Keywords: 
• transform margins /
• equatorial Atlantic /
• submarine fans /
• sedimentary characteristics /
• depositional models

Abstract: [Objective] According to the spreading, subducting, and shearing between lithospheric plates, the continental margin could be classified into three types: the passive margin, active margin, and the transform margin. Although transform margins have a short period of investigation, they fostered giant hydrocarbon discoveries in recent years. For example, in Ivory Basin., Guyana Basin, and Ruvuma Basin, a lot of hydrocarbons were discovered. ExxonMobil even listed the depositional characteristics of submarine fans on transform margins as the key field of oil and gas prospecting. Due to the study about transform margins is relatively weak, compared with the classical submarine fans, there are less works on those fans on the transform margins. [Methods] Using the late drift stage of Potiguar margin as an example, the current study utilizes the PaleoScan-based 3D intelligent interpreting approach and RGB color blending of spectral decomposition to reveal depositional characteristics and models of deep-water fans on transform margins. [Results] Submarine fans on Potiguar transform margin is composed of deep-water channels and terminal fans. In cross sections, deep-water channels continuously stacked, resulting in unpunctuated channel-growth patterns. In map view, the documented channel-lobes complexes are volumetrically small with a lack of overbank elements, and converged and stacked into a rim-shaped planform distribution pattern. [Conclusions] The unpunctuated channel-growth patterns in cross sections are interpreted to be depositional responses to narrow shelfs; the shelfs on Potiguar margin have widths of 30-60 km, with an average value of 43 km. Those narrow shelfs encouraged the continuous delivery of terrestrial sediments into deep-water sites during any periods of the base-level fluctuations. The depositional characteristics of channel-lobe complexes in map view are ascribed to the narrow and steep slopes of Potiguar transform margin. Those slopes have widths of 10-30 km and gradients of 4°-8°, whose average values are 23 km and 5.4°, respectively. Such basin margin topography frosted vigorous sediment-gravity flows with high velocity and strong incise ability, which disfavoured overbank spilling and in turn, resulted in small-scale channel-lobe complexes in map view. Furthermore, due to the existence of seamounts and/or marginal ridges, gravity flows were blocked from moving further downstream, thus resulting in a rim-shaped planform distribution pattern of channel-lobe complexes.