Bog iron ores are well-known lumps of Fe-(oxy)hydroxides (goethite, limonite) found along streams and in seasonally flooded, low-lying areas. Historic literature of the Bourtangermoor, a former raised bog in the north of the Netherlands and adjacent Germany, however, revealed a second, rare type of bog iron ores, exclusively composed of siderite (Fe-carbonate) with accessory vivianite (Fe-phosphate), minerals only stable under anaerobic conditions. In this research we compared historic literature and maps mainly from the first half of the 20th century, when parts of the bog were still intact, with present-day seepage data to allow analysis whether recent seepage could be used to reconstruct the location of historic bog iron ores in the Bourtangermoor. Our results showed two distinctly different present-day seepage patterns: one related to shallow aquifers, one to deeper aquifers. Present-day seepage from deeper aquifers was related to historic siderite bog iron ore deposits (deposits exclusively limited to the lower, early formed, still groundwater-fed part of the raised bog). Present-day seepage – deep or shallow – did not show a clear relation to historic classic-type bog iron ores (lumps of goethite and limonite). We conclude that present-day seepage patterns from deep aquifers can be used to reconstruct historic siderite bog iron ores in the Bourtangermoor. Present-day seepage patterns – deep or shallow – are however not representative for historic bog iron ores deposited along streams. Our results could be useful for wetland restoration projects as iron can contribute to nutrient-poor conditions by capturing phosphate in bog iron ores and for archaeological research regarding the potential use of bog iron ores by past societies.

中文翻译：

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重建布尔坦格莫尔 (Bourtangermoor) 历史悠久的沼泽铁矿床，该沼泽曾是荷兰的一个凸起沼泽

沼泽铁矿石是著名的铁（氧）氢氧化物块（针铁矿、褐铁矿），产于溪流沿岸和季节性洪水泛滥的低洼地区。然而，布尔坦格莫尔（Bourtangermoor）是荷兰北部和邻近德国的前凸起沼泽地，其历史文献揭示了第二种稀有类型的沼泽铁矿石，完全由菱铁矿（碳酸铁）和副铁铁矿（磷酸铁）组成。 ，矿物质仅在厌氧条件下稳定。在这项研究中，我们主要将 20 世纪上半叶的历史文献和地图与当前的渗流数据进行了比较，当时沼泽的部分区域仍然完好无损，以便分析是否可以使用最近的渗流来重建历史沼泽的位置布尔坦格莫尔的铁矿石。我们的结果显示了两种截然不同的当今渗流模式：一种与浅层含水层有关，一种与较深的含水层有关。当今较深含水层的渗漏与历史上的菱铁矿沼泽铁矿床有关（矿床仅局限于较低的、早期形成的、仍由地下水供给的凸起沼泽部分）。如今的渗漏——无论深浅——与历史经典型沼泽铁矿石（针铁矿和褐铁矿块）没有显示出明显的关系。我们得出的结论是，当今深层含水层的渗流模式可用于重建布尔坦格莫尔历史悠久的菱铁矿沼泽铁矿石。然而，当今的渗流模式（无论深浅）并不代表历史上沿溪流沉积的沼泽铁矿石。我们的研究结果可能对湿地恢复项目有用，因为铁可以通过捕获沼泽铁矿石中的磷酸盐来导致营养贫乏的条件，也可以用于有关过去社会对沼泽铁矿石的潜在使用的考古研究。