The strong association between coronae and chasma has been extensively discussed (e.g.[1], [2]). One example of this relationship is the 10,000 km long Parga Chasmata which connects Atla Regio with Themis Regio. Based on detailed mapping of graben fissure systems and interpreted rift faults along a 1500 km long segment of Parga Chasmata, Graff et al. [2] recognized that many coronae represent the locus of local triple junction rift centres within the broader rift zone. We have selected a region along Parga Chasmata, about 2000 km southeast from Atla Regio, for detailed study. For this area the grouping of rift segments and coronae into local triple junction centres [2]. The goal of this present research is to provide detailed mapping (1:500,000 scale) of the graben fissure systems, lava flows and rift faults integrated with the topographic changes in order to provide insights into setting of these corona within the rift. Our mapping builds on the previous reconnaissance-scale mapping (1:5,000,000 scale) of Taussig Quadrangle (V–39) by [3].11000 grabens have been mapped and  are provisionally grouped and colour-coded into distinct sets (with radiating, circumferential and linear geometries) which are interpreted to represent dyke swarms. Notably there is an impressive radiating swarm centred on Maram corona, a possible radiating swarm focussed on a second centre, and a circumferential system surrounding a third centre Additional extensive linear swarms are present which may belong to giant radiating systems linked to magmatic centres outside the map area. Along with continued mapping of grabens, the research will also turn to mapping of flows and integrating the flows and grabens into a geological history. The nature of the sharp topographic changes across Maram corona will also be addressed.  References: [1]    V. E. Hamilton and E. R. Stofan, “The geomorphology and evolution of Hecate Chasma, Venus,” Icarus, vol. 121, no. 1, pp. 171–194, 1996, doi: 10.1006/icar.1996.0077.[2]    J. R. Graff, R. E. Ernst, and C. Samson, “Evidence for triple-junction rifting focussed on local magmatic centres along Parga Chasma, Venus,” Icarus, vol. 306, pp. 122–138, May 2018, doi: 10.1016/J.ICARUS.2018.02.010.[3]    B. A. W. Brian, E. R. Stofan, and J. E. Guest, “Geologic Map of the Taussig Quadrangle ( V – 39 ), Venus,” 2005.  

This study provides sedimentological and stratigraphic insights into the Ediacaran fluviolacustrine successions of the Amane-n’Tourhart and Tifernine basins. The Amane-n’Tourhart Basin developed in a post-caldera volcanic setting along the margin of the Oued Dar’a Caldera, whereas the Tifernine Basin formed in a pre-caldera tectono-volcanic context associated with caldera development. The successions provide valuable information about the sedimentary processes operating in late Ediacaran continental environments. Field observations, facies analysis, and petrography reveal a variety of siliciclastic, carbonate, mixed siliciclastic–carbonate, and volcaniclastic facies. These facies form associations indicative of alluvial fan, floodplain, and shallow-water lacustrine settings. Alluvial fan deposits are dominated by conglomerates and sandstones forming braided systems. Fluviolacustrine successions show a transition from clay-rich siltstones with calcareous nodules to nodular and massive limestones, marking a gradual shift from fluvial to lacustrine conditions. Laminated limestones and stromatolites indicate intermittent microbial activity that contributed to carbonate precipitation. Sedimentation was strongly influenced by volcanic inputs and climatic fluctuations, alternating between humid and arid conditions. These factors drove cycles of channel incision, sediment infill, and lake expansion–contraction, illustrating the dynamic interplay of volcanism and climate that modulated deposition in these Ediacaran continental basins, with broad relevance to our understanding of this critical window in the Earth’s history.