Two Tephra Layers Bracketing Late Holocene Paleoecological Changes in Northern Germany

2002 ◽  
Vol 57 (3) ◽  
pp. 314-324 ◽  
Author(s):  
Christel van den Bogaard ◽  
Walter Dörfler ◽  
Rainer Glos ◽  
Marie-Josée Nadeau ◽  
Pieter M. Grootes ◽  
...  
Keyword(s):  
Bronze Age ◽  
Late Holocene ◽  
Vegetation Change ◽  
Volcanic Ash ◽  
Probability Distributions ◽  
Explosive Volcanism ◽  
Peat Bogs ◽  
Northern Germany ◽  
Tephra Layers ◽  
Petrology And Geochemistry

AbstractPaleoecological records from two Holocene peat bogs in northern Germany are linked by two microscopic volcanic ash layers, correlated by petrology and geochemistry to explosive volcanism on Iceland. The younger “Microlite tephra” cannot be correlated to any known eruption, while the older tephra layer is identified as a deposit of the Hekla 3 eruption. The tephra layers are dated by an age–depth regression of accelerator mass spectrometry 14C ages that have been calibrated and combined in probability distributions. This procedure gives an age of 730–664 cal yr B.C. for the “Microlite tephra” event and 1087–1006 cal yr B.C. for the Hekla 3 event. Accordingly, the tephra layers were deposited during the late Bronze Age. At this time, human settlement slowly increased pressure on the environment, as indicated by changes in woodland pollen composition at the two bogs. The tephra-marker horizons further show that the palynologically defined transition from the Subboreal to the Subatlantic Period is synchronous in the investigated area. However, the macroscopic visible marker in peat, the change from fibrous to sapric peat, the “Schwarztorf-Weißtorf-Kontakt,” is asynchronous. Bog vegetation did not immediately react in unison to a climatic change at this pollen zone boundary; instead, the timing of vegetation change depended on the location within the bog.

scholarly journals High-resolution stalagmite stratigraphy supports the Late Holocene tephrochronology of southernmost Patagonia

2021 ◽  
Author(s):  
Björn Klaes ◽  
Gerhard Wörner ◽  
Katrina Kremer ◽  
Klaus Simon ◽  
Denis Scholz ◽  
...  
Keyword(s):  
High Resolution ◽  
South America ◽  
Large Volume ◽  
Critical Region ◽  
Late Holocene ◽  
Volcanic Ash ◽  
Explosive Volcanism ◽  
Geochemical Data ◽  
Karst Cave ◽  
Icp Ms

Abstract Volcanic ash layers are important markers for the chronostratigraphy of paleoclimate and paleoenvironmental archives at the southern tip of South America. However, this requires that tephras are well-dated. We report geochemical data from the MA1 stalagmite formed in a non-karst cave near Mt. Burney volcano in southernmost Patagonia (~53°S). High-resolution LA-ICP-MS analyses, SEM imagery, and NanoSIMS enable to identify volcanogenic signals during the last 4.5 kyrs BP from sub-annual trace element variations and tephra particles in distinct laminae. The new 230Th/U-chronology of MA1 provides precise dating of tephra from Mt. Burney (MB) and Aguilera (A) at 4216 +93/−193 yrs BP (MB2), 2291 ± 33 yrs BP (MB3), 853 +41/−60 yrs BP (MB4) and 2978 +91/−104 yrs BP (A1). This unique high-resolution record of MA1 holds potential to date further eruptions from Southern Andean volcanoes for the tephrochronology in this critical region, and potentially also large-volume explosive volcanism off South America.

scholarly journals A cryptotephra record from the Lake Victoria sediment core record of Holocene palaeoenvironmental change

The Holocene ◽  
2018 ◽  
Vol 28 (12) ◽  
pp. 1909-1917 ◽  
Author(s):  
Christine S Lane ◽  
Catherine M Martin-Jones ◽  
Thomas C Johnson
Keyword(s):  
Volcanic Ash ◽  
River Flow ◽  
Lake Victoria ◽  
Explosive Volcanism ◽  
Climatic Conditions ◽  
East African ◽  
Fine Grained ◽  
Palaeoenvironmental Change ◽  
Tephra Layers ◽  
Glass Shards

The sediment record from Lake Victoria is an important archive of regional environmental and climatic conditions, reaching back more than 15,000 cal. years before present (15 ka BP). As the largest lake by area in East Africa, its evolution is key to understanding regional palaeohydrological change during the late Pleistocene and Holocene, including controls on the Nile River flow. As well as important palaeoenvironmental proxies, the lake contains a unique record of explosive volcanism from the central Kenyan Rift, in the form of fine-grained volcanic ash (tephra) layers, interpreted as airfall deposits. In the V95-1P core, collected from the central northern basin of the lake, tephra layers vary in concentration from 10s to 10s of 1000s of glass shards per gram of sediment. None of the tephra are visible to the naked eye, and have only been revealed through careful laboratory processing. Compositional analyses of tephra glass shards has allowed the tephra layers to be correlated to previously unrecognized eruptions of Eburru volcano around 1.2 and 3.8 ka, and Olkaria volcano, prior to 15 ka. These volcanoes lie ~300 km east of the core site in the Kenyan Rift. Our results highlight the potential for developing cryptotephra analysis as a key tool in East African palaeolimnological research. Tephra layers offer opportunities for precise correlation of palaeoenvironmental sequences, as well as windows into the eruption frequency of regional volcanoes and the dispersal of volcanic ash.

scholarly journals Late-Holocene forest resilience in the central Pyrenean highlands as deduced from pollen analysis of Lake Sant Maurici sediments

The Holocene ◽  
2021 ◽  
pp. 095968362110332
Author(s):  
Valentí Rull ◽  
Núria Cañellas-Boltà ◽  
Teresa Vegas-Vilarrúbia
Keyword(s):  
Bronze Age ◽  
Middle Ages ◽  
Iron Age ◽  
Late Holocene ◽  
High Elevation ◽  
Roman Period ◽  
High Mountain ◽  
Southern Central ◽  
Central Pyrenees ◽  
The Middle Ages

Palynological analysis of the last ca. 4300 cal year BP using a sediment core taken from high mountain (ca. 1900 m elevation) Lake Sant Maurici sediments (southern-central Pyrenees) showed remarkable vegetation constancy during the Bronze Age and the Middle Ages. Records of the Iron Age and the Roman period were missing due to a major sedimentary gap. During the studied periods, the vegetation around the lake was largely dominated by pine ( Pinus) forests with birch ( Betula), oak ( Quercus) and hazel ( Corylus) trees, as is the case today. The composition of these forests and the abundance of their components remained quite stable, despite the occurrence of temperature and moisture shifts. The degree of human disturbance, notably that of pastoralism and cereal cultivation by scattered and temporary settlements, was very low and had little or no effect on the dominant forests. This situation contrasts with most high-elevation (subalpine and alpine) environments of the central Pyrenees that were massively anthropized during the Middle Ages. Further research should be aimed at finding sediments corresponding to the Iron Age and the Roman period to verify whether the vegetation constancy can be extended throughout the Late-Holocene. Past records of this type may allow the estimation of natural and anthropogenic thresholds for irreversible forest changes, which would be useful for conservation purposes.

Cultural change and population dynamics during the Bronze Age: Integrating archaeological and palaeoenvironmental evidence for Schleswig-Holstein, Northern Germany

The Holocene ◽  
2019 ◽  
Vol 29 (10) ◽  
pp. 1607-1621 ◽  
Author(s):  
Jutta Kneisel ◽  
Walter Dörfler ◽  
Stefan Dreibrodt ◽  
Stefanie Schaefer-Di Maida ◽  
Ingo Feeser
Keyword(s):  
Population Dynamics ◽  
Material Culture ◽  
Bronze Age ◽  
Cultural Change ◽  
Food Production ◽  
Quantitative Information ◽  
Northern Germany ◽  
Social Phenomena ◽  
Boom And Bust ◽  
The Bronze Age

In archaeology, change in material culture is viewed as indicating social or cultural transformation and is the basis of our typo-chronological classification of phases and periods. The material culture from northern Germany reveals both quantitative and qualitative changes during the Bronze Age. At the same time, there is also evidence for ‘boom and bust’ cycles in population density/size, as indicated by changing human impact on the environment in several Bronze Age palaeoenvironmental records. These demographic fluctuations may relate to the observed changes in social phenomena in aspects of ideology, technology, food production and habitation. For example, innovations in food production, such as the adoption of new crops and agricultural techniques, could have led to population growth. While usually viewed by archaeologists as a ‘negative’ development, population stress or collapse may have favoured the emergence of new cultural phenomena. In order to test the cause-and-effect relationship between population dynamics and sociocultural change, we synthesise the archaeological evidence – qualitative and quantitative information from settlements, deposition finds (hoards), burials, material culture and architectural remains – for the Bronze Age in northern Germany, mainly Schleswig-Holstein, and compare it with the boom and bust pattern seen in the palaeoenvironmental record. The synchronicity of changes at ca. 1500 BC and ca. 1100 BC reflects the relationship between phases of major sociocultural transformation in the archaeological datasets and booms and busts in the palaeoenvironmental record of the region seen as a proxies for palaeo-demography. This sets the stage for a better understanding of the transformation of practices and relationships in the Bronze Age communities of the region.

Chemical Composition of Ice Containing Tephra Layers in the Byrd Station Ice Core, Antarctica

1988 ◽  
Vol 30 (3) ◽  
pp. 315-330 ◽  
Author(s):  
Julie M. Palais ◽  
Philip R. Kyle
Keyword(s):  
Chemical Composition ◽  
Silicate Glass ◽  
Residence Time ◽  
Volcanic Ash ◽  
Global Climate ◽  
Ice Core ◽  
Volcanic Eruptions ◽  
Tephra Layers ◽  
The Antarctic ◽  
Hydrolysis Of

The chemical composition of ice containing tephra (volcanic ash) layers in 22 sections of the Byrd Station ice core was examined to determine if the volcanic eruptions affected the chemical composition of the atmosphere and precipitation in the vicinity of Byrd Station. The liquid conductivity, acidity, sulfate, nitrate, aluminum, and sodium concentrations of ice samples deposited before, during, and after the deposition of the tephra layers were analyzed. Ice samples that contain tephra layers have, on average, about two times more sulfate and three to four times more aluminum than nonvolcanic ice samples. The acidity of ice samples associated with tephra layers is lowered by hydrolysis of silicate glass and minerals. Average nitrate, sodium, and conductivity are the same in all samples. Because much of the sulfur and chlorine originally associated with these eruptions may have been scavenged by ash particles, the atmospheric residence time of these volatiles would have been minimized. Therefore the eruptions probably had only a small effect on the composition of the Antarctic atmosphere and a negligible effect on local or global climate.

scholarly journals Identification and correlation of distal tephra layers in deep-sea sediment cores, Scotia Sea, Antarctica

1998 ◽  
Vol 27 ◽  
pp. 285-289 ◽  
Author(s):  
S. G. Moreton ◽  
J. L. Smellie
Keyword(s):  
Deep Sea ◽  
Volcanic Ash ◽  
Sediment Cores ◽  
Quaternary Deposits ◽  
Deep Sea Sediment ◽  
Scotia Sea ◽  
Ash Layer ◽  
Tephra Layers ◽  
Major Oxide ◽  
Water Depths

Quaternary deposits in six sediment cores from the Scotia Sea, Antarctica, were examined for the presence of volcanic ash layers. The cores were recovered from water depths of 3369-4025 m. Altogether, 23 ash layers were found, 18 of which have been investigated by electron-probe microanalysis. Deception Island is identified as the source of all the ash layers analyzed. The upper ash layer in each core can be correlated across all six cores, over a distance of -100 km, on the basis of its unusual bimodal composition, major oxide geochemistry and stratigraphie position. Two other ash layers can also be correlated between several of the cores.

scholarly journals Volcanic ash, victims, and tsunami debris from the Late Bronze Age Thera eruption discovered at Çeşme-Bağlararası (Turkey)

2021 ◽  
Vol 119 (1) ◽  
pp. e2114213118
Author(s):  
Vasıf Şahoğlu ◽  
Johannes H. Sterba ◽  
Timor Katz ◽  
Ümit Çayır ◽  
Ümit Gündoğan ◽  
...  
Keyword(s):  
Bronze Age ◽  
Volcanic Ash ◽  
Thick Layer ◽  
Archaeological Site ◽  
Tsunami Deposit ◽  
Late Bronze Age ◽  
Mediterranean Studies ◽  
Ash Layer ◽  
Time Capsule ◽  
Thera Eruption

The Late Bronze Age Thera eruption was one of the largest natural disasters witnessed in human history. Its impact, consequences, and timing have dominated the discourse of ancient Mediterranean studies for nearly a century. Despite the eruption’s high intensity (Volcanic Explosivity Index 7; Dense Rock Equivalent of 78 to 86 km) [T. H. Druitt, F. W. McCoy, G. E. Vougioukalakis, Elements 15, 185–190 (2019)] and tsunami-generating capabilities [K. Minoura et al., Geology 28, 59–62 (2000)], few tsunami deposits are reported. In contrast, descriptions of pumice, ash, and tephra deposits are widely published. This mismatch may be an artifact of interpretive capabilities, given how rapidly tsunami sedimentology has advanced in recent years. A well-preserved volcanic ash layer and chaotic destruction horizon were identified in stratified deposits at Çeşme-Bağlararası, a western Anatolian/Aegean coastal archaeological site. To interpret these deposits, archaeological and sedimentological analysis (X-ray fluorescence spectroscopy instrumental neutron activation analysis, granulometry, micropaleontology, and radiocarbon dating) were performed. According to the results, the archaeological site was hit by a series of strong tsunamis that caused damage and erosion, leaving behind a thick layer of debris, distinguishable by its physical, biological, and chemical signature. An articulated human and dog skeleton discovered within the tsunami debris are in situ victims related to the Late Bronze Age Thera eruption event. Calibrated radiocarbon ages from well-constrained, short-lived organics from within the tsunami deposit constrain the event to no earlier than 1612 BCE. The deposit provides a time capsule that demonstrates the nature, enormity, and expansive geographic extent of this catastrophic event.

The Tilia decline: vegetation change in lowland Britain during the mid and late Holocene

2011 ◽  
Vol 30 (3-4) ◽  
pp. 394-408 ◽  
Author(s):  
Michael J. Grant ◽  
Martyn P. Waller ◽  
Jon A. Groves
Keyword(s):  
Late Holocene ◽  
Vegetation Change

scholarly journals Epistemic uncertainties and natural hazard risk assessment – Part 2: Different natural hazard areas

2016 ◽  
Author(s):  
K. J. Beven ◽  
S. Almeida ◽  
W. P. Aspinall ◽  
P. D. Bates ◽  
S. Blazkova ◽  
...  
Keyword(s):  
Debris Flows ◽  
Volcanic Ash ◽  
Natural Hazard ◽  
Epistemic Uncertainty ◽  
Probability Distributions ◽  
Good Practice ◽  
Pyroclastic Flows ◽  
Dam Safety ◽  
Landslides And Debris Flows ◽  
Hazard Risk Assessment

Abstract. This paper discusses how epistemic uncertainties are considered in a number of different natural hazard areas including floods, landslides and debris flows, dam safety, droughts, earthquakes, tsunamis, volcanic ash clouds and pyroclastic flows, and wind storms. In each case it is common practice to treat most uncertainties in the form of aleatory probability distributions but this may lead to an underestimation of the resulting uncertainties in assessing the hazard, consequences and risk. It is suggested that such analyses might be usefully extended by looking at different scenarios of assumptions about sources of epistemic uncertainty, with a view to reducing the element of surprise in future hazard occurrences. Since every analysis is necessarily conditional on the assumptions made about the nature of sources of epistemic uncertainty it is also important to follow the guidelines for good practice suggested in the companion Part 1 by setting out those assumptions in a condition tree.

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