If you didn't know any better, you might wonder if this image title described a horrible medical malady, but in reality it refers to a very old geological record of our Earth, and that is essentially what we are viewing here in this image, photographed in Blacktail Canyon off of the Colorado River in the Grand Canyon.

In this canyon are great examples of the "Great Unconformity" coined by John Wesley Powell, and along the way in the Vishnu Shist formation layer are all sorts of clast inclusions of white zoroaster pegmatite jutting out of the shist, just before being covered by the Tapeats formation above it. These types of inclusions are common hints to a geologist to recognize a nearby unconformity. The Great Unconformity represents a gap in the Earth's time record where nearly 1.5 billion years of rock history is missing.