A box core and a trigger weight core were recovered from the Mackenzie Slope (Canadian Beaufort Sea) and combined into a composite sequence (AMD0214-03BC/TWC: 03CS) to investigate dinocyst assemblages and the mineralogical and geochemical compositions. This allowed the estimation of sea-surface conditions and documentation of changes in detrital inputs related to Late Holocene ocean-climate variability over the last 2700 years. The trends of detrital proxies and freshwater palynomorphs were similar to the reconstructed changes in large-scale ocean–atmosphere climate modes, such as the Pacific Decadal Oscillation (PDO) and Arctic Oscillation (AO). The palynological data reveal four distinct time intervals. The first period from 700 to 0 BCE was characterized by high surface and benthic productivities. This and the high freshwater palynomorph flux recorded in this period imply considerable freshwater input from the Mackenzie River with northern Mackenzie Basin sediment sources and enhanced transport of nutrient-rich Pacific water along the Mackenzie Slope. From 0 to 1500 CE, the weather conditions were possibly drier, with a decrease in the Mackenzie River discharge and nutrient supply. Milder sea-surface conditions associated with the Medieval Warm Period (800–1525 CE) likely promoted more prolonged seasonal sea-ice melting. The period from 1500 to 1900 CE featured increasing fresh water and a mixed provenance of detrital particles (with most particles originating from the northern Mackenzie Basin and a minor contribution from the southern basin). Colder conditions associated with the Little Ice Age period (1525–1865 CE) likely promoted longer sea-ice durations on the Mackenzie Slope. The final period, from 1900 CE to the present, has been dominated by taphonomic processes rather than climatic variations. Overall, this study provides a better understanding of the evolution of land–ocean interactions on the Mackenzie Slope.

中文翻译：

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过去 2700 年来，波弗特海（加拿大北极地区）Mackenzie Slope 古海面条件和沉积物动力学的演变

从 Mackenzie 斜坡（加拿大波弗特海）中回收了一个箱形岩心和一个触发重量岩心，并将它们组合成一个复合序列（AMD0214-03BC/TWC：03CS），以研究双囊壳组合以及矿物学和地球化学成分。这使得可以估计海面条件并记录过去 2700 年来与全新世晚期海洋气候变化相关的碎屑输入变化。碎屑代理和淡水孢粉体的趋势类似于大尺度海洋-大气气候模式的重建变化，如太平洋年代际涛动（PDO）和北极涛动（AO）。孢粉学数据揭示了四个不同的时间间隔。从公元前 700 年到公元前 0 年的第一个时期的特点是表面和底栖生产力高。这一点以及这一时期记录的高淡水孢粉型通量意味着大量淡水输入来自 Mackenzie 河和 Mackenzie 盆地北部沉积物来源，以及沿 Mackenzie 斜坡的富含营养的太平洋水的输送增强。从公元 0 年到 1500 年，天气条件可能更加干燥，麦肯齐河的流量和养分供应减少。与中世纪暖期（公元 800-1525 年）相关的较温和的海面条件可能促使季节性海冰融化的时间更长。公元 1500 年至 1900 年期间，淡水增加和碎屑颗粒的混合来源（大多数颗粒来自麦肯齐盆地北部，少量来自南部盆地）。与小冰河时代（公元 1525 年至 1865 年）相关的较冷条件可能促使麦肯齐斜坡上的海冰持续时间更长。最后一个时期，从公元 1900 年到现在，主要是埋藏过程而不是气候变化。总体而言，这项研究提供了对 Mackenzie Slope 陆地-海洋相互作用演变的更好理解。