REBel without a pause
First off, it's not a lovely DARK and DEEP shadow. Re-read the end of my previous post to get an idea of why it's SO DARK!
Secondly, you're right it is 1:30 local time but what season? Late winter, the sun is not directly overhead(90 degrees), it's 65 degrees in altitude (incidence angle 35 deg).
Also the slope the gullies are formed on is mostly inclined towards the sun, which decreases the amount of light falling on the slope and it's recessed gullies.