Publications

The Meratus Complex, located in SE Kalimantan, records accretion and collision along the Sundaland margin during the mid-Cretaceous. Several authors have suggested that the resultant suture continues northwards beneath the Kutai Basin, possibly extending as far north as Sabah, where ophiolitic and arc-type rocks are well documented. Prominent features such as the Kutai Lakes Gravity High, have been suggested to be the expression of the Meratus Suture as it is downthrown towards the north beneath the Kutai Basin. This paper presents a suite of observations from literature review, satellite mapping, biostratigraphy, well and seismic data, and builds upon a previous IPA manuscript that proposed a new model for the uplift history of the Meratus Complex. We discuss the results of structural mapping of onshore East Kalimantan derived from SRTM, Landsat 7 ETM+ and Bouguer Gravity data. Structural trends are presented, highlighting lineations and basement lineaments which have previously been interpreted to cross Borneo. We integrate these observations with biostratigraphy and subsurface data, to provide a framework for better understanding the deformation of East Kalimantan from a regional perspective. We interpret structural trends across Borneo that reflect distinct mechanisms for deformation under compressional forces. The Adang Line-Paternoster Fault lies in the approximate location of a basement high which separates the Barito Basin to the south from the Kutai Basin in the north. We interpret this lineament as a Paleogene feature that later facilitated differing responses to compression associated with the Australia-Eurasia collision from the Miocene onwards. To the south of the Adang-Paternoster, approximate NW-SE compression was bulwarked against the newly emergent Schwaner Mountains, causing concentrated uplift in the Meratus. North of the Adang-Paternoster, deformation in the lithosphere was distributed more widely, resulting in less dramatic uplifts and detachment faulting and folding, as observed in the Samarinda Anticlinorium.