scholarly journals Middle Pleistocene Cave Sediments and Their Mammalian Fossil Assemblage Discovered at Tarumi, Niimi, Okayama Prefecture, Western Japan

2004 ◽  
Vol 43 (5) ◽  
pp. 331-344 ◽  
Author(s):  
Takashi Inada ◽  
Yoshinari Kawamura
Keyword(s):  
Middle Pleistocene ◽  
Fossil Assemblage ◽  
Cave Sediments ◽  
Western Japan ◽  
Mammalian Fossil ◽  
Okayama Prefecture

New advances on the magnetic chronostratigraphy of cave sediments in Atapuerca Gran Dolina, Spain

2021 ◽  
Author(s):  
Josep M Pares ◽  
Mathieu Duval ◽  
Isidoro Campaña ◽  
José M. Bermúdez de Castro ◽  
Eudald Carbonell
Keyword(s):  
Magnetic Polarity ◽  
Age Dating ◽  
Middle Pleistocene ◽  
Geologic History ◽  
Cave Sediments ◽  
Normal Polarity ◽  
Gran Dolina ◽  
Geomagnetic Polarity ◽  
Quartz Grains ◽  
Numerical Dating

<p>Magnetostratigraphy has proven to be a powerful and versatile method as well the first line of defence for dating sediments. When properly anchored to the Geomagnetic Polarity Time Scale (GPTS), chron boundaries provide a basis for numerical dating by correlating the local magnetostratigraphy to the GPTS. A caveat and intrinsic limitation when anchoring magnetic stratigraphy to the GPTS is that we deal with essentially a binary code, a sequence of normal and reverse polarity zones. To overcome such limitation biostratigraphy or (ideally) numerical (absolute) age dating is required. Unfortunately, numerical dating of sediments is typically hampered by the lack of amenable minerals for the application of standard methods such as Ar-Ar, requiring thus the use of less conventional methods. Burial dating is possible using methods such as Electron Spin Resonance (ESR) on optically bleached quartz grains. Similar to luminescence, ESR is a paleodosimetric method that provides the time elapsed since the last exposure of quartz grains to natural sun light. Cave sediments are particularly amenable for paleodosimetric methods, as sediments are preserved in the dark and the ESR signal should survive over the geologic history of the deposits. On the down side, we date the moment when the quartz grain enters the karst system, not its deposition. If the transit time is too long, this might be an issue and we would be significantly overestimating the true burial age. Caves at Atapuerca (N Spain) hold the richest Quaternary paleontological record in Eurasia, including fossils and lithic tools. Sediments in these caves have been traditionally dated via magnetostratigraphy by identifying the Matuyama-Brunhes reversal (0.78 Ma) thus providing the Lower to Middle Pleistocene boundary. Nevertheless, the appearance of older sediments in the caves required the combination of paleomagnetism with methods such as ESR to interpret older intra-Matuyama Subchrons. In the deepest levels of the Gran Dolina cave, close to the floor of the cavity, a number of short intervals of normal polarity have been identified in the fluviatile sediments belonging to TD1 unit, which we interpret in terms of Subchrons using ESR ages of quartz grains. We will discuss both paleomagnetic data and interpret the magnetic polarity stratigraphy in the view of the ESR ages obtained from the Multiple Centre (MC) approach. </p>

scholarly journals A discovery of the microfossil faunas from the Otake Formation in Okayama Prefecture, western Japan.

1985 ◽  
Vol 61 (5) ◽  
pp. 197-199 ◽  
Author(s):  
Kimiyoshi SADA ◽  
Yukimasa OHO ◽  
Masashi INOUE ◽  
Toshio KOIKE ◽  
Daiji OKADA ◽  
...  
Keyword(s):  
Western Japan ◽  
Okayama Prefecture

Extraction of Inundation Areas Due to the July 2018 Western Japan Torrential Rain Event Using Multi-Temporal ALOS-2 Images

2019 ◽  
Vol 14 (3) ◽  
pp. 445-455 ◽  
Author(s):  
Wen Liu ◽  
◽  
Fumio Yamazaki ◽  
Yoshihisa Maruyama
Keyword(s):  
Aerial Photographs ◽  
Rain Event ◽  
Visual Interpretation ◽  
Web Based ◽  
Inundation Area ◽  
Survey Report ◽  
Multi Temporal ◽  
Western Japan ◽  
Intensity Images ◽  
Okayama Prefecture

A series of heavy rainfalls hit the western half of Japan from June 28 to July 8, 2018. Increased river water overflowed and destroyed river banks, causing flooding over vast areas. In this study, two pre-event and one co-event ALOS-2 PALSAR-2 images were used to extract inundation areas in Kurashiki and Okayama Cities, Okayama Prefecture, Japan. First, water regions were extracted by threshold values from three-temporal intensity images. The increased water regions in July 2018 were obtained as inundation. Inundated built-up areas were identified by the increase of backscattering intensity. Differences between the pre-and co-event coherence values were calculated. The area with decreased coherence was extracted as a possible inundation area. The results of a field survey conducted on July 16, 2018 were used to estimate the optimal parameters for the extraction. Finally, the results from the intensity and coherence images were verified by making comparisons between a web-based questionnaire survey report and the visual interpretation of aerial photographs.

Hipparion material from Gaojiashan locality in the Late Miocene of Linxia Basin, Gansu, China and associated mammalian fossil assemblage

2017 ◽  
Vol 30 (5) ◽  
pp. 677-693
Author(s):  
Yikun Li ◽  
Wen He ◽  
Shanqin Chen ◽  
Shiqi Wang ◽  
Boyang Sun ◽  
...  
Keyword(s):  
Late Miocene ◽  
Fossil Assemblage ◽  
Linxia Basin ◽  
Mammalian Fossil

scholarly journals Vegetational History of the Area around Kashira Island in the Inland Sea, Okayama Prefecture, Western Japan.

1998 ◽  
Vol 50 (3) ◽  
pp. 189-200 ◽  
Author(s):  
Toshiyuki FUJIKI ◽  
Yoshimune MORITA ◽  
Norio MIYOSHI
Keyword(s):  
History Of ◽  
Western Japan ◽  
Okayama Prefecture

scholarly journals Distribution and Characteristics of Slope Movements in the Southern Part of Hiroshima Prefecture Caused by the Heavy Rain in Western Japan in July 2018

2019 ◽  
Vol 14 (6) ◽  
pp. 894-902
Author(s):  
Hideaki Goto ◽  
Yasuhiro Kumahara ◽  
Shoichiro Uchiyama ◽  
Yoshiya Iwasa ◽  
Tomoru Yamanaka ◽  
...  
Keyword(s):  
Heavy Rain ◽  
Slope Movement ◽  
Aerial Photographs ◽  
Large Area ◽  
Geospatial Information ◽  
Mountain Ranges ◽  
Slope Movements ◽  
Western Japan ◽  
Hiroshima Prefecture ◽  
Okayama Prefecture

Record-breaking heavy rainfall in July 2018 caused an extremely large number of slope movements over a broad area of western Japan. We mapped the distribution of slope movements in the southern part of Hiroshima Prefecture through an interpretation of aerial photographs that were acquired after the rainfall by the Geospatial Information Authority of Japan, and counted a total of 8,497 slope-movement starting points. The widespread distribution of slope movements – from Etajima City of Hiroshima Prefecture to Kasaoka City of Okayama Prefecture – suggests that the heavy rain affected a very large area. The starting points of debris flow during this disaster were commonly close to the crest of mountain ranges. We compared the distribution of slope movements to the 24-hr rainfall accumulation during the heaviest rainfall event to clarify the factors that caused regional difference in slope-movement distribution. We found the area of highest density of the slope movements was consistent with the area receiving a cumulative rainfall of >250 mm. This observation indicated that the position of slope-movement starting points was not related to differences in geology.

scholarly journals Mortality by Age Group and Municipality in the July 2018 Torrential Rainfall

2019 ◽  
Vol 14 (6) ◽  
pp. 912-921
Author(s):  
Miho Ohara ◽  
◽  
Naoko Nagumo
Keyword(s):  
Mortality Rates ◽  
Age Group ◽  
Historical Records ◽  
Target Setting ◽  
Total Death ◽  
Western Japan ◽  
Hiroshima Prefecture ◽  
Torrential Rainfall ◽  
Okayama Prefecture ◽  
Nagasaki Prefecture

The July 2018 torrential rainfall caused tremendous damage to western Japan, claiming the lives of 237 people. This research analyzed the mortality due to the disaster by age group and municipality and compared it with historical records of past wind and flood disasters. The analysis confirmed that the total death toll of 237 including 115 deaths in Hiroshima Prefecture alone was the second highest in 41 years since 1978, following 427 deaths including 294 in Nagasaki Prefecture in the Nagasaki Great Flood in 1982. The analysis also found that the mortality rate in the age group 70 years and more was extremely high in Mabi Town of Kurashiki City, Okayama Prefecture and Saka Town, Hiroshima Prefecture, compared with that recorded in past disasters. Moreover, the paper discusses practical target setting for future mortality reduction by comparing the mortality rates in past disasters.

scholarly journals A fossil aphid gall from the middle Pleistocene sediment in Hyogo Prefecture, western Japan

2019 ◽  
Vol 22 (3) ◽  
pp. 270-274
Author(s):  
Minoru Tsukagoshi ◽  
Ken Sawada ◽  
Shin‐ichi Akimoto
Keyword(s):  
Middle Pleistocene ◽  
Western Japan ◽  
Hyogo Prefecture ◽  
Pleistocene Sediment

scholarly journals Emergent Littoral Deposits in the Eastern Canary Islands

1981 ◽  
Vol 15 (2) ◽  
pp. 199-208 ◽  
Author(s):  
Joaquin Meco ◽  
Charles E. Stearns
Keyword(s):  
Late Pleistocene ◽  
Canary Islands ◽  
Natural Science ◽  
Middle Pleistocene ◽  
Gran Canaria ◽  
Early Pliocene ◽  
Fossil Assemblage ◽  
Marine Deposits

AbstractK-Ar ages (A. Abdel-Monem, P. D. Watkins, and P. W. Gast, 1971, American Journal of Science 271, 490–521; this paper) and revised paleontological determinations (J. Meco, 1977, “Los Strombus neogenos y cuatenarios del Atlantico euroafricano”, Las Palmas, Ediciones del Excmo. Cabildo Insular de Gran Canaria) show that “Quaternary” (R. Crofts, 1967, Quaternaria 9, 247–260; G. Lecointre, K. J. Tinkler, and G. Richards, 1967, Academy of Natural Science of Philadelphia Proceedings 119, 325–344) littoral deposits on Lanzarote and Fuerteventura are early Pliocene and late Pleistocene. Early and middle Pleistocene strand lines are not represented. Early Pliocene littoral and marine deposits contain a characteristic fossil assemblage: Strombus coronatus, Nerità emiliana, Gryphaea virleti, Patella cf. intermedia, and Rothpletzia rudista. Differences in elevation record differential post-Pliocene uplift of the coastal platforms on which they lie. Late Pleistocene beach deposits at low elevations belong to two groups, an older with Strombus bubonius and a younger without. Differences in elevation of early Pliocene littoral deposits are reflected by differences in elevation of late Pleistocene beach deposits nearby.

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