Executive summary

We report here on the delivery of geomorphological (or morphostratigraphic) maps of regions on Mercury, the Moon and Mars as a result of Planmap activities and conforming to the Planmap mapping standards document. These are the first tranche of maps to be delivered as D2.2.

List of Acronyms

Introduction

We document here the geomorphological (or morphostratigraphic) maps delivered in the first tranche of such products within this project. There are 3 new maps covering parts of Mercury (plus one previous map), 2 for the Moon, and 2 for Mars.

Mercury

Hokusai quadrangle

Jack Wright et al. have produced a geological map of the Hokusai (H05) quadrangle of Mercury at 1:3M scale using MESSENGER data. The Hokusai quadrangle is in Mercury’s mid-northern latitudes (0–90°E, 22.5–65°N) and covers almost 5 million km², or 6.5%, of the planet’s surface. This map has been accepted for publication in Journal of Maps (Figure 1).

Linework was digitized at the 1:400,000 scale for final presentation at the 1:3,000,000 scale, mainly using a ~166 m/pixel monochrome basemap. Three major photogeologic units of regional extent were mapped: intercrater, intermediate, and smooth plains, and this is relevant to the evolving discussion among Mercury mappers about whether an 'intermediate plains' unit exists as a mappable unit, and how it should be interpreted.

There are two versions, offering alternative depictions of materials of craters ≥ 20 km in diameter according to their degradation state. PM-MER-MS-H05_3cc_01 divides craters exceeding 20 km diameter into three degradation classes, and PM-MER-MS-H05_5cc_01 is the same mapping except that it divides the same craters among five degradation classes. The former conforms with the three previously published MESSENGER-based Mercury quadrangle maps, whereas the latter conforms to practice from the Mariner-10 era and also with a global map under production by the MESSENGER team. This is an excellent example of how, in the modern era of digital maps, the map-maker can provide the user with alternative versions, empowering the users to make their own choice as to which version best suits their needs or interests.

This map will provide science context and targets for the ESA-JAXA BepiColombo mission to Mercury.

Figure 1a: Hokusai quadrangle geological map (version with 3 crater classes), source https://data.planmap.eu/pub/mercury/PM-MER-MS-H05_3cc

Figure 1b: Hokusai quadrangle geological map (version with 5 crater classes), source https://data.planmap.eu/pub/mercury/PM-MER-MS-H05_5cc

Victoria quadrangle

We have added to the archive a copy of the geologic map of the Victoria quadrangle by Valentina Galluzzi et al. (Figure 2), which pre-dates the Planmap project. This is of interest because it borders the Hokusai quadrangle. It is available only in a 3 crater classes version. The map is provided as an in-kind contribution to Planmap and does not display the banner of other Planmap map products (see https://data.planmap.eu/, D7.2-public)

Figure 2: In-kind contribution to Planmap, Victoria Quadrangle geologic map. Source: https://data.planmap.eu/pub/mercury/PM-MER-MS-H02_3cc

Rembrandt basin special interest area

Andrea Semenzato et al. have produced a morphostratigraphic map of the Rembrandt basin (Figure 3) and surrounding areas using MESSENGER data, PM-MER-MSG-Rembrandt_01. Rather than being a map of a conventional mapping quadrangle, this covers a 'special interest area' (in this case about half the size of a quadrangle) as a means to investigate the 715 km diameter Rembrandt basin, which is the 2nd-largest well-preserved impact basin on the planet. This is a substitute in place of the Beethoven basin that was suggested in the initial DoA.

Several distinct geologic units can be identified inside and outside the basin, with different morphostratigraphic characteristics. Most of these units can be associated with geologic processes that are related to the basin impact event. The Rembrandt basin is peculiarly cross-cut by an extensive lobate scarp, named Enterprise Rupes, which played an important role in the post-impact modification process that shaped the basin.

The improvements of imagery data provided by the NASA MESSENGER spacecraft offer the possibility to unravel this complex series of events. In fact, these events constitute the stratigraphic evolution of the Rembrandt basin and are part of the geologic history of the planet itself.

Figure 3: Rembrandt basin map, source: https://data.planmap.eu/pub/mercury/PM-MER-MS-Rembrandt

Moon

South Pole-Aitken basin, Apollo basin special interest area

Misha Ivanov et al. conducted a geological analysis of the northern portion of the South Pole-Aitken (SPA) basin, which is the largest recognized and likely the oldest impact structure on the Moon. The mapping effort resulted in a 1:500,000 scale geologic map of a 1000 km wide area covering the pre-Nectarian Apollo basin and its surroundings, PM-MOO-MS-SPAApollo_01 (Figure 4). The map is based on the Lunar Reconnaissance Orbiter Wide Angle Camera Global Mosaic with additional unit definition using the Lunar Reconnaissance Orbiter Laser Altimeter digital elevation model and Clementine iron and titanium maps.

This large-scale mapping effort permitted the unraveling of the major sequence of impact and volcanic events that have shaped the northeastern section of the South Pole-Aitken Basin throughout its evolution, and allowed the identification of the oldest materials related to South Pole-Aitken Basin formation. Analysis of the distribution and concentrations of iron and titanium in the different units within the SPA basin allows the characterization of the structure of the ancient lunar crust and mantle. These results introduce important constraints on the current models of the early evolution of the Moon.

Figure 4: South Pole-Aitken basin, Apollo basin geologic map, source: https://data.planmap.eu/pub/moon/PM-MOO-MS-SPAApollo

Copernicus crater special interest area

Copernicus is a complex crater on the Moon about 96 km in diameter, located south of the Imbrium basin. It has an almost circular shape, a central peak, a flat floor and well developed wall terraces. Tusberti et al. used a variety of data to identify various units and features, enabling them to generate a geological map, resulting in an output at 1:400.000 scale. Among the units mapped are: 5 main floor units (Hummocky material 1, Hummocky material 2, Smooth material 1, Smooth material 2, Central Peak material) mapped both using morphology and spectral information; 2 main Wall units (Terraces and Gentle Scarps, Steep Scarps) and Linear landforms such as Open fractures or Rim and Wall faults.

Figure 5: Copernicus crater geologic map, source: https://data.planmap.eu/pub/moon/PM-MOO-MS-Copernicus

Mars

Crommelin crater special interest area

This 1:160.000 scale map by Pesce et al. covers the rim and interior of Crommelin crater (Figure 6), an approximately 110 km diameter in western Arabia Terra (PM-MAR-MS-Crommelin_01). It is of special interest  because of the prominent bulging and the well–exposed stratigraphic sequence in its interior made essentially by ELD (equatorial layered deposits). It appears that aeolian erosion has exposed cross-sections through layered units making it possible to clearly identify the stratigraphic sequence of the crater infilling units. Indeed, this crater presents a wide variety of geologic-morphologic units, going from a basaltic plateau sequence to layered sequences (where fluid activity was hypothesised, Franchi et al., 2014). Impact craters and their ejecta blanket are also visible as well as aeolian-related morphologies (both erosional and depositional) such as mesas, yardangs, dune fields and dust devil tracks.

Figure 6: Crommelin crater geologic map, source: https://data.planmap.eu/pub/mars/PM-MAR-MS-Crommelin

Arsinoes chaos special interest area

The geological map of Arsinoes and Pyrrhae Chaos (by Erica Luzzi et al.) includes the two chaotic terrains and the surroundings (Figure 7). The digitization was made at the CTX resolution (scale 1:500.000) but the chosen output is at 1:2.000.000 scale. In this area it is possible to observe the stratigraphic relationships between the basaltic bedrock (identified in the Chaotic terrain unit) and the overlying sedimentary deposits (Light-toned Layered Unit and Cap Unit). The structural features were also mapped and interpreted as grabens/fissures, probably originated from early volcanic processes. This mapping will help us to investigate the origin of the collapse that formed the chaotic terrains and the subsequent sedimentary environment.

This map substitutes for the Nili Fossae study that had been suggested in the initial DoA. We have dropped Nili Fossae because it is no longer a candidate landing site.

Figure 7: Arsinoes and Pyrrhae Chaos geological map, source: https://data.planmap.eu/pub/mars/PM-MAR-MS-Arsinoes

Metadata tables

The file naming conventions of Planmap maps are described in D7.2-public (Rossi et al., 2019a) as well as in D7.3-public (Rossi et al., 2019b) and D7.4-public Rossi et al., 2019c).

Mercury

PM-MER-MS-H05_3cc_01 - Hokusai Quadrangle (H05), 3-crater-classes map

PM-MER-MS-H05_5cc_01 - Hokusai Quadrangle (H05), 5-crater-classes map

PM-MER-MSG-Rembrandt_01 - Rembrandt Basin

Moon

PM-MOO-MS-SPAApollo_01 - SPA Apollo Basin

PM-MOO-MS-Copernicus_01 - Copernicus crater

Mars

PM-MAR-MS-Crommelin_01 - Crommelin crater

PM-MAR-MS-Arsinoes_01 - Arsinoes and Pyrrhae Chaos

References

Brandt, C. H., Rossi, A. P. and the Planmap consortium (2019b) D7.2, Planmap Data Fusion Portal, Planmap deliverable, available online at D7.2-public, https://data.planmap.eu/ - https://maps.planmap.eu/

Galluzzi, V., Guzzetta, L., Ferranti, L., Di Achille, G., Rothery, D. A., & Palumbo, P. (2016). Geology of the Victoria quadrangle (H02), Mercury. Journal of Maps, 12(sup1), 227-238.

Ivanov, M. A., Hiesinger, H,, van der Bogert, C. H., Orgel, C., Pasckert, J. H., and Head J. W. (2018). Geologic History of the Northern Portion of the South Pole‐Aitken Basin on the Moon. Journal of Geophysical Research: Planets, 123, 10, 2885–2612.

Luzzi, E., Rossi, A. P., and Brandt, C. H. (----) Geological mapping of Arsinoes and Pyrrhae Chaos.

Pesce, D., Pozzobon, R., and Massironi, M. (----) Geological Map of the Crommelin Crater, Mars.

Rossi, A. P., Penasa, L., Pozzobon, R., and the Planmap consortium (2019a) D7.3, Data Management Plan, update 1, Planmap deliverable, available online at D7.3-public.

Rossi, A. P., Brandt, C. H., and the Planmap consortium (2019c) D7.4, Public data/code dlivery, Planmap deliverable, available online at D7.4-public.

Semenzato, A., Massironi, M., Pozzobon, R., Galluzzi, V., Rothery, D. A., and Ferrari, S. (2018). Discovering Rembrandt basin's subsurface and Enterprise Rupes: 3D-model based on stratigraphic mapping and structural analysis. EPSC abstracts, 12, EPSC2018-344.

Tusberti., F., Pozzobon, R., and Massironi, M. (----) Geological Map of the Copernicus Crater, Inner Floor and Walls.

Wright, J., Rothery, D. A., Balme, M. R., and Conway, S. J. (2019). Journal of Maps (accepted).