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九州大学総合研究博物館が所蔵する玉泉館資料の古代瓦から，飛鳥～平安時代に相当する瓦資料32点を選び，内部断面の電子顕微鏡装置（EPMA）による岩相分析を行った．瓦は部分的に内部が熔解している熔結組織と，内部が焼き固まっている焼結組織を呈するものに分けられる．焼結組織をもつ瓦断面からは，残存鉱物として，花崗岩由来の石英，斜長石，曹長石，正長石，黒雲母，白雲母，火山岩由来の火山ガラス，斜長石，黒雲母が観察された．材料物質はおおむねこれらの混合物であり，材料供給地の特定は難しい．含まれる火山ガラスは，その化学組成から姶良カルデラ起源の姶良Tn（AT）火山灰，鬼界カルデラ起源のアカホヤ（K-Ah）火山灰と同定された．瓦内部に残存する鉱物と火山ガラスの組み合わせによって，瓦の焼成温度を推定した．焼結組織を呈する瓦は雲母の残る低温焼成（650～850℃）と，雲母はないが火山ガラスを包有する中間焼成（850～1150℃）のものに分けられる．一方，熔結組織は高温焼成（1150～1400℃）によって作られたものであった．観察した高温焼成の瓦は比較的少数で，瓦生産の黎明期には，高温焼成技術が確立されていなかった可能性を示唆している．, A series of lithological analysis for ancient roof tiles has been carried out using the electron microprobe technique. Thirty-two roof tile samples were selected from the Gyoku-sen-kan collection in the Kyushu University Museum, and are typologically-dated from the Asuka to Heian Periods, corresponding to the 7th to the 12th centuries AD. Based on electron microscopic observation, the textures of roof tiles’ interiors are divided in two types, such as sintered and welded textures that correspond to lower and higher firing temperatures, respectively. From the sections of sintered textured samples, quartz, K-feldspar, albite, plagioclase, biotite and muscovite of granitic origin, and glass shards, plagioclase and biotite of volcanic origin were identified. Mineral and glass assemblages suggest source materials were mixtures and it is difficult to identify distinct source areas. The contained volcanic glasses are derived from Aira caldera (AT) and Kikai caldera (K-Ah), which are meaning the firing temperature was not reached about magma temperature. The results indicate that there are three different firing temperatures, namely: lower (650-850℃) with mica; medium (850-1150℃) with volcanic glass; and higher (1150-1400℃) without volcanic glass and welded texture. It is suggested that high-temperature firing technique of kiln was not established yet in the early period of roof tile manufacturing in Kyushu area.

Late Pleistocene tephras derived by large explosive volcanic eruptions are widespread in the Mediterranean and surrounding areas. They are important isochronous markers in stratigraphic sections and therefore it is important to constrain their sources. We report here tephrochronology results using multiple criteria to characterize the volcanic products of the Late Pleistocene Ciomadul volcano in eastern-central Europe. This dacitic volcano had an explosive eruption stage between 57 and 30 ka. The specific petrological character (ash texture, occurrence of plagioclase and amphibole phenocrysts and their composition), the high-K calc-alkaline major element composition and particularly the distinct trace element characteristics provide a strong fingerprinting of the Ciomadul volcano. This can be used for correlating tephra and cryptotephra occurrences within this timeframe. Remarkably, during this time there were several volcanic eruptions produced tephras with similar glass major element composition. However, these tephras differ from Ciomadul ones by glass trace element abundances, ratios of strongly incompatible trace elements and distinctive mineral cargo that serve as discrimination tools. We used (U-Th)/He zircon dates combined with U-Th in-situ rim dates along with luminescence and radiocarbon dating to constrain the age of the explosive eruptions of Ciomadul that yielded distal tephra layers, but lack of identified proximal deposits.

Following on the discovery (in 2011) of a layer of distal tephra from the Pomici di Avellino eruption (Somma-Vesuvius, EU5) in the Agro Pontino (southern Lazio, Italy), further detailed study of the Holocene sediment archives in this graben and in the nearby Fondi coastal basin showed that distal tephra from this EU5 eruption occurs as a rather continuous, conspicuous layer. Two other, less conspicuous tephra layers were found, identified as the earlier Astroni 6 eruption from the Campi Flegrei (Fondi basin) and the later AP2 eruption of the Somma-Vesuvius (Agro Pontino). The identification of the distal tephra layers rests upon a combination of criteria, including stratigraphy, macro characteristics, mineralogy, geochemical data on glass composition, Sr-isotopic ratios, and the known tephrochronology for the period concerned, i.e. between c. 2500 and 1000 BCE. 14C datings serve to constrain their age. No significant spatial variation in the characteristics of the main tephra layer (EU5) was observed, other than distinct fining with increasing distance from the vent. Based on a detailed palaeogeographical reconstruction, the occurrence and preservation of these tephra are explained by the local environmental conditions governing their preservation during this time span (the Central Italian Bronze Age), and by the later evolution of the area. The observations underpin that multiple corings are needed to fully assess whether sedimentary hiatuses exist in palaeorecords, based on cores from sediment archives. Lastly, our study shows that hazard evaluations for future eruptions by Campanian volcanoes should pay more attention to their potential impacts on distal areas.

The presence of the Early Bronze Age Avellino (AV) tephra in the Holocene lacustrine deposits of the Agro Pontino and Fondi basin provides a unique opportunity to reconstruct the Holocene depositional environment at the time of AV-tephra deposition. Marine terraces of the last Pleistocene transgression have been consolidated by soil formation and incised during the last glacial. This created a gully landscape in the Fondi basin and in the southeastern Agro Pontino. The inland central part of the Agro Pontino was drained by one major gully. At the final part of subsequent Holocene sea level rise, beach ridges closed the southeastern marine lagoons, creating a lacustrine and marshy environment. Shortly after, the Avellino eruption deposited its sandy tephra in these freshwater environments. By comparing altitudes of the AV-tephra in different environments two major implications emerge. First, at those locations where the AV-tephra is underlain by thick Holocene peaty and clayey deposits, significant subsidence occurred, while this has been limited at locations where the Pleistocene marine terrace occurs close to the surface. This subsidence is independently checked by comparing a modern LiDAR DEM and a detailed DEM from 1928. Second, the altitude of the AV-tephra reflects sea level in the coastal positions around −1.5 to −2 m a.s.l., while the only gully draining the lacustrine and marshy inland Agro Pontino was blocked around 0.5 m a.s.l. by the expanding sediment wedge of the Amaseno River, the major draining axis of the Agro Pontino. The AV-tephra layer will continue to play an important role in regional geological, palaeoenvironmental and geo-archaeological research.

Clearly defined distal tephras are rare in rockshelter sediment records. Crvena Stijena, a Palaeolithic site in Montenegro, contains one of the longest (> 20 m) rockshelter sediment records in Europe with deposits ranging in age from Middle Pleistocene to mid-Holocene. A distinctive tephra is clearly exposed within the well stratified record approximately 6.5 m below the present land surface. We present geochemical data to confirm that this tephra is a distal equivalent of the Campanian Ignimbrite deposits and a product of the largest Late Pleistocene eruption in Europe. Originating in the Campanian volcanic province of southwest Italy, this tephra has been independently dated to 39.3 ka. It is a highly significant chronostratigraphic marker for southern Europe. Macrostratigraphic and microstratigraphic observations, allied with detailed particle size data, show that the tephra layer is in a primary depositional context and was transported into the rockshelter by aeolian processes. This site is unique because the tephra forms an abrupt boundary between the Middle and Upper Palaeolithic records. Before they can be used as chronostratigraphic markers in rockshelter and cave-mouth environments, it is essential to establish the stratigraphic integrity of distal tephras and the mechanisms and pathways involved in their transport and deposition.

Kamchatka is one of the world's most active volcanic regions and has hosted many explosive eruptions during the Holocene. These eruptions had the potential to disperse tephra over wide areas, forming time-synchronous markers wherever those tephras are found. Recent research in Kamchatka has begun to focus on the geochemical analysis of individual glass shards in order to characterise tephra layers. We have applied this approach to the study of visible tephras from three lakes - one in central and two in northern Kamchatka - with the aim of identifying key tephras and potential issues in the application of distal (>100 km from an active volcano) tephra in volcanically complex regions. In total, 23 tephras from 22 tephra beds have been geochemically analysed, representing products from at least four volcanic systems in Kamchatka. We demonstrate that distal lake sediments in the region can yield reliable tephrostratigraphies, capturing tephra from eruptions that have the greatest potential to disperse volcanic ash beyond the region. We draw attention to issues relating to correlating and distinguishing key marker horizons from the highly active Shiveluch Volcano, namely the need to ensure inter-lab comparability of geochemical data and good chronological control of the proximal and distal tephras. Importantly, we have also extended the known distribution of two key tephra isochrons from the Ksudach volcano. Our work contributes valuable glass geochemical on data several key marker beds that will facilitate future tephra and palaeoenvironmental research within and beyond Kamchatka. (C) 2015 Elsevier B.V. All rights reserved.

北陸地方東部(金沢平野～富山平野間)に位置する活断層の平均変位速度を明らかにするために，本地域に広く分布する河成段丘群の編年を行った．本地域は，段丘構成層中に編年の指標となる火山灰層を純層で確認できることは稀であるために，本研究では段丘を覆う被覆土壌層の採取を行い，これに微量に含まれる火山起源の鉱物を用いて段丘形成時期の推定を行った．また，本地域は一般に圃場整備や都市化の影響を受け自然露頭に恵まれないため，砺波平野を除く各地域では被覆土壌層の採取を主にボーリング掘削によって行った．富山平野～金沢平野間に分布する河成段丘面は，被覆土壌層や段丘構成層に挟在する火山灰層の層位，段丘面の分布形態，開析程度，傾斜，現河床からの比高，礫層の風化程度等よりⅠ面～Ⅻ面の12面に区分される．これらの段丘面のうち，Ⅸ面構成層上位にはAT(26-29ka)が，Ⅶ面構成層上位にはDKP(55ka)が，Ⅳ面を覆う被覆土壌層下位にはK-Tz(95ka)がそれぞれ挟在する．本研究によって，北陸地方のような火山灰稀産地域においても，広域的な河成段丘面の編年・対比は十分に可能であることが確認された．, Fluvial terraces are widely distributed in the eastern part of Hokuriku region, composed of the Toyama, Tonami, and Kanazawa Plain, northern part of Central Japan. In this area, the age of terraces has not been reported, as volcanic ashes are rarely visible within terrace deposits and overlying loamy soil, and outcrops are quite few in this area. In this study, we carried out drilling survey on these terraces to obtain overlying loamy soil samples and extracted some well-known wide-spread volcanic ashgrains from these samples after ultrasonic washing. Late Quaternary fluvial terraces in the eastern part of Hokuriku region are divided into 12 levels: terrace 1 to 12 in descending order. Terrace 4 is overlain by the Kikai-Tozurahara tephra (95ka), Terrace 6 is overlain by the Daisen-Kurayoshi tephra (55 ka) and Terrace 8 is overlain by the Aira-Tanzawa tephra (26-29 ka), respectively. From the tephrochronology and the sedimentary facies of terrace deposits, we estimate that each terrace was formed at MIS (Marine Oxygen Isotope Stage) 6 (terrace 1), MIS 5e (terrace 2), MIS 5d (terrace 3), MIS 5c (terrace 4), MIS 5b or 5a (terrace 5), MIS 4 or 4-3 boundary (terrace 6), MIS 3 (terraces 7, and 8), MIS 3 or 3-2 boundary (terrace 9), MIS 2 (terrace 10), and Holocene period (terraces 11, and 12), respectively. This study shows that the combination of the drilling of loamy soil and the precise microtephra analysis of fluvial terraces in rarely volcanic ashes and outcrops area can estimate of the formative age of these terraces., 論説

Sivo-pepeljasti sloj i pepeljasta leća otkopani u Veloj spili na Korčuli na dubini od oko 5,80 m, odnosno 6,25 m, sastoje se od vulkanskoga pepela izbačenoga tijekom erupcije napuljskoga žutog tufa (NYT) prije približno petnaest tisuća godina i tijekom erupcije piroklastike Ponti Rossi prije šesnaest tisuća godina na Flegrejskim poljima pokraj Napulja. Na spomenutome području, ali i na drugim vulkanskim područjima, dobro su istražene i radioizotopnim metodama K-Ar i 40Ar/39Ar izravno datirane brojne erupcije čiji distalno istaloženi prah i pepeo (tefra) mogu poslužiti za realnije datiranje arheoloških događaja od dosad uobičajenih načina. Sloj NYT stratigrafski je smješten na vrhu pleistocenskih taložina vrlo bogatih ostacima koji ukazuju na ljudsko djelovanje. Te su taložine po sadržaju i po svojstvima potpuno drukčije od sloja nastaloga u ranome holocenu. U kulturnome smislu sloj NYT smještamo na kraj paleolitika. Sloj iznad njega pripada samomu kraju paleolitika, a naredni označava početak mezolitika. Kraj pleistocena posebno je zanimljiv jer označava vrijeme tijekom kojega se uzdiže razina mora, mijenjaju se klima te biljni i životinjski svijet, zbog čega dolazi do značajnih promjena u egzistenciji ljudske zajednice, koja je morala mijenjati strategiju preživljavanja. Kao posebno se pitanje nameće utjecaj kataklizmičkih erupcija na okoliš, a samim time i na razvitak ljudske zajednice, odnosno pojedinih prapovijesnih kultura., The layer of grey ash and ash-lens excavated in Vela Spila Cave on the island of Korčula at a depth of approximately 5.8 m, and 6.25 m, consist respectively of volcanic ash ejected during the eruption of Neapolitan Yellow Tuff (NYT) roughly 15 ka ago and during eruption of the Ponti Rossi pyroclastics 16 ka ago in the Phlegraean Fields near Naples. In this area, and in other volcano zones, a number of eruptions have been thoroughly examined and directly dated by K-Ar and 40Ar/39Ar dating methods, and their distal deposited dust and ash (tephra) can serve to date archaeological events more accurately than previously customary methods. The NYT layer is stratigraphically situated atop Pleistocene sediments rich in remains indicating human activity. The composition and properties of these sediments make them entirely different from the layers deposited in the Early Holocene. In the cultural sense, the NYT layer is placed at the end of the Palaeolithic. The layer above it belongs to the uppermost Palaeolithic, while the subsequent layer marks the beginning of the Mesolithic. The end of the Pleistocene is particularly interesting as it indicates an era when sea levels rose and the climate, flora and fauna underwent changes, which in turn led to significant change in the existence of human communities, which had to adjust their survival strategies. A particular question that arises is the impact of cataclysmic volcanic eruptions on the ecology of the environment and, consequently, on the development of human communities and individual prehistoric cultures.