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大洋钴探计划(ODP)112航次的岩芯和地球物理资料的研究结果确定了穿过秘鲁边缘至中陆坡的早始新世一第四纪正断层的陆相沉积层序以及一个15千米宽、在下陆坡之下的晚中新世一第四纪增生杂岩.在渐新世期间,始新世陆架和下陆坡的海底遭受侵蚀,并在中中新世洋侧部分沉降至下陆坡深度。这种沉降和缺失的古新世陆坡表明正常板块会聚时的构造侵蚀。纳兹卡洋脊的俯冲局部地加速了构造侵蚀,遗留下一个陡崖,而附近没有相应的压性构造。紧靠侵蚀陡崖的晚中新世沉积物增生了。尽管板块会聚史相似,晚中新世弧前盆地的快速沉降和邻近一盆地的稳定说明了弧前盆地沉降的局部构造机制。在陆架和上陆坡,底水氧很好保存在第四纪沉积物的交互层和硅藻土内。全球海平面的升降是引起这些相变周期的根本原因。在晚中新世,于现在中心以西约100千米海岸形成现代陆坡的构造边缘上升。沉积物富含有机碳,经强烈的微生物作用引起的有机质分解在硫酸盐还原带和甲烷作用带内是很明显的。碳酸盐胶结物的井下同位素特征清楚地表明了孔隙流体的垂向演化顺序。根据甲烷气体水合物、埋深、低氯化物孔隙流体的关系,提出了在活动边缘孔隙流体内促使氯化物消耗的一个附加过程,即释放粘土夹层水而无矿物相变。陆架沉积物亦含有存在于整个探区从北到南长达500多千米的地下卤水。尽管氧同位素成分表明了蒸发岩被海水溶解,但对卤水剩余物的来源仍然不清楚。
The results of the core and geophysical data from the Ocean Exploration Project (ODP) 112 voyage identified the terrestrial sedimentary sequence of the Early Pliocene-Quaternary normal faults that traversed the Peruvian mid-continental slope and a 15 km Late Quaternary accretionary complex under the lower slope, during the Oligoceses, the seabed of the Eocene shelf and the lower slope suffered erosion and settled to the lower slope on the side of the mid-Miocene depth. This subsidence and absence of the Paleocene slope indicate the tectonic erosion of normal plate convergence. The subduction of the Nazca ridge accelerated the tectonic erosion locally, leaving behind a cliff without a corresponding compressive structure nearby. Late Pleistocene sediments near eroded precipits proliferated. Despite the similar panel convergence history, the rapid subsidence of the late Paleozoic pre-archeal basin and the stability of the adjacent basin illustrate the local tectonic mechanism of subsidence in the forearc basin. On the shelf and upper slopes, the bottom water oxygen is well preserved within the interaction layers and diatomaceous earth of Quaternary sediments. The global sea level rise and fall is the root cause of these phase transitions. In the late Miocene, the tectonic margins of modern slopes about 100 km west of the present center rose. Sediments are rich in organic carbon and the decomposition of organic matter by strong microbes is evident within the sulphate and methane bands. The downhole isotopic characteristics of carbonate cements clearly demonstrate the vertical evolution of pore fluids. According to the relationship between methane gas hydrate, burial depth and low chloride pore fluid, an additional process of promoting chloride consumption in the active edge pore fluid is proposed, that is, clay intercalated water is released without mineral phase transition. Shelf sediments also contain underground brine present in the entire exploration area up to 500 kilometers long from north to south. Although the oxygen isotopic composition indicates that evaporite is dissolved in seawater, the source of residual brine remains unclear.