Abstract The shallow continental shelf in the Cape Fear Region of southwestern Onslow Bay, North Carolina, contains lag deposits with an abundance of megatoothed shark teeth belonging to Otodus megalodon (Agassiz 1835) and Otodus chubutensis (Ameghino 1906) that derive from the Pliocene Yorktown and Miocene Pungo River formations, respectively. These teeth exhibit different frequencies and orientations of macroborings identified as Gastrochaenolites torpedo Kelly and Bromley (1984), Gastrochaenolites lapidicus Kelly and Bromley (1984), Maeandropolydora sulcans Voigt (1965) and ?Entobia isp. attributed to endolithic bivalves, serpulid worms and clionaid sponges. Different frequencies and orientations of macroborings seen in lag deposits containing O. megalodon and O. chubutensis teeth are the result of repeated exhumation and reworking in response to bathymetrically controlled wave-based erosion during storm events and glacioeustatically driven sea-level cyclicity across Onslow Bay. Chronological ranges of O. megalodon and O. chubutensis teeth that contain macroborings indicate that these lag deposits may have been forming since the late early Miocene.

中文翻译：

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来自美国北卡罗来纳州昂斯洛湾水下陆架的 Otodus megalodon 和 Otodus chubutensis 鲨鱼牙齿的宏观钻孔：对滞后沉积形成过程的影响

摘要 北卡罗来纳州昂斯洛湾西南部的开普菲尔地区的浅层大陆架含有大量的巨齿鲨齿，属于 Otodus megalodon (Agassiz 1835) 和 Otodus chubutensis (Ameghino 1906)，它们来自上新世约克镇和分别为中新世 Pungo River 地层。这些牙齿表现出不同频率和方向的宏观钻孔，确定为 Gastrochaenolites torpedo Kelly 和 Bromley (1984)、Gastrochaenolites lapidicus Kelly 和 Bromley (1984)、Maeandropolydora sulcans Voigt (1965) 和 ? 归因于内石双壳类动物、serpulid 蠕虫和 clionaid 海绵。在含有 O. megalodon 和 O. 的滞后沉积物中看到的大孔的不同频率和方向。chubutensis 牙齿是在风暴事件期间反复挖掘和重新加工以应对测深控制的波浪侵蚀的结果，以及横跨昂斯洛湾的冰川驱动的海平面周期性变化。O. megalodon 和 O. chubutensis 牙齿的年代范围包含大孔表明这些滞后沉积物可能自中新世晚期晚期开始形成。