We have developed 3D inversion models derived from airborne gravity and magnetic data, which are constrained by seismic and well data, in eastern Somaliland. The density model reveals a northwest–southeast-trending basin, 125 km long and 25 km wide and called the Dood Arale Basin. The basin comprises two subbasins separated by a basement high and is infilled by up to 2500–3200 m of sediments. Smaller and shallower subbasins are also identified to the west of Lafaweyne and northeast of Dararweyne. The density model shows that the top basement in the platform areas is at approximately 1500–1700 m in depth and shallows to approximately 300 m at the Bur Anod, Hagraajin, and Hagrin Ranges and northwest of Eil Afwein. The basement depths in these areas are more uncertain and could be deeper because they occur in areas of high gravity anomalies caused by a combination of near-surface high-density sediments and high-density plutonic bodies within the basement. The susceptibility model indicates that the basement consists of very weakly magnetized metasediments of the Inda Ad Complex intruded by three northeast–southwest-trending magnetic bodies with upper surfaces at depths of approximately 300–3000 m. These magnetic bodies are interpreted as plutonic complexes of similar age and composition to the Lower Cretaceous syenite intrusions outcropping at Gorei in the Shilah Madu Range. Seismic reflection profiles image the sedimentary sequences, but they do not clearly map the top basement or detect any of the plutonic bodies. The plutonic bodies could have controlled the location of the basin’s border faults and contributed to the high geothermal gradient recorded at the Faro Hills-1 well. The Upper Cretaceous Gumburo and Jesomma Formations in the basin could potentially have reached maturation close to and above the plutonic bodies within the center of the basin.

中文翻译：

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重力和磁数据的 3D 约束反演图像基底和深成体：来自索马里兰东部 Dood Arale 盆地的案例研究

我们已经开发了 3D 反演模型，这些模型源自于索马里兰东部的航空重力和磁力数据，这些数据受到地震和井数据的限制。密度模型显示了一个西北-东南走向的盆地，长 125 公里，宽 25 公里，称为 Dood Arale 盆地。该盆地包括两个子盆地，由一个基底高隔开，并被高达 2500-3200 米的沉积物填充。在 Lafaweyne 以西和 Dararweyne 东北部也发现了更小和更浅的子盆地。密度模型显示，平台区的顶部基底深度约为 1500-1700 m，Bur Anod、Hagraajin 和 Hagrin Ranges 以及 Eil Afwein 西北部的浅层深度约为 300 m。这些地区的基底深度更不确定，可能更深，因为它们发生在由近地表高密度沉积物和基底内高密度深成体组合引起的高重力异常区域。磁化率模型表明，基底由 Inda Ad 杂岩的非常弱磁化的变沉积物组成，被三个东北-西南走向的磁体侵入，上表面深度约为 300-3000 m。这些磁体被解释为与在 Shilah Madu Range 的 Gorei 出露的下白垩统正长岩侵入体具有相似年龄和组成的深成复合体。地震反射剖面对沉积序列进行成像，但它们没有清楚地绘制顶部基底或探测到任何深成体。深成体可能控制了盆地边界断层的位置，并促成了 Faro Hills-1 井记录的高地温梯度。盆地中的上白垩统 Gumburo 和 Jesomma 地层可能在盆地中心的深成体附近和上方达到成熟。