At an old mining camp in the mountains above Cazadero in Sonoma County
is a Mars-like panorama of steep crumbling red slopes, bizarre
mineralized formations and green serpentine rock.
The 11-square-mile area, called the Cedars, is a mysterious land of
one-of-a-kind geological phenomena next to the Austin Creek State
Recreation Area and Armstrong Redwoods State Reserve that almost nobody
in the Bay Area knows anything about.
That's because it's almost impossible to get there - yet it is a land
rich with possible answers to many scientific questions, and it could
be a source of information for climate scientists searching for a way to
fight global warming.
Recently, a Chronicle reporter and photographer rode in a caravan of
four-wheel-drive vehicles that crossed Austin Creek seven times as it
wound its way over thickly forested hills and past dilapidated
homesteads to reach what conservationists agree is a remarkable
landscape that must be preserved.
A conservation easement was purchased on some of the land, and the
U.S. Bureau of Land Management now owns 2,000 acres in the center, but
the vast majority of this important geologic region is private property,
subject to the whims of the owners.
Privately owned lands
Seventy-seven percent of the rugged hills and woodlands are owned by
ranchers, outdoorsmen and homesteaders, whose parcels range in size from
40 to 700 acres. The core area, where the mineral deposits and odd
calcium carbonate formations can be seen, is 8 miles as the crow flies
from the nearest parking area and accessible only via a winding dirt
road that is often impassable.
"There is no legal access, which means we have to work
collaboratively with the owners and partners to develop a plan for the
area," said Roger Raiche, a botanist and landscape architect who, with
his partner, David McCrory, just completed the sale of 500 acres in the
main canyon that the BLM will control.
"Easements are limited to docent-led tours or scientific study," said
Raiche, who is actively working with several nonprofit
land-preservation groups to protect the rest of the 35,000 acres that
conservationists have named the Cedars Conservation Region.
The tour of the canyon illustrated why so many are so eager to
preserve the land. The rocky, mineral-rich oasis is essentially a giant
block of the igneous rock known as peridotite that was squeezed up
through the Earth's crust over the past 200 million years. The giant
upwelling relieved intense pressure inside the Earth and allowed the
exposed rock to expand.
The steep, crumbling cliffs are the result of that expansion. They
are also, geologists say, one of the best examples in the world of a
rare metamorphic transformation - the peridotite from the Earth's mantle
is changing before our eyes into the signature green rock known as
serpentine.
"I see this as a kind of Shangri-la, a hidden treasure," said Ralph Benson, executive director of the Sonoma Land Trust.
The ongoing metamorphic process has caused a chain reaction of
geologic wonders. Spring water filled with white calcium carbonate
bubbles through fissures in the rock, creating large crystalline
formations that line pools and form undulating patterns along Austin
Creek, including a spectacular 5,000-year-old snow-like sheet that flows
over a waterfall.
The deposits are an example of carbon sequestration in nature,
experts say, a potential source of information for scientists fighting
global warming.
"Here is nature (sequestering carbon) for us," said McCrory, who
co-owns a landscape design business with Raiche. "Geology and
geo-chemistry experts are really interested in these springs."
Unique plant species
NASA scientists are particularly intrigued, McCrory said, because the
highly alkaline springs harbor uniquely specialized microbes that may
offer clues to how life could form on otherwise inhospitable planets.
The
weathered hills, which are high in magnesium, iron and chromium, are
also home to five species of orchid and at least eight plant species
that don't exist anywhere else, including the Cedars manzanita.