Geological, petrographic, and structural investigation of Gada’Ale Volcano and surrounding areas, Northern Afar Depression, Ethiopia
摘要
The Gada’Ale area in northeastern Ethiopia, part of the Erta’Ale Volcanic Chain, exhibits diverse geology that includes recent basalt flows, volcanic and tectonic features that reflect ongoing magma–tectonic interactions. It has not yet been studied from a geologic, petrographic and structural perspective due to its inaccessibility and extremely high temperature, making it challenging environment for field studies. This study is therefore, the first to document the geology, petrography, dome–caldera structural relationships and their connection to active rift kinematics in this region, addressing a significant gap in the Gada’Ale area. The research highlights significant geological formations, including basalt rocks, recent sediments, hydrothermally altered deposits, and evaporites. Petrographic results of this study indicate that the basalt rocks exhibit aphanitic and vesicular textures, dominated by plagioclase, few clinopyroxene and olivine minerals. Using remote sensing data and field observations, we mapped the lithological units, and volcano-tectonic structures of the study area. Our results reveal various volcanic and tectonic features, such as shield volcanoes, fractures and faults, a salt dome, a collapsed caldera, lava tubes and maar volcanoes, highlighting the interactions between magmatism and tectonics. In particular, the study identifies the prevalence of NNW–SSE–trending extension fractures that align with regional tectonic patterns. This research enhances our understanding of the geological evolution of the northern Afar region and highlights the significance of ongoing geological activity in the Gada’Ale area for future studies.