[pct-l] Does anyone know some SoCal geology?

[ROYROBIN@xxxxxxx (ROYROBIN@xxxxxxx)]

--
[ Picked text/plain from multipart/alternative ]
In a message dated 3/12/03 7:21:58 AM Pacific Standard Time,
lynniegk@hotmail.com writes:

> I am having some trouble understanding the crazyness of the southern
> California
> geologic past.  I have gathered that, 'a lof of stuff got pushed together'
> but
> I have to start writing papers on this pretty soon, so is there anyone who
> could help me with a really basic chronologic understanding?  Or at the
> very
> least some cool formations that I will see, and can say I will photograph,
> along
> the trail?
>
First, a disclaimer:  I'm only an amateur with an interest in geology.

The San Andreas fault is very well defined in N. Cal. but breaks up into a
series of parallel fault lines in S. Cal.  This is seen very clearly if you
fly from SF to the LA area.  The parallel faults that the PCT crosses from
about Warner Springs (B1) to where it turns north to cross the Mojave Desert
(E10) seem to trigger at random, causing the terrain to be stirred clockwise
by God's big stick.  You can see the result of this along I-5 particularly
around Pyramid Lake between Tejon Pass and Castaic.  The hills are a random
jumble, little modified as yet by water erosion.

On the PCT, along the north fork of Mission Creek just south of Big Bear, you
can see the same kind of hills.  They reminded me of the mountains in Japan
which were probably formed by the same kind of fault line activity.  This is
interesting country that is, in geologic time, being continuously churned.
Once we understand what's happening in this area, it's a little scary to see
our highways, dams and power lines spanning these moving ripples of dirt and
rock.