Fourth- to third-order cycles in the Hakobuchi Formation: Shallow-marine Campanian final deposition of the Yezo Group, Nakagawa area, northern Hokkaido, Japan
Fourth- to third-order cycles in the Hakobuchi Formation: Shallow-marine Campanian final deposition of the Yezo Group, Nakagawa area, northern Hokkaido, Japan
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DOI：
10.1111/j.1440-1738.2010.00716.x
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发表时间：
2010-12-01
期刊：
影响因子：
1.5
通讯作者：
TakamatsuO, Daisuke
中科院分区：
文献类型：
--
作者：
Ando, Hisao;Tamura, Yoshitaka;TakamatsuO, Daisuke
叶佐群在日本北方的北海道有广泛的纵向分布。它代表了白垩纪（早阿普特阶-晚马斯特里赫特阶）和晚古新世弧前盆地填充沿着古亚洲大陆东缘。在北方北海道的中川地区，叶藏群的最上部由箱渊组组成。沿着Yezo盆地西缘，24个沉积相（F）代表6个相组合（FA），表明主要为风暴为主的内陆棚至滨岸环境，其次为滨岸沙脊、外陆棚、河口和河流环境。这些组合的叠加模式，厚度和相趋势允许六个沉积序列（DS）的歧视。Inoceramids Sphenoceramus schmidti和Inoceramus balticus，菊石Metaplacenticeras subtilistriatum，提供晚早到晚坎帕尼亚年龄的限制，这大约370米厚的沉积和隆起的最后阶段的Yezo弧前盆地。六个浅海至次非海相砂岩为主的沉积层序包括四个10至110米厚的向上变粗的海退序列（FS 1），偶尔与薄，小于10米厚，向上变细的海侵序列（FS 2）。下DS 1 -3、中DS 4 -5和上DS6代表三个沉积层序组（DS 1 -3）。从层序地层学的角度来看，这些向东延伸和向西退变的浅海沉积体系可能反映了第三级和第四级相对海平面的变化。
The Yezo Group has a wide longitudinal distribution across Hokkaido, northern Japan. It represents a Cretaceous (Early Aptian-Late Maastrichtian) and Late Paleocene forearc basin-fill along the eastern margin of the paleo-Asian continent. In the Nakagawa area of northern Hokkaido, the uppermost part of the Yezo Group consists of the Hakobuchi Formation. Along the western margin of the Yezo basin, 24 sedimentary facies (F) represent 6 facies associations (FA), suggesting prevailing storm-dominated inner shelf to shoreface environments, subordinately associated with shoreface sand ridges, outer shelf, estuary and fluvial environments. The stacking patterns, thickness and facies trends of these associations allow the discrimination of six depositional sequences (DS). Inoceramids Sphenoceramus schmidti and Inoceramus balticus, and the ammonite Metaplacenticeras subtilistriatum, provide late Early to Late Campanian age constraints to this approximately 370-m thick final stage of deposition and uplift of the Yezo forearc basin. Six shallow-marine to subordinately non-marine sandstone-dominated depositional sequences include four 10 to 110-m thick upward-coarsening regressive successions (FS1), occasionally associated with thin, less than 10-m thick, upward-fining transgressive successions (FS2). The lower DS1-3, middle DS4-5 and upper DS6 represent three depositional sequential sets (DSS1-3). These eastward prograding and westward retrograding recurring shallow-marine depositional systems may reflect third- and fourth-order relative sealevel changes, in terms of sequence stratigraphy.