Abstract

The linking zone between Claritas Fossae and Noctis Labyrinthus represents one of the most structurally complex areas on Mars and has so far received limited attention in the scientific literature. In this work, we aim to reconstruct the tectonic structural framework of this area by combining regional-scale geological structural mapping of tectonic lineaments and agglomerative hierarchical clustering. For the clustering analysis, five attributes were considered for each of the 1729 mapped lineament: azimuth, sinuosity, length, position, and the age of the terrain on which they occur. A total of 68 tests were conducted using different combinations of attributes and relative weights. The most geologically and statistically meaningful solution identified six clusters with specific orientations occurring on both Noachian and Hesperian terrains. This allowed us to relate individual clusters with the different phases of evolution proposed in the literature for the Thaumasia region. In addition, comparison with previous regional tectonic models indicates that some clusters can be confidently related to the Claritas Fossae, others to the Noctis Labyrinthus. Results indicate that the study area effectively represents the place where the two regional-scale tectonic domains interacted during multiple phases of deformation. The highlighted polyphase evolution started during the Noachian and continued through episode(s) of reactivation during the Hesperian, as a result of the tectonic interference between Claritas Fossae and Noctis Labyrinthus.

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