rss_2.0Geologos FeedSciendo RSS Feed for Geologos 's Cover power of colour in geoheritage studies and marketing: some tentative reflections<abstract> <title style='display:none'>Abstract</title> <p>Colour is a common physical property in exposures of unique geological objects, but is only marginally addressed in geoheritage literature. We here present our point of view on how this feature can be treated in geoheritage studies, with the general aim at setting up a broad discussion. Three functions of colour in geoheritage are outlined, namely geological interpretation (e.g., compositional and genetic peculiarities of sedimentary rocks), higher visibility due to colour contrast and aesthetic attractiveness to geotourists. Assessment of colour at geosites is challenging, especially because of uncertain colour nomenclatures. We propose to focus on colour identification, calculation of the number of colours, qualitative evaluation of colour contrast and comparison of colours of a given geological object to its landscape context. Geoheritage colours may have different meanings to geosite visitors, and colour-emotion associations revealed by national and international studies are important to trace these meanings.</p> </abstract>ARTICLE2021-05-12T00:00:00.000+00:00Tidally dominated Miocene deltaic deposits and pipe rocks in the Tebessa Basin, eastern Algeria: sedimentological and ichnological characteristics<abstract> <title style='display:none'>Abstract</title> <p>Analyses of sedimentology, ichnology and depositional environments of Langhian–Tortonian siliciclastic deposits in the southern Tebessa Basin (eastern Algeria) have revealed a tidally dominated deltaic setting with a high concentration of vertical burrows. From south to north, two depositional environments are here distinguished in the Tebessa Basin: a subaerial lower delta plain in the Oum Ali region with the trace fossils <italic>Ophiomorpha</italic> and <italic>Skolithos linearis</italic>, and a proximal delta front with numerous <italic>Skolithos</italic>, situated in the Hjer Essefra area. The occurrence of <italic>Skolithos</italic> pipe rock in this Miocene subtidal domain is unusual. Pipe rocks have been commonly reported from shallow and well-oxygenated environments, especially from Cambrian strata; their number decreased significantly during the Ordovician, coupled with an increase in biodiversity. Here different deltaic subenvironments and tidal signals that are exceptionally well preserved in outcrops are analysed and interpreted. Different ichnotaxa are briefly described, and the uncommon density and size of <italic>Skolithos</italic> pipe-rock in these Miocene strata are discussed.</p> </abstract>ARTICLE2021-05-12T00:00:00.000+00:00Lacustrine deltas and subaqueous fans: almost the same, but different – a review<abstract> <title style='display:none'>Abstract</title> <p>Although deltas and subaqueous fans are both formed in the same near-shore zones of basins, the hydraulic conditions for their formation, development and sedimentary records are different. The present review discusses the results of previously published studies of fan deltas (Gilbert-type deltas) and subaqueous fans of lacustrine and glaciolacustrine environments. The depositional mechanisms of deltas and subaqueous fans, textural and structural features of the lithofacies associations and their typical lithofacies are presented. The characteristics of subaqueous fans, which are still relatively poorly understood and are often overlooked in sedimentological interpretations of lacustrine sedimentary successions, receive particular attention. The palaeoenvironmental and lithological differences between deltas and sub-aqueous fans are highlighted.</p> </abstract>ARTICLE2021-05-12T00:00:00.000+00:00Depositional environment of the Bagh-e-Vang Formation – the only occurrence of upper Lower Permian in Iran<abstract> <title style='display:none'>Abstract</title> <p>A transgression of the Tethys Ocean occurred in east central Iran, like in other areas of the Tethys Ocean, around the Yakhtashian/Bolorian (regional chronostratigraphical units corresponding with the Artinskian/Kungurian of the Early Permian) transition. This led to the development of a carbonate platform that is represented in the Shirgesht area on the northern part of the Tabas Block by the Bagh-e-Vang Formation, which constitutes the only known sedimentary unit from the late Early Permian in Iran. Field data and thin-section analysis indicate deposition on a carbonate ramp with barriers separating a lagoonal area with intertidal mud flats from the open-marine environment. The overall transgressive development is indicated by the presence of open-marine sediments on top of the barrier and lagoonal sediments.</p> </abstract>ARTICLE2021-05-12T00:00:00.000+00:00Assessment of river water infiltration conditions based on both chloride mass-balance and hydrogeological setting: the Krajkowo riverbank filtration site (Poland)<abstract> <title style='display:none'>Abstract</title> <p>In the present work measurements of chloride concentrations were used to assess the variability of infiltration conditions and contributions of surface water and local groundwater to the discharge of wells at Krajkowo riverbank filtration site (western Poland). Tests were performed on samples from 26 wells located in a well gallery close to the River Warta. Due to higher chloride concentrations in river water in comparison with local groundwater, significant differences in concentrations in samples from individual wells were noted. In particular, lower chloride concentrations in 11 wells were recorded, which can be linked to the local occurrence of low-permeability deposits in the superficial zone; a locally higher degree of riverbed sediment clogging in the highly convex meandering zone, where strong erosion of the riverbed occurred, which in turn led to increased clogging; the occurrence of a more intensive groundwater inflow into the river valley due to water infiltration from a smaller river entering the River Warta valley, as well as unfavourable conditions for the infiltration of surface water to the lower part of the aquifer with a greater thickness. Differences in chloride concentrations observed were also used to quantify approximately river water contribution to the well production. The average contribution of the River Warta to the recharge of the entire well gallery was estimated at 59.8%.</p> </abstract>ARTICLE2021-05-12T00:00:00.000+00:00Book reviews: Earth materials. Introduction to mineralogy and petrology (Second edition), by Cornelis Klein and Anthony R. Philpotts, 2017. Cambridge University Press, Cambridge, UK. 616 pages. Paperback: price £44.99 ISBN: 9781316608852. reviews: , by M. Engel, J. Pilarczyk, S.M. May, D. Brill & E. Garrett (Eds.), 2020. Elsevier Inc., Amsterdam. 848 pages. Paperback: price €156,19, ISBN 9780128156865; e-Book: price €156,19, ISBN 9780128156872 reviews: Forecasting and planning for volcanic hazards, risks, and disasters, by Paolo Papale (Ed.), 2020. Elsevier, London, 708 pages. Paperback: price $150.00, ISBN 9780128180822. induced by ice-sheet advances in NE Poland<abstract xml:lang="en"><title style='display:none'>Neotectonics induced by ice-sheet advances in NE Poland</title><p>Differences in the geological structure of the hard-rock substratum of the Warmia and Mazury regions (NE Poland) resulted during the Pleistocene in different reactions on the load exerted by the land-ice masses. In the (western) Warmia province, vertical glacio-isostatic movements caused cyclic erosional events affecting the relatively thick sedimentary cover, which became more compacted. In contrast, the thinner sedimentary cover of the rigid crystalline basement favoured quiet sedimentation in the (eastern) Mazury province. The zone in between these two areas runs NNE-SSW for some 80 km. It is several kilometres wide and is composed of landforms that owe their origin to the sedimentary infilling of crevasses. This intermediate zone formed an interlobe are between the two huge ice lobes that covered the Warmia and Mazury areas during the last ice age. The basement of the zone coincides with the crystalline craton slope, which is accompanied to the west by a parallel marginal trough.</p><p>Cyclic advances and retreats of the Pleistocene ice sheet induced neotectonic mobility. Glacio-isostatic processes resulted in the intermediate zone in block movements (uplift and subsidence) that affected the whole Cenozoic succession, creating mainly vertical discontinuity zones. Glacio-isostasy also induced vertical tectonic movements within the older deposits, reaching down to the crystalline basement. A tectonic graben thus developed. It is bounded by flexures accompanied on both sides by positive structures that may indicate transpressional movements with a strike-slip stress component.</p></abstract>ARTICLE2009-12-24T00:00:00.000+00:00Easily-accessible digital palaeontological databases-a new perspective for the storage of palaeontological information<abstract xml:lang="en"><title style='display:none'>Easily-accessible digital palaeontological databases-a new perspective for the storage of palaeontological information</title><p>Techniques that allow to render diverse types of palaeontological data as publicly available internet resources are described. In order to develop an easily accessible digital palaeontological database, three steps should be followed: (1) digitization of the studied specimens, (2) acquisition of morphometric data, and (3) contribution of the data to open and searchable geoinformatic (palaeontological) databases. Digital data should be submitted to internet databases that allow a user to fetch various types of information from dispersed sources (semantic web services).</p></abstract>ARTICLE2009-12-24T00:00:00.000+00:00Large-scale land-suitability mapping in the GIS environment for the construction site of the University Olympic Village in Izmir (Turkey)<abstract xml:lang="en"><title style='display:none'>Large-scale land-suitability mapping in the GIS environment for the construction site of the University Olympic Village in Izmir (Turkey)</title><p>Participants of the 23<sup>rd</sup> University Olympic Games held in Izmir (Turkey) were hosted in a Universiade Olympic Village that had to be newly constructed. A risk analysis has been performed to assess potential engineering problems at the envisaged construction site. The risk analysis was largely based on a new, large-scale land-suitability map that was prepared in the GIS environment with much detail for this type of construction work. Information was collected from several maps, in combination with mapping in the field, drilling and seismic data. Geological, geotechnical, geophysical and morphological data were then superimposed on these analyses. This sequence of overlay analyses was performed with the help of GIS software (MapInfo Professional 7.5); this resulted in five hazard maps. Risk points (1-11) were then attributed to the different zones in the five digital hazard maps.</p><p>A land-suitability map indicating the suitability for envisaged constructional activities was subsequently obtained in the form of an overlay of the five hazard maps, thus allowing to calculate a total risk for each zone on this map. The land-suitability map that was thus obtained, has been prepared for a 1:1,000 scale development plan; such a large scale is uncommon in this context.</p></abstract>ARTICLE2009-12-24T00:00:00.000+00:00Differences in the regional stratigraphy of NE Poland caused by vertical movements due to glacioisostasy<abstract xml:lang="en"><title style='display:none'>Differences in the regional stratigraphy of NE Poland caused by vertical movements due to glacioisostasy</title><p>Geological mapping in combination with geophysical investigations and borehole analyses show differences of the Pleistocene between the Warmia and Mazury palaeogeographic provinces in NE Poland. The (more western) Warmia province has a crystalline basement that is covered by a folded sedimentary succession of 2-4 km thick. The (more eastern) Mazury province (eastern) has a basement that forms part of the rigid East European crystalline craton, which is covered by a sedimentary cover of only 1-1.5 km thick.</p><p>Cyclic loading by the Pleistocene ice sheets in this area induced glacioisostatic processes of different intensities, resulting in changing palaeogeographic conditions. The changes were increased by intense neotectonic activity that was induced by the ice sheets in the intermediate zone between the two provinces, stretching along the western slope of the crystalline craton. Significant part of intermediate zone forms a belt of crevasse-infill landforms deposited between the Warmia and Mazury lobes of the last glaciation. Studied deposits reveal a cyclic reactivation of the interlobe zone during the successive Pleistocene glaciations. Considerable variations of the relief of the top-Neogene, vertical discontinuities cutting the Pleistocene and Neogene, stratigraphic gaps within the Pleistocene succession, and thick glaciolacustrine successions result from the vertical neotectonic movements in the intermediate area between the two provinces.</p></abstract>ARTICLE2009-12-24T00:00:00.000+00:00Palynology of the Palaeogene and Neogene from the Warmia and Mazury areas (NE Poland)<abstract xml:lang="en"><title style='display:none'>Palynology of the Palaeogene and Neogene from the Warmia and Mazury areas (NE Poland)</title><p>Pollen, phytoplankton and microfauna from the Palaeogene and Neogene of two boreholes in NE Poland have been studied. Borehole Klucznik 1 is located in the Warmia area, and borehole Sąpłaty 3 borehole in the Mazury area. The oldest palynomorph assemblage comes from the Klucznik sediments; it consists of phytoplankton from the Early Palaeocene (Danian) D1 and D2 dinocyst zone, and from the Selandian D3 zone. The Eocene is present in the both the Klucznik and the Sąpłaty successions. The Middle Eocene assemblage has been dated as late Bartonian and belongs to the D11 dinocyst zone. The Late Eocene (Priabonian) D12 dinocyst zone is also present in both boreholes. Sporomorphs of a Late Eocene palynomorph assemblage point on the proximity of land and on terrestrial vegetation. The dinocyst zone D13, characteristic for the earliest Oligocene ('Latdorfian') has been found in both profiles as well. A Neogene sporomorph assemblage dating from the Middle Miocene (Early Serravallian) occurs only in the Sąpłaty profile. This sporomorph assemblage is correlated with pollen zone VIII. Pollen zone IX is present in the uppermost part of the Middle Miocene (Middle Serravallian). Late Miocene deposits (Late Tortonian) with pollen zone XI are present, too. The Miocene deposits accumulated in densely vegetated swamps, resulting now in the occurrence of lignite. The sedimentary conditions in the Warmia and Mazury regions were identical during the Neogene and Palaeogene, implying that both provinces belonged at the time to one sedimentary basin.</p></abstract>ARTICLE2009-12-24T00:00:00.000+00:00Predictive diagenetic clay-mineral distribution in siliciclastic rocks as a tool for identifying sequence boundaries in non-marine successions: the Coalspur Formation, west-central Alberta<abstract xml:lang="en"><title style='display:none'>Predictive diagenetic clay-mineral distribution in siliciclastic rocks as a tool for identifying sequence boundaries in non-marine successions: the Coalspur Formation, west-central Alberta</title><p>The study of upper Cretaceous-lower Tertiary fluvial deposits of the Coalspur Formation in the Foothills region of west-central Alberta reveals that the distribution of early authigenic kaolinite has a well-defined relation to the sequence stratigraphic framework. In this context, it has been observed that the kaolin mineral content increases in sandstones lying below subaerial unconformities, which mark the most significant stratigraphic hiatuses and hence the sequence boundaries in fully fluvial successions. The increased abundance of authigenic kaolinite immediately below sequence boundaries may have been caused by the infiltration of meteoric water during times of subaerial erosion, resulting in the dissolution of unstable minerals (e.g., micas and feldspar) and the formation of kaolinite and secondary porosity. It is therefore suggested that the change in clay mineral assemblages in the stratigraphic section depends in part on the position of the analyzed sandstone samples relative to the sequence boundaries. In a larger context, the method of using authigenic clays to delineate depositional sequences in non-marine successions needs to be evaluated on a case-by-case basis, as the diagnostic early diagenetic minerals underlying the sequence boundary may change as a function of palaeoclimate and also as a function of late diagenetic processes.</p></abstract>ARTICLE2009-12-24T00:00:00.000+00:00Thanks to the journal’s reviewers and geochemistry of rare earth elements in the Moyil Valley alteration zones, Meshkinshahr (northwest Iran)<p>Sabalan Mountain (northwest Iran) witnessed intense volcanic activity during the Cenozoic (Plio-Pleistocene). The result of this manifests itself in the conical geometry of the Sabalan stratovolcano and ahigh hydrothermal gradient around it, which can be detected by geological phenomena such as hot springs, smoke gases and steam outlet pores. The high hydrothermal slope and upward migration of hot water in this area have caused extensive alteration zones in the host rocks. A mineralogical study of alteration zones in thewells drilled in the Moyil Valley to the northwest of Sabalan Mountain has revealed the presence of phyllic, argillic, calcitic and propylitic alterations in volcanic rocks (trachyandesite) and alteration phyllic and propylitic ones in monzonite rocks. In chondrite-normalised rare-earth-element diagrams, trachyandesite rocks exhibit an HREEs enrichment when compared to MREEs and LREEs in propylitic and calcitic alteration zones. This result can be explained by the acidic nature of hydrothermal fluids containing complex ions such as (SO<sup>-2</sup>, Cl<sup>-</sup>). The (La/Yb)<sub>cn</sub>, (La/Sm)<sub>cn</sub> and (Tb/Yb)<sub>cn</sub> ratios for argillic, phyllic, propylitic and calcitic alteration zones have revealed that they are higher in fresh rocks compared to altered rocks, suggesting the enrichment of HREEs in comparison to LREEs and MREEs. The anomalies of Eu do not change remarkably in the argillic and propylitic alteration zones of trachyandesite rocks; apparently, alteration hadno effect on them. Such behaviour reflects the presence of gold cations in Eu<sup>+3</sup> formed at temperatures below 250°C. Eu anomalies increased in propylitic alteration zones in monzonite rocks and calciticand phyllic alteration zones in trachyandesiterocks.</p>ARTICLE2020-12-31T00:00:00.000+00:00Book reviews: Fundamentals of invertebrate palaeontology. Microfossils of reservoir parameters on the basis of well logging and DST of Miocene gas reservoirs in the central part of the Carpathian Foredeep, Poland<p>In the Polish part of the Carpathian Foredeep, an intensification of gas exploration and exploitation from Miocene strata took place in the middle of the twentieth century. In spite of a good degree of geological and reservoir recognition, the area of the Carpathian Foredeep is still considered to be prospective for the discovery of new gas reservoirs. Here we analyse statistically selected reservoir parameters of Miocene deposits, such as total porosity, effective permeability and reservoir water inflow. These parameters have been determined on the basis of interpretations of results of well logs and reservoir tests with tubular bed samplers (DST, Drill Stem Test). Analytical results in the form of regression and dependence of the logarithm of permeability as a function of porosity show a weak correlation. However, in the study area, the distribution of porosity values for Miocene strata is close to normal.</p>ARTICLE2020-12-31T00:00:00.000+00:00The human imprint on the unique geological landscape of the Western Caucasus<p>Human intervention in the geological environment is commonly thought to pose a threat to geoheritage. However, new information from the Western Caucasus where unique geological features are concentrated in Mountainous Adygeya, implies that man-made features in fact add value to geoheritage. Such features include a lengthy artificial niche in the Guama Gorge, accumulations of large artificial clasts along the road leading to the Lagonaki Highland and the Khadzhokh Quarry with the artificial Red Lake. These contribute to the regional uniqueness of geosites and can be classified as geomorphological, sedimentary, economical and hydro(geo)logical geoheritage types. Interestingly, these artificial features have natural analogues in the study area. Such integrity of local geological landscapes urgently require special interpretations for guided excursions and explanatory panels for correct comprehension of the origin of these unique features on the part of unprepared tourists. Generally, the human imprint on geological landscapes of Mountainous Adygeya is significant and occasionally positive, which makes the entire geodiversity hotspot of special, international interest and an object for further investigations.</p>ARTICLE2020-12-31T00:00:00.000+00:00Book reviews: Problems and solutions in structural geology and tectonics