ABSTRACT The Waitapu Shell Conglomerate is an important marker horizon in the eastern Whanganui Basin, occurring within a Pleistocene volcaniclastic record that contains early eruption products from the Taupo Volcanic Zone. The unit comprises a cross-bedded pebbly-shell conglomerate containing the first influx of Kaukatea Pumice (c. 0.9 Ma) within the Rangitikei succession. We document soft sediment deformation structures that occur in close stratigraphic proximity to the Waitapu Shell Conglomerate and other laterally equivalent units within the basins Castlecliffian outcrop belt. Soft sediment deformation structures formed through a combination of liquefaction and fluidisation, triggered by a range of mechanisms, including evidence of high sedimentation rates, loading, slope instability and potential for wave and earthquake-induced seismicity. Lateral changes in depositional style toward the basins eastern margin relate to relative position on the paleo-shelf, reduction of accommodation space, intermittent preservation of low stand deposits and proximity to the uplifting paleo-axial range.

中文翻译：

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旺格努伊盆地，史前地震档案？Waitapu Shell Conglomerate (c. 0.9 Ma)，新西兰北岛

摘要 怀塔普贝壳砾岩是旺格努伊盆地东部的一个重要标志层，发生在更新世火山碎屑记录中，该记录包含陶波火山带的早期喷发产物。该单元包括一个交错层理的卵石壳砾岩，其中包含 Rangitikei 层序中第一批涌入的 Kaukatea Pumice（约 0.9 Ma）。我们记录了发生在靠近怀塔普贝壳砾岩和盆地 Castlecliffian 露头带内其他横向等效单元的地层附近的软沉积物变形结构。软沉积变形结构通过液化和流化相结合形成，由一系列机制触发，包括高沉积速率、载荷、斜坡不稳定性以及波浪和地震诱发地震活动的可能性。