Abstract: This study presents a comparative investigation of the emplacement conditions for gabbroic intrusion sexposed on Dee and Cecilia islands, located along the South Shetland Islands to the north of the Antarctic Peninsulain Western Antarctica. Crystallization temperatures and emplacement pressures were calculated using two-pyroxene geothermobarometry, and oxygen fugacity conditions were additionally constrained based on Fe–Ti oxide pairs. Petrographically, the Dee intrusions are characterized by fine-grained, holocrystalline porphyritic textures composed of plagioclase, clinopyroxene, orthopyroxene, olivine, and opaque minerals. The Cecilia intrusion displays broadly similar mineral assemblage but coarser-grained holocrystalline granular textures. Plagioclase in the Deeintrusions predominantly exhibits normal zoning, whereas plagioclase crystals in the Cecilia intrusion commonlyshow oscillatory and locally reverse zoning, together with sieve textures and embayment structures. Two-pyroxene geothermobarometric calculations suggest that the Dee intrusions crystallized at temperatures of approximately1,030–1,090 ºC and pressures of 2.5–3.5 kbar, corresponding to relatively shallow upper-crustal emplacement.In contrast, the Cecilia intrusion yields crystallization temperatures of 1,000–1,170 ºC and pressures of 4.5–6.5kbar, consistent with deeper emplacement at mid- to lower-crustal levels. Fe–Ti oxide barometry indicates that bothintrusions crystallized under oxidizing redox conditions, with the Cecilia intrusion recording systematically higheroxygen fugacity values relative to the Dee intrusions.When field, petrographic, and mineral chemistry data are evaluated together, the Dee and Cecilia intrusionsare interpreted to represent mafic magmatic bodies emplaced at different crustal levels within the South Shetland Arc magmatic system. Future geochronological studies will lead the investigation of the timing of emplacementand further assess the relationship between the crustal evolution of these mafic intrusions and the regional tectonic framework.