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Cenozoic mass-transport facies and their correlation with relative sea-level change, New Jersey continental margin

机译：新泽西州大陆边缘新生代大规模输运相及其与相对海平面变化的关系

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Mass-transport deposits reveal something of the timing, source areas and depositional processes that contributed to the evolution of the New Jersey continental margin. Many of the mass-transport deposits rest upon prominent stratal surfaces and sequence boundaries permitting evaluation of the relationship between mass wasting and eustatic change. Five distinct mass-transport facies representative of intercanyon regions of the slope, canyons and continental rise settings are recognized in the Ocean Drilling Program Leg 150 Sites (902-906). These mass-transport deposits consist predominantly of muddy slumps and debris flows, and to a lesser extent sandy mass flows and gravity-related flows. The styles of soft-sediment deformation, mineralogy, and biostratigraphy of these mass-transport deposits provide new information on the mass-wasting history of the continental margin. At intercanyon sites beneath the continental slope (Sites 902-904), mud with disseminated sand occurs mainly at sequence boundaries and related stratal surfaces in upper Oligocene to upper Miocene sections. In contrast, muddy and sandy debris flows and slumps occur at sequence boundaries, stratal surfaces and within sequences in upper Miocene through Pleistocene sections. The type and preservation of mass-transport facies (10-15 percent of the total sediment recovered) on the continental slope through time, is associated with changes in sediment progradation during the Miocene, which led to a change in the morphology and gradient of the slope throughout the late Neogene. Mass-wasting facies are best preserved (36 percent of the total sediment) in the canyon-fill deposits recovered from Site 906. The fill of modern Berkeley Canyon is composed of debris flows, whereas the fill of a buried middle Miocene canyon consists of clast supported slumps, debris flows, and turbidites, which document an early episode of canyon excavation and infilling. Apparently the middle Miocene canyon cutting event occurred very rapidly (approx 2.5 Ma) and can be correlated to a prominent glacioeustatic sea-level lowering event (13.5 +- 0.5 Ma). Approximately 30 m of debris flows and slumps accumulated at Site 905 on the continental rise during the middle Miocene. Lithologies and benthic foraminifer assemblages show that this material was derived from the continental slope. Downslope transport was again significant during the early Pleistocene at Site 905 when 215 m of slumps and debris flows accumulated. The lithology and age of the clasts and matrix suggest that these deposits resulted from episodes of canyon excavation deep into the lithified rocks of the adjacent continental slope.
机译：大规模运输的沉积物揭示了促成新泽西州大陆边缘演变的某些时间，震源区和沉积过程。许多传质沉积物位于显着的地层表面和层序边界上，从而可以评估质量消散与欣喜变化之间的关系。在海洋钻探计划第150条站点（902-906）中，识别出代表斜坡的峡谷间区域，峡谷和大陆上升背景的五个不同的大量运输相。这些物质运输沉积物主要由泥泞的坍塌和泥石流组成，在较小程度上由沙质物质流和与重力有关的物质流组成。这些大规模沉积物的软沉积变形，矿物学和生物地层学的样式为大陆边缘的大规模消灭历史提供了新的信息。在大陆斜坡下方的峡谷间位置（站点902-904），含散布的泥浆主要发生在上新世至中新世上层的层序边界和相关的地层表面。相反，在中新世至更新世剖面中，层序界线，地层表面和层序内部发生泥泞和沙质泥石流和塌陷。随着时间的推移，大陆坡上的大规模运移相的类型和保存（占沉积物总回收量的10-15％）与中新世期间沉积物沉积的变化有关，这导致了中新世的形态和梯度变化。整个新近纪晚期的斜坡。在从906号站点回收的峡谷填充矿床中，能最好地保存质量消散的相（占沉积物总量的36％）。现代的伯克利峡谷的填充物由泥石流组成，而中新世中层峡谷的填充物则由碎屑组成。支撑的塌陷，泥石流和浑浊，记录了峡谷开挖和充填的早期情况。显然，中新世中部峡谷切割事件发生得非常快（约2.5 Ma），并且可能与突出的冰川恒流海平面下降事件（13.5±0.5 Ma）有关。在中新世中期，大陆上升段905处堆积了大约30 m的泥石流和塌陷。岩性和底栖有孔虫的组合表明，这种物质是从大陆斜坡中获得的。在早更新世的905号站点，当215 m的塌陷和泥石流堆积时，下坡的运输又很重要。岩屑和基质的岩性和年龄表明，这些沉积物是由于峡谷开挖深入相邻大陆斜坡的石化岩石而产生的。

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