Tolstoj (crater)

Mercury crater data


caption =
latitude = 16.3
N_or_S = S
longitude = 163.5
E_or_W = W
diameter = 390 km
depth =
region = Tolstoj quadrangle
eponym = Leo Tolstoy

Tolstoj is a large, ancient impact crater at latitude -15, longitude 165 on Mercury. It was named after Leo Tolstoy. The albedo feature Solitudo Maiae appears to be associated with this crater. [Davies, M. E., Dwornik, S. E., Gault, D. E., and Strom, R. G., 1978, Atlas of Mercury: National Aeronautics and Space Administration Special Publication SP-423, 128 p.]

The impact that produced the Tolstoj Basin occurred very early in the history of Mercury. Two ragged, discontinuous rings approximately 356 km and 510 km in diameter encompass the structure but are poorly developed on its north and northeast sides; a third partial ring with a diameter of 466 km occurs on its southeast side. Diffuse patches of material of dark albedo lie outside the innermost ring. The central part of the basin is covered by smooth plains material. Hapke and others [Hapke, Bruce, Danielson, G. E., Jr., Klaasen, Kenneth, and Wilson, Lionel, 1975, Photometric observations of Mercury from Mariner 10, 1975: Journal of Geophysical Research v. 80, no. 17, p. 2431–2443.] have suggested that the dark-albedo materials associated with the Tolstoj Basin margins are distinctly bluer than the surrounding terrain, whereas the plains filling the interior are distinctly redder.

Despite Tolstoj’s great age and its embayment by the ancient inter-crater plains, it retains an extensive and remarkably well preserved, radially lineated ejecta blanket around two-thirds of its circumference. The ejecta tends to be blocky and only weakly lineated between the inner and outer rings. Radial lineations with a slight swirly pattern are best seen on the southwest side of Tolstoj. The unusual rectilinear map pattern of the ejecta suggests: (1) control of the ejecta pattern by prebasin structures, (2) preferential burial along structural trends of an originally symmetrical ejecta blanket by the intercrater plains material, or (3) formation of Tolstoj by an oblique impact from the northwest that produced an ejecta blanket with bilateral symmetry and little or no deposition uprange. Analysis of stereophotography of Tolstoj ejecta northeast of the crater suggests that this deposit has been upwarped to a higher elevation relative to the surrounding plains.

References

*cite web| url=http://astrogeology.usgs.gov/Projects/PlanetaryMapping/DIGGEOL/mercury/h8/h8.pdf| title=Geologic Map Of The Tolstoj (H-8) Quadrangle Of Mercury| first= Gerald G.| last= Schaber| coauthors= John F. McCauley| year=1980 Prepared for the National Aeronautics and Space Administration by U.S. Department of the Interior, U.S. Geological Survey. Published in hardcopy as USGS Miscellaneous Investigations Series Map I–1199, as part of the Atlas of Mercury, 1:5,000,000 Geologic Series. Hardcopy is available for sale from U.S. Geological Survey, Information Services, Box 25286, Federal Center, Denver, CO 80225)

External links

* [http://history.nasa.gov/SP-423/h8.htm Tolstoj quadrangle maps]