar radiation was evaluated based on the numerical simulations. The results showed that the peak temperature of the system (on the western side of the steel web) was 49.59 Co (at 16:00). Regarding time-varying solar temperature distribution of the steel-concrete composite box girder-ballastless track system, a difference was found between the western and eastern sides of the steel webs. Finally, the vertical temperature gradient model of the steel-concrete composite box girder-ballastless track system was established according to the most unfavorable temperature. The results provided a reference for constructing and maintaining a steel-concrete composite box girder equipped with the ballastless track.

Spatiotemporal Characteristics and Hazard Assessments of Maize (Zea mays L.) Drought and Waterlogging: A Case Study in Songliao Plain of China

The Songliao Plain is the largest maize (Zea mays L.) cropland area in China and, thus, is most influenced by water stress. To mitigate the adverse impact of water stress on maize yield and quality, various agricultural irrigation strategies have been implemented. Based on land surface temperature and an enhanced vegetation index, this study constructed the temperature vegetation dryness index (TVDI) and combined the Hurst index and Sen trend to analyze the spatiotemporal characteristics of drought and waterlogging. From the correlation between TVDI and gross primary productivity, the weight coefficients of different growth cycles of maize were derived to determine the drought and waterlogging stresses on maize in Songliao Plain for 2000–2020. The drought hazard on the western side of Songliao Plain was high in the west and low in the east, whereas the waterlogging hazard was high in the east. Waterlogging likely persisted according to the spatiotemporal trends and patterns of drought and waterlogging. During the second growth cycle, maize was most severely affected by water stress. There was a spatial heterogeneity in the severity of the hazards and the stress degree of maize. For the reason that precipitation in the study area was concentrated between mid-late July and early August, maize was susceptible to drought stress during the first two growth stages. Irrigation concentrated in the early and middle stages of maize growth and development in the western part of the Songliao Plain reduced the drought stress-induced damage. Spatiotemporally-detected drought and waterlogging couplings and hazards for maize in the Songliao Plain for 2000–2020 provide actionable insights into the prevention and mitigation of such disasters and the implementation of water-saving irrigation practices at the regional scale.

Phylogeographic investigation of the bladder grasshopper Bullacris unicolor (Orthoptera Pneumoroidea) in South Africa

There are several factors, such as genetic drift, gene flow and migration that affect the population genetic structure and phylogeographic distribution of genetic lineages within single species. Previous studies of the bladder grasshoppers, Bullacris unicolor of South Africa, showed divergence in mitochondrial CO1 (cytochrome c oxidase subunit 1) haplotype diversity and significant genetic structure. In this study, we revisit these findings adding more samples from different locations and using mitochondrial CO1 and Internal transcribed spacer (ITS) gene sequences. We tested the hypothesis that the western, northern and eastern distribution ranges of B. unicolor show different population genetic patterns, corresponding with isolation-by-distance. Mitochondrial CO1 and ITS data were collected for 99 individuals from 12 localities across the Western, Northern and Eastern sides of South Africa. Overall, significant variation in genetic structure was found across the localities as indicated by F ST analyses. Haplotype and phylogeographical analyses suggested that restricted gene flow played a role in shaping current genetic patterns, although isolation-by-distance was not supported, as confirmed by Mantel tests. Phylogenetic trees of both genetic sequences revealed two major clades, with western and northern sides. Also, the major clades exhibit a few sub-clades within the localities, showing other factors shaping the genetic structure of B. unicolor include the geographical barriers, and most likely due to changes in habitat specificity and habitat fragmentation. Taken together, this study aims to contribute information on the population structure and genetic diversity of B. unicolor populations across South Africa.

Spatial and temporal effects on the value of ecosystem services in arid and semi-arid mountain areas—A case study from Helan Mountain in Ningxia, China

In the context of global warming and the continued increase in greenhouse gas emissions, the expansion of the global arid and semi-arid zones will accelerate, and there will be a risk of further land degradation. Changes in land use are one of the human activities that cause the increase in CO2 concentration in the global atmosphere. This article takes Helan Mountain as the research object which is located in the arid and semi-arid regions. It analyzes the spatial and temporal effects of land use changes, ecosystem service value, and ecological risk of land use in Helan Mountain by using GIS technology and five periods of land use data in 2000, 2005, 2010, 2015, and 2020. The study results show the following: First, due to land use changes in the arid and semi-arid zones, grasslands lost the largest area (in total 50,407.11 ha) during the study period. Construction land is the highest dynamic land type that increased by 22,364.73 ha. Land use generally shows a trend of increasing before decreasing, with an inevitable increase in the degree of utilization. Second, the total ecosystem service value decreased by 0.1148 million yuan from 5,674.5490 to 5,674.6638 million yuan, which shows a slight change in the overall ecosystem service value. Third, the ecological risk of land use could be divided into five classes, with a transformation characteristic from high and low ecological risk to comparatively high, medium, and comparatively low ecological risk. Fourth, the western side of Helan Mountain is the principal supply area for ecosystem services in the entire study area, which is an area with high-grade ecological risk at the same time. The vulnerability and importance of this area need to be given high priority. This study will provide spatial guidelines for the protection and restoration of ecological security issues such as environmental damage and land degradation in the arid and semi-arid regions of the mountains.

Climate change during the last deglaciation at central equatorial African mountains

The “inverse modelling through iterative forward modelling” (IMIFM) approach is used to reconstruct the last deglaciation climates from central equatorial African mountains. Unlike other approaches that use statistical models, it directly incorporates the effects of changes in atmospheric CO2 concentrations on vegetation through a process-based vegetation model, but the results strongly depend on the model used. Therefore, two generally related but different equilibrium vegetation models are used for evaluating the dependence of the results on the choice of vegetation model. Our climate reconstructions show that long-term temperature increases during the last deglaciation, as seen in Greenland, were absent from many of the target sites. Moreover, there are few common long-term trends of climatic responses during the last deglaciation among central equatorial African mountains’ sites despite the relatively close of those sites. No systematic climate responses were also found between the eastern and western sides of the Congo basin. While there is consistency in the long-term trends and their amplitudes regarding temperature reconstructions with both models, there are large differences between the sites in the long-term hydroclimatic reconstructions, particularly during arid periods. This difference may be attributed to the carbon-water use efficiency in the vegetation models. This study implies that the IMIFM approach is effective for climate reconstructions in equatorial African mountains, where modern pollen samples are not plentiful. Although low atmospheric CO2 concentrations do not largely influence temperature reconstructions for the last deglaciation, they significantly affect the hydroclimate reconstructions, especially when drought-tolerant biomes are dominant.

Extremely hot East Asia and flooding western South Asia in the summer of 2022 tied to reversed flow over Tibetan Plateau

In the summer (July and August) of 2022, unprecedented heat wave occurred along the Yangtze River Valley (YRV) over East Asia while unprecedented flood occurred over western South Asia (WSA), which are located on the eastern and western sides of Tibetan Plateau (TP). Here, by analyzing the interannual variability based on observational and reanalysis data, we show evidences that the anomalous zonal flow over subtropical Tibetan Plateau (TP) explains a major fraction the extreme events occurred in 2022. As isentropic surfaces incline eastward (westward) with altitude on the eastern (western) side of the warm center over TP in summer, anomalous easterly (westerly) flow in upper troposphere generates anomalous descent (ascent) on the eastern side of TP and anomalous ascent (descent) on the western side of TP via isentropic gliding. The anomalous easterly flow is extremely strong to reverse the climatological westerly flow over subtropical TP in 1994, 2006, 2013 and 2022. The easterly flow in 2022 is the strongest since 1979, and it generates unprecedented descent (ascent) anomaly on the eastern (western) side of TP, leading to extreme heat wave over YRV and extreme flood over WSA in 2022. The anomalously strong easterly flow over subtropical TP in 2022 is dominated by atmospheric internal variability related to mid-latitude wave train, while the cold sea surface temperature anomaly over the tropical Indian Ocean increases the probability of a reversed zonal flow over TP by reducing the meridional gradient of tropospheric temperature.

Postglacial fluctuations of western outlet glaciers of the Southern Patagonian Icefield reconstructed from fjord sediments (Chile, 50°S)

Postglacial fluctuations of Southern Patagonian Icefield (SPI) glaciers are well constrained on the leeward side of the Andes, but they remain mostly unknown on the windward side of the icefield, where most glaciers are marine-terminating. Here, we reconstruct the postglacial fluctuations of the HPS19, Penguin, and Europa glaciers along the hyperhumid western side of the SPI using a multi-proxy sedimentological and geochemical analysis of a 12.2 m long sediment core from Wide Channel (50°S). Results show that the glaciers retreated into Penguin and Europa fjords by 11.2 cal kyr BP and that they were relatively stable and marine-terminating between 11.2 and 5.8 cal kyr BP. Thereafter, they fluctuated rapidly, with four marked episodes of glacier shrinkage at 5.8–4.8, 3.9–2.4, 1.0–0.2 cal kyr BP, and during the 20th century. Although the HPS19, Penguin, and Europa glaciers were calving into Penguin and Europa fjords during most of the Holocene, our data suggest that they retreated to land-based positions between 5.8 and 4.8 cal kyr BP. The comparison of our sediment record with geological archives from both sides of the Patagonian icefields (46°–56°S) suggests synchronous glacier variability on multi-centennial timescales during the Neoglacial period, which is particularly clear after 2.5 cal kyr BP. We conclude that western SPI outlet glaciers remained relatively stable during the first half of the Holocene but fluctuated considerably during the Neoglacial period, and that they retreated to locations further inland than today during the first retreat of the Neoglacial period between 5.8 and 4.8 cal kyr BP.

Effect of the Grijalva-Usumacinta system on the circulation adjacent to the eastern shelf of Yucatan

Turbidity is a good indicator to determine the quality of the water; it is a measure of the number of particles in suspension in the water. Using ocean color data, we analyzed the seasonal variability of turbidity in front of the Campeche Bank and part of the confluence zone of the coastal currents coming from the Tamaulipas-Veracruz and Campeche platforms [94°W-87.6°W and 18°N-24°N]. The extended platform has several river discharges that are strongly influenced by winds and the loop current coming from the Strait of Yucatan. 2003-2020 was analyzed using satellite images (reflectance, Chlorophyll, sea surface temperature, and altimetry), reanalyzed winds and discharges from the grijalva-usumacinta river system. We used seasonal climatologies, Hovmoller diagrams, and Orthogonal and Complex Empirical Functions to describe the data. In addition, through the “Coastal and Regional Ocean Community model-CROCO) the surface fields of Salinity and velocity were incorporated into the analysis. The results indicated that the seasonal turbidity and its intensification in autumn and winter on the western side of the Campeche platform are due mainly to the contribution of intense flows from the Grijalva-Usumacinta which is further dynamically mix in autumn by the southwest winds, the cyclonic gyres, and the return currents. In spring-summer, the same forcing persists; however, the turbidity decreases due to the ineffectiveness of the intense zonal winds to produce Ekman transport.

БРЕКЧІЇ ОБРУШЕННЯ – "НОВИЙ" ТИП ТЕХНОГЕННИХ ГЕОЛОГІЧНИХ УТВОРЕНЬ/ТІЛ/РОДОВИЩ КРИВОРІЗЬКОГО ЗАЛІЗОРУДНОГО БАСЕЙНУ

On the basis of geological mapping, structural, mineralogical, petrographic, geochemical, petrophysical studies in the Pivdennyi and Pivnichnyi iron ore quarries of the Saksahansk district of the Kryvyi Rih iron ore basin (Kryvbas), a "new" morphological and genetic type of anthropogenic formations – collapse breccias formed as a result of rock masses displacement over underground mining zones – has been identified. These breccias make up huge volumes within the quarries, forming virtually new large-scale anthropogenic geological bodies with morphology, material composition and physical properties that differ from the original parent rocks. They occupy almost 100 % of the axial areas of the quarries, as well as significant volumes of their western ("hanging") sides. Together with the remnants of ferruginous quartzite and rich ore leftover from underground mining, they are the subject of modern industrial mining. Breccia collapses are new anthropogenic geological rocks. Genetically and morphologically, they fully correspond to the essence of anthropogenic formations and it is quite legitimate to apply the conceptual and legal framework of anthropogenic deposits to them in case of their economically feasible extraction, just as it is generally recognised for bulk dumps and sludge dumps. All this raises the question of the relevance of including these formations in the modern classifications of anthropogenic deposits of Kryvbas as a separate type.

Использование вероятностно-статистических методов для анализа формирования генерационного потенциала глубокопогруженных отложений Верхнепечорской впадины

The Upper Pechora Basin is located in the north of the Pre-Ural foredeep. The structure of the upper horizons of the sedimentary cover is well studied, but there is a poor information about deeply buried sediments confined to the eastern side of the depression. Therefore, modeling of the formation of oil and gas potential of great depths is of interest. In this paper, the problem is solved by applying probabilistic and statistical methods. The values of the total generation potential, the concentration of organic carbon, the rate of burial, the depth and the thickness of the layers were used for the analysis. In addition, since the Upper Pechora Basin is characterized by a sharply asymmetric structure, it was divided into two tectonic zones: the western (outer slope) and the eastern (inner slope). As a result, fundamental differences have been established in the conditions of generation potential formation for the studied types of organic matter and tectonic zones. Comparison of the average values of generation potential and the factors influencing its formation showed the presence of statistical differences between the types of kerogen in the deeply buried sediments of the Upper Pechora Basin, as well as between tectonic zones. Correlation analysis has determined that both positive and negative relationships with varying degrees of closeness are observed between the studied indicators. Using linear discriminant analysis, it was determined that sapropel and humus organic matter are separated quite clearly, and the mixed type practically does not stand out according to the specified characteristics, it was also revealed that the separation occurs on a tectonic basis. A step-by-step regression analysis for each of the parameters under consideration, carried out for these types of kerogen separately, confirmed a significant difference in the accumulation processes of sapropel and humus types of kerogen, as well as the western and outer sides of the depression. Thus, the conducted probabilistic and statistical analysis showed the regulatory role of tectonic factors in the processes of generation potential formation.

Causes of the Record-breaking Drought in Taiwan in 2020-2021

<p>2020年梅雨季提早結束，夏季沒有侵臺颱風，秋冬季雨量亦明顯偏少，2021年春雨也是寥寥可數，就在水庫快要見底之際，望眼欲穿的梅雨終於在5月底到來，臺灣旱象才得以逐漸緩解。此次旱災除在經濟上有許多損失外，亦對民眾生活造成諸多不便，值得深入了解形成旱象的物理機制。</p> <p>統計2020年6月至2021年5月的臺灣雨量，達到1910年有紀錄以來的最少，堪稱為百年大旱。本報告分析此段期間的大尺度環流，推測造成臺灣百年大旱的可能原因，並歸納主要發現如下：①2020年6月至9月的少雨，主要是極端偏強的副熱帶高壓造成，當時的副高不僅在強度上達到最強，持續時間亦為1949年之後的最持久；副高偏強可能與熱帶各洋面同時出現海溫異常有關，包含反聖嬰在中東太平洋的偏冷、印度洋及大西洋的偏暖。②臺灣2020年秋冬季雨量偏少，可能與反聖嬰及菲律賓海偏暖有關。③2021年臺灣春雨偏少，主因應該是菲律賓海溫偏暖，其次為逐漸減弱的反聖嬰，負相位的太平洋年代際震盪亦有少許的貢獻；當菲律賓海偏暖時，會在其西側產生氣旋式環流，為臺灣及東亞沿岸帶來水氣較少的東北風距平，進一步造成臺灣春雨較少；反聖嬰有利上述偶合系統的維持。④2021年3月中旬至5月期間的熱帶季內振盪較為活躍，季內振盪可能使臺灣4月中下旬的西南水氣源減少，5月季內振盪乾區逐漸接近臺灣，進而造成臺灣少雨。簡而言之，2020-2021年的臺灣百年大旱不是單一因素造成的極端事件，而是許多因素同時出現的複合現象。</p> <p> </p><p>During 2020, an earlier-ended Mei-Yu season combined with a typhoon-absent summer, followed by notably low rainfall from following autumn to spring in 2021, Taiwan’s accumulated rainfall from June 2020 to May 2021 broke the lowest record since 1910, we report the unique characteristics and physical mechanism of this extreme event.</p> <p>The possible causes of the drought event are presented as follows. ①The duration and strength of subtropical high over the Western North Pacific from Jun to September were the longest and strongest since 1949. The abnormal subtropical high maybe caused by the compounding effects from cool sea surface temperature (SST) over the central to eastern equatorial Pacific associated with La Niña, and warm SST in the northern Indian Ocean and the tropical Atlantic. ②The warmest SST appeared in the Philippine Sea through October 2020 to Marth 2021, concurrent with La Niña, generated the dry condition near Taiwan. ③ The less spring rainfall in Taiwan in 2021 could be directly attributed to the warmest SST in the Philippine Sea and indirectly to the weakening La Niña , whereas negative phase of the Pacific Decadal Oscillation seemed to have little effect. An anomalous cyclone usually appeared in the western side of the warm Philippine Sea and brought dry northeasterly anomaly to the East Asian coast, resulting in less spring rainfall in Taiwan, and the La Niña would favor and maintain this atmosphere-ocean coupled system. ④ In April-May 2021, active tropical intra-seasonal oscillation caused weaker moist southeasterly in middle to late April, and also resulted in dry condition before the end of May.</p> <p>In conclusion, the most serious drought event in 2020-2021 since 1910 was caused by the compounding effect from various influencing factors that occurred concurrently and sequentially. How much of these abnormal conditions were caused by the warming trend in recent decades, which is not investigated in this study, warrants further studies.</p> <p> </p>

Discovery of New Hydrothermal Ore Fields “Korallovoe” (13°07′ N) and “Molodezhnoe” (13°09′ N) in the Middle Atlantic Ridge

During the 41th scientific cruise of the R/V “Professor Logachev” in 2019, two new ore fields were discovered within the Russian exploration area of the Mid-Atlantic Ridge. The “Korallovoye” ore field is located in the middle part of the rift valley ridge and lies on a gentle slope in the depth range of 2800–2850 m. The “Molodezhnoye” ore field is located at a distance of approximately 5 km northeast of the “Korallovoye” field and lies on a less steeper section of the slope between 3500 and 3550 m in depth. The “Korallovoye” and “Molodezhnoye” fields are confined to the outcrop of a gabbro-peridotite massif on the western side of the Mid-Atlantic Rift valley. The total number of discovered ore fields in the Russian exploration area has been increased to 14 sites.

Дистанционное слежение за орланами-белохвостами из Забайкалья, Россия: миграция, зимовка, летнее пребывание

Дистанционное слежение за орланами-белохвостами из Забайкалья, Россия: миграция, зимовка, летнее пребывание

Ethnobotanical Uses, Phytochemistry, Biological Potential and Structural Modification of Himachalane Present in Cedrus deodara

Cedrus deodara, often known as “deodara,” is native to the Western side of the Himalayas. It is a medicinal herb, with a wide range of pharmacological activities that have proven to be beneficial in treating various health problems. The demand for essential oils is growing at a rapid pace. The leaves and wood of Cedrus deodara contain a variety of essential oils. The three components are α-himachalene, β-himachalene and γ-himachalene. Cedrus deodara essential oils have more applications, particularly in stress-related diseases. The main purpose is to collect and report all the essential information about various Himachalene in Cedrus deodara. An exhaustive literature search was undertaken to construct this study, utilizing linked publications published in various journals. This mini review’s findings compile the chemical modification and synthesis of different Himachalene in Cedrus deodara. This study brings together and gives an up-to-date evaluation of important sesquiterpenes isolated from cedar essential oil, a family of plentiful and accessible natural materials.

Age and Origin of Fluvial Deposits in the Vistula River Valley Near Tarnobrzeg (Sandomierz Basin, Poland): Insights from Sediment Dating and Analysis

Abstract The present research aimed to determine the age and origin of a 4-m sequence of fluvial deposits located in Siedleszczany on the western side of the Tarnobrzeg Monadnock in the Vistula River valley. Initially, these deposits were thought to be sediments of the overflood (Vistulian) terrace. The study revealed that the sand deposits are relatively young Late Holocene sediments, spanning from the 8th century AD to the 15th–16th centuries AD, and the organic material originated from erosion of older Holocene deposits of various ages. This finding was supported by palynological analysis, which identified, besides Holocene pollen grains, also those from Late Glacial and other Quaternary periods, and even from pre-Quaternary ones. Extreme floods in the Vistula valley may be specified as the origin of the sandy sediments in Siedleszczany. Similar large floods occurred in the past when ice jams blocked the main riverbed, leading to the formation of overflow channels. These floods caused rapid erosion of the flood-plain and deposition of sandy sediments in the sheltered marginal areas of the valley, away from high-velocity flood flows. As a result, the fluvial deposits in Siedleszczany, in the Vistula valley, resemble palaeoflood slackwater deposits observed in various regions worldwide.

Enhancing viscosity quality testing accuracy in the automotive industry

The present study aims to examine an issue pertaining to the precision of viscosity measurements crucial to the rubber processing industry within the Western side of Romania, where viscosity is being tested using the PREMIER™ MDR MOVING DIE RHEOMETER by Alpha Technologies. Control charts have raised the alarm regarding the consistency of the analysis results, and therefore a root cause analysis has brought to light a mechanical issue of the rheometer for which a solution has been proposed and implemented. Ultimately, the study shows the enhancement of the viscosity quality testing from the initial state identified until the actual situation, after action was implemented and proven to be efficient.

Structural evolution of the southern part of the Suvanyak metamorphic complex and its framing (Southern Urals)

The mesostructural parageneses of the Suvanyak metamorphic complex that composes the western part of the Uraltau zone (antiform), as well as the complexes that compose the western side of the Zilair synclinorium and the Sakmara zone (allochthon), adjacent to the Uraltau zone, are studied. The sequence of their formation and the structural evolution of the studied region have been established. It is shown that in the deformational history of the studied region, associated with the Late Paleozoic intercontinental collision, which assured the geodynamic evolution of the Ural paleo ocean, three stages of deformation are distinguished. The first stage of the D1 deformation, expressed in the formation of the F1 folds and associated thrusts of western and southwestern vergence, is associated with the movement of the Sakmara allochthon in an eastern direction. The second stage of the D2 deformation is marked by the formation of the F2 folds and folded thrusts of eastern and northeastern, less often southeastern vergence, due to back thrusting processes. Back thrusting occurred under conditions of sublatitudinal compression directed from east to west, while the entire package of allochthonous plates did not shift to the west. The reason for this could be the presence of a significant obstacle that did not allow allochthon to carry out further advance in the western direction. With continued pressure from the east, from the volcanogenic formations of the former Magnitogorsk island arc and the impossibility of moving to the west, the more eastern complexes moved under the more western ones, and the latter, respectively, moved eastward. The third stage of deformation D3, marked by the formation of asymmetric S folds with steeply dipping hinges, corresponds to the post-collision strike-slip movements widespread throughout the Ural folded region, which finally shaped the structural appearance of the region.

Hiekkapohja hydrothermal system – ore mineral, lithogeochemical and paleomagnetic evidence from the Paleoproterozoic Central Finland Granitoid Complex

The Paleoproterozoic Svecofennian Central Finland Granitoid Complex (CFGC) has been regarded as an area of low mineralisation potential. The Hiekkapohja area, 20km north-east of the town of Jyväskylä, host a concentration of variable metalliferous showings. Samples from mineralised boulders and outcrops display variable combinations of anomalously high concentrations of Cu, Mo, Zn, Pb, W, Pb, Ag, As, and Au. The area is composed mainly of peraluminous and ferroan granitoids. The dominant porphyritic Hiekkapohja granodiorite (~1.88 Ga) is cross-cut by the equigranular Soimavuori granite of similar age. The porphyritic Lehesvuori granite on the western side of the study area represents marginally older (~1.89 Ga) magmatism. The paragenetic sequence of the ore minerals shows that the Hiekkapohja area has been affected by at least two separate stages of hydrothermal activity. The first mineralisation stage was widespread, crystallising typically chalcopyrite, pyrrhotite, sphalerite, galena, arsenopyrite, magnetite and Ag-bearing minerals. After the first stage, a low temperature oxidising phase formed hematite and marcasite. The second mineralisation stage enclosed low temperature minerals, such as marcasite and native Ag and Ag-minerals, as inclusions inside chalcopyrite, pyrite, pyrrhotite, sphalerite, and arsenopyrite. The mineralised samples typically display signs of K-metasomatism and less commonly signs of propylitic alteration. During the second mineralisation stage the fluid flow was controlled by the dominant 120°–135° trending shear zones. Both the hydrothermal activity and the regional geology indicate that porphyry type ore forming processes have occurred in the Hiekkapohja area. Paleoproterozoic resetting of the remanent magnetisation is further evidence for the role of the hydrothermal system.