This lovely lady is just a small part of the Verdugo Mountains. I sometime hike around her. Which is why she was a perfect first subject. She's also a short walk away from where I live.
The whole thing is a Fault Block, which is kinda like when you squish two bits of land together. Common along the West Coast.
She consists mostly of Gnesis, Diorite and Quartz.
and according to Wikipedia(I'll get better sources when I get better at this stuff) She is aprox. 2.3 Million years old. Which is pretty young for mountain.