Vegetational and coastal environmental changes have been interpreted from a 600cm long and 764014C yr B.P. old sediment core from Lago Crispim located in the northeastern Pará State in northern Brazil. The radiocarbon dated sediment core was studied by multi-element geochemistry, pollen and charcoal analysis.Holocene Atlantic sea-level rise caused an elevation of local water table, which allowed the formation of organic deposits in a probably former inter-dune valley. Dense, diverse and tall Amazon rain forest, and some restinga (coastal vegetation) covered the study area at the beginning of the record at 764014C yr B.P. Mangrove vegetation developed along rivers close to the core site at that time. Subsequent decrease in less mangrove vegetation near the study site indicates a sea-level regression, beginning since around 700014C yr B.P. Lower sea-levels probably favoured the formation of a local Mauritia/Mauritiella palm swamp at 662014C yr B.P. Oscillations of higher and lower sea-level stands probably changed the size of the local palm swamp area several times between 6620 and 363014C yr B.P. Sea-level transgression at around 363014C yr B.P., caused marked coastal environmental changes: the development of mangroves near the site, the replacement of the local palm swamp by a Cyperaceae swamp, the substitution of the surrounding former Amazon rain forest and some restinga vegetation mainly by salt marshes. High amount carbonised particles suggest a strong human impact by burning on the coastal ecosystems during this late Holocene period.Highest concentrations of NaCl and also Ca, Mg and K in the upper sediment core indicate that the Atlantic was close during the late Holocene period. The core site, which is today 500m from the coastline and only 1-2m above modern sea-level, was apparently never reached by marine excursions during the Holocene.Less representation of mangrove since ca. 184014C yr B.P., may be related due to a slightly lower sea-level or to human impact in the study region. The modern shallow lake seems to be formed recently by road construction, forming an artificial dam.

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来自亚马逊河东部帕拉州东北部的 Lago Crispim 记录的全新世植被和沿海环境变化

从位于巴西北部帕拉州东北部的 Lago Crispim 的 600 厘米长和 764014C 年 BP 旧沉积岩芯中可以解释植被和沿海环境变化。通过多元素地球化学、花粉和木炭分析研究了放射性碳测年的沉积物核心。全新世大西洋海平面上升导致当地地下水位升高，这使得有机沉积物在可能以前的沙丘间山谷中形成。764014C yr BP 记录开始时，研究区覆盖了密集、多样和高大的亚马逊雨林，以及一些restinga（沿海植被） 红树林植被在当时靠近核心站点的河流沿岸发育。随后研究地点附近红树林植被减少表明海平面回归，自 BP 700014C 左右开始 较低的海平面可能有利于在 662014C yr BP 形成当地的 Mauritia/Mauritiella 棕榈沼泽 高低海平面的波动可能在 6620 到 363014C yr BP 海平面之间多次改变了当地棕榈沼泽的面积363014C yr BP 附近的海侵造成了显着的沿海环境变化：该地点附近的红树林的发展，当地的棕榈沼泽被莎草科沼泽取代，周围的前亚马逊雨林和一些主要被盐沼主要的restinga 植被取代. 在全新世晚期，大量碳化颗粒表明对沿海生态系统的燃烧对人类产生了强烈的影响。最高浓度的 NaCl 和 Ca，上部沉积物核心中的 Mg 和 K 表明大西洋在全新世晚期接近。今天距离海岸线 500m 且仅比现代海平面高 1-2m 的核心地点显然从未在全新世期间通过海洋游览到达。184014C yr BP，可能与研究区域的海平面略低或人类影响有关。现代的浅湖似乎是最近修路形成的，形成了人工水坝。