Camp dels Ninots is a mixed hard-soft maar-diatreme located in the Catalan Volcanic Zone (NE of Iberia), in which intra-maar lake sediments have preserved one of the most remarkable Pliocene fossil records in Europe. Geophysical surveys combined with the geological map and 11 boreholes, including two new continuous intra-crater drill cores, have enabled the construction of a 3D geological model of this maar-diatreme and its basement. The formation of this maar-diatreme started with a vent-opening phreatomagmatic explosion at the intersection between a regional fault and the Paleozoic groundwater level at a depth of 210 m. We infer and calculate the geometry, dip direction and dip angle of this regional fault. During the eruption, mixed Strombolian and phreatomagmatic episodes occurred, forming the tuff ring and filling the diatreme with minimum estimated volumes of 0.012 and 0.004 km³, respectively. The diatreme infill is composed of three main lithofacies that include tuff-breccias, welded scoriae, and mafic intrusions into the phreatomagmatic breccias. Thus, the stratigraphy of the diatreme succession suggests a progression of explosive events from deeper to shallower zones with short lateral migration of explosion vents, which control its final morphology, without evidence for significant deep enlargement of the diatreme during the later phases. This generated a wide funnel-shaped with low diatreme wall angles that differs from kimberlite pipes with great depths and sharp slope geometries. Hence, such 3D geological model helps to understand the complex architecture of maar-diatreme structures, highlighting the lack of geological modeling of this type of monogenetic system.

Camp dels Ninots 是位于加泰罗尼亚火山带（伊比利亚东北部）的硬-软混合玛珥地貌，其中玛珥湖内沉积物保存了欧洲最显着的上新世化石记录之一。地球物理勘测与地质图和 11 个钻孔（包括两个新的连续火山口内钻芯）相结合，能够构建这个马尔迪亚特雷姆及其基底的 3D 地质模型。这个maar-diatreme的形成开始于210 m深度的区域断层和古生代地下水位之间的交汇处的通风口潜水岩浆爆炸。我们推断并计算了该区域断层的几何形状、倾角方向和倾角。在喷发期间，发生了混合的斯特龙博利和岩浆事件，³、分别。火山岩充填体由三种主要岩相组成，包括凝灰岩角砾岩、熔结熔渣和镁铁质侵入岩浆角砾岩。因此，火山口层序的地层表明爆炸事件从更深的区域向浅层发展，爆炸口的短横向迁移控制了其最终形态，没有证据表明在后期阶段火山口有显着的深层扩大。这产生了一个宽漏斗形，具有低直径壁角，不同于具有大深度和陡峭坡度几何形状的金伯利岩管。因此，这种 3D 地质模型有助于理解 maar-diatreme 结构的复杂结构，突出了此类单生系统地质建模的缺乏。