Fluvial Deposits in Fluvial Deposits in Margaritifer BasinMargaritifer Basin

Kevin K. Williams and John A. GrantCenter for Earth and Planetary Studies, Smithsonian Institution

Corey M. FortezzoDepartment of Geology, Northern Arizona University

Fluvial Deposits in Fluvial Deposits in Margaritifer BasinMargaritifer Basin

Noachian through Amazonian terrains

complex and interesting fluvial history

interesting minerals

other water/ice related features

nearby volcano-water interactions

veins of gold

at this point, it looks ‘safe’

LocationLocation

MC-19 is eastMC-19 is eastof Valles Marinerisof Valles Marineris

Argye

Margaritifer basin

MB1: 12º 40.97’ S / 338º 06.34’ EMB2: 11º 41.83’ S / 337º 16.95’ E

MB1

MB2

Overview of geologic settingMargaritifer basin is located at the confluence plain of the UHLM, Samara, and Parana-Loire valley systems

These three valley systems drain a large area of Mars, andit appears that water ponded in Margaritifer basin. -> possibility of sampling material from a broad area of the martian highlands

Widespread fluvial activity extended from the Noachian intothe mid- to late-Hesperian

Latest activity in MB extended into the Amazonian

Nplh: Noachian hilly plains

Npl1: Noachian plateau sequence

Hch: Hesperian channel

Large scale geologic map

1:500,000 geologic map

More detailed unit boundaries

Younger units in Margaritifer basin

Nearby, chaos, collapse, volcanics, Noachian remnants

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1:500,000 geologic map

More detailed unit boundaries

Younger units in Margaritifer basin

Nearby, chaos, collapse, volcanics, Noachian remnants

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Edge of channel in MB

MOC imageNASA/JPL/MSSS

MOC image E04-00861NASA/JPL/MSSS

Layering in plains of Margaritifer basin

Amazonian plains

MOC imageNASA/JPL/MSSS

MOC image E04-00861NASA/JPL/MSSS

Layering in plains of Margaritifer basin

High res. imaging in landing circles will likely reveal layering there

THEMIS VIS views

THEMIS VIS views

Within Margaritifer basin, fluvial activity took place from the

Noachian through the Amazonian

Geomorphic evidence suggests that water ponded in MB

and infiltrated into the subsurface, possibly getting

re-mobilized during collapse and outwash through Ares Valles

The basin plain is mainly smooth with higher remnants

and areas where the layers of deposited material are exposed

where they have been etched into

Nearby activity also includes chaotic terrain, collapse, and

a volcanic feature that may have interacted with water/ice

Past through recent/present areas of habitable potential

Prolonged accumulation of water

Access to spatially and temporally diverse material

Increase in geologic features and potential for habitability

Elevation

Landing ellipses are lower than -2 km

MB1: -2120 mMB2: -2535 m

Slopes calculated from MOLA

>15º

5º < x < 15º

3º < x < 5º

≤ 3º

Requirement: <3º over 2-5 km

Very low within landing ellipses

Rock abundance ~10% (need more info)

Surface roughness

TES dust coverage

Requirement: low

Essentially 0 at landing sites

TES thermal inertia

Requirement: > 100 J m-2 s-0.5

MB1: 264-428 avg. = 315

MB2: 289-378 avg. = 331

1

2

TES hematite(on 0 - 0.2 scale)

TES carbonates

MB1: 0.07 - 0.08

MB2: 0.06 - 0.08

MB1: low but .025 to NE

MB2: ~ 0.02

TES sulfates

MB1: 0.03 - 0.05

MB2: 0.04 - 0.08

Engineering summary

Elevation: very low. lots of time to slow down

Slopes: generally gentle, but more info will be helpful

Surface roughness: landing ellipses appear to meet requirements and allow access to nearby rougher ROIs

Thermal inertia: High thermal inertia

Minerals: Relatively high levels of hematite, carbonates, and sulfates

Albedo: < 0.25

Summary

•Margaritifer basin has a complex and long-lived fluvial history that involves ponding of water

•This area provides access to materials from diverse areas of the martian highlands

•These materials also span fluvial activity from the Noachian though the Amazonian

•Layers from episodes of activity likely exist in landing area

•Nearby chaos, collapse, and volcanics increase scientific interest and potential for habitability

•At this stage, both circles appear safe