Variation in thermal structure with crustal thickness for the crust beneath the Peninsular Malaysia

Abstract

We present a regional thermal structure as well as a new crustal thickness model beneath the Peninsular Malaysia and the surrounding regions. Curie point depth estimates for the entire area range between ∼ 17 – 46 km with a mean of 29 km. The estimated crustal thickness for the study area varies from ∼ 28 – 35 km with an average of ∼ 31 km. Uplifted Curie depths (20 – 25 km) and deeper Moho depths (30 – 34 km) are observed over most parts of Peninsular Malaysia continent. In contrast, the NW Peninsular Malaysia continent and the southern Thailand are characterized by deeper Curie depths between 30 and 40 km. These regions with deeper Curie depths are coincident with the oldest dated rocks on the Sibumasu terrane. The observation of larger Curie depths in NW Peninsular Malaysia implies that the region is presently thermally stable than the remaining parts of the Peninsular. Consistent with deeper crustal thickness (30 – 35 km), the west Sumatra block yields the deepest Curie point depth that ranges between 30 and 46 km. The west Sumatra block and the NW Peninsular Malaysia have low Bouguer anomalies and comparable crustal thickness indicating similarity in regional features. This suggests that these regions are linked by a common ancient continental core. A comparison between the Curie depths and crustal thickness shows that the upper mantle beneath the Island of Sumatra, Singapore, Malay basin, NW Peninsular Malaysia continent, and southern Thailand are significantly magnetized.