Late Amazonian–Aged Channel and Island Systems Located East of Olympus Mons, Mars

Pires

et al. 2019

Sci Rep

Drainage basins are essential to Geohydrology and Biodiversity. Defining those regions in a simple, robust and efficient way is a constant challenge in Earth Science. Here, we introduce a model to delineate multiple drainage basins through an extension of the Invasion Percolation-Based Algorithm (IPBA). In order to prove the potential of our approach, we apply it to real and artificial datasets. We observe that the perimeter and area distributions of basins and anti-basins display long tails extending over several orders of magnitude and following approximately power-law behaviors. Moreover, the exponents of these power laws depend on spatial correlations and are invariant under the landscape orientation, not only for terrestrial, but lunar and martian landscapes. The terrestrial and martian results are statistically identical, which suggests that a hypothetical martian river would present similarity to the terrestrial rivers. Finally, we propose a theoretical value for the Hack’s exponent based on the fractal dimension of watersheds, γ = D/2. We measure γ = 0.54 ± 0.01 for Earth, which is close to our estimation of γ ≈ 0.55. Our study suggests that Hack’s law can have its origin purely in the maximum and minimum lines of the landscapes.

Section: Resultssupporting

confidence: 56%

A universal approach for drainage basins

Pires

et al. 2019

Sci Rep

“…These events have distances around 90° as computed by MQS. We find a backazimuth of 85° for S1153a (Figure 8a), and locate both of these events in the approximate area of Olympus Mons (Figure 6), which is surrounded by a basal scarp of 2–10 km height and thrust faults as young as <40 Ma (Weller, 2015), as well as potential grabens cutting through young, late Amazonian terrain (Hargitai & Gulick, 2018). S0185a and S0234c can be paired with the impact S1094b I .…”

Section: Discussionmentioning

confidence: 90%

“…Considering the large uncertainties for S1153a, we assume both events occurred roughly in the same region. Given the presence of faulting in late Amazonian terrain south‐east of Olympus Mons (Hargitai & Gulick, 2018), a source in this general region seems more plausible and we locate these two events around Olympus Mons (Figure 6b and Figure S10 in Supporting Information ).…”

Section: Resultsmentioning

confidence: 98%

Mapping the Seismicity of Mars With InSight

Ceylan,

Giardini,

Clinton

et al. 2023

JGR Planets

The InSight seismometers have recorded more than 1300 events. Ninety‐eight of these, named the low‐frequency family, show energy predominantly below 1 Hz down to ∼0.1 Hz. The Marsquake Service identified seismic phases and computed distances for 42 of these marsquakes, 24 of which have backazimuths. Hence, the locations of the majority of low‐frequency family events remain undetermined. Here, we use an envelope shape similarity approach to determine event classes and distances, and introduce an alternative method to estimate the backazimuth. In our analysis, we use the highest quality marsquakes with known distances as templates, including the largest event S1222a, and assign new distances to similar group of events for which distance estimates were not previously available. We find the Tharsis region to be more active than initially perceived on the basis of 5 newly located events near Valles Marineris and Olympus Mons. We relocate two marsquakes with little or no S‐wave energy in the NE of the Elysium Bulge. The event epicenters in Cerberus Fossae follow a north‐south trend due to uncertainties in location, while the fault system is in the NW‐SE direction; therefore, these events are re‐projected along the observed fault system based on our interpretations. The marsquakes in our interpreted catalog are predominantly observed in the northern hemisphere of Mars above the equatorial dichotomy boundary.

“…This intense hydrological activity may have resulted in the widespread formation or fluvial transportation and resedimentation of smectites (Weitz et al., 2022). Some flooding events are even younger and are associated with the locations of major late Amazonian volcanic activity (Hargitai & Gulick, 2018). Another clue to groundwater activity may be the deformation of floor‐fractured craters (FFCs).…”

Section: Introductionmentioning

confidence: 99%

Hydrothermal Alteration of Ultramafic Rocks in Ladon Basin, Mars—Insights From CaSSIS, HiRISE, CRISM, and CTX

et al. 2023

The evolution of the Ladon basin has been marked by intense geological activity and the discharge of huge volumes of water from the Martian highlands to the lowlands in the late Noachian and Hesperian. We explore the potential of the ExoMars Trace Gas Orbiter/Color and Stereo Surface Imaging System color image data set for geological interpretation and show that it is particularly effective for geologic mapping in combination with other data sets such as HiRISE, Context, and Compact Reconnaissance Imaging Spectrometer for Mars. The study area displays dark lobate flows of upper Hesperian to early Amazonian age, which were likely extruded from a regional extensional fault network. Spectral analysis suggests that these flows and the underlying rocks are ultramafic. Two distinct altered levels are observed below the lobate flows. The upper, yellow‐orange level shows hundreds of structurally controlled narrow ridges reminiscent of ridges of listwanite, a suite of silicified, fracture‐controlled silica‐carbonate rocks derived from an ultramafic source and from serpentine. In addition to serpentinite, the detected mineral assemblages may include chlorite, carbonates, and talc. Kaolin minerals are detected in the lower, white level, which could have formed by groundwater alteration of plagioclase in the volcanic pile. Volcanism, tectonics, hydrothermal activity, and kaolinization are interpreted to be coeval, with hydrothermal activity and kaolinization controlled by the interactions between the aquifer and the hot, ultramafic lobate flows. Following our interpretations, East Ladon may host the first listwanite ridges described on Mars, involving a hydrothermal system rooted in a Hesperian aquifer and affecting ultramafic rocks from a magmatic source yet to be identified.