I took a section of the N Fensal RADAR mosaic that shows a really nice tectonic ridge and deposition layer sequence. This is in the T28 RADAR Swath and is located at [33N, 20W] in the part of N Fensal Sand Sea Basin that is transitioning into the Temperate Bland Zone.
Happily, the W edge of the T28 RADAR swath seems to be right along the boundary of the Sand Sea, as evidenced by the RADAR dark (v. smooth) parts along the W edge of the swath. In some sections of the edge, "typical" dune sands can be seen. This same section also shows exposed tectonic ridge tops, evidence by the RADAR bright thin highly fractal looking (eroded) details. So in this section of T28 we can see a nice cross section of Titan from the ridge tops down to the flats of the Sand Sea basin.
I attempted to work out the sequence from ridge tops (yellow in the figure), through lower layers (green), to the uniform bland (uncolored medium RADAR gray) and into the smoother river and sea deposits (dark blue and purple shades). Some RADAR-brighter areas that did not show obvious fine fractal-like details were also left uncolored.
Click to view attachmentClick to view attachmentThe first graphic shows a colorized RADAR image, and the second graphic shows a hypothetical cross section.
[The subtle RADAR details are probably easier to see from PIA09217].
A few interesting observations:
* The tectonic ridges are very regularly spaced.
* The lower deposits seem to follow a very regular pattern: ridge tops (yellow)-->RADAR med bright (light green)-->RADAR darker med bright (darker green)-->bland margin (uncolored)-->stream and bays (dark blue and purple).
* The windblown deposits (greens) form dunes. These dunes seem smaller and seem to have a different aspect than the Equatorial dune sea dunes. (Brown squares indicate dune fields). Streams follow tectonic valleys.
* Streams seem to meander all over in the bland margin areas. This pattern resembles muddy sloughs more than a tumbling mountain stream. The streambeds are all dark. Bright streambeds are not visible in this area.
* There are some RADAR-bright deposits that seem to be located at the margin of streams. Could this be cryopumice or crusty zone materials?
It is not clear if the different RADAR brightness in the uncolored gray/green zone is due to different materials or different textures. It is entirely possible that there is a layer of atmospheric deposition products that have washed out and wind-sorted themselves between the ridges.
-Mike