scholarly journals Earth’s oldest tsunami deposit? Early Archean high‐energy sediments in the ca 3.48 Ga Dresser Formation (Pilbara, Western Australia)

2022 ◽  
Author(s):  
Eric A. Runge ◽  
Jan‐Peter Duda ◽  
Martin J. Van Kranendonk ◽  
Joachim Reitner
Keyword(s):  
Western Australia ◽  
High Energy ◽  
Tsunami Deposit

A mid-Holocene candidate tsunami deposit from the NW Cape (Western Australia)

2016 ◽  
Vol 332 ◽  
pp. 40-50 ◽  
Author(s):  
Simon Matthias May ◽  
Simon Falvard ◽  
Maike Norpoth ◽  
Anna Pint ◽  
Dominik Brill ◽  
...  
Keyword(s):  
Western Australia ◽  
Tsunami Deposit

Identification of suspected paleotsunami deposits study from Karapyak Beach, Pangandaran area, West Jawa, Indonesia

2021 ◽  
Vol 36 (2) ◽  
Author(s):  
Aswan Aswan ◽  
Yan Rizal
Keyword(s):  
Thin Layer ◽  
Energy Flow ◽  
Fine Sand ◽  
High Energy ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
Tsunami Deposit ◽  
Tsunami Deposits ◽  
Rock Fragments ◽  
Coarse Grains

Identifying and constraining palaeotsunami deposits can be a vital tool for establishing the periodicity of earthquakes and their associated tsunami events beyond the historical records. However, the deposits can be difficult to establish and date. In this study we used the characteristics of the 2006 Pangandaran tsunami deposit as a reference for identification of paleotsunami deposits in Karapyak Beach, Pangandaran area, West Java, Indonesia. Similar to the 2006 Pangandaran tsunami deposit, the Karapyak Beach paleotsunami deposit is characterized by light brown loose sand materials overlying a dark brown paleosoil layer with erosional contact. A thin layer that varies in thickness is locally found right above the erosional contact, with non-laminated coarser grain in the lower part that gradually change into medium to fine sand-sized in upper part. The base of the lower part is rich with broken mollusc shells and corals, and the mid-top of the lower part may contain several intact molusc shells and corals, rock fragments and anthropogenic products (rooftile). Those types of fragments are absent in the upper part of the thin layer. Grain size analysis shows a mixture of fine and coarse grains in the lower part of 2006 tsunami deposits as well as in the suspected paleotsunami deposits, suggesting uprush high energy flow during sedimentation. Fining upward sequence above mixed grain layers reflects waning flow or pre-backwash deposition. Foraminifera analysis also shows a mixture of shallow and deep marine foraminifera in the two deposits. Based on the characteristics of the 2006 tsunami deposits, there are at least four identified paleotsunami deposits at Karapyak Beach, Pangandaran area.

Depositional settings and palynofacies assemblages of the Upper Triassic fluvio-deltaic Mungaroo Formation, northern Carnarvon Basin, Western Australia

2020 ◽  
Vol 90 (4) ◽  
pp. 403-428
Author(s):  
Joe Scibiorski ◽  
Daniel Peyrot ◽  
Simon Lang ◽  
Tobias H.D. Payenberg ◽  
Adam Charles
Keyword(s):  
Western Australia ◽  
Lower Energy ◽  
High Energy ◽  
Upper Triassic ◽  
Floodplain Lakes ◽  
Northern Carnarvon Basin ◽  
Active Channels ◽  
Organic Particles ◽  
Abandoned Channels ◽  
Carnarvon Basin

ABSTRACT Palynofacies analysis was carried out on 92 core samples from the fluvio-deltaic Middle to Upper Triassic Mungaroo Formation, Northern Carnarvon Basin, Western Australia. The analyses demonstrate that each depositional environment (“depofacies”) sampled has a characteristic palynofacies assemblage reflecting the varied origins, transport, sorting, and preservation histories of organic particles in sediments. The sampling covered a wide range of depofacies identified in fluvial channel, floodplain, crevasse splay, distributary channel, and tidal zone paleoenvironments and included laminated to massive mudstones and siltstones, cross-bedded sandstones, immature pedogenically altered paleosols, and coals. Although each depofacies has a characteristic palynofacies association, there is a high degree of variability within and overlap between preparations. Black-opaque particles were the dominant component in active fluvial, crevasse, and distributary channels. In contrast, palynomorphs, brown wood particles, and cuticle were more common in abandoned channels, floodplain lakes, and other lower-energy environments. The composition of palynomorphs also varies greatly between depofacies due to factors including the bioproductivity of the surrounding vegetation source area, water-table levels, preservation potential, and the fluid dynamic properties of organic particles. The depofacies were grouped into five “process regimes” (active channels, abandoned channels, lakes and periodically flooded areas, paleosols and swamps, tidal mudflats) based on their dominant depositional process. Depofacies in the same process regime tended to have similar palynofacies associations. Active channels yielded similar assemblages irrespective of whether they were fluvial, crevasse, or distributary channels because their dominant characteristic is high flow energy, which encourages the bypass of finer-grained particles, enhances the mechanical degradation of plant debris, and may inhibit local vegetation growth. Organic particles found in lower-energy environments (e.g., floodplain lakes) are on average larger, more elongate, and better preserved than particles found in high-energy environments (e.g., active channels). Although this study was restricted to samples from the upper Samaropollenites speciosus and lower Minutosaccus crenulatus biostratigraphic zones in a geographically limited area, its results are not influenced by the specific taxonomic composition of the vegetation but by the physiographic structure of surrounding plant communities; this suggests that palynofacies analysis could be used to distinguish depositional environments in deltaic settings from other stratigraphic intervals.

scholarly journals Discovery of a tsunami deposit from the Bronze Age Santorini eruption at Malia (Crete): impact, chronology, extension

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Laurent Lespez ◽  
Séverine Lescure ◽  
Ségolène Saulnier-Copard ◽  
Arthur Glais ◽  
Jean-François Berger ◽  
...  
Keyword(s):  
Bronze Age ◽  
Sediment Cores ◽  
High Energy ◽  
Tsunami Deposit ◽  
Marine Fauna ◽  
Run Up ◽  
New Research ◽  
Erosional Event ◽  
The Bronze Age ◽  
Geomorphological Survey

AbstractA geomorphological survey immediately west of the Minoan town of Malia (Crete) shows that a tsunami resulting from the Bronze Age Santorini eruption reached the outskirts of the Palatial center. Sediment cores testify a unique erosional event during the Late Minoan period, followed locally by a high energy sand unit comprising marine fauna. This confirms that a tsunami impacted northern Crete and caused an inundation up to 400 m inland at Malia. We obtained a radiocarbon range of 1744–1544 BCE for the secure pre-tsunami context and an interval 1509–1430 BCE for the post-event layer. Examination of tsunami deposits was used to constrain run-up not exceeding 8 m asl. The results open the field for new research on the Bronze Age Santorini tsunami regarding both impact and consequences for the Minoan civilization.

The Effect of Light Quality on the Germination of Eight Species From Sandy Habitats in Western Australia.

1993 ◽  
Vol 41 (3) ◽  
pp. 321 ◽  
Author(s):  
DT Bell
Keyword(s):  
Western Australia ◽  
Light Quality ◽  
Red Light ◽  
Monochromatic Light ◽  
Coastal Dunes ◽  
High Energy ◽  
Germination Percentage ◽  
Light Conditions ◽  
Light Inhibition ◽  
Effect Of Light

The impacts of darkness and a range of monochromatic light conditions on germination was documented for eight native and naturalized species growing in sandy habitats in Western Australia. Four lake-margin species, Juncus articulatus, J. microcephalus, J. pallidus and Isolepis prolifera, germinated under red (c. 520-640 nm) light, but remained dormant in the dark or when illuminated with far-red (720 nm) or blue (430-490 nm) light. Sunlight-stimulated germination could be beneficial to these very small seeded species, which may not have sufficient reserves for seedlings to establish following deep burial. Oenothera stricta, a short-lived ruderal species, was also stimulated by red light, a response possibly related to germination following disturbance of overlying vegetation. Trachyandra divaricata, a dune inhabiting species, was inhibited by red light. Inhibition by the wavelengths of light dominant in full sunlight was thought to be a response beneficial to species of blowing sand habitats where germination on the dry surface could prove detrimental. Oenothera drummorndii , also a species of coastal dunes was inhibited under high energy light (430-490 nm) but showed no percentage gemination differences in light of wavelengths between 520 and 720 nm and under dark conditions. Asphodelus fistulosus, a species of similar life-fonn characteristics to Trachyarndra divaricata, showed no effect on germination percentage of varying light quality.

Formation, morphology and preservation of high-energy carbonate lithofacies: Evolution of the cool-water Recherche Archipelago inner shelf, south-western Australia

2008 ◽  
Vol 207 (1-4) ◽  
pp. 41-55 ◽  
Author(s):  
David A. Ryan ◽  
Brendan P. Brooke ◽  
Lindsay B. Collins ◽  
Michelle I. Spooner ◽  
Paulus J.W. Siwabessy
Keyword(s):  
Western Australia ◽  
High Energy ◽  
Inner Shelf ◽  
Cool Water

The E-ring: interactions with plasma and implications for its evolution

1984 ◽  
Vol 75 ◽  
pp. 599-602
Author(s):  
T.V. Johnson ◽  
G.E. Morfill ◽  
E. Grun
Keyword(s):  
Time Scale ◽  
Particle Density ◽  
High Energy ◽  
Particle Removal ◽  
Density Region ◽  
Drag Forces ◽  
Orbit Evolution ◽  
History Of ◽  
Ring Particle ◽  
Ring Material

A number of lines of evidence suggest that the particles making up the E-ring are small, on the order of a few microns or less in size (Terrile and Tokunaga, 1980, BAAS; Pang et al., 1982 Saturn meeting; Tucson, AZ). This suggests that a variety of electromagnetic and plasma affects may be important in considering the history of such particles. We have shown (Morfill et al., 1982, J. Geophys. Res., in press) that plasma drags forces from the corotating plasma will rapidly evolve E-ring particle orbits to increasing distance from Saturn until a point is reached where radiation drag forces acting to decrease orbital radius balance this outward acceleration. This occurs at approximately Rhea's orbit, although the exact value is subject to many uncertainties. The time scale for plasma drag to move particles from Enceladus' orbit to the outer E-ring is ~104yr. A variety of effects also act to remove particles, primarily sputtering by both high energy charged particles (Cheng et al., 1982, J. Geophys. Res., in press) and corotating plasma (Morfill et al., 1982). The time scale for sputtering away one micron particles is also short, 102 - 10 yrs. Thus the detailed particle density profile in the E-ring is set by a competition between orbit evolution and particle removal. The high density region near Enceladus' orbit may result from the sputtering yeild of corotating ions being less than unity at this radius (e.g. Eviatar et al., 1982, Saturn meeting). In any case, an active source of E-ring material is required if the feature is not very ephemeral - Enceladus itself, with its geologically recent surface, appears still to be the best candidate for the ultimate source of E-ring material.

Analysis of electron-diffraction intensity profiles using a photodiode-array detection system

1983 ◽  
Vol 41 ◽  
pp. 322-323
Author(s):  
J. B. Warren
Keyword(s):  
Electron Diffraction ◽  
Diffraction Pattern ◽  
Detection System ◽  
High Energy ◽  
Photographic Emulsion ◽  
Diffraction Intensity ◽  
Silicon Photodiode ◽  
Photodiode Array Detection ◽  
Analog To Digital ◽  
Photodiode Array

Electron diffraction intensity profiles have been used extensively in studies of polycrystalline and amorphous thin films. In previous work, diffraction intensity profiles were quantitized either by mechanically scanning the photographic emulsion with a densitometer or by using deflection coils to scan the diffraction pattern over a stationary detector. Such methods tend to be slow, and the intensities must still be converted from analog to digital form for quantitative analysis. The Instrumentation Division at Brookhaven has designed and constructed a electron diffractometer, based on a silicon photodiode array, that overcomes these disadvantages. The instrument is compact (Fig. 1), can be used with any unmodified electron microscope, and acquires the data in a form immediately accessible by microcomputer.Major components include a RETICON 1024 element photodiode array for the de tector, an Analog Devices MAS-1202 analog digital converter and a Digital Equipment LSI 11/2 microcomputer. The photodiode array cannot detect high energy electrons without damage so an f/1.4 lens is used to focus the phosphor screen image of the diffraction pattern on to the photodiode array.

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