scholarly journals Volcanic ash layer depth: Processes and mechanisms

2015 ◽  
Vol 42 (2) ◽  
pp. 637-645 ◽  
Author(s):  
H. F. Dacre ◽  
A. L. M. Grant ◽  
N. J. Harvey ◽  
D. J. Thomson ◽  
H. N. Webster ◽  
...  
Keyword(s):  
Volcanic Ash ◽  
Layer Depth ◽  
Ash Layer

scholarly journals A Study on Appling the Expert System for Correlating Volcanic Ash Layer

1987 ◽  
Vol 1987 (12) ◽  
pp. 105-110
Author(s):  
Kaichiro YAMAMOTO ◽  
Younosuke NAKAGAWA
Keyword(s):  
Expert System ◽  
Volcanic Ash ◽  
Ash Layer

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 Quantifying uncertainties in marine volcanic ash layer records from ocean drilling cores

2014 ◽  
Vol 357 ◽  
pp. 218-224 ◽  
Author(s):  
Sue H. Mahony ◽  
R.S.J. Sparks ◽  
Nick H. Barnard
Keyword(s):  
Volcanic Ash ◽  
Ocean Drilling ◽  
Ash Layer

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.

Fission-track age of the volcanic ash layer in the Bisan-seto Group around the Bannosu region of the eastern parts of the Seto Inland Sea, Japan

2006 ◽  
Vol 112 (10) ◽  
pp. 608-611
Author(s):  
Michiharu Ikeda ◽  
Shuji Kobayashi ◽  
Yuki Ohno ◽  
Naoki Nishizaka ◽  
Masayuki Sakakibara ◽  
...  
Keyword(s):  
Volcanic Ash ◽  
Fission Track ◽  
Seto Inland Sea ◽  
Ash Layer ◽  
The Seto Inland Sea

scholarly journals Supplemental Material: Geochemical indications for the Paleocene-Eocene Thermal Maximum (PETM) and Eocene Thermal Maximum 2 (ETM-2) hyperthermals in terrestrial sediments of the Canadian Arctic

2021 ◽  
Author(s):  
L. Reinhardt ◽  
et al.
Keyword(s):  
Organic Carbon ◽  
Volcanic Ash ◽  
Graphical Representation ◽  
Canadian Arctic ◽  
Early Eocene ◽  
Thermal Maximum ◽  
Ash Layer ◽  
Terrestrial Sediments

<div>Contains figures of most depleted δ<sup>13</sup>C values of selected early Eocene hyperthermals and age of volcanic ash layer MA-1 with graphical representation of error ranges. Additionally, tables of all δ<sup>13</sup>C data, organic carbon contents, thicknesses of clastic intervals, and details of U-Pb zircon analyses are provided.<br></div>

scholarly journals Tephra layers in the marine environment: A review of properties and emplacement processes

2021 ◽  
pp. SP520-2021-50
Author(s):  
Armin Freundt ◽  
Julie C. Schindlbeck-Belo ◽  
Steffen Kutterolf ◽  
Jenni L. Hopkins
Keyword(s):  
Volcanic Ash ◽  
Layer Structure ◽  
Sediment Cores ◽  
Submarine Landslides ◽  
Natural Processes ◽  
Ash Layer ◽  
Tephra Layers ◽  
Emplacement Processes ◽  
Volcaniclastic Deposits ◽  
Important Marker

AbstractThis review focusses on the recognition of volcanic ash occurrences in marine sediment cores and on using their appearance and properties to deduce their origin. Widespread marine tephra layers are important marker horizons for both volcanological as well as general geological investigations. We describe ash detection by visual inspection and logging of sediment cores. Ash layer structure and texture, particle morphologies and lithological compositions of primary volcanic deposits are summarized and processes modifying them are discussed, both natural processes acting on and in the seafloor, i.e., erosion and bioturbation, and man-made modifications during drilling/coring and core preparation. We discuss primary emplacement processes of marine fall and flow tephra deposits derived from either subaerial or submarine sources in order to identify distinguishing properties. We also elaborate on processes generating secondary, resedimented volcaniclastic layers such as submarine landslides and shelf erosion as well as fluvial input and ice-rafting, and how they can be distinguished from primary volcaniclastic deposits, which is essential in tephrostratigraphy. Finally, methods of tephra correlation between cores and on-land deposits/volcanoes are illustrated because they allow us to extend the 1-D information from single cores to 3-D distribution and facies changes of tephras and to bridge the land-sea gap.

Discussion on ‘Acheulian and Tephra from Upland Western Maharashtra, (Deccan Volcanic Province), Peninsular India’, by Deo et al. 2021 (SP 515)

2021 ◽  
pp. jgs2021-120
Author(s):  
Nicholas J.G. Pearce ◽  
Emma Gatti ◽  
Hema Achyuthan
Keyword(s):  
Volcanic Ash ◽  
Fission Track ◽  
Human Occupation ◽  
Deccan Volcanic Province ◽  
Peninsular India ◽  
Volcanic Province ◽  
Ash Layer ◽  
Wide Range ◽  
The Subject ◽  
Toba Caldera

Acheulean artefacts are widely known from archaeological complexes in India and commonly comprise handaxes, picks and cleavers. These provide information on human occupation and evolution across India, and have been the subject of much research on stone technology. In some of these sites, artefacts are associated with a Pleistocene volcanic ash layer derived from the Toba caldera in Sumatra, but various studies have derived a wide range of ages from this deposit leading to differing schools of thought as to the age of the tephra. Recent trace element, fission track and mineralogical studies (since 2011), have enabled accurate recognition of each Toba eruptive unit across their fall out, but these approaches continue to be overlooked in some studies where artefacts and Toba tephra co-exist in India. This leads to significant errors in tephra identification, and thus hampers any derived age interpretations. Most recently, this includes the study by Deo et al. (2021) who, in Geological Society Special Publication 515 (Tiwari et al., 2021), report ages for artefacts and tephra from two sites in the Deccan Volcanic Province which have become pivotal in many arguments, namely Morgaon and Bori. Here we address these issues and reiterate the methods for identification of the three main Toba tephra deposits.

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