In this task, you're given a question, along with a context passage. The passage will not have a direct answer to the question, but can include some information and a clue for the answer. Assuming you can only obtain information about one entity in the passage, your job is to determine whether information from the passage can be used to answer the question. Indicate your choice as 'a' for Yes or 'b' for No.

Question: How many years long was the period in which copper mineralization and pipe formation occurred? Passage:The copper ore deposits are those of a typical copper porphyry and associated alteration-mineralization. These altered zones include chalcopyrite, pyrite, bornite and molybdenite as hypogene minerals and chalcocite as a supergene mineral. The ore body surrounds the Braden Pipe in a continuous ring with a width of 2000 feet. The pipe is a geologic structure in the shape of an inverted cone, having a surface diameter of 4000 feet, and consisting of post-pipe breccia called the Braden Formation. The boundary of the pipe is marked by this post-pipe breccia and a pre-pipe breccia forming a belt up to 200 feet wide. "The Braden Pipe was a center of strong mineralization and structural weakness before the pipe was formed." Copper mineralization and pipe formation occurred in the Pliocene. Ore was originally mined from the Fortuna orebody at the southwest quadrant starting in 1906. Since 1922, the larger Teniente orebody has also been mined on the east side. "The best grade of ore is found in altered andesite or in andesitic flow breccia adjacent to the pre-pipe breccia."
b