Artificial Outcrops Research Articles

3D geophysical image translated into photorealistic virtual outcrop geology using generative adversarial networks

Outcrop analogues play a pivotal role in resolving meter-scale depositional facies heterogeneity of carbonate strata. Two-dimensional outcrops are insufficient to decipher the 3D heterogeneity of carbonate facies. Near-surface geophysical methods, notably ground-penetrating radar (GPR), can be employed to step into 3D and extend the dimensionality of the outcrops to behind the outcrop. However, interpreting geophysical images requires specific geophysical expertise, often unfamiliar to field geologists who are more familiar with the actual rock than the geophysical data. A novel generative adversarial network (GAN) application is presented that constructs a photorealistic 3D virtual outcrop behind-the-outcrop model. The method combines GPR forward modeling with a conditional generative adversarial network (CGAN) and exploits the apparent similarities between outcrop expressions of lithofacies with their radargram counterparts. We exemplified the methodology and applied it to the open-source GPR data acquired from the Late Oxfordian-Early Kimmeridgian Arabian carbonate outcrop. We interpret a 4 km long outcrop photomosaic from a digital outcrop model (DOM) for its lithofacies, populate the DOM with GPR properties, and forward model the synthetic GPR response of these lithofacies. We pair the synthetic GPR with DOM lithofacies and train them using CGAN. Similarly, we pair the DOM lithofacies with outcrop photos and train them using CGAN. We chain the two trained networks and apply them to construct an approximately 2 km long 2D and an approximately 60 m2 3D volume of photorealistic artificial outcrop model. This model operates in a visual medium familiar to outcrop geologists, providing a complementary instrument to visualize and interpret rock formation instead of geophysical signals. This virtual outcrop replicates the visual character of outcrop-scale lithofacies features, such as the intricate bedding contacts and the outline of reef geobodies.

Paleoenvironmental changes during the Late Pleistocene in Buenos Aires province (Argentina), using foraminifera fauna as proxy data

This paper describes the lithological and micropaleontological characteristics of a new record corresponding to the last interglacial for Buenos Aires province. Foraminifera were analyzed from an artificial outcrop 4 m thick (36°34′0.97″ S and 57°22′54.43″ W), from the quarry situated in the town of General Conesa, Buenos Aires province at an approximate elevation of 4 m a.s.l. Benthic foraminifera fauna was constituted by a predominance of calcareous forms represented mostly by the species Buccella peruviana and Ammonia parkinsoniana. The micropaleontological and lithological characteristics of all the sedimentary units involved in this locality suggest deposits associated with a transition from a low-energy shallow intertidal or subtidal zone to a higher-energy beach or supratidal environment. Although, the topographic height does not enable conclusive assignment of the age of this coastal deposit (>79.500 kyr), the environmental conditions could be correlated with the penultimate transgressive event that occurred at the beginning of the Late Pleistocene (MIS 5), which would have occurred in a shallow environment with changes in the marine influence. These findings provide new information that contributes to better understanding of the paleoenvironmental evolution of this region where two marine transgressions and two wind deposits have been recognized.

MONUMENTS OF GEOLOGY IN THE KORSUN-SHEVCHENKIVSKY STATE HISTORICAL AND CULTURAL RESERVE

Geological monuments are natural and artificial outcrops that most vividly reflect the features of the geological structure of the territory. The attribution of objects on the territory of the State Historical and Cultural Reserve in Korsun-Shevchenkivskyi to geological monuments is determined by the possibility to study in detail the petrographic composition of granite varieties of Korsun-Novomyrhorod pluton - one of the two large intrusions of anorthosite-rapakivi-granite formation on the Ukrainian shield. Preservation of natural outcrops allows to observe the change of the state of anorthosite-rapakivi-granite complex under the influence of natural factors. The outcrops of these rocks, including in the form of islands, create a unique picturesque landscape of the valley of the river Ros.

Database of petrophysical properties of the Mid-German Crystalline Rise

Abstract. Petrophysical properties are a key element for reservoir characterization but also for interpreting the results of various geophysical exploration methods or geophysical well logs. Furthermore, petrophysical properties are commonly used to populate numerical models and are often critically governing the model results. Despite the common need for detailed petrophysical properties, data are still very scarce and often not available for the area of interest. Furthermore, both the online research for published property measurements or compilations, as well as dedicated measurement campaigns of the selected properties, which require comprehensive laboratory equipment, can be very time-consuming and costly. To date, most published research results are often focused on a limited selection of parameters only, and hence researching various petrophysical properties, needed to account for the thermal–hydraulic–mechanical behaviour of selected rock types or reservoir settings, can be very laborious. Since for deep geothermal energy in central Europe, the majority of the geothermal potential or resource is assigned to the crystalline basement, a comprehensive database of petrophysical properties comprising rock densities, porosity, rock matrix permeability, thermal properties (thermal conductivity and diffusivity, specific heat capacity) as well as rock mechanical properties as compressional and shear wave velocities, unconfined compressive strength, Young's modulus, Poisson's ratio, tensile strength and triaxial shear strength was compiled from measurements conducted at the HydroThermikum lab facilities of the Technical University of Darmstadt. Analysed samples were mostly derived from abandoned or active quarries and natural or artificial outcrops such as road cuts, riverbanks or steep hillslopes. Furthermore, samples of the cored deep wells Worms 3 (samples from 2175–2195 m), Stockstadt 33R (samples from 2245–2267 m), Weiterstadt 1 (samples from 2502–2504 m), Tiefbohrung Groß-Umstadt/Heubach, B/89–B02 and the cored shallow wells (Forschungsbohrung Messel GA 1 and 2) as well as GWM17 Zwingenberg, GWM1A Zwingenberg, Langenthal BK2/05, EWS267/1 Heubach, and archive samples of the Institut für Steinkonservierung e.V. in Mainz originating from a comprehensive large-scale sampling campaign in 2007 were investigated. The database (Weinert et al., 2020b; https://doi.org/10.25534/tudatalib-278) aims to provide easily accessible petrophysical properties of the Mid-German Crystalline Rise, measured on 224 locations in Bavaria, Hessen, Rhineland-Palatinate and Thuringia and comprising 26 951 single data points. Each data point is addressed with the respective metadata such as the sample identifier, sampling location, petrography and, if applicable, stratigraphy and sampling depth (in the case of well samples).

ЦЕРИЙ В КОМПОНЕНТАХ ЛАНДШАФТА ШЕРЛОВОГОРСКОГО ГОРНОРУДНОГО РАЙОНА (ЮГО-ВОСТОЧНОЕ ЗАБАЙКАЛЬЕ)

Актуальность исследования заключается в необходимости познания биогеохимии лантаноидов в природно-антропогенном ландшафте. Целью работы является изучение поведение церия в геосистеме уникального редкометалльно-олово-полиметаллического Шерловогорского горнопромышленного района в Юго-Восточном Забайкалье. Методология исследования заключается в изучении поведения церия в звеньях цепи: горная порода (руда)→почва (технозем)→растение→корневая система→наземная часть. Отбор проб почвообразующих горных пород, руд, почв и растений проведен в течение полевых сезонов 2001–2016 гг. Пробы почв отобраны в соответствии с ГОСТ 17.4.4. 02-84, по искусственным обнажениям. В работе использованы данные анализа 37 проб горных пород и руд, 211 почв, 119 техноземов и 215 проб (3225 экземпляров) травянистых растений. Методика работы заключалась в минералого-геохимическом изучении горных пород и руд с использованием оптической и электронной микроскопии. Химический состав горных пород, минералов, почв, техноземов и растений изучен методами ICP MS. Результаты. Впервые изучено поведение церия в ландшафте Шерловогрского рудного поля. Основным источником церия в почвах и технозамах рудного района является монацит-(Се). Он находится в грейзенах и кварцево-жильных телах, локализованных в Шерловогорском гранитном массиве, окисленных рудах, хранящихся на складах некондиционных руд и отвалах. Другими носителями церия являются агардит и гоудейит. Он входит также в состав флюорита (8,2–1182 ppm), вольфрамита (0,4–11,1ppm), глин остаточных полостей в жилах, продуктивных на камнесамоцветное сырье (3,3–206 ppm). Незначительны содержания церия в берилле (0,1–1,2 ppm) и топазе (0,2–2,81 ppm). Содержание Се в сульфидном минеральном комплексе в жилах с камнесамоцветным сырьем варьирует от 5,6 до 99,4 ppm. В мелкообломочном материале почв и техноземов содержание Ce находится в пределах 0,0051–0,0384 %. В экспериментах показана возможность выноса церия на ландшафт водными растворами, содержащими до 0,73 ppm. На всех участках среднее содержание в почвах находится в пределах 3,3–310 ppm, а в техноземах – 30–377 ppm. Максимальное содержание церия (ppm) установлено в корнях травянистых растений (1,0–3,9) (КБП 0,02–0,03), а минимальное – в их наземных частях (0,8–1,4) (КБП 0,01–0,02). Это свидетельствует о весьма незначительном захвате его растениями и низком содержании в кормовой части пастбищных растений. Однако насколько это безопасно для домашних животных, пока не известно и требует специальных исследований.

SOLONSKE SECTION AND THE PERSPECTIVES OF THE STUDY OF PLEISTOCENE CARPATHIAN FORELAND

The article presents the results of the field study of the two artificial outcrops of the Pleistocene deposits, which are located in the suburbs Solonske near Drohobych city. Outcrops (careers) are located within the terrace of the Tysmenytsia River. The height of the terrace is about 50 m above the river level and changes along the distance from the mountains. The main attention in the article is paid to the study of the structure of the upper (covering) stratum of the terrace with a thickness of about 26 m, and also to the characteristics of its consolidated stratigraphic section. The basis of this stratum consists of the layers of non-carbonate loams and clays. They are more or less enriched of iron compounds and gleyed. Between them there are four horizons of buried soils of the interglacial and interstadial rank. Based on the observations made in the field, it was found that the sediments of the covering stratum have mainly river origin. The conditions of their accumulation, as well as the conditions for the formation and transformation of ancient soils, are considered; eight pre-Holocene lito- and pedostratigraphic layers of different rank are singled out. The division of the covering stratum of the terraces into three main layers is sub¬stan¬tiated, which is equivalent to the stratigraphic units of the glacial and interglacial rank. Comparison of the Solonske section with other sections of the similar height terraces, in particular with well-known outcrops near the village Dubrivka (section Dubrivka) gives grounds to assume that the formation of a local terrace occurred during the Marine Isotopic Stages 12 to 10. Consequently, the Solonske section represents a short strati¬gra¬phic interval of the Middle Pleistocene (not the three main Pleistocene units as stated in the results of its previous study). It can be the basis for studying only a few (two to three) horizons of the glacial/interglacial rank. At the same time, it is potentially a very impor¬tant key section of the Solonske (Dubrivska, Dovhivska, Varnytska) terrace of the Pre-Dniester. The studying of Solonske outcrops makes it necessary to revise the popular notions about the origin and the age of the so-called covering stratum of the river terraces of the Carpathian Foreland and Podolian Pre-Dniester, its stratigraphic filling and significance. Key words: alluvial deposits; terraces; soil-loess sequence; Middle Pleistocene; Dniester valley; Carpathian Foreland; Solonske section.

New biocenosis model of Vendian (Ediacaran) sedimentation basin of Podilia (Ukraine)

The aim of this study is to fully research all aspects of the distribution, development, conditions of burial and preservation of the Ediacaran biocomplex. Thiswork summarizes and extends all data on the unique Vendian invertebrates that are distributed in the natural and artificial outcrops of the Dniester River Basin within Podilia (Ukraine). One of the basic locations of the annual observation was a quarry of rubble stone production near the Dniester hydroelectric station-1, Novodnistrovsk city, which exposes a continuous section of the deposits of the Lomoziv, Yampil, Lyadova and Bernashivka Beds lying on a crystalline basement. This paper shows the outcomes of long-term fieldwork of the Upper Ediacaran which include deposits of the Mogyliv-Podilsky and Kanylivka Group. The researched section is characterized by its clastic composition and the absence of carbonate formations. The basic paleontological collection has more than two thousand specimens, for instance, the imprints of molluscous fauna, traces of their live activity, the remains of flora and fossils of a problematic nature. The most numerous and informative collection of these fossils is located in the stock of the Geological Museum of the Taras Shevchenko National University of Kyiv. The collection contains unique material, including a number of Ediacaran fossils described for the first time. On the whole within Podilia region, more than 100 species have been described in detail. The main areas of biota accumulation in the outcrops are associated with argillites, argillite-siltstones and their contact with sandstones. The best preservation of the imprints is detected in the boundary of facial transitions. Research has revealed that there is a decrease in the numerical and species composition of the molluscous biota, and the dynamic increase in evolution of burrowing organisms and plants within the Podilia Basin during the late Vendian. Such a phenomenon led to an environmental change, increase in oxygen and appearance of new groups of organisms that were subsequently displaced invertebrates. This occurred at the Precambrian/Cambrian transition, and in the geological literature is described as the «Cambrian explosion». Studies have found that the total number of taxonomic composition of the Eidacaran in Podilia is similar to the orictocoenosis of Southern Australia and the White Sea. Nevertheless, the Podilia biocomplex is more ancient than the Southern Australian and the White Sea, it is much younger than the Avallonian.

Nyílt rendszerű magmás folyamatok: magmakeveredés, kristálycsere és kumulátum-recirkuláció nyomai a Ditrói alkáli masszívumban (Orotva, Románia)

A Tarniţa Komplexum a Keleti-Kárpátokban (Románia) felszínre bukkanó Ditrói alkáli masszívum északi területének jellemző ultramafikus és mafikus kőzetegyüttese. A komplexum Ny-i részén, az Orotva-patak és a Felső-Pietrăriei-patak összefolyásánál található mélységi magmás kőzettestben kialakított mesterséges feltárás egyedülálló betekintést enged az egykori magmatározóban zajlott, több magma között lejátszódott keveredési és elegyedési folya matokba, illetve az új magmabenyomulások során feltépett, korábban kikristályosodott magmás kőzetfragmen tumok bekeveredési folya mataiba. A feltárásban látható befogadó kőzetben (szürke, közép- és durvaszemcsés, irányított szövetű diorit) négy különböző keveredési kőzetzárvány (mafikus kőzetzárvány; földpátszemes kőzetzárvány; porfíros (földpátaggregátumos), mafikus kőzetzárvány és ultramafikus kőzetzárvány) és egy eltérő eredetű felzikus kőzetzárvány típus figyelhető meg. A keveredési kőzetzárványok modális összetételük alapján mezokrata és melanokrata dioritok, valamint piroxénhorn blenditek, a felzikus kőzetzárványok pedig hololeukokrata dioritok. A különböző magmák közötti keveredés (mingling) legfontosabb bélyege az egymással — és a befogadó kőzet ásványainak orientált elhelyezkedésével — párhuzamos, megnyúlt, finomszemcsés, lencse alakú kőzetzárványok meg jele nése. A szögletes felzikus xenolitok és ultramafikus kőzetzárványok korábbi kumulátumok recirkulációját felté telezik, amelyek a benyomuló magmával kerültek a magmatározóba. A keveredési kőzetzárványok mafikus pereme és a közelükben megfigyelhető „slírek” további fontos jellemzői a legalább két magma keveredése során kialakuló szerke ze teknek. A magmaelegyedés gyakori velejárója a kristálycsere (crystal transfer). A vizsgált ásványok számos esetben mutatnak olyan jellegzetes mikroszöveti bélyegeket, amelyek e kristálycsere-folyamathoz köthetők a benyomuló és a befogadó magma, illetve a benyomuló magma és a feltépett kumulátumok között: a különféle zónásságot mutató és különbözőzárványgazdag plagioklászok, az amfibolköpennyel rendelkező piroxének és a plagioklászokban megjelenő tűs apatit kristályok. A jelen tanulmányban bemutatott részletes petrográfiai vizsgálatok rávilágítanak a Ditrói alkáli masszívum magmatározóinak összetett és változatos fejlődéstörténetére, amelyben meghatározó szerepet játszottak a nyílt rendszerű magmás folyamatok.

Про змінення положення південної границі Дніпровського (риського) зледеніння

On the basis of newly discovered factual material, this paper analyses the issue of the reassigning the position of the southern border of distribution of the Dnieper (Riss) glacial tongue, which is considered the southernmost glacier tongue of the glacial period in Europe. The article provides critical analysis of the history of glacial theory and the contribution of scientists from different countries. The article analyses the evolution of the views of researchers - from the drift origin of boulder-loam deposits, described in works by R Murchison, C Lyell, D Tilas and C Darwin, to the idea of glacial origin, the first supporters of which included Pierre Martel, Jean-Andre Deluc, Bernhard Friedrich Kuhn, Ignaz Venets , Albrecht Bernardi, Louis Agassiz and others. The paper evaluates the contribution of Russian scientists who studied continental glaciations, including P O Kropotkin, S M Nikitin, O O Inostrantsev, P Y Armashevsky, N I Krishtofovich, G E Shurovsky, F B Schmidt and others. The article also presents the position of V G Pazynych, an opponent of glacier theory, on the numerous differences of opinion in the interpretation of the framework of the theory and on the necessity of developing a complex model of glaciations, which would include consideration of both exaration and drift. This article presents for the first time the results of solving the problem of restoring the geological relic, the “Domotkanski valuny” [lit. Domotkan boulders – translator`s note] as an important object of geological heritage on the southern border of the Dnieper glacial tongue. The paper presents a study of Kalytva mountain as a terminal moraine formation, which was formed during the Dnieper glacial epoch. Kalytva mountain is a fine example of manifestations of glaciotectonic activities, moraine,fluvio- and limno - glacial deposits with erratic boulders and paleogenic outliers. The article proves the possibility of division of the Dnieper climatolith into lower, -middle, and upper Dnieper stadials and shows the correspondence of limno-glacial deposits, moraine and fluvio-glacial deposits of the middle Dnieper stadials to the upper part of the “Shevchenkivska suite”. We have shown that the periglacial zone situated to the south of the line Volnohorsk-Petrykivka-Yurivka is characterized by absence of boulder loams, by much more homogenous and weathered section of sub-aerial Quaternary deposits and by a lens of fluvio-glacial deposits. The discovery of the artificial outcrop of limno glacial moraine deposits between Spasske and Podhorodne villages enables us not only to determine the main clearly-manifested differences between eolian and limnetic loams but also to delineate more precisely the borders of the periglacial zone of the Dnieper glaciations, which was earlier marked almost 100 km to the north – in the region of the Orel river far from its confluence with the Dnieper. Field studies in the interfluve between the Dnieper, Kilchen and Samara found significant evidence for proving that the southern border of the periglacial zone of the Dnieper Glacial Epoch lies considerably further south than had been assumed previously.

A Gerecse pannóniai puhatestűi és lelőhelyeik: rétegtan, őskörnyezet és fejlődéstörténet

A Gerecse földtani térképezése során a Magyar Földtani és Geofizikai Intézet geológusai új, vagy régen feledésbe merült és részletesen soha nem dokumentált pannóniai feltárásokat azonosítottak a hegység északi előterében, az onnan dél felé felnyúló völgyekben, és a hegység belsejében is. Az ezekből begyűjtött puhatestű fauna (kiegészítve a már korábban ismert tatai puhatestű faunával és régebbi gyűjteményi anyagokkal) és a feltárásokban megfigyelhető szedimentológiai jellemzők alapján a pannóniai rétegsor itt is, mint az egész Dunántúli-középhegység északnyugati peremén, egyetlen transzgresszív-regresszív ciklusból áll. A ciklus transzgresszív szárnyát a tatai téglagyári feltárásokban a vékony transzgresszív bázisrétegre települő Száki Formáció kékesszürke agyagja és az abban megőrződött mély szublitorális fauna, míg a Gerecse központi részén, a tardosi Vályus-kút környékén, 375 méter tengerszint feletti magasságban a lignites agyaggal kezdődő rétegsor fedőjében települő, szintén mély szublitorális puhatestűeket tartalmazó agyag képviseli. A dunaszentmiklósi Iván halála-völgyben valószínűleg egy szökőár hozta létre a kréta fekü anyagából képződött konglomerátumot, homokos mátrixában tömegesen megjelenő zárt (két teknős) pannóniai kagylóhéjakkal. Az üledékciklus regresszív szárnyát az Újfalui Formáció képződményei adják; ezek legjobb feltárásai a Gerecse északi előterében, a Neszmély környéki völgyekben (Nyáraska-völgy, Disznós-kúti-völgy, Csekendi-völgy) és Süttő környékén találhatók. A formációt felépítő felfelé sekélyedő, néhány méter vastag ciklusok faunája a kagylók uralta sekély szublitorális együttesekből, a csigák magas diverzitásával jellemzett litorális faunákból és végül mocsári puhatestű együttesekből áll. Gyűjteményi anyagokban előfordulnak folyóvízi fajok is. A transzgresszív szárny a Congeria czjzeki zóna felső részébe tartozik, míg a regresszív szárny a Lymnocardium ponticum zóna része; a teljes ciklus képződésének kora 9,4–8,7 millió év lehetett. A fáciesek elterjedése alapján a transzgresszió már tagolt térszínen játszódott le, majd az üledékképződéssel egyidejűleg is folyt a terület vetődéses deformációja, de a tatai és vályus-kúti rétegsorok közötti nagy magasságbeli különbség csak további vetőmozgásokkal, a Gerecse utólagos kiemelkedése nyomán jöhetett létre.

Petreşti-Arini – An important but ephemeral Upper Cretaceous continental vertebrate site in the southwestern Transylvanian Basin, Romania

The Transylvanian region of Romania preserves some of the most unusual and iconic dinosaurs in the global fossil record, including dwarfed herbivores and aberrant carnivores that lived during the very latest Cretaceous (Maastrichtian) in an ancient island ecosystem (the Haţeg Island). A series of artificial outcrops recently exposed during a hydroelectric project, the Petreşti-Arini section near Sebeş in the Transylvanian Basin, records a 400+ meter sequence documenting the transition from fully marine to terrestrial environments during the Campanian–Maastrichtian. Calcareous nannofossil biostratigraphy indicates that the lower marine beds in this section, part of the uppermost Bozeş Formation, can be assigned to the CC22 biozone, corresponding to the lower–mid upper Campanian. These beds smoothly transition, via a brackish-water unit, into the fully continental Maastrichtian Sebeş Formation. Dinosaur and pterosaur fossils from the uppermost Bozeş Formation can be assigned a late Campanian age making them the oldest well-dated terrestrial fossils from the Haţeg Island, and indicating that the classic Haţeg dinosaur fauna was becoming established by this time, coincident with the first emergence of widespread land areas. Vertebrate fossils occur throughout the overlying Sebeş Formation at the site and are dominated by the small-bodied herbivorous dinosaur Zalmoxes. The dominance of Zalmoxes, and the absence of many taxa commonly seen elsewhere in Maastrichtian sites in Romania, suggests the possibility that either the Petreşti-Arini section preserves a somewhat unusual near-shore environment, or the earliest Haţeg Island dinosaur communities were structured differently from the more diverse communities later in the Maastrichtian. Alternatively, due to the limited sample size available from the studied succession, it is also conceivable that sampling biases give an incomplete portrayal of the Petreşti-Arini local fauna. Support for any one of these alternative hypotheses requires further data from Petreşti-Arini as well as from the larger Transylvania area.

The Plio-Pleistocene fluvio-lacustrine Upper Valdarno Basin (central Italy): stratigraphy and Basin fill evolution

The Upper Valdarno Basin stands out from the Neogene-Quaternary basins of the Northern Apennines given its outstanding fossil mammal record, good quality of natural and artificial outcrops and remarkable chronological control on the basin-fill succession. The present paper aims to summarize the stratigraphic and sedimentological studies focused on the Upper Valdarno Basin during the past decades, and integrate them with recent investigations. The Upper Valdarno Basin is located about 35 km SE of Florence between the Chianti Mountains and the Pratomagno Ridge. It consists of a main asymmetric tectonic depression filled with 550 m of Plio-Pleistocene fluvio-lacustrine deposits (Upper Valdarno Basin s.s.) and a minor basin known as the Palazzolo sub-basin. The Upper Valdarno Basinfill is made of three unconformity-bounded units, named Castelnuovo dei Sabbioni (CSB), Montevarchi (VRC), Torrente Ciuffenna (UFF) synthems, whereas the Palazzolo sub-basin fill consists of the Fosso Salceto (OLC) and Torrente Ciuffenna (UFF) synthems. The Upper Valdarno Basin formed during Late Pliocene because of the tectonic damming of a northeastward flowing drainage. The early phase of basin development is recorded by the accumulation of fluvial gravels in vallive settings, whereas the definitive of these streams damming caused the development of lacustrine conditions at about 3.1 Ma. The accumulation of deltaic sand fed from the SW margin caused the lake filling and stopped the deposition of the CSB Synthem.Before 2.58 Ma, a tectonic phase caused uplift of the basin and partial erosion of the CSB deposits. Deposition of the lower part of the VRC Synthem occurred during a marked basin broadening and accumulation of alluvial fan successions, which were capped by aeolian-reworked alluvial sand deposited at about 2.5 Ma. At about 2.3 Ma, a new deformative phase caused further basin widening, erosion along the SW margin and development of a small lake inthe central areas. Deposition of the upper part of the Montevarchi Synthem started just after this tectonic phase and was characterized by development of axial fluvial drainage and marginal alluvial fans.During the Early Pleistocene (Olduvai Subchron, 1.95-1.78 Ma) a subsidence pulse promoted development of floodplain lakes and swamps in the axial part of the basin, where thick organic-rich mud were accumulated. During late Early Pleistocene the capture of the paleo-Arno River, which started to flow into the basin, caused the development of a marked unconformity. This unconformity was covered by fluvial and alluvial fan deposit in the axial part and along the margin respectively.

Early Permian tetrapod ichnofauna from the Intra-Sudetic Basin, SW Poland

Tetrapod footprints from Late Palaeozoic deposits of Poland have been known for 150 years, but are poorly studied. Here we present the first comprehensive analysis of an extensive assemblage of fossil tracks from two artificial outcrops near Tłumaczów in the Polish part of the Intra-Sudetic Basin. Accompanied by conifer macrofloral remains and a few invertebrate traces, all footprints occur in reddish to greyish-brown, fluvio-lacustrine siltstones and sandstones of the Early Permian Słupiec Formation. Based on the study of nearly 120 slabs with tracks and trackways, we discern four distinct types of tetrapod footprints. These are assigned to the ichnotaxa Amphisauropus kablikae (Geinitz and Deichmüller, 1882), Ichniotherium cottae (Pohlig, 1885), Dimetropus leisnerianus (Geinitz, 1863), and Dromopus lacertoides (Geinitz, 1861) that can be referred to seymouriamorph, diadectomorph, “pelycosaurian”-grade synapsid and early sauropsid track makers. The Tłumaczów vertebrate track assemblage represents a typical early Early Permian (Asselian–Sakmarian) ichnofauna. Remarkable features are the dominance of footprints of terrestrially-adapted tetrapods and the relative abundance of diadectomorph tracks supporting interpretation of the fossil-bearing strata as part of an intermontane hinterland basin outside the range of semiaquatic anamniotes.

The invertebrate fauna of the Middle Miocene (Lower Badenian) sediments of Kralice nad Oslavou (Central Paratethys, Moravian part of the Carpathian Foredeep)

An artificial outcrop of Middle Miocene sediments at Kralice nad Oslavou has been studied in detail, all fragments retrieved from the bulk samples were evaluated and described. The most common fossils were bryozoans, foraminifers and echinoderms, but molluscs also occured. The faunal content indicates a shallow-marine environment with normal marine salinity and high oxygen levels. Increased volcanic activity in the hinterland was documented by volcano-detritic material in the sediment. Neotypes of bryozoans Kionidella moravicensis Prochazka, 1893 and Umbonula spinosa (Prochazka, 1893) are designated.

Image processing and analysis in geotechnical investigation

The approach of image processing of underground working face photographs using the system for image processing and analysis LUCIA is given. There are given image analysis examples of different types of geological structures in a rock profile. The method was verified by pictures of tunnel faces and by artificial outcrops. This method is relatively inexpensive and applicable for daily geotechnical practice and for an assessment of properties for advance of boom tunnelling machines and prediction of their cutting performance. (A) This paper was presented at Safety in the underground space - Proceedings of the ITA-AITES 2006 World Tunnel Congress and the 32nd ITA General Assembly, Seoul, Korea, 22-27 April 2006. For the covering abstract see ITRD E129148. Reprinted with permission from Elsevier.

Artificial Outcrops Give Real Experience in Interpreting a Geologic History: The CMUland Group Project for Historical Geology Courses

A basic goal of historical geology courses is for students to gain an understanding of the methods, theories, and logic used in interpreting geologic histories. This is traditionally taught as a series of individual, isolated lessons in identification of rocks, fossils, and sedimentary structures and interpretations of radiometric dating, sequences of events, past depositional environments, and past tectonic events. A supplemental project incorporating these lessons teaches students to evaluate different types of data and use critical thinking to reconstruct a geologic history. Here, a semester-long, group project has been developed that allows students to use their lab- and classroom-honed skills on real rocks in a field setting. Our “field area” includes 11 artificial outcrops, representing six rock types. Students must: (1) identify rock types and fossils; (2) calculate radiometric ages; (3) recognize stratigraphic contacts, geologic structures, and cross-cutting relationships; and (4) critically evaluate this data to give a chronological history of past environments, tectonic events, and even climate. Assessment shows that student learning was enhanced greatly as a result. Not only did students acquire more experience and a deeper understanding in the mechanics of historical geology, they also gained an appreciation for the work required to interpret a geologic history.

Palynology and palynostratigraphy of Maastrichtian, Paleocene, and Eocene strata in the Denver Basin, Colorado

Palynological analysis provides data for determinations of ages and paleoenvironments of Maastrichtian, Paleocene, and Eocene strata in the Denver Basin. These strata were sampled on the surface at natural and artificial outcrops (construction sites) and in the subsurface via auger, drill core, and well cuttings. Extensive artificial outcrops existed temporarily during construction of the Denver International Airport. The Kiowa core, drilled as part of the Denver Museum of Nature & Science9s Denver Basin Project, is the principal palynostratigraphic reference section for the basin. It is supplemented by data from the Castle Pines core. Palynostratigraphic zonations of the Kiowa and Castle Pines cores are correlated with magnetostratigraphic zonations in the same cores. Regionally known palynostratigraphic biozones are present in the basin, as follows: Aquilapollenites striatus Interval Zone (Maastrichtian) in the Fox Hills and Laramie Formations; Wodehouseia spinata Assemblage Zone (uppermost Maastrichtian) in the lower part of the D1 sequence; Zones P1 through P3 (lower Paleocene) in the upper part of the D1 sequence; Zone P6 (uppermost Paleocene) locally at the base of the D2 sequence; and Zone E (lowermost Eocene) in the D2 sequence, above the basin-wide paleosol unit. The K–T boundary is bracketed by samples from the Kiowa and Castle Pines cores and is located within centimeters at the West Bijou Site. The Paleocene–Eocene boundary is determined to be within the paleosol unit of the Denver Basin, near the base of the D2 sequence. These and other palynological age determinations supplement independent paleobotanical and vertebrate paleontological research in the Denver Basin.

État des recherchessur la faune de Mammifères du Montien de Hainin (Belgique)

The search for a european Paleocene mammal fauna older than the Thanetian has been a long one… The discovery at last of a few micromammal teeth in continental Montian was made almost by chance when I. Godfriaux of the Mons School of Mines asked me for identification of bone scraps recovered from a small-diameter boring conducted by him in 1970 in the type area of the Montian at Hainin. The country beeing flat and low, even artificial outcrops are rare and incomplete, so the boring was necessary for a better knowledge of the stage. Despite the unusual setting for a mammal quarry (at a depth between 10 and 25 m, in unconsolidated sediments below the water table) this discovery prompted us to apply for à Fonds National de la Recherche Scientifique grant. Thanks to this enlightened Belgian institution I. Godfriaux was able to open in 1973 a conventional pit, earth-proofed by a steel pipe, equipped with a water-pump and wide enough for a little man to shovel at the bottom. A bad accident interrupted the excavation for months but it was resumed and ended in 1974. The concentration in mammal remains proved tobe variable but never high nor nil, so we had to wash and sieve all of the sediments below marine Landenian. Most of the teeth beeing very small we used a 0,43 mm mesh! All the matrix has been pretreated at Mons and the residue has been sent to Montpellier where it is in the process of beeing re-washed-and-sieved and sorted. At the present rate we will not be through before years! The material presently sorted ranges from 11 m to 17 m depth and comprises 91 mammals fragments which are entire or incomplete isolated teeth and a very few bones. Lower vertebrate remains, mainly fish teeth and scales, are much more abundant. The biggest mammal is a multituberculate, seemingly referable to Catopsalis. Let us note incidentally that this genus is unknown in North America later than Puercan times. Most mmamals are very small tribosphenic eutherians. Among them are nyctitheres, adapisoricids, erinaceomorphs, apatemyids and possibly miacids (or paroxyclaenids). There are a few small bunodonts; one of them approaches Louisina and Microhyus, a group of condylarths endemic to Europe. Metatherians are problematic. On geological grounds this fauna is Montian, that is to say older than Thanetian. On paleontological grounds the provisional impression is of an older age than the classical Upper Paleocene faunas of North America and Europe (French Thanetian and Walbeck). As expected this fauna exhibits North American affinities but also a moderate degree of endemicity. The study of animal and plant fossils from Hainin will be conducted on an international cooperative basis under the supervision of I. Godfriaux, the work of mammalogists beeing organised from now on by B. Sigé.

Commentary on “Radioactive waste storage in the arid zone”

The length of the reference list in the paper ‘Radioactive Waste Storage in the Arid Zone’ by Isaac Winograd (EOS, 55,884–894, 1974) suggests that the author read extensively. However, at least two of the references contain information, if examined intensively, that tends to refute the author's assertion of the lack (or low value) of deep infiltrations under interfluve areas. A photograph in a work by Ruhe [1967, p. 61] shows stringers of caliche descending into the subsoil in an area of about 8 in. (∼203 mm) of precipitation annually. Brown [1956] pointed out that caliche under surface depressions extended tens of meters down into the vadose zone of the High Plains in an area of 16–22 in. (∼404–559 mm) of precipitation. Abundant natural and artificial outcrops observed by the writer reinforce these evidences of deep infiltration through the vadose zone in interfluve areas where precipitation does not exceed 10 in. (254 mm) per year. There is no reason why ‘periodic recharge by see page’ should not occur under minor as well as ‘major arroyo bottoms’ or why ‘deep infiltration beneath closed depressions’ should not occur under small depressions in semiarid areas as well as under the larger ones of the High Plains.

Growth and submarine fossilization of algal cup reefs, Bermuda*

ABSTRACTSmall charges of explosives were used to section cup‐shaped reefs that occur on the margins of the Bermuda Platform. Study of these artificial outcrops, up to 10 m high, and the samples collected from them show how the reef‐building community is rapidly converted to well‐lithified reef rock in the marine development.The reefs, known locally as boilers and breakers, occur along the wave‐swept south shore of the Bermuda Islands and around the northeast and northwest margins of the Platform. They are cup‐shaped, up to 30 m in long dimensions, and rise up to the sea surface as much as 12 m above the surrounding sea floor. The reefs are built by an intergrowth of encrusting organisms, principally crustose coralline algae, an encrusting hydrozoan, Millepora sp., and an attached gastropod, Dendropoma irregulare.The growth framework of these algal cup reefs has extensive voids: large and intermediate‐sized growth framework and shelter pores; borings of bivalves and sponges; and both intra‐ and inter‐particle pores. A variety of vagile and sessile organisms (coelobites) inhabit these pores: an encrusting Foraminifera, Homotrema rubrum, is the most abundant attached coelobite; the tests of a variety of benthic Foraminifera and ostracods are common: branched coralline algae, barnacles, bivalves, ahermatypic corals, bryozoans, and burrowing crustaceans occur in varying abundance.Beginning millimetres below the living surface, internal sediments accumulate in the extensive voids. Coarse‐grained skeletal sand derived from the surface of the reefs is characteristic of the larger voids; lime mud with the tests of planktonic Foraminifera and planktonic algae occurs generally in the smaller voids. Most specimens from the interior of the reefs show multiple generations of internal sediment that vary in grain size, composition, and colour. The sand‐sized sediments are pumped into the voids by the frequent and intense wave action; the lime mud settles out in the smaller, less agitated pores.Cementation of internal sediments and surrounding growth frame begins centimetres below the living surface; it is so pervasive that marble‐hard reef rock is developed within 1/2 m or less. The cement is principally high‐magnesium calcite of micrite size, and subordinately acicular aragonite, but there are locally wide variations in crystal size and morphology. The occurrence of the cement within the reefs well below sea level, the isotope ratios of the cement crystals, the mineralogy, and the age inferred from radiocarbon age determinations of the growth frame all indicate that the cement is submarine and deposited from water of oceanic composition.The algal cup reefs of Bermuda demonstrate the reef‐building ability of a community of encrusting organisms that form only crusts in the intertidal zone of the Mediterranean and Northern Brazil. The cup reefs of the northern margins of the Bermuda Platform are true reefs, not merely veneers covering eroded blocks of Pleistocene limestone. In their composition, location, and early diagenesis, the cup reefs closely resemble the algal or lithothamnion ridge of Pacific atolls. Synsedimentary cementation of internal sediments and growth frame makes a major contribution to the rigidity of these ocean‐facing reefs and atoll rims.The assemblage of features that characterize the submarine fossilization of the cup reefs is widespread elsewhere in the modern seas: the floors of the Persian Gulf and parts of the Mediterranean; the margins of Pacific atolls; and the reefs off the north coast of Jamaica. This fossilization is characterized by reiterated generations of coelobites, internal sediments, and synsedimentary cements that can in time replace a major part of the original growth framework. Major variations in the sequence of these generations from pore to pore is the signature of this kind of fossilization. The same features of fossilization are described from reefs in the Devonian, Permian, and Triassic.