
Our first stop was Garapata Beach on Hwy 1, where there's an awesome
exposure of a vertical fault which juxtaposes Salinian granites against
younger sandstones. The fault zone is full of gooey clay gouge and
surrounding smaller shear zones in the sandstone offer great opportunities
to look at cemented breccia and rock damage related to
faulting. Facilitator Greg Stock led off the
discussion, with Will Fox, Christie Rowe and Debbie
Prinkey looking on and Matt Paulson somehow not looking
on. (photo: P. Adams)

We watched the sunset from this beach, which got us to Andrew Molera
campground a little late, but I think it was worth it. (photo: P. Adams)
The headland at the mouth of the Big Sur River, Andrew Molera State
Park. The headland is composed of Franciscan Formation rocks, and is one
of the few places along the Big Sur coastline where an old marine terrace
can be observed. You can see the terrace surface at the same level (~12m
above the ocean) looking across to the far shore. This view looking
SW. (Photo: C. Rowe)
Grad student Debbie Prinkey shows off the beautiful faulted pillow
basalt structures in Franciscan greenstone. The pillows form when lava
erupts underwater (see this
USGS page for more explanation of pillows). (Photo: C.Rowe)
The Franciscan Formation has what has been referred to as a "plum
pudding" structure, that is that there are harder blocks in a softer
matrix. The blocks can range in size from a grain of sand to the size of
a large house, or a Big Sur bed and breakfast. When the sea cuts the soft
cliffs back, sometimes a harder block might be left hanging offshore, like
this one. All along the Big Sur coastline, it's very common to see big
rocks near the shoreline when you're in Franciscan
Formation. (Photo: C.Rowe)
On the beach at the mouth of the Big Sur River, we observed another
awesome Big Sur phenomenon: the sorting of garnet
(+magnetite?) sand. (Photo: K. Jordahl)
Pete Adams gave an excellent explanation of sea cliff formation, and
current geomorphologic theories about how seacliffs retreat, particularly
in an environment like Big Sur where there is a big contrast in
erodability between rock types. It appears as if Greg Martin is seriously
considering Pete's hypotheses. (Photo: C.Rowe)
This awesome cliff overlooks a tiny indentation in the coastline called
Seal Cove, where sea lions tend to gather and wave their fins in the air
to regulate their body temperature. You can kind of make out a little
cluster of them in the water at about 10 o'clock to the lupine in the
foreground. The cliff itself, typical of Salinian block rocks, is very
steep and very high. It's easy to see that big landslides can and do
occur on slopes like this, and they can account for the erosion of a lot
of rock material, even if they occur relatively rarely. (Photo: C.Rowe)
Heading south from Andrew Molera, we hiked down a little switchbacked road
at Partington Point. This is a unique spot along the coast because
there's a submarine canyon which brings deep water right up to the cliff
face, and therefore was the only place residents of Big Sur used to be
able to bring a ship up to shore. The coastal access was built for the
purpose of exporting Tan Oak bark for making leather. (Photo: C.Rowe)
Never a dull moment with Hellatite. Half way down the path, earth science
major Matt Paulson went diving into the bushes to retrieve this 5' gopher
snake, christened "Chuck". Chuck turned out to be quite good natured and
spent about an hour with us while we ate lunch and did some
exploring. Will, Courtney and Greg aren't as horrified as they look - all
three ended up holding Chuck for some cold-blooded quality
time. (Photo: C.Rowe)
An awesome sight awaited the group when we descended the
path. Unfortunately this photographer failed to capture it effectively,
but if you'll take my word for it, the girl in the red hat is watching
three gray whales, two adults and a juvenile, passing by within about 50
feet of the shore. For two members of our group from inland states, this
was their first whale sighting, and it was even exciting for the most
jaded Californians among us. (Photo: C.Rowe)
The hard-rock nerds got a treat at Partington Point, where the bedrock is
Salinian Block diorite with a lot of felsic veins which have been highly
faulted. Here's grad student Christie Rowe oggling a text-book quality
microfault which offsets the planar felsic vein above her
head. (Photo: P.Adams)
Our next stop was Gamboa Point, just south of the University of California
Big Creek Reserve. In fact, you can see the Big Creek Bridge in this
northward view from Gamboa. Just north of the bridge, the steep rubbly
slide face on the front of the mountain is a clear example of the type of
giant landslides that dominate erosion in Big Sur. This is an area of
massive sliding of Franciscan Formation rocks. On the south end of the
bridge, toward us, the Sur-Nacimento fault outcrops in the cliff face and
those light colored rock outcrops visible near the top of the cliff are
Salinian block granites. These two slopes behave differently because of
the relative strengths of their rocks. Offshore of the Franciscan slope
you can see the famous "Square Black Rock" which makes a good landmark to
help locate yourself if you happen to be mapping in the Big Creek
Reserve. (Photo: C.Rowe)
Greg Stock does an amazing job of describing the kind of processes which
move material around in Big Sur, and the current theories and research
work about the uplift of the Santa Lucia Mountains and the general study
of geomorphology. It seems intuitive when looking at the Big Sur coastline
that it must be rising very quickly out of the ocean, so quickly that the
ocean and rivers haven't had time to smooth it out and cut it
down. However, actually figuring out how long and how fast the range has
been rising is another matter. Will Fox and Judy Marks - geologists in
training - may have the answers someday. (Photo: C.Rowe)
Unfortunately due to the Easter weekend, we lost some of our number on
Saturday before the capstone experience of the weekend, the hike to the
summit of 5152' Cone Peak. Here's a view from the trail, looking down
across the wide Pacific. Limekiln Creek, one of the western drainages of
Cone Peak, is the steepest mountain slope in the Lower 48. Its plummeting
descent to the ocean over the distance of only a few miles is steeper than
the precipitous plunge from Mt. Whitney to Death Valley, the amazingly
adjacent highest and lowest points in the Lower 48. (Photo: C.Rowe)
Here's the part of the group who summitted on Saturday afternoon:
That's Greg Stock standing in the back, sitting in front of
him left to right are Debbie Prinkey, Kelsey Jordahl, Will Fox and
Courtney Grisman, and in the front are Christie Rowe, Matt
"Paulson" Paulson, and Pedro Adams. I wish I had a close-up of the
beautiful garnet granulite we were sitting on. Come by my office if you
want to see it (E&MS A109). (Photo: P. Adams)
Greg Stock picked out a legendary campsite for us Saturday night at Pruitt
Ridge. We were fortunate to be joined by Sarah Hamilton, the Coordinator
of Big Sur Ornithology Lab at Andrew Molera State Park. BSOL had a
record weekend, capturing 60 migratory birds for tagging and
release. (Photo: P. Adams)
Our own reptile charmer Matt Paulson captured this male Western Fence
Lizard (Sceloporus occidentalis) using the grass noose in his
hand. Quite a crafty guy. We were glad to see (and catch) many of these
little guys since the NYT reported in 1998 that they actually
reduce the incidence of Lyme disease in their home range by killing
the disease in the ticks that bite them! I'm not kidding! (Photo: C.Rowe)
We had one last fabulous stop at Jade Cove on Sunday - naturally I didn't
take any pictures, so please send me some if you have any - Jade Cove is a
major collection site for the famous Big Sur Jade, which occurs in
Franciscan Rocks and has been mined for years. A 9000lb block was winched
in from the subtidal zone at Jade Cove in 1971.
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