Der vorliegende Band ist der erste Teil eines Lernskriptes zur Einführung in die Geomorphologie, Geochronologie und Bodengeographie. Inhaltlich behandelt er ausgewählte Grundlagen der allgemeinen Geologie vom Schalenbau der Erde bis hin zu Vulkanismus und Erdbeben sowie zudem einige relative und numerische Methoden der Altersbestimmung (Geochronologie) vor allem in der jüngeren Erdgeschichte des Quartärs. In einem Exkurs wird unter dem Aspekt Oberflächengesteine eine knappe Einführung in das Thema „Löss und Paläoböden als Umweltarchiv in Deutschland“ gegeben. Zielgruppe des Lernskriptes sind Lehramt- und Bachelor-Studierende der physischen Geographie, aber durchaus auch der Quartärgeologie und Archäologie. Das Skript soll kein Lehrbuch sein, sondern durch die gestellten Fragen und Aufgaben motivieren, Lehrbücher in das extrem wichtige Selbststudium stärker einzubinden.
This study focuses on the accuracy of the Electron Spin Resonance (ESR) dating method applied to small land snail shells from eolian loess deposits, and from shell bearing clods of sandy loam and marl in fluvial gravel deposits in the Bavarian Alpine Foreland. Due to the small size of land snail shells and lack of specimens available for ESR analysis it was necessary to reduce individual aliquot sample weights to 0.02-0.07 g. While the reduction in sample weight inevitably lowers the signal-to-noise ratio and thus may also negatively influence the precision on the equivalent dose due to even smallest weight variations between the single aliquots, the dating results are in good agreement with independent age control. In general, the ESR ages are mostly within the age interval of previous and new luminescence or radiocarbon dating results. We show that ESR dating of small terrestrial gastropods in most cases allows differentiating between shells of Holocene, Late or Middle Wurmian (last glacial, MIS 3, 2), penultimate glacial (MIS 6) or penultimate interglacial (MIS 7) age with errors between c. 10%-15%.
Fossil coral reef terraces at the northern coast of Cuba in the vicinity of the Bay of Matanzas are forming a prominent flight of terraces. These terraces were already studied by several investigators, but a chronological classification based on numerical dating is still missing. In this study we focus on the lowest unit, the Seboruco terrace, which is assumed to be of MIS 5e age. The morphology of the Seboruco terrace and associated sea-level markers (reef crests and notches) were mapped and their altitude was measured over the whole study area in the field and by using remote sensing. The fossil corals building up the terrace were surveyed in numerous natural outcrops. The species of the fossil coral reefs were determined and subdivided in different facies zones. Fossil corals were taken for numerical dating by Electron Spin Resonance (ESR) and Uranium-series (U-Th) to establish a chronology of the MIS 5e coral reef formation. Both dating techniques yielded age results in good agreement with each other and the stratigraphic context. Corresponding to the field evidence, the age data indicates one MIS 5e sea-level highstand around 126 ka. Some younger ESR ages may be explained by the recrystallization of aragonitic corals and/or by U leaching. At one locality east of Matanzas, the radiometric results for an underlying coral reef body suggest an MIS 7 age. The sea-level markers for the MIS 5e highstand range from 5.5 m a.s.l. (reef crest) to a maximum of 7 m (notches) west of the Bay of Matanzas resulting in relatively low uplift rates of 0.003 m/ka and 0.036 m/ka when applying early MIS 5e sea-level estimates from tectonically stable coasts in the Caribbean between +2.5 m and +6.6 m. Inside the Bay of Matanzas itself, the elevation of sea-level markers increases to more than 10 m a.s.l. indicating a stronger uplift rate of 0.027 m/ka to 0.060 m/ka here.
Until now, reliable chronological classifications based on numerical ages for many Pleistocene fluvial deposits in the Alpine Foreland were rare. In this study, new numeric data (ESR, OSL, 14C) from Middle and Upper (Late) Pleistocene Hochterrassen (high terraces) and Übergangsterrassen (transitional terraces) in the Bavarian Alpine Foreland are presented. The dating results imply that the Hochterrassen gravel sensu stricto were deposited during the penultimate glacial (MIS 6, Rissian), and that underlying older gravel accumulation are predominantly of penultimate interglacial (MIS 7, Riss–Riss interglacial) age. In some areas of the Hochterrassen in the Danube valley south of Regensburg (interglacial Hartinger Schichten, Harting layers), and in some areas of the Rainer Hochterrasse (basal gravel unit I), Hochterrassen gravels are underlain by much older interglacial gravel deposits. These interglacial basal gravel deposits illustrate that the downcutting of these valleys far away from areas of Pleistocene foreland glaciations happened predominantly during warm-temperate interglacial or late-glacial periods. One last interglacial (MIS 5e, Riss–Würm interglacial) Hochterrasse is morphologically preserved in the Isar valley. This Jüngere Moosburger Hochterrasse is composed of the Fagotienschotter (Fagotia gravel, named after the gastropod Fagotia acicularis). The next younger terraces are the Early to Middle Würmian (MIS 5d to MIS 3?) Übergangsterrassen (transitional terraces), whereas the younger one of the two Übergangsterrassen was formed most probably during the Middle Würmian (MIS 3).
Der vorliegende Band ist der vierte Teil einer Reihe physisch-geographischer Arbeiten, die in den Jahren 2012 bis 2014 am Bamberger Lehrstuhl fur physische Geographie und Landschaftskunde in Zusammenarbeit mit dem Bayerischen Geologischen Dienst des Landesamtes fur Umwelt (LfU) entstanden sind. Dabei handelt es sich um quartargeologische Kartierungen des Donautals zwischen Sontheim an der Brenz und Dillingen.
Der vorliegende Band ist der dritte Teil einer Reihe physisch-geographischer Arbeiten, die in den Jahren 2007 bis 2015 am Bamberger Lehrstuhl fur physische Geographie und Landschaftskunde entstanden sind. Dabei handelt es sich um quartargeologische Kartierungen im Lech-, Schmutter- und Wertachtal.
Hochterrassen sind eine im nördlichen Alpenvorland weit verbreitete geomorphologische Form, denen traditionell eine Entstehung während der Riss-Kaltzeit zugeordnet wird. Allerdings sind oftmals unterschiedliche Terrassenniveaus innerhalb der Hochterrassen zu beobachten, deren Altersstellung noch unbekannt ist. Dieses Thema wird hier am Beispiel der Langweider und Rainer Hochterrassen im unteren Lechtal mit Hilfe relativer und numerischer Datierungsmethoden untersucht. Das morphologisch tiefste Teilniveau, welches nur am westlichen Rand der Rainer Hochterrasse erhalten ist, stellt höchstwahrscheinlich eine frühwürmzeitliche Übergangsterrasse dar. Das nächsthöhere Niveau der Jüngeren Hochterrasse muss älter sein als das letzte Interglazial. Dafür sprechen die warmzeitliche Parabraunerde, die in Resten am Top des Terrassenkörpers erhalten ist, und die würmzeitliche Lössdeckschicht, welche durch Lumineszenzmessungen und Paläoböden datiert werden kann. Die Jüngere Hochterrasse besteht aus zwei gestapelten Kieskörpern, welche mindestens zwei Akkumulationsphasen zugeordnet werden können. Der hangende Kieskörper entstand während der Sauerstoff-Isotopenstufe (MIS) 6 und der liegende Kieskörper zwischen MIS 7 und MIS 10 (oder älter). Es ist jedoch nicht geklärt, in welcher Aufschüttungsperiode während des Mittelpleistozäns die Ablagerung des liegenden Kieskörpers stattfand. Das höchste Teilniveau, die Ältere Hochterrasse zeigt auch eine Stapelung zweier Kieskörper, für diese liegen aber bisher keine numerischen Altersdaten vor.
This paper reports soil development over time in different climates, on time-scales ranging from a few thousand to several hundred thousand years. Changes in soil properties over time, underlying soil-forming processes and their rates are presented. The paper is based on six soil chronosequences, i.e. sequences of soils of different age that are supposed to have developed under the similar conditions with regard to climate, vegetation and other living organisms, relief and parent material. The six soil chronosequences are from humid-temperate, Mediterranean and semi-arid climates. They are compared with regard to soil thickness increase, changes in soil pH, formation of pedogenic iron oxides (expressed as Fe-d/Fe-t ratios), clay formation, dust influx (both reflected in clay/silt ratios), and silicate weathering and leaching of base cations (expressed as (Ca+Mg+K+Na)/Al molar ratios) over time. This comparison reveals that the increase of solum thickness with time can be best described by logarithmic equations in all three types of climates. Fe-d/Fe-t ratios (proportion of pedogenic iron Fed compared to total iron Fe-t) reflects the transformation of iron in primary minerals into pedogenic iron. This ratio usually increases with time, except for regions, where the influx of dust (having low Fe-d/Fe-t ratios) prevails over the process of pedogenic iron oxide formation, which is the case in the Patagonian chronosequences. Dust influx has also a substantial influence on the time courses of clay/silt ratios and on element indices of silicate weathering. Using the example of a 730 ka soil chronosequence from southern Italy, the fact that soils of long chronosequences inevitably experienced major environmental changes is demonstrated, and, consequentially a modified definition of requirements for soil chronosequences is suggested. Moreover, pedogenic thresholds, feedback systems and progressive versus regressive processes identified in the soil chronosequences are discussed.
Advancements of digital image processes (DIP) and availability of multispectral and hyperspectral remote sensing data have greatly benefited mineral investigation, structure geology mapping, fault pattern, and landslide studies: site-specific landslide assessment and landslide quantification. The main objective of this research was to map the geology of the central region of Kenya using remote-sensing techniques to aid rainfall-induced landslide quantification. The study area is prone to landslides geological hazards and, therefore, it was necessary to investigate geological characteristics in terms of structural pattern, faults, and river channels in a highly rugged mountainous terrain. The methodology included application of PCA, band rationing, intensity hue saturation (IHS) transformation, ICA, false color composites (FCC), filtering applications, and thresholding, and performing knowledge-based classification on Landsat ETM + imagery. PCA factor loading facilitated the choice of bands with the most geological information for band rationing and FCC combination. Band ratios (3/2, 5/1, 5/4, and 7/3) had enhanced contrast on geological features and were the input variables in a knowledge-based geological classification. This was compared to a knowledge-based classification using PCs 2, 5, and IC1, where the band ratio classification performed better at representing geology and matched FCC [IC1, PC5, saturation band of IHS (5,7,3)]. Fault and lineament extraction was achieved by filtering and thresholding of pan-band8 and ratio 5/1 and overlaid on the geology map. However, the best visualization of lineaments and geology was in the FCC [IC1, PC5, saturation band of IHS (5,7,3)], where volcanic extrusions, igneous, sedimentary rocks (eolian and organic), and fluvial deposits were well discriminated.
Advances in classification using multispectral remote sensing imagery have gained increasing attention in solving environmental problems, and the management of disasters such as floods and landslides, due to their wide coverage and enabling ease of access in times of calamities. Multispectral data has facilitated the mapping of soils, land-cover, and structural geology, all of which are factors affecting landslide occurrence. The main aim of this research was to map landslide-affected areas using remote sensing techniques for the central region of Kenya, where landslide disasters are common occurrences. The study area has a highly rugged terrain, and rainfall has been the main trigger of recent landslide events. False colour composite (FCC), Principal Component Analysis (PCA), Independent Component Analysis (ICA), spectral indices in the form of Normalised Difference Index (NDI), and knowledge-based classification formed the methodology. PCA and ICA were performed on Landsat data sets, and the components with the most geologic information after factor loading analysis were chosen to be used in a colour composite. The blue component of the colour composite was a spectral index involving bands 7 and 3 for Landsat ETM+, or bands 7 and 4 for Landsat OLI. The FCC formed the inputs for knowledge based classification with the following 13 classes: runoff, extreme erosions, other erosions, landslide areas, highly erodible, stable, weathering rocks, agriculture, green, new forest regrowth areas, as well as clear, turbid, and salty water. Validation of the mapped landslide areas with field GPS locations of landslide affected areas showed that 66% and 62% of the points coincided well with landslide areas mapped in the years 2000 and 2014, respectively. The classification maps showed extreme erosions taking place along drainage channels and other erosions in agricultural areas; with highly eroble zones charchaterised by already weathered rocks or deposit area, while fluvial deposits mainly characterised runoff areas. Thus, landuse and rainfall processes play a major role in landslide processes in the study area.
Availability of multispectral remote sensing data cheaply and its higher spectral resolution compared to remote sensing data with higher spatial resolution has proved valuable for geological mapping exploitation and mineral mapping. This has benefited applications such as landslide quantification, fault pattern mapping, rock and lineament mapping especially with advanced remote sensing techniques and the use of short wave infrared bands. While Landsat and Aster data have been used to map geology in arid areas and band ratios suiting the application established, mapping in geology in highland regions has been challenging due to vegetation land cover. The aim of this study was to map geology and investigate bands suited for geological applications in a study area containing semi arid and highland characteristics. Therefore, Landsat 7 (ETM+, 2000) and Landsat 8 (OLI, 2014) were compared in determining suitable bands suited for geological mapping in the study area. The methodology consist performing principal component and factor loading analysis, IHS transformation and decorrelation stretch of the FCC with the highest contrast, band rationing and examining FCC with highest contrast, and then performing knowledge base classification. PCA factor loading analysis with emphasis on geological information showed band combination (5, 7, 3) for Landsat 7 and (6, 7, 4) for Landsat 8 had the highest contrast and more contrast was enhanced by performing decorrelation stretch. Band ratio combination (3/2, 5/1, 7/3) for Landsat 7 and (4/3, 6/2, 7/4) for Landsat 8 had more contrast on geologic information and formed the input data in knowledge base classification. Lineament visualisazion was achieved by performing IHS transformation of FCC with highest contrast and its saturation band combined as follows: Landsat 7 (IC1, PC2, saturation band), Landsat 8 (IC1, PC4, saturation band). The results were compared against existing geology maps and were superior and could be used to update the existing maps.
The coastal deposits of Bonaire, Leeward Antilles, are among the most studied archives for extreme-wave events (EWEs) in the Caribbean. Here we present more than 400 electron spin resonance (ESR) and radiocarbon data on coarse-clast deposits from Bonaire's eastern and western coasts. The chronological data are compared to the occurrence and age of fine-grained extreme-wave deposits detected in lagoons and floodplains. Both approaches are aimed at the identification of EWEs, the differentiation between extraordinary storms and tsunamis, improving reconstructions of the coastal evolution, and establishing a geochronological framework for the events. Although the combination of different methods and archives contributes to a better understanding of the interplay of coastal and archive-related processes, insufficient separation, superimposition or burying of coarse-clast deposits and restricted dating accuracy limit the use of both fine-grained and coarse-clast geoarchives to unravel decadal- to centennial-scale events. At several locations, distinct landforms are attributed to different coastal flooding events interpreted to be of tsunami-genic origin. Coastal landforms on the western coast have significantly been influenced by (sub)-recent hurricanes, indicating that formation of the coarse-clast deposits on the eastern coast is likely to be related to past events of higher energy.
Prehistoric storm records are relatively scarce in most parts of the world. This article presents storm records derived from coral rubble‐based geological archives of the Houtman Abrolhos Archipelago located off the west coast of Australia, where the southernmost coral reefs of the Indian Ocean are found. Winter storm swell from the circum‐Antarctic ‘Brave Westerlies’, as well as tropical cyclone waves, have left numerous ridge systems on dozens of islands of the archipelago, all composed of coral rubble from adjacent reefs. At three islands, seven ridge systems were dated by three different methods: U‐series (68 dates), radiocarbon (64 dates), electron spin resonance (7 dates); 139 radiometric dates span the last 5500 years of the Holocene. In contrast to the geomorphological interpretation, the age sequences show ‘inversions’, hiatuses and different ages for the same ridge, all pointing to complicated ridge formation processes. Time gaps, some exceeding 1000 years, are interpreted as phases of erosion and not as phases without storm activity. Copyright © 2012 John Wiley & Sons, Ltd.
Im Rahmen einer geomorphologisch/quartärgeologischen Neuaufnahme der Lechterrassen zwischen Kinsau und Klosterlechfeld konnte die bisher bekannte jungpleistozäne Terrassentreppe neu aufgenommen und teilweise revidiert werden. Nach aktuellem Stand umfasst diese insgesamt 17 morphologisch voneinander abgesetzte Terrassenkörper. Die chronostratigraphische Einordnung der Lechterrassen stützt sich vor allem auf morphostratigraphische Befunde sowie einzelne absolute Altersdatierungen (14C) an Schneckenschalen und Holzfragmenten aus deren Flussbettsedimenten bzw. an Flusssanden (OSL). Die älteste bisher bekannte früh- bis mittelwürmzeitliche Lechterrasse wird als „Übergangsterrasse“ bezeichnet. Sie besitzt, im Gegensatz zu den jüngeren Lechterrassen, eine etwa einen Meter mächtige Deckschicht aus sandstreifigem Löss. Sie ist älter als die hochglaziale, über Schmelzwasserbahnen mit den würmhochglazialen Jungendmoränenständen im Raum Hohenfurch verknüpfte Hauptniederterrasse (HNT). Die Hauptniederterrasse und ihre Teilfelder nehmen flächenmäßig bis zu 65% des Talgrundes südlich von Landsberg ein und sind mit der würmhochglazialen äußeren Jungendmoräne verbunden. Dagegen ist eine direkte morphologische Verbindung der späthochglazialen Niederterrassen (Stufe von Altenstadt, Stufe von Schongau-Peiting) mit würmzeitlichen Abschmelzständen nicht mehr erhalten. Neben der Hauptniederterrasse und ihren Teilfeldern sowie den beiden späthochglazialen Niederterrassen (Stufen von Altenstadt, Stufe von Schongau-Peiting) existieren drei weitere spätglaziale Niederterrassen, die Stufe von Unterigling, die Zwischenstufe und die sogenannte Stufe von Friedheim. Nach der 14C-Datierung einer Schneckenschale dürfte die jüngste der drei Stufen, die Stufe von Friedheim, eine jüngerdryaszeitliche Bildung sein, die noch vor etwa 10 120 a BP in Ausbildung begriffen war. Die holozänen Terrassen bilden ebenfalls eine Terrassentreppe mit bis zu zehn einzelnen Stufen, die im Zeitraum vom frühen Präboreal bis in die jüngere Neuzeit entstanden sind.
Gegenstand dieser Studie ist die würm-spätglaziale und holozäne Talentwicklung am Zusammenfluss von Lech und Donau im Nördlichen Alpenvorland. Die morphologischen Formen im Untersuchungsgebiet wurden mit Hilfe von Geländekartierungen und digitalen Geländemodellen aufgenommen. Die Ablagerungen beider Flüsse wurden in zahlreichen Aufschlüssen untersucht und deren Alter mit Radiokarbon- sowie Lumineszenzdatierungen bestimmt. Daneben wurden auch archäologische Daten und historische Karten genutzt, um die Altersstellung der einzelnen Terrassen einzugrenzen. Im Untersuchungsgebiet bildet eine spätglaziale Niederterrasse die älteste Flussterrasse innerhalb des Talbodens, die allerdings nur im Donautal unterhalb der Lechmündung erhalten ist. In beiden Tälern sind präboreale bis boreale Terrassenflächen nur kleinräumig verbreitet, während ein Sockelschotter gleichen Alters weiträumig unter jüngeren Ablagerungen anzutreffen ist. Atlantische Flussbettablagerungen sind im Untersuchungsgebiet nicht zu finden. Dagegen dominieren subboreale und subatlantische Terrassen das Lechmündungsgebiet. Die heutigen Flussläufe von Lech und Donau werden von bis zu sechs subatlantischen Terrassen begleitet. Deren Verbreitung und morphologisches Erscheinungsbild verweist im Donautal oberhalb der Lechmündung auf einen mäandrierenden Flusslauf, die der jüngsten Lechterrasse auf ein verzweigtes Gerinnebettmuster. Unterhalb der Lechmündung treten dagegen Übergangsformen beider Flussgrundrisstypen auf.
ESR dating has become an efficient tool in earth sciences for geochronological studies on different kinds of littoral deposits (coral reefs terraces, beach ridge systems, aeolianites) during the last ten years. Improvements in annual dose rate (D’) estimation and the newly developed approach for equivalent dose (DE) determination (DE -Dmax plot procedure) increase the precision of ESR dating of Holocene and Pleistocene corals as well as marine and terrestrial mollusc shells. This is strongly supported by the comparison of ESR dating results with other numeric dating methods such as radiocarbon and TIMS Uranium series analysis (TIMS 230Th/234U). The latter is the main focus of this paper. The uncertainties associated in ESR dating of Holocene corals coincide with the variability of 14C ages caused by the marine reservoir effect. The dating of Pleistocene corals permits the differentiation between the main marine isotope stages (MIS) 5, 7, 9, 11 and 13 as well as between sub-stages 5e3/2 and 5e1, 5c, and 5a2 and 5a1. The average error range when dating corals is between 5 to 8%. Furthermore, ESR dating of marine and terrestrial mollusc shells has yielded some promising results and permits the differentiation between the interglacial MIS 1, 5, 7 and 9 with an average dating error range of 10 to 15%. ESR dating of quartz is another promising dating technique for Quaternary and even Neogene geological formations. The presence of quartz in volcanic rocks, tephra, fault gouge and sediments (heated or unheated) allows determining the last time of heating, fault movement or sunlight exposure. Although challenged by several experimental issues, ESR dating of quartz is often the only method able to produce numerical ages for older formations. ESR has also been applied to a wide variety of other materials such as foraminifera, speleothems, travertines, calcretes and tooth enamel. The most common and reliable application is the ESR dating of mammal teeth, which becomes in conjunction with laser ablation U-series dating, an important method for determining the age of archaeological sites beyond the time range of the 14C dating method back to about 200 to 300 ka. [Elektronen Spin Resonanz (ESR)-Datierung quartärer Materialien] Kurzfassung: ESR hat sich im letzten Jahrzehnt bei der Datierung verschiedenster littoraler Ablagerungen (Korallenriffterassen, Strandwallsysteme, Dünen) als effizientes Datierungswerkzeug etabliert. Verbesserungen in der Bestimmung der jährlichen Dosisleistung (D’) und ein neu entwickelter Ansatz zur Bestimmung der Äquivalent Dosis (DE – Dmax Verfahren) haben die Präzision der ESR-Datierung sowohl an holozänen und pleistozänen Korallen als auch an marinen und terrestrischen Molluskenschalen verbessert. Dies wurde durch den Vergleich mit anderen numerischen Datierungsverfahren wie Radiokohlenstoff und TIMS-Uranserien-Analyse (TIMS 230Th/234U) unterstützt. Der Vergleich mit letzterer Methode steht im Fokus dieses Artikels. Die mit der ESR-Methode verbundenen Ungenauigkeiten bei der Datierung holozäner Korallen liegt in der Größenordnung der Variabilität von 14C-Altern, die durch den marinen Reservoireffekt bedingt ist. Die Datierung pleistozäner Korallen erlaubt die Differenzierung der wichtigen marinen Isotopenstadien (MIS) 5, *Addresses of authors: G. Schellmann, Universität Bamberg, Lehrstuhl Geographie II – Physische Geographie, Am Kranen 1, D-96045 Bamberg. E-Mail: gerhard.schellmann@ggeo.uni-bamberg.de; K. Beerten, Universität zu Köln, Geographisches Institut, Albertus-Magnus-Platz, D-50923 Köln. E-Mail: kbeerten@unikoeln.de; U. Radtke, Universität zu Köln, Geographisches Institut, Albertus-Magnus-Platz, D-50923 Köln. E-Mail: u.radtke@uni-koeln.de 7, 9,11 und 13 sowie der Untereinheiten 5e3/2 und 5e1, 5c und 5a1 und 5a2. Der durchschnittliche Fehler bei der Datierung von Korallen liegt zwischen 5 bis 8%. Weiterhin hat die Datierung mariner und terrestrischer Mollusken mittels ESR viel versprechende Resultate geliefert, die eine Differenzierung der Interglaziale MIS 1, 5, 7 und 9 ermöglichen, bei einem Fehler von 10-15%. Die ESR Datierung von Quarz ist eine weitere viel versprechende Datierungstechnik für quartäre und sogar neogene geologische Formationen. Das Vorkommen von Quarz in vulkanischen Gesteinen, Tephren, Störungen und Sedimenten (thermisch beeinflusst und unbeeinflusst) ermöglicht die zeitliche Bestimmung des letzten Zeitpunkts vor der Erhitzung, Störung oder der Aussetzung von Sonnenlicht. Obwohl durch einige experimentelle Ergebnisse angezweifelt, ist die ESR Datierung von Quarz die einzige Möglichkeit Altersdaten älterer Ablagerungen zu liefern. ESR wurde auch bei einer Vielzahl anderer Materialien angewendet, wie zum Beispiel Foraminiferen, Speleothemen, Travertinen, Kalkkrusten und Zahnschmelz. Die gebräuchlichste und zuverlässigste Anwendung ist die ESR-Datierung von Mammutstoßzähnen. Im Zusammenspiel mit der Laser-Ablation Uranserien Datierung ist ESR eine wichtige Methode zur Altersbestimmung archäologischer Fundstätten jenseits der Bestimmungsgrenzen der Radiokohlenstoffmethode bis in den Bereich von 200 bis 300 ka.
Geomorphologic and chronostratigraphic investigations in various coastal localities along the middle and south Patagonian Atlantic coast, from Bahia Vera (44 degrees S) in the north to San Julian (49 degrees S) in the south, confirm a rich sequence of Holocene beach ridge systems and littoral and valley-mouth terraces. Beach ridges are present up to 10 m above current highest tide level (hTw) and date to the early mid-Holocene transgression maximum. Beach-ridge deposits represent high-energy, wave dominated coastal environments, whereas valley-mouth terraces and littoral terraces (elevations of 5.5-6.5 m above hTw) developed in wave-protected coastal environments.The surface elevation of these littoral forms suggest that the middle and south Patagonian Atlantic coast is likely undergoing a slow glacio-isostatic uplift on the order of 0.3-0.4 mm/a since the mid-Holocene. The early Holocene sea-level rise reached the modern coastline by 8100 C-14 years ago (c. 8600 cal BP) at the latest. Sea level at that time was most likely near its present position. The Holocene transgression maximum lasted from 6900 to at least 6200 C-14 BP (c. 7400 to 6600 cal BP), raising relative sea level to about 2 m to a maximum of 3 m above the present level, after which sea level declined to the present level. Two significant sea-level falls of at most 1 m occurred: a) between 6200 and 6000 C-14 BP (c. 6600 to 6400 cal BP), and b) between 2600 and 2400 C-14 BP (c. 2300 to 2050 cal BP).We assume, that both significant sea-level falls were predominantly driven by eustatic changes of ocean volume, whereas both thermo-steric changes and changes of tides may also have contributed to these relatively strong sea-level drops. Gravitational changes driven by Greenland ice growth (sensu Mitrovica et al., 2001) may also have amplified any eustatic portion of sea-level fall. The trend of a general sea-level decline since the mid-Holocene transgression maximum seems to be predominantly glacio-isostatically driven. (c) 2010 Elsevier B.V. All rights reserved.