A black 'tarry' substance is outlined in red, and the mouth of a cave in blue. 

 

 

Here's the area it came from.  The illumination is from the right, but some of kind of black dust is blowing strongly from 2:00 to to 8:00.   Now I'll give you some enlargements of objects mostly from the upper right of this picture.  There are lots of anomalies here; I only picked the 3 most obvious ones. 

Here it is larger.  The substance seems to have a well-defined edge on the right and to be rather viscous.  Maybe it's even lava.  The left arm seems to have flowed around several obstacles.

 

This image was once located at http://www.msss.com/moc_gallery/images/M0100396.html

It's hard to believe that the images now located at http://ida.wr.usgs.gov/html/m01003/m0100396.html depicts the same site on Mars as the image I grabbed from  http://www.msss.com/moc_gallery/images/M0100396.html in May 2000.  Did this image reveal too much?  Was the contrast deliberately altered to obfuscate the details I saw when I grabbed the image in May 2000?

CONTINUE