Abstract. The Congo Basin has been affected by several earthquakes for which the in-situ stress has not yet been reported. This study aims to determine the in-situ stress related to earthquakes in the Congo Basin, particularly those located in the north portion of the Republic of Congo (RC) and in the northwest portion of the Democratic Republic of Congo (DRC). The combined analysis of seismic history of the Congo Basin and of in-situ paleo-stress in the Inkisi Group allowed us to distinguish onshore earthquakes that are linked with preexisting zones of fractures on the continent and offshore earthquakes that are directly linked with transform faults. The Inkisi Group has been affected by two phases of strike-slip tectonics. The first phase, with a direction of compression N142°, is a result of the Gondwanide orogenesis in the Paleozoic. The second phase, with a compression direction of N078°, is related to the present-day stress of earthquakes in the Congo Basin. This phase is still active and is likely attributable to ridge push from the opening of the Atlantic Ocean. It is therefore appropriate that infrastructure construction in Brazzaville and Kinshasa considers seismic risk in the Inkisi bedrock of this area. As an example, we note that several masonry fences along the Congo river have developed fractures.

中文翻译：

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布拉柴维尔和金沙萨的新构造：将刚果盆地的地震活动性与印基西组的原地应力联系起来

摘要。刚果盆地受到几次地震的影响，目前尚无关于地应力的报道。这项研究的目的是确定与刚果盆地地震有关的原地应力，特别是位于刚果共和国（RC）北部和刚果民主共和国（DRC）西北部的地震。对刚果盆地地震历史和因基西组的原地古应力的综合分析，使我们能够区分与大陆上已有的断裂带相关的陆上地震和与转换断裂直接相关的近海地震。印基西组受到走滑构造两个阶段的影响。第一阶段的压缩方向为N142°，是古生代冈德奈德造山作用的结果。第二阶段 压缩方向为N078°的地震与刚果盆地当前的地震应力有关。这个阶段仍然很活跃，可能归因于大西洋开放带来的山脊推力。因此，布拉柴维尔和金沙萨的基础设施建设考虑该地区因基西基岩的地震风险是适当的。例如，我们注意到刚果河沿岸的几处砖石围墙已经形成裂缝。