Université Grenoble Alpes, Institut des Sciences de la Terre, Institut de Recherche pour le Développement, Grenoble 38000, France.
Centre de Recherches en Archéologie et Patrimoine, Université libre de Bruxelles, Brussels, 1050, Belgium.
Proc Natl Acad Sci U S A. 2023 Jan 10;120(2):e2215882120. doi: 10.1073/pnas.2215882120. Epub 2023 Jan 3.
Holocene climate in the high tropical Andes was characterized by both gradual and abrupt changes, which disrupted the hydrological cycle and impacted landscapes and societies. High-resolution paleoenvironmental records are essential to contextualize archaeological data and to evaluate the sociopolitical response of ancient societies to environmental variability. Middle-to-Late Holocene water levels in Lake Titicaca were reevaluated through a transfer function model based on measurements of organic carbon stable isotopes, combined with high-resolution profiles of other geochemical variables and paleoshoreline indicators. Our reconstruction indicates that following a prolonged low stand during the Middle Holocene (4000 to 2400 BCE), lake level rose rapidly ~15 m by 1800 BCE, and then increased another 3 to 6 m in a series of steps, attaining the highest values after ~1600 CE. The largest lake-level increases coincided with major sociopolitical changes reported by archaeologists. In particular, at the end of the Formative Period (500 CE), a major lake-level rise inundated large shoreline areas and forced populations to migrate to higher elevation, likely contributing to the emergence of the Tiwanaku culture.
全新世高海拔安第斯地区的气候特征是渐变和突变的交替，这些变化扰乱了水文循环，影响了景观和社会。高分辨率古环境记录对于将考古数据置于上下文中以及评估古代社会对环境变化的社会政治反应至关重要。本研究通过基于有机碳稳定同位素测量的转换函数模型，结合其他地球化学变量和古滨线指标的高分辨率剖面，重新评估了提提卡卡湖的中全新世至晚全新世水位。我们的重建表明，在中全新世（公元前 4000 年至公元前 2400 年）经历了一个长时间的低水位之后，湖泊水位在公元前 1800 年迅速上升了约 15 米，然后又以一系列步骤上升了 3 到 6 米，在公元 1600 年后达到了最高值。最大的湖泊水位上升与考古学家所报道的重大社会政治变化相吻合。特别是，在形成期（公元 500 年）结束时，一次大规模的湖水位上升淹没了大片滨岸地区，迫使人们迁移到更高的海拔，这可能促成了蒂瓦纳库文化的出现。
