Geology Corner (Egypt and Jordan edition)

Here are two unanswered geological questions from our trip to Egypt and Jordan:

1. Why is the desert sand red in Jordan?

Red Desert Sand

High iron oxide content in the sandstone from which the sand was formed.

2. Why are there black streaks in the rocks in the Sinai Peninsula?

Black intrusions in the rock on the Sinai Peninsula?

I can’t find this one out.  My working theory is that these are igneous intrusions into the sandstone.

(Intrusion: An igneous rock body that has forced its way in a molten state into surrounding rock.)

Many moons have passed since I studied this stuff so if anyone can confirm these or offer better theories, I’m all ears!