<abstract xml:lang="en" xmlns="http://www.w3.org/1999/xhtml">During the Cenozoic, until the Middle Miocene, the Niger Delta grew through pulses of sedimentation over an oceanward-dipping continental basement into the Gulf of Guinea; thereafter progradation took place over a landward-dipping oceanic basement. A 12,000 m thick succession of overall regressive, offlapping sediments resulted that is composed of three diachronous siliciclastic units: the deep-marine pro-delta Akata Group, the shallow-marine delta-front Agbada Group and the continental, delta-top Benin Group.Regionally, sediment dispersal was controlled by marine transgressive/regressive cycles related to eustatic sea-level changes with varying duration. Differential subsidence locally influenced sediment accumulation. Collectively, these controls resulted in eleven chronostratigraphically confined delta-wide mega-sequences with considerable internal lithological variation.The various sea-level cycles were in or out of phase with each other and with local subsidence, and interfered with each other and thus influenced the depositional processes. At the high inflection points of the long-term eustatic sea-level curve, floodings took place that resulted in delta-wide shale markers. At the low inflection points, erosional channels were formed that are often associated, downdip, with turbidites in low-stand sediments (LSTs). The megasequences contain regional transgressive claystone units (TST) followed by a range of heterogeneous fine-to-coarse progradational or aggradational siliciclastic (para)sequence sets formed during sea-level high-stand (HST).An updated biostratigraphic scheme for the Niger Delta is presented. It also updates a sedimentation model that takes into consideration local and delta-wide effects of sea-level cyclicity and delta tectonics. Megasequences were formed over time intervals of ~5 Ma within individual accurate megastructures that laterally linked into depobelts. The megasequences form the time-stratigraphic frame of the delta and are the backbone for the new delta-wide lithostratigraphy proposed here. Such a new lithostratigraphy is badly needed, in particular because of the vigorous new activity in the offshore part of the Niger Delta (not covered in this contribution). There, as well as in the onshore part of the delta, the traditional lithostratigraphic subdivision of the Cenozoic Niger Delta section into three formations is insufficient for optimum stratigraphic application; moreover, the various informal subdivisions that have been proposed over time are inconsistent.</abstract>

Stratigraphy and sedimentology of the Niger Delta

<abstract xml:lang="en" xmlns="http://www.w3.org/1999/xhtml">The Pleistocene to Holocene succession in the Gaza Strip, Palestine, consists of an alternation of calcareous sandstones and reddish fine-grained deposits (palaeosols). The palaeosols can be subdivided into two main groups based on the sand-sized versus clay- to silt-sized grains: (1) the sandy hamra palaeosols, and (2) the loess and loess-derived palaeosols. The hamra palaeosols can, in turn, also be subdivided into two main types according to their colour and grain size: (1) light brown loamy to sandy hamra palaeosols, and (2) dark brown sandy clay hamra palaeosols. The hamra palaeosols are polygenetic and originated in humid environments. Their red colour results from ferric oxides coating the sand grains, but also by illuviation. The various pedogenitic units and their gradual transition to loess palaeosols are due to different phases of dust accretion. Both groups of palaeosols developed during the last glacial. They are considered to represent different climate environments: hamra palaeosols represent humid climates, whereas the loess and loess-derived palaeosols represent dry and semi-dry climates.</abstract>

The nature of the Pleistocene-Holocene palaeosols in the Gaza Strip, Palestine

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Geologos

GEOLOGOS is an international, peer-reviewed journal publishing research results and review articles covering all earth-science disciplines, with a focus on the geology of central and eastern Europe. Studies on areas of poorly known geology (e.g. Asia and Africa) are also published. Articles from non-European areas should be universal and problem-related, while purely regional issues are avoided.  Over the last years, Geologos has published studies on many topics, including:    mineralogy and geochemistry  sedimentology (siliciclastics and carbonates, sedimentary structures, facies analysis)  palaeontology (invertebrate palaeontology, trace fossils, micropalaeontology)  stratigraphy and petroleum geology (sequence stratigraphy)  glacial geology (Pleistocene palaeogeography and stratigraphy, lithology of glaciogenic deposits)  hydrogeology (groundwater circulation, groundwater flow models, drainage systems, deep aquifers)  meteorites (Morasko meteorite fall).    GEOLOGOS has been issued since 1995 as the journal of the Institute of Geology, Adam Mickiewicz University (AMU) in Poznań, Poland.  GEOLOGOS is an open access journal; all content is freely available without charge.  Three issues of GEOLOGOS are published each year. Electronic versions of all papers are published on the Sciendo platform.  Why subscribe and read    Journal on geology of Central and Eastern Europe as well as other areas of poorly known geology   Why submit    Quick publication, colour pages free of chargé. To publish in GEOLOGOS, authors are not required to pay an Article Processing Charge.   Reviewing    Each manuscript, as a rule, is reviewed by two referees, commonly one Polish and one foreign. Reviews are double-blind.   Rejection Rate    About 40%    Archiving  Sciendo archives the contents of this journal in Portico - digital long-term preservation service of scholarly books, journals and collections.  Plagiarism Policy  The editorial board is participating in a growing community of Similarity Check System's users in order to ensure that the content published is original and trustworthy. Similarity Check is a medium that allows for comprehensive manuscripts screening, aimed to eliminate plagiarism and provide a high standard and quality peer-review process. 

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Stratigraphy and sedimentology of the Niger Delta

The nature of the Pleistocene-Holocene palaeosols in the Gaza Strip, Palestine

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