Abstract We report on the Strombolian to Violent Strombolian eruption of Montana Grande which occurred between 789 and 725 BCE in the Guimar Valley on the NE flank of Tenerife island. The eruption produced a ca. 180 m-high scoria cone, a thick fallout deposit mostly dispersed southwest and a vast lava flow field that extends east of the cone, towards the coast, for 3.3 × 2.2 km. The eruption occurred in an unusual geodynamic context, outside the North West Rift and North East Rift zones and out of Las Canadas caldera which are the main geological structures of Tenerife, where the volcanic activity concentrated during the Holocene. The tephra and lava have a trachybasalt composition similar to products of the recent activity of Tenerife but characterized by a distinct trace element pattern (Ta depletion relative to Nb), that points to a distinct source for the magma feeding the eruption and an ascent history along the whole crust which is independent and different from the central feeding system of the Teide-Pico Viejo volcanic complex. The study of this eruption, which until now had been completely neglected, adds new significant data for the correct definition of volcanic risk in Tenerife.

中文翻译：

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被遗忘的喷发：特内里费岛蒙大拿州的玄武岩火山渣锥

摘要 我们报告了公元前 789 至 725 年间发生在特内里费岛东北侧吉马尔河谷的蒙大拿州格兰德的斯特龙博利式到猛烈的斯特龙博利式喷发。喷发产生了大约。180 m 高的火山渣锥，厚厚的沉降沉积物主要分散在西南方向，以及从锥体以东向海岸延伸 3.3 × 2.2 公里的巨大熔岩流场。此次喷发发生在一个不寻常的地球动力学环境中，位于西北裂谷和东北裂谷带之外以及加拿大拉斯火山口之外，这是特内里费岛的主要地质结构，火山活动在全新世集中。火山灰和熔岩的粗玄武岩成分类似于特内里费岛最近活动的产物，但其特征是具有独特的微量元素模式（相对于 Nb 的 Ta 耗竭），这指向了一个独特的岩浆源，它为整个地壳的喷发和上升历史提供了能量，它独立于并不同于泰德-皮科维耶霍火山复合体的中央供给系统。对这次喷发的研究，迄今为止一直被完全忽视，为正确定义特内里费岛的火山风险增加了新的重要数据。