Palaeogeographical Studies Research Articles

Natural and anthropogenic factors affecting intense slope processes in Eastern Europe during the Modern Period: Serteyka river valley, Russia

Detailed palaeogeographical studies of the accumulative fan in the Serteyka River valley in W Russia and underlying biogenic deposits were carried out. The base of a representative core of biogenic sediments in the distal zone is dated to 1291 BC, while its top to 1631 AD. In this paper, palynological, plant macrofossils, Chironomide and Cladocera, geochemical, geochronological and sedimentological analysis were performed. Four phases of biogenic deposition were distinguished by pollen and geochemical analyses. Two of them coincide with the climatic fluctuation during Medieval Climate Anomaly and Little Ice Age. During the formation of the fan, overbank deposits were accumulated also, indicating numerous and intense floods, which are in line with the trend observed for other sites in this region. The accumulative fan is formed by lower, middle and upper deluvia and agricultural diamicton in its top. All units have specific sedimentological and geochemical features as well as low admixture of plant macrofossils. The beginning of the formation of this relief form dates back to the second half of the 17th century AD, and the end of the accumulation falls on the second half of the 18th century AD. Our work suggests that natural conditions had an impact on the formation and development of studied accumulative fan, however, the decisive factor causing the intensification of the slope processes were related with deforestation resulted from strong human impact, which was marked in palynological and macrofossils analyses (e.g. increase in the contribution of plants macrofossils related to agriculture).

The myth of the Highland Cretaceous revealed by the art of palaeogeographic mapping

Abstract Since the term was coined in 1873, palaeogeography has provided a powerful map-based tool for synthesizing, visualizing, and testing diverse regional data and hypotheses, but there are problems in deducing the palaeogeography of areas with few data points. As an example, the Scottish Highlands are better mapped and more studied than almost any other ancient orogen, yet questions remain on the persistence of topography since the Caledonian orogeny and the possibility of Cretaceous marine inundation. This paper reviews the data available on Scottish Cretaceous outcrops using published geological maps and memoirs to extract data: outcrop length, stratigraphic thickness and component units, elevation range of the outcrop and subcrop formations. All Cretaceous rocks in western Scotland were deposited in shallow marine and shoreline environments; deposits thin northwards and appear to be close to a feather edge. Elevation data are used to construct a Cretaceous surface which intersects present-day topography at low to intermediate altitudes. It is concluded that the Scottish Highlands were largely emergent during the Late Cretaceous, confirming previous palaeogeographic studies.

The organic geochemistry of Permian high latitude sediments in two boreholes in the southern Sydney Basin, New South Wales, Australia

Twenty six samples of Permian high latitude sedimentary rocks from the southern Sydney Basin were analysed using organic geochemical methods for their thermal maturity, organic matter inputs, and depositional environment. Fourteen samples are from the Elecom Clyde River (ECR) DDH01 borehole (inland; Southern Highlands), and 12 are from the ECR-DDH07 borehole (coastal; near Nowra). The analysed formations are the Berry Siltstone, the Nowra Sandstone, the Wandrawandian Siltstone, the Snapper Point Formation and the Pebbley Beach Formation. This study is the first organic geochemical study of samples from the Berry Siltstone and Nowra Sandstone. The formations mostly have total organic carbon varying from 1 to 2 wt%, but the Snapper Point Formation is leaner in TOC (0.2–0.7 wt%). The samples vary from low to very high thermal maturity. The samples from the ECR-DDH01 borehole are in the early to middle of the oil window (vitrinite reflectance equivalent = 0.60–0.80%), based on hopane, sterane, alkylnaphthalene, alkylphenanthrene, alkylbiphenyl, and alkyldibenzothiophene thermal maturity parameters. The samples from the ECR-DDH07 borehole are much more thermally mature, in the late part of the oil window to the early gas window (vitrinite reflectance equivalent = 1.2–1.7%). This high thermal maturity has led to the loss of nearly all polycyclic biomarkers, and the thermal rearrangement of many groups of compounds, including monomethylalkanes. The ECR-DDH01 borehole location and time-equivalent outcrop samples south-west of Ulladulla have similar thermal maturities and are close to the margins of the Sydney Basin, and it is estimated to have previously been covered by about 3 km of overburden. In contrast, the samples in the ECR-DDH07 borehole were buried much deeper, with about 4–5 km of overburden, which means that only limited information about their source inputs and depositional environment could be recovered. Aliphatic biomarker, n-alkane and aromatic data are consistent with an overall strong terrigenous organic matter input for the samples from the ECR-DDH01 borehole. Sterane/hopane ratios are mostly low, but only a few compounds diagnostic of specific source inputs were identified. There is a microbially-dominated sample near the base of the Snapper Point Formation (high C29 αβ hopane/C30 αβ hopane ratio and 2α-methylhopanes), and high amounts of parent polycyclic aromatic hydrocarbons in some samples from the Berry Siltstone, likely reflecting an occasional pyrogenic signature from palaeo-forest fires. Several parameters, including sterane carbon number distributions, terpane ratios and the relative abundance of dibenzofuran compared to phenanthrene show that the samples from the ECR-DDH01 borehole have a more strongly terrigenous signal than the previously analysed outcrop samples. This is inferred to be because the ECR-DDH01 location was closer to the palaeo-shoreline than the likely more distal outcrop samples. Based on the pristane/phytane ratio and hopane distributions, deposition of the sediments was under varying oxicity conditions, from highly oxic to suboxic. The inferred environments are marine shale/lacustrine and fluvial/deltaic, so the organic geochemical data agrees with the Permian depositional history of the southmost part of the Sydney Basin previously inferred from sedimentological and palaeogeographic studies.

Palaeogeographic significance of rugose corals: El Guadiato Area (Southwestern Spain) as a case study

Carboniferous rugose corals are useful for palaeoecological, palaeoenvironmental and palaeogeographic studies. However, most analyses are qualitative and/or comprise corals from long stratigraphical intervals, and detailed palaeogeographic studies in the Carboniferous from western Palaeotethys are scarce. This report presents a quantitative analysis of the late Visean coral assemblages from the El Guadiato Area (Southwestern Spain), which has been thoroughly studied during the last 30 years. This case study aims to check the utility of rugose corals in detailed palaeogeographic studies, reconstructing tectonic movements in the suture zone between the Ossa Morena and Centroiberian domains in the Iberian Massif. Sixty-one rugose coral species from the El Guadiato Area were included in the analyses. Moreover, two other late Visean rugose coral faunas have been added as an external reference: Los Santos de Maimona (Southwestern Spain) and Kingscourt (Ireland). The presence/absence datasets have been treated with paired group (UPGMA) Hierarchical Clustering and a Detrended Correspondence Analysis. The results of this study support previous observations about the palaeogeography of the El Guadiato Area, backing the hypothesis that the strike slip faults of the area produced large lateral displacements. The results of analyses conducted at this level of detail appear to be conditioned by palaeoenvironmental differences, but the results of the comparison with Los Santos de Maimona and with Kingscourt’s faunas look promising for future larger comparisons between different basins.

Prospect evaluation based on integrated petroleum system analysis: Block E case study, south-eastern edge of Precaspian Basin (Kazakhstan)

Generative potential and thermal maturity for Upper Palaeozoic source rocks from the south-eastern edge of Precaspian Basin were determined using Rock–Eval. A high hydrocarbon source rock generative potential and high degree of thermal maturity for the Lower Permian, Mid-Carboniferous strata have been revealed based on 39 rock samples. TOC values of 0.4–5.5% have been obtained for mature source rocks. Integrated geochemical analysis determined from Rock–Eval studies combined with 1D basin modelling was utilized in order to reconstruct thermal evolution for the Upper Palaeozoic source rocks. Calibrated 1D models for three wells had been constructed to understand petroleum system. For two deep exploration wells (Nur-1 and Tassym SE-1), which penetrated pre-salt strata at the depths of 5.7 and 7 km, respectively, the impact of salt diapirism on timing of maturation was modelled. Type II kerogen was used, which is based on previous palaeogeographic studies. The stratigraphic framework and major stages of geodynamic evolution were analysed. Salt-related structural traps in post-salt strata have been described based on 3D seismic data, and additional intra-salt sediment packages have been delineated. Discovered producing oil fields in the Upper Triassic and Jurassic–Cretaceous stratigraphic sections are mainly confined to the four-way dip structural closures above the steep flanks of salt structures. Based on burial and thermal modelling, the maturation and generation behaviour of kerogen Type II below salt-related minibasins and close to thick salt diapirs were inferred. For Lower Permian SR with type II kerogen, the generation peak (maturity over 50%) occurs in Middle to Late Jurassic. For predominantly carbonate and terrigenous-carbonate Mid-Carboniferous marine SR, generation peak occurs earlier below salt withdrawal minibasins. Implications for deeper hydrocarbon prospectivity were made for the study area, and methodology for evaluating hydrocarbon potential adopting 1D basin modelling technique and geochemical data is presented.

Zastosowanie ziemskich izotopów kosmogenicznych w datowaniu glin lodowcowych – potencjał, ograniczenia i perspektywy badawcze

Application of in situ cosmogenic nuclides in dating glacial till – research potential, limitations and prospects. A b s t r a c t. Determination of numerical age for glacial till is one of the most intriguing issues in glacial geology and geomorphology. Till layers are unequivocal evidence of ice sheets advances and retreats, and therefore they are very important for Quaternary palaeoclimatic reconstructions. Herein, we present a review dedicated to the methodology of glacial till dating with in situ cosmogenic nuclides. This relatively novel approach enables direct dating of deposition of till and its exposure after deglaciation. Getting reliable numerical age (in years) of till opens a new prospect for reconstructions of past glaciations and palaeogeographic studies. Despite some limitations of applying in situ cosmogenic exposure and burial dating, we argue that this technique may be successfully employed in studies of glacial deposits in Poland.

Self‐constraining of low‐energy rivers explains low channel mobility and tortuous planforms

AbstractMeandering rivers are abundant on Earth, from the largest rivers to the smallest tributaries. The classical view of meandering rivers is a sinuous planform with rounded bends, which grow and migrate until they are cut‐off. However, many low‐energy meandering rivers have planforms that are much more complex than this classical view due to the heterogeneity of their alluvium, and show relatively limited channel migration. Based on a detailed palaeogeographic study of the Dommel River in The Netherlands, it is inferred that low‐energy meandering rivers may develop tortuous planforms with sharp bends, owing to self‐formed deposits that increasingly constrain the channel mobility. This mechanism is corroborated by data from 47 meandering river reaches of varied scale from around the world, which show that erosion‐resistant floodplain deposits are preserved in the river banks when the river energy is below a critical threshold. The term ‘self‐constraining’ is proposed for low‐energy rivers where an increase in bank stability over time results in progressive tortuous planforms and reduced mobility. A conceptual model, based on the dataset, shows that the increase in bank stability over time also increases the energy required to break out of the tendency to self‐constrain. Self‐constraining thereby enhances the resilience of the system to bank erosion, while an unexpected increase in bank erosion may occur if river energy exceeds the critical threshold. This study provides a novel explanation for the evolution of low‐energy river planforms and dynamics, and provides new insights on their responses to climate changes.

At the edge of the Cantabrian sea. New data on the Pleistocene and Holocene archaeological open-air site of Bañugues (Gozón, Asturias, Spain): Palaeogeography, geoarchaeology and geochronology

Located at the center of the Cantabrian coast in a sedimentary terrace currently at the sea shore, the site of Bañugues (Gozón, Asturias) is one of the key places for studying the first settlements of the Iberian North. In the present work, we show the results of the geoarchaeological study undertaken on the bay of Bañugues and on the stratigraphic sections of the site that still subsist. Likewise, we have included the palaeogeographic study of the coast from the Cape Peñas area; the OSL ages obtained; and the revision (technological and taphonomic analysis) of the archaeological materials coming from the diggings of the 1970s. The lithostratigraphic sequence of Bañugues is composed of two well differentiated units: (1) lower, on the alteration of the substrate formed by breccia and silty and sandy materials with Palaeolithic remains, deposited by solifluction; (2) upper, disconforming from the other, formed by intertidal beachlike silt and sands, with technological remains from the Mesolithic. Concerning the chronology of the lithic materials from the Middle Palaeolithic, the fact that it was part of a solifluction deposit prevents at this moment its precise comprehension.

Topography and melting dynamics of ice‐cored ridges: evidence from the geometry, kinematics and sedimentary evolution of collapse structures within kame deposits, eastern Poland

In earlier studies, the topography and melting dynamics of ice‐cored ridges within marginal zones of the Pleistocene ice sheets were routinely reconstructed based only on conceptual and qualitative models supported by geomorphological, sedimentological and palaeogeographical studies. Here, a novel approach based on detailed structural analysis of two collapse structures affecting Pleistocene kame deposits is presented. The high regularity of the geometry of synclines and related strain fields as well as the patterns of subsidence of the folded strata are all interpreted as evidence of topography of ice‐cored ridges and their melting dynamics. The topography is described in terms of elongation, orientation and cross‐sectional shape of ice‐cored ridges. In turn, the melting dynamics are assessed based on a semi‐quantitative model of different relative rates of backwasting and downwasting. The topography of ice‐cored ridges, derived independently from the morphology of the related supraglacial landforms, is interpreted as an effect of ablation controlled by debris bands within parent ice. The reconstructed ice‐cored ridges are considered to represent the second‐order topographic features within a wide ice‐cored depression. The sedimentary evolution of collapse structures expressed as migration of their hinges/depocentres provides new semi‐quantitative insight into melting dynamics of ice showing the predominance of backwasting over downwasting. This evolution concerns the final stage of de‐icing, which was probably preceded by lowering of the ice‐cored topography and progressive formation of the ice‐cored ridges.

Chronostratigraphy of the late Vistulian in central Poland and the correlation with Vistulian glacial phases

The Vistulian decline was a period of rapid environmental events. The authors correlated ages of the last Scandinavian Ice Sheet limits in northern Poland with ages of prominent events adapting the conditions of periglacial environment of Central Poland in response to the Late Vistulian climate warming. Ages from previous thematic geological and palaeogeographical studies were collected. The approach used indicates that despite methodological uncertainties and sometimes inconsistency of ages, it is especially helpful in timing of first warming signals (ca. 19–18 cal ka BP) and establishing of environmentally bipartite 3 millennia of the Oldest Dryas in the extraglacial zone. Abrupt warming at the onset of the Bølling-Allerød is well registered in biotic and abiotic archives available from Central Poland and remains in agreement with the large recession of the southern ice sheet margin.

Loess and other Quaternary sediments in Germany

ABSTRACTGeo- and palaeoecological studies focusing on the late Pleistocene require a detailed knowledge of the spatial distribution of aeolian sediments. In Germany, existing maps are either on large scales, have a regional focus or show significant inaccuracies such as artificial boundaries within different geological units. To obtain a more detailed, seamless map of the distribution of aeolian sediments and their potential source areas, we combined and reanalysed available geodata, using a Geographical Information System. The resultant maps (scale: approx. 1:2,600,000) show the link between source areas and the late Quaternary aeolian deposits in Germany and can provide one context for further work on, e.g. palaeogeographical studies. This work was compared with other already published datasets and the problems of sediment mapping at a small scale were discussed.

Impacts of Holocene perturbations of the Onega-Ladoga hydrological system on the ancient coastal population

Neolithic settlers of the periphery area of the Last Glaciation were affected during the Holocene by dramatic sequences of the catastrophic environmental transformations. This statement is developed in the paper based on geodynamic approach which is important to understand factors of social-cultural development of those territories. The paper contains results of the investigations of environmental cataclysms in the Onega-Ladoga hydrosystem during the last 7 ca. Three major paroxysms (5,7, 5,3, 3,1 BP) have been identified basing on stratigraphical and spatial analyses of the reference archaeological and palaeogeographical studies of the Vuoksa, Svir and Neva rivers. In each of the mentioned case large earthquake had resulted in drastic water cataclysms. Environment and hydrological regime of the main water basins were chanced and these perturbations stipulated disastrous consequences for lives, livelihoods and migrations of on-shore Neolithic communities.

On palaeogeographic map

The palaeogeographic map is a graphic representation of physical geographical characteristics in geological history periods and human history periods. It is the most important result of palaeogeographic study. The author, as the Editor-in-Chief of Journal of Palaeogeography, Chinese Edition and English Edition, aimed at the problems of the articles submitted to and published in the Journal of Palaeogeography in recent years and the relevant papers and books of others, and integrated with his practice of palaeogeographic study and mapping, wrote this paper. The content mainly includes the data of palaeogeographic mapping, the problems of palaeogeographic mapping method, the “Single factor analysis and multifactor comprehensive mapping method —— Methodology of quantitative lithofacies palaeogeography”, i.e., the “4 steps mapping method”, the nomenclature of each palaeogeographic unit in palaeogeographic map, the explanation of each palaeogeographic unit in palaeogeographic map, the explanation of significance of palaeogeographic map and palaeogeographic article, the evaluative standards of palaeogeographic map and palaeogeographic article, and the self-evaluation. Criticisms and corrections are welcome.

The Etruscan “Volumni Hypogeum” Archeo-Geosite: New Sedimentological and Geomorphological Insights on the Tombal Complex

Geoarchaeology is a multidisciplinary field that uses the methods and the contents of Earth Sciences for a more complete and detailed investigation of historical sites (Waters 1992; Rapp and Hill 1998; Goldberg and Macphail 2005; Ghilardi and Desruelles 2009). In particular, the geoarchaeologycal investigation of a site focuses on the study of stratigraphic sequences and on the clear understanding of the geomorphological and palaeogeographic setting of the area. One of the main goals is to better recognize the ancient environmental context in which the settlement was established. This approach is rather recent, given that the systematic stratigraphic analysis of excavation sites has been used only since the end of the nineteenth century, while the geomorphological reconstruction of the palaeogeographic environment has been applied only since the 1980s (Ghilardi and Desruelles 2009). Moreover, important information is obtained from the study of environmental changes occurred from the period during which the settlement was established until nowadays. Since the location of a historical place is strictly related to the geographica l condi t ions of the s i t e , the palaeogeographic study is essential to localize the position of a site or to understand its time evolution. In this context, the use of geographical information systems (GIS) technology plays an important role, allowing for the investigation of natural and/or artificial characteristics of the Earth surface (Moore et al. 1991; Nelson et al. 2009; Melelli et al. 2012). The great flexibility of these techniques allows us to compare and integrate data provided by Social Sciences as well as Sciences, thus providing unique indications for Geoarchaeology. Until now the integration of Earth Sciences and Archaeology has been mainly used for archaeological purposes. Indeed, Earth Sciences have been used as a Btool^ for archaeological research, with a few feedbacks or advantages for the geological field. On the contrary, now, new potential connections are emerging, with the development of new branches of the Earth Sciences, including the geological heritage identification and promotion. Geological outcrops and geomorphological features characterized by intrinsic, cultural, economic, scientific and educational values are defined in the scientific literature as Bgeosites^ (Panizza and Piacente 2008). These geological heritages are defined as Bany place, area or territory where you can define a geological and geomorphological interest for conservation^ (Grey 2004); in addition to the abiotic values, they can have a strong historical, archaeological and cultural relevance (Melelli 2014; Pica et al. 2015). In order to promote the geological heritage with cultural added values, some archaeological sites, where the stratigraphic or geomorphological surrounding conditions are relevant, can be defined as Barchaeo–geosite^ (Gregori et al. 2005; Gustavsson et al. 2006; Gungor et al. 2012). Moreover, this new approach for the investigation of an archaeological site allows us to export its value from the academic context to a more wide audience, thus increasing its touristic value, and consequently, the economic value of the area. Accordingly, geotourism (a particular branch of tourism interested in the knowledge of the geological heritage) is the * Laura Melelli laura.melelli@unipg.it

Neolithic settlement sites in Western Turkey — palaeogeographic studies at Çukuriçi Höyük and Arvalya Höyük

Çukuriçi Höyük and Arvalya Höyük are two prehistoric settlement mounds (tells) located in parallel striking valleys in the environs of Ephesus, W Turkey. They were studied with geoarchaeological methods in order to reconstruct their environmental setting, areal extension and distinct settlement phases, as well as the vegetation history. Both tells are situated on small ridges flanked by rivers and their alluvial plains which were suitable for cultivation. The Neolithic coastline was located at a distance of c. 1.5–2km to the north. Çukuriçi Höyük covers an area of c. 200m×100m; its strata have a total thickness of at least 8.50m. The oldest remains, dating from the 7th millennium BC, represent an advanced Neolithic culture closely linked to the sea. The oldest foundations reveal that the site was intentionally chosen on the ridge within the still naturally wooded vegetated landscape. Other than Çukuriçi Höyük, Arvalya Höyük has not yet been excavated. However, geophysical measurements and corings revealed that it covers an area of c. 100m×60m, and that it is constructed of several settlement layers with a total thickness of at least 3.50m. Radar and geomagnetic images show building structures including fireplaces and pits, surrounded by a rampart-ditch construction as a potential enclosure.

Inflation in the number of monospecific genera in brachiopods: progress or regression? A trivial approach to a real problem

Since the 19th century, about 1800 brachiopod genera or subgenera have been erected for the period covering the Silurian to the Devonian. In recent years, there has been a pronounced increase in the number of genera containing a single species. Without questioning the technological advances, one can, however, question the value and usefulness of monospecific genera both for systematics and palaeogeographical studies. Some editorial policy regarding erection of new monospecific genera and/or the evaluation of calls for projects are now needed.

Results of the struggle at ancient Ephesus: natural processes 1, human intervention 0

Abstract Coastal areas have been prime locations for habitation and commerce. Early authors such as Pausanias (second century CE), and Strabo (64 or 63 BCE–24 CE) noted the impacts of shoreline changes. Geomorphological and subsurface geological data, combined with archaeological excavation and ancient texts, indicate a long interplay between natural processes of estuarine infilling by sediments from the Küçük Menderes River (ancient Cayster River) and multiple attempts of human intervention to preserve the harbours of Ephesus. Strabo noted that harbour engineering efforts there, such as the construction of a mole to prevent siltation, instead created a sediment trap that made things worse. The pre-Holocene river valley was inundated by Holocene sea-level rise that formed the ancient Gulf of Ephesus. Extensive palaeogeographical studies, based on sediment coring, geomorphology, archaeology and history, have provided details of the problems the inhabitants faced in keeping vital harbours in operation. Dating and analysis of sedimentary deposits has allowed the description of shifting river courses, floodplain changes, human intervention, and anthropogenic deposits at Ephesus. During and following Classical times sediment deposition rapidly began to fill in the embayment, requiring the inhabitants to regularly shift the harbours westward. Ultimately, it was to no avail.

Kelp genes reveal effects of subantarctic sea ice during the Last Glacial Maximum.

The end of the Last Glacial Maximum (LGM) dramatically reshaped temperate ecosystems, with many species moving poleward as temperatures rose and ice receded. Whereas reinvading terrestrial taxa tracked melting glaciers, marine biota recolonized ocean habitats freed by retreating sea ice. The extent of sea ice in the Southern Hemisphere during the LGM has, however, yet to be fully resolved, with most palaeogeographic studies suggesting only minimal or patchy ice cover in subantarctic waters. Here, through population genetic analyses of the widespread Southern Bull Kelp (Durvillaea antarctica), we present evidence for persistent ice scour affecting subantarctic islands during the LGM. Using mitochondrial and chloroplast genetic markers (COI; rbcL) to genetically characterize some 300 kelp samples from 45 Southern Ocean localities, we reveal a remarkable pattern of recent recolonization in the subantarctic. Specifically, in contrast to the marked phylogeographic structure observed across coastal New Zealand and Chile (10- to 100-km scales), subantarctic samples show striking genetic homogeneity over vast distances (10,000-km scales), with a single widespread haplotype observed for each marker. From these results, we suggest that sea ice expanded further and ice scour during the LGM impacted shallow-water subantarctic marine ecosystems more extensively than previously suggested.

Dating impact craters: palaeogeographic versus isotopic and stratigraphic methods – a brief case study

AbstractIsotopic and stratigraphic ages of the ~ 80 km diameter Puchezh-Katunki (Russia; 220 ± 10 to 167 ± 3 Ma) and the ~ 20 km diameter Obolon (Ukraine; 215 ± 25 to 169 ± 7 Ma) impact structures are associated with significant age uncertainties. As a case study, reconstructions of the palaeogeography at the time of crater formation (Late Triassic to Middle Jurassic) based on recent palaeogeographic maps help further to constrain impact ages. Palaeogeographic studies suggest that Puchezh-Katunki is older than 170 Ma and that Obolon is younger than 185 Ma. This also rules out that Obolon formed during a ~ 214 Ma Late Triassic multiple impact event as recently discussed.

Geosciences research in East Antarctica (0°E–60°E): present status and future perspectives

Abstract In both palaeoenvironmental and palaeogeographical studies, Antarctica plays a unique role in our understanding of the history of the Earth. It has maintained a unique geographical position at the South Pole for long periods. As the only unpopulated continent, the absence of political barriers or short-term economic interests has allowed international collaborative science to flourish. Although 98% of its area is covered by ice, the coastal Antarctic region is one of the well-studied regions in the world. The integrity and success of geological studies lies in the fact that exposed outcrops are well preserved in the low-latitude climate. The continuing programme of the Japanese Antarctic Research Expedition focuses on the geology of East Antarctica, especially in the Dronning Maud Land and Enderby Land regions. Enderby Land preserves some of the oldest Archaean rocks on Earth, and the Mesoproterozoic to Palaeozoic history of Dronning Maud Land is extremely important in understanding the formation and dispersion of Rodinia and subsequent assembly of Gondwana. The geological features in this region have great significance in defining the temporal and spatial extension of orogenic belts formed by the collision of proto-continents. Present understanding of the evolution of East Antarctica in terms of global tectonics allows us to visualize how continents have evolved through time and space, and how far back in time the present-day plate-tectonic regime may have operated. Although several fundamental research problems still need to be resolved, the future direction of geoscience research in Antarctica will focus on how the formation and evolution of continents and supercontinents have affected the Earth's environment, a question that has been addressed only in recent years.