A marine sediment core located off the southernmost part of the Baja California Peninsula, NE Pacific, is analyzed to investigate a submarine mass failure. We examine the lithofacies and sedimentary structures, the total organic (TOC) and inorganic (TIC) carbon, the grain size composition, and the degree of fragmentation in foraminifera tests. The core BB03 consists of five lithostratigraphic units, from bottom to top, U1 to U5. Radiocarbon dating (AMS ¹⁴C) indicates that this sequence is inverted, where the deepest strata U1–U2 date at ~ 4,162 cal yr BP, U3–U4 at ~ 14,406 cal yr BP, and the shallower strata U5 at ~ 18,759–19,445 cal yr BP. Analysis of core and multibeam bathymetric data evidenced a submarine mass failure of the slump type, characterized by abruptly inverted layers with soft-sediment deformation structures. The event’s timing is constrained both with AMS ¹⁴C and the well-known stratigraphic identification of laminated or bioturbated layers in this highly productive upwelling zone. The event occurred during the Late Holocene as constrained by a maximum age of ~ 4,000 years. Although there is no explicit evidence on the cause of the submarine slump, the geomorphic characteristics and the close spatial connection with other submarine mass failures suggest a close relationship with the Tosco-Abreojos fault having acted either as a preconditioning factor or as a triggering mechanism. Finally, this study represents one of the few studies of submarine mass failures at the NE Tropical Pacific margin, aiming to identify how the transported sediments interact with the regional morphology and the formation of modern seafloor structures.

分析位于太平洋东北部下加利福尼亚半岛最南端的海洋沉积物核心，以调查潜艇质量故障。我们检查了岩相和沉积结构、总有机 (TOC) 和无机 (TIC) 碳、粒度组成以及有孔虫测试中的破碎程度。核心BB03由五个岩石地层单元组成，从下到上，U1到U5。放射性碳测年 (AMS ¹⁴C) 表明这个序列是倒置的，其中最深的地层 U1-U2 位于约 4,162 cal yr BP，U3-U4 位于约 14,406 cal yr BP，较浅的地层 U5 位于约 18,759-19,445 cal yr BP。对岩心和多波束测深数据的分析证明了坍塌类型的海底质量破坏，其特征是具有软沉积物变形结构的突然倒置层。事件的时间受到 AMS ^{14 的}限制C 和众所周知的地层识别在这个高产上升流带中的层状或生物扰动层。该事件发生在全新世晚期，最大年龄约为 4,000 年。虽然没有明确的证据表明潜艇坍塌的原因，但地貌特征和与其他潜艇质量故障的密切空间联系表明，与托斯科-阿布雷奥霍斯断层作为预处理因素或触发机制的密切关系。最后，这项研究是对东北热带太平洋边缘海底大规模破坏的少数研究之一，旨在确定输送的沉积物如何与区域形态和现代海底结构的形成相互作用。