@article{oai:nagoya.repo.nii.ac.jp:00029846,
 author = {隈, 隆成 and KUMA, Ryusei and 長谷川, 精 and HASEGAWA, Hitoshi and 坂井, 卓 and SAKAI, Takashi},
 journal = {名古屋大学博物館報告},
 month = {Mar},
 note = {Ashiya Group distributed in North Kyushu consists entirely of mid-Oligocene shallow marine sediments with intercalation of hummocky cross-stratified sandstone (HCS sandstone). Previous studies suggested that HCS sandstone formed during storm dominant conditions and HCS wavelength reflects the storm intensity . However, relationship between sedimentary facies, grain size, and wavelength of HCS sandstone are not clarified yet. We examined sedimentary facies, wavelength, amplitude, and grain size characteristics of HCS sandstone in the Ashiya Group. Three types of sedimentary facies in the HCS sandstones, such that amalgamated, partly-amalgamated, and non-amalgamated types, were observed in the Ashiya Group. Amalgamated HCS sandstone shows larger in wavelength, amplitude, and grain size than partly-amalgamated and non-amalgamated HCS sandstones. This observation suggests wavelength of HCS sandstone are influenced by sedimentary facies and grain size, which are possibly related to the formation depth of HCS sandstone. In addition, we compared the wavelength and grain size of amalgamated HCS sandstone in between the Lower Cretaceous Choshi Group, the mid-Oligocene Ashiya Group, and the mid-Miocene Misaki Group. Although grain sizes of the amalgamated HCS sandstone in three groups show similar size (150-200 mm), wavelengths of three groups are different markedly; i.e., longer in the Cretaceous Choshi Group and shorter in the Miocene Misaki Group. Thus, we suggest that different wavelength of HCS sandstone in between the Miocene, the Oligocene, and the Cretaceous strata can be reflectedto the different storm intensity at that time., 九州北部に分布する芦屋層群は漸新世中頃の浅海性堆積物からなり， ハンモック状斜交層理砂岩（hummocky cross-stratified sandstone：HCS砂岩）を多数介在する．HCS砂岩は暴風雨時に形成されると考えられ， その波長は嵐強度を反映している可能性が指摘されている． しかし， 異なる時代のHCS砂岩の波長から過去の嵐強度の変遷を復元するにあたり， その形成水深を規定するのが困難という問題点があった． そこで本研究では， 芦屋層群の堆積相とHCS砂岩の波長， 粒径の関係を調べ， 形成水深との関係性を検討した． 芦屋層群に見られる癒着HCS砂岩と単層HCS砂岩の粒径・ 波長を比べると， 癒着HCS砂岩の方が単層HCS砂岩よりも粒径が大きく，波長も大きいという特徴があった． これは芦屋層群のHCS砂岩の波長の大きさは， 形成水深に関係する堆積相や粒径と相関することを示唆している．そこで，癒着HCS砂岩のみに対して，芦屋層群と他地域のHCS砂岩 （白亜系銚子層群と中新統三崎層群）の粒径と波長とを比較検討した． その結果， 癒着HCS砂岩で比較すると粒径はおおよそ同じ（150-200 mm） であるにも関わらず，波長は白亜系銚子層群が有意に大きいことが明らかになった． このように， 同じ堆積相で同程度の粒径を示すにも関わらずHCS砂岩の波長に明確な違いが見られることは，中新世・漸新世・白亜紀当時の嵐強度の違いを反映している可能性が示唆される．},
 pages = {1--12},
 title = {漸新統芦屋層群に見られるハンモック状斜交層理砂岩の堆積相・粒径・波長の関係と，白亜系銚子層群，中新統三崎層群との比較},
 volume = {35},
 year = {2020}
}