Quaternary Caspian Sea level variations depended on geophysical processes (affecting the opening and closing of gateways and basin size/shape) and hydro-climatological processes (affecting water balance). Disentangling the drivers of past Caspian Sea level variation, as well as the mechanisms by which they impacted the Caspian Sea level variation, is much debated. In this study we examine the relative impacts of hydroclimatic change, ice-sheet accumulation and melt, and isostatic adjustment on Caspian Sea level change. We performed model analysis of ice-sheet and hydroclimate impacts on Caspian Sea level and compared these with newly collated published palaeo-Caspian sea level data for the last glacial cycle. We used palaeoclimate model simulations from a global coupled ocean-atmosphere-vegetation climate model, HadCM3, and ice-sheet data from the ICE-6G_C glacial isostatic adjustment model. Our results show that ice-sheet meltwater during the last glacial cycle played a vital role in Caspian Sea level variations, which is in agreement with hypotheses based on palaeo-Caspian Sea level information. The effect was directly linked to the reorganization and expansion of the Caspian Sea palaeo-drainage system resulting from topographic change. The combined contributions from meltwater and runoff from the expanded basin area were primary factors in the Caspian Sea transgression during the deglaciation period between 20 and 15 kyr BP. Their impact on the evolution of Caspian Sea level lasted until around 13 kyr BP. Millennial scale events (Heinrich events and the Younger Dryas) negatively impacted the surface water budget of the Caspian Sea but their influence on Caspian Sea level variation was short-lived and was outweighed by the massive combined meltwater and runoff contribution over the expanded basin.

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In order to improve our understanding of the NW-Amazonian Craton evolution, we present new petrographic, geochemical and geochronological analyses of 27 samples from the geotectonic Rio Negro-Juruena Province in eastern Colombia (Guainía and Vaupés departments). New LA-ICP-MS zircon U-Pb ages suggest that the oldest known rocks in Colombia are metamorphic rocks (migmatitic gneisses) with ages between ~ 1850 and ~ 1800 Ma, and gneisses and granitoids with ages between ~ 1800–1720 Ma which form part of the Mitú Complex, interpreted as the result of Statherian collisional and orogenic events (Querari Orogeny). Detrital zircons in low-grade meta-sedimentary sequences of the Tunuí Group (sandstones, conglomeratic sandstones and mudstones), that crop out over almost the entire basement, indicate older than ~ 1770 Ma source rocks. Intrusions of different suites of granitic rocks with syn- to post-collisional affinities suggest a termination of the collisional events between ~ 1600–1500 Ma which had affected the whole region, occasionally metasomatically overprinting parts of the Tunuí meta-sedimentary sequence. The recognizable metamorphic and magmatic-processes finish with ~ 1400–1340 Ma anorogenic granites without signs of tectonic deformation, resembling anorogenic granites in the Western Amazonian Craton in Brazil and the Parguaza Batholith in Venezuela. This study allows us to conclude that the basement records the collision of a continental arc (Rio Negro-Juruena Province) against the NW-Amazonian Craton (Ventuari-Tapajos Province) and its subsequent transition to anorogenic conditions in a continental rift setting long before the actual stable craton conditions.

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Alluvial diamonds have been found in Suriname since the late 19th century, but to date the details of their origin remain unclear. Here we describe diamonds from Paramaka Creek (Nassau Mountains area) in the Marowijne greenstone belt, Guiana Shield, north-eastern Suriname. Thirteen samples were studied, consisting mainly of euhedral crystals with dominant octahedral and dodecahedral habits. They had colourless to brown to slightly greenish body colours, and some showed green or (less commonly) brown irradiation spots. Surface features showed evidence of late-stage resorption that occurred during their transport to the earth's surface. The studied diamonds were predominantly type IaAB, with nitrogen as both A and B aggregates. In the DiamondView most samples displayed blue and/or green luminescence and concentric growth patterns. Their mineral inclusion assemblages (forsterite and enstatite) indicate a peridotitic (possibly harzburgitic) paragenesis.

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The Armina Formation along the Coppename River is a part of the 2.26-2.10 Ga Paleoproterozoic Marowijne Greenstone Belt of Suriname. It is in faulted contact with the 2.08-2.05 Ga Bakhuis Granulite Belt. This paper studies the relation between these units based on field observations, petrographic, geochemical and age data. The metaturbidites show a volcanic arc-type setting in the north, and a continental arc setting in the south. No traces of any Bakhuis provenance could be demonstrated in the metaturbidites. Detrital zircons from the Armina metaturbidites show ages around 2162 ± 30 Ma, which is similar to the age of Armina Formation detrital zircons elsewhere in northern Suriname. As Bakhuis sillimanite gneisses also show inherited zircons between 2120 and 2150 Ma, the Bakhuis granulites and Armina metaturbidites protoliths might be coeval and share a common provenance area. Younger granites intruding the Armina metaturbidites show ages of 2005 (Voltzberg), 2004 (Raleigh Falls) and 1990 Ma (Vankaaikisula), slightly higher than most Wonotobo granites in western Suriname.@en

The Caspian Sea is an evolutionary island whose rich and endemic fauna have evolved in partial isolation over the past two million years. Baseline studies of pre-20^th Century communities are needed in order to assess the severity of the current Caspian biodiversity crisis, which mostly involves invasive species. An inventory of late Holocene shelly assemblages (c. 2000–2500 cal yr BP) from outcrops in and around Great Turali Lake (Dagestan, Russia) shows a diverse nearshore community consisting of 24 endemic Caspian species, two invasive species and two Caspian native species that lived in a shallow embayment with mesohaline salinities of circa 5–13 psu (parts per thousands). This pre-crisis Holocene Caspian mollusc community serves as a baseline against which modern mollusc diversity measurements can be evaluated. Examination of faunas from similar environments living today and in the past illustrates the dramatic changes in nearshore communities during the 20^th Century. Our study identifies a habitat that may have served as a refuge, but that is currently under threat from invasive species. The severity of the Caspian biodiversity crisis is comparable with other well-known biodiversity crises in semi-isolated ecosystems such as the cichlid fish communities of Lake Victoria, Africa.

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The Pontocaspian (Black Sea - Caspian Sea) region has a very dynamic history of basin development and biotic evolution. The region is the remnant of a once vast Paratethys Sea. It contains some of the best Eurasian geological records of tectonic, climatic and paleoenvironmental change. The Pliocene-Quaternary co-evolution of the Black Sea-Caspian Sea is dominated by major changes in water (lake and sea) levels resulting in a pulsating system of connected and isolated basins. Understanding the history of the region, including the drivers of lake level and faunal evolution, is hampered by indistinct stratigraphic nomenclature and contradicting time constraints for regional sedimentary successions. In this paper we review and update the late Pliocene to Quaternary stratigraphic framework of the Pontocaspian domain, focusing on the Black Sea Basin, Caspian Basin, Marmara Sea and the terrestrial environments surrounding these large, mostly endorheic lake-sea systems.@en

Proterozoic metamorphic and igneous rocks belonging to the Guiana Shield form the basement of the Colombian territory from its eastern borders westwards to at least the eastern flanks of the Central Cordillera. A small part of the Amazonian basement underlain by felsic metavolcanics records the Trans-Amazonian Orogeny (2.26–1.98 Ga), the major orogenic event that shaped most of the Guiana Shield. The main part of the Colombian Amazonian and Orinoquian basement and of the adjacent Venezuelan and Brazilian territories consists of high-grade, largely supracrustal metamorphic rocks which accreted onto the Trans-Amazonian basement during the Querarí Orogeny (1.86–1.72 Ga) and was intruded by Mesoproterozoic anorogenic plutons around 1.59–1.51 Ga. The Andean Precambrian basement crops out in upthrust blocks all along the Eastern and eastern Central Cordillera, from the Garzón Massif in the south to the Guajira Peninsula in the north, and continues further northeast into Venezuela and eastwards into the Subandean basins. The Andean basement consists mainly of granulites and other high-grade metamorphic rocks, mainly of supracrustal origin, as well as minor plutons, formed during the Grenvillian Orogeny (1.1–0.9 Ga) caused by the collision of Amazonian and Laurentia. Echos of this collision are also discernable in the adjacent Amazonian basement as large shear faults, folding and low-grade metamorphism of Mesoproterozoic sandstone sequences, thermal mineral age resetting and minor alkaline magmatism.

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The interior of the Guiana region in north‐eastern South America was one of the last mountain areas to be explored in the Americas; the flat and rocky summit of Roraima was ascended for the first time only in 1884. This is one of more than 60 such table mountains, called tepuis by the local indigenous inhabitants. Most of these mountains and mountain ranges, distributed over the still largely inaccessible interfluvium between the Amazon and Orinoco rivers, have now been identified and mapped. Some have been partially explored scientifically, but the majority are still virtually unexplored. The geology, hydrology, climate, biodiversity, contemporary and evolutionary biology and exploration of the region are discussed in this chapter. Four different age groups of sandstone plateaus occur in the region: the Roraima tepuis, the Neblina tepuis, the Tunuí sandstone plateaus and the Chiribiquete–Araracuara sandstone plateaus. The latter are located in Colombia, while the first three are mainly found in Venezuela and adjacent Brazil and Guyana. The relatively isolated mountain summits of the Guiana tepuis above ~1500 m form the Pantepui Province of the Guiana biogeographical region, one of the most biologically interesting bioregions of the Neotropics. This province harbors an assemblage of highly characteristic biota: the flora consists of almost 130 plant families with 336 (including 61 endemic) genera and over 2100 (with almost 1300 endemic) species, which are distributed in several floristic areas. The animal life – of which birds, mammals, frogs and lizards are the best known – is characterized by similarly high levels of endemicity, in spite of relatively low population densities, probably due to the low nutrient contents of the dominant plant groups. Recent genetic studies show that diversification of this rich and endemic biota, once thought to have taken place in nearly complete isolation, is in fact characterized by sparse but continuous biotic interchange with other regions and ecosystems in South America. In this sense, the Guiana Highlands have functioned both as a source and a sink of diversity to the rest of the continent. Although some of the lineages colonizing the tepuis were pre‐adapted to the mountain environment, most had to develop features to cope with the novel ecological conditions encountered. Phylogenetic analyses further show that current diversity may be underestimated, with both well‐differentiated and cryptic species awaiting discovery. @en

Wie zich zorgen maakt over een stijgende zeespiegel, zo schrijft Salomon Kroonenberg in 'Spiegelzee', vergeet dat de mensheid zoiets al eerder heeft meegemaakt. Zo'n 120.000 jaar geleden stond de zeespiegel zes meter hoger dan nu, en lag Amersfoort aan zee. In het koudste deel van de laatste ijstijd, 20.000 jaar geleden, stond hij juist 120 meter lager, en lag de Noordzee droog. De stijging die door het afsmelten van de ijskappen daar weer op volgde ging soms wel twintig keer zo snel als nu. Onze voorouders hebben onvoorstelbare zeespiegelveranderingen meegemaakt, die grote gevolgen voor hun leefmilieu hadden. Kroonenberg vertelt op toegankelijke wijze welke oorzaken daaraan ten grondslag liggen en hoe we dat te weten zijn gekomen. De laatste zesduizend jaar is onze zeespiegel redelijk stabiel, en wereldwijde peilschaalmetingen van de laatste eeuw laten nog geen versnelling zien. Wie inziet hoe inventief onze voorouders zich met weinig middelen aan zeespiegelveranderingen aanpasten, hoeft niet bang te zijn dat wij dat in de toekomst niet ook zelf zouden kunnen@en

Salomon Kroonenberg duikt in de ‘Surinaamse erfenis’ van professor Jan Pieter Bakker, de grote man van de Amsterdamse fysisch geografen in de jaren
1940-60. Omdat Bakker veel bevindingen publiceerde in congresbundels en gedenkboeken van collega’s in Duitsland, Frankrijk en Oost-Europa, bleven zijn inzichten vrijwel onbekend in Suriname.@en

The sedimentological, metamorphic, petrographic and geochemical characteristics of the Armina Formation, part of the Paleoproterozoic Greenstone Belt of Suriname in South America, are described, based on field, geochemical and petrographic evidence obtained through fieldwork along the Marowijne River and study of diamond drill cores from Rosebel Gold Mine (RGM). The metagreywackes show characteristic features of deposition by turbidity currents: coarse-grained, poorly sorted graded greywackes, covered by fine-grained, parallel-laminated phyllitic beds, often with convolute structures and climbing ripples. Their immature character and composition suggest deposition in an arc-trench environment. In the Marowijne River three different facies of metagreywackes are distinguished: (1) the greyish Bonnidoro Falls facies, characterised by common red millimetre-sized pseudomorphs after siderite in the finer beds, (2) the green Paroe Tabiki metagreywacke facies, with decimetre-sized calcsilicate nodules, both metamorphosed in the lower greenschist facies with chlorite as the main mafic mineral, and (3) the grey Armina Falls metagreywacke facies, geochemically similar to the Bonnidoro type but of higher metamorphic grade with biotite as the main mafic mineral. The metagreywackes from the Marowijne River show a predominance of quartz, plagioclase and lithic (tonalitic) clasts, suggesting exhumation of tonalite–trondhjemite– granodiorite plutons before deposition of the turbidites. There is a slight increase in maturity from (1) to (3), suggesting increasing weathering in the source areas. The metagreywackes of the RGM (JZone) have a predominantly metavolcanic origin, suggesting that they have a different provenance area than the Marowijne metagreywackes. Geochemically the spread in composition within each facies is larger than between the facies because of the wide range in grain sizes in each turbidite sequence. A large part of the rocks from the RGM, classified by previous authors as arenites, are geochemically and petrographically metagreywackes. Only a few RGM samples are real arenites, and plot as a separate cluster in geochemical factor score plots because of their low Fe and Na contents. @en

The Proterozoic basement of Suriname consists of a greenstone–tonalite–trondhjemite–granodiorite belt in the northeast of the country, two highgrade belts in the northwest and southwest, respectively, and a large granitoid–felsic volcanic terrain in the central part of the country, punctuated by numerous gabbroic intrusions. The basement is overlain by the subhorizontal Proterozoic Roraima sandstone formation and transected by two Proterozoic and one Jurassic dolerite dyke swarms. Late Proterozoic mylonitisation affected large parts of the basement. Almost 50 new U–Pb and Pb–Pb zircon ages and geochemical data have been obtained in Suriname, and much new data are also available from the neighbouring countries. This has led to a considerable revision of the geological evolution of the basement. The main orogenic event is the Trans-Amazonian Orogeny, resulting from southwards subduction and later collision between the Guiana Shield and the West African Craton. The first phase, between 2.18 and 2.09 Ga, shows ocean floor magmatism, volcanic arc development, sedimentation, metamorphism, anatexis and plutonism in the Marowijne Greenstone Belt and the adjacent older granites and gneisses. The second phase encompasses the evolution of the Bakhuis Granulite Belt and Coeroeni Gneiss Belt through rift-type basin formation, volcanism, sedimentation and, between 2.07 and 2.05 Ga, high-grade metamorphism. The third phase, between 1.99 and 1.95 Ga, is characterised by renewed high-grade metamorphism in the Bakhuis and Coeroeni belts along an anticlockwise cooling path, and ignimbritic volcanism and extensive and varied intrusive magmatism in the western half of the country. An alternative scenario is also discussed, implying an origin of the Coeroeni Gneiss Belt as an active continental margin, recording northwards subduction and finally collision between a magmatic arc in the south and an older northern continent. The Grenvillian collision between Laurentia and Amazonia around 1.2–1.0 Ga caused widespread mylonitisation and mica age resetting in the basement. @en

Gold has been a major economic asset for Suriname for more than a century. The long history of gold mining, concentrated in large parts of a greenstone belt in the northeast of the country, began with small-scale artisanal extraction activities and has recently seen the development of major open-pit operations. Despite the range of mining activities, Suriname’s gold deposits and occurrences are under-explored from a scientific point of view. Primary gold mineralisations in the greenstone belt occur in multiple forms, and although their origin is commonly related to the Palaeoproterozoic Trans-Amazonian orogeny, the controls of ore formation in specific cases often remain obscure. This contribution presents an abridged overview of currently available information on the geological setting and characteristics for some of the main deposits where gold is extracted. In view of the consistent link between gold metallogeny and granitoid–greenstone belts in the northern Guiana Shield, the mineralised settings in Suriname are discussed in a regional context. @en

This article is based on long-term research of aquatic landscapes in the Volga River delta which was held in 2010–2012 and included investigation and sampling of bottom sediments in deltaic lagoons, fresh-water bays, small channels, oxbow lakes, and part of the deltaic near-shore zone. Contrasting hydrological regime and suspended matter deposition together with huge amount of water plants in the river delta provide for the formation of different types of subaquatic soils. The purpose of this research is to reveal the properties of the subaquatic soils in the Volga River deltaic area and to propose pedogenetic approaches to the diagnostic of aquazems as soil types. It is suggested to name the horizons in aquazems in the same way as in terrestrial soils in the recent Russian soil classification system, and apply symbols starting with the combination of caps – AQ (for “aquatic”). The aquazems’ horizons are identified and their general properties are described. Most typical of aquazems is the aquagley (AQG) horizon; it is dove grey, homogeneous in color and permeated by clay. The upper part is usually enriched in organic matter and may be qualified for aquahumus (AQA) or aquapeat (AQT) horizons. In case of active hydrodynamic regime and/or strong mixing phenomena, the oxidized (AQOX or aqox) horizon, or property could be formed. It is yellowish-grey, thin, and depleted of organic matter. The main types of aquzems specified by forming agents and combinations of horizons are described. @en

This special issue of the Netherlands Journal of Geosciences / Geologie en Mijnbouw contains the proceedings of the Conference on the Economic Geology of Suriname, held on 16 January 2015 in The Hague, the Netherlands, to honour Dr Eddie Jharap (Fig. 1), founder and former Chief Executive Officer of Staatsolie, Suriname. At this conference the President of the Royal Netherlands Geological and Mining Society (KNGMG), Drs Lucia van Geuns, awarded him the prestigious Van Waterschoot van der Gracht Medal, the highest honour available to an earth scientist in the Netherlands. Dr Jharap expressed his gratitude in a warm and humble speech which highlighted both his strong personal motivation to contribute to the development of Suriname, and his astonishing accomplishments since the 1980s in founding and developing Staatsolie.@en