From Sutro to Shining Sutro
Froze my ass off Sunday when it was surprisingly sunny and I foolishly thought it wouldn’t be that windy on top of Twin Peaks. (Hint: very windy.) But hey, got a decent Sutro to Sutro panorama from the top of the north peak. (Click to zoom, 7000 pixels wide)
(The panorama got a little wonky pointing towards the sun — I was blinded and struggling to keep my balance thanks to the 30 mph gusts (the lengths I go for art). Anyway, the east side of the south peak got cut off, whoops, but it was cold. But if you zoom in you can see the crazy bastard who was sitting up there the entire time.
Hey, did you know that the south peak is supposedly called “Noe Peak” and the north is “Eureka Peak”? Me neither.
Hey, did you also know that the two peaks are actually different types of rocks? The north peak is our old friend Franciscan Complex chert (Early Cretaceous and (or) Late Jurassic) and south is Franciscan Complex volcanic rocks (Jurassic). (But don’t worry, the very very top of the south peak is chert. GO CHERT!)
View from the top (north up). Red is chert, purple is Franciscan Complex Volcanic (hey, good name for a band!)
And from the view most familiar to most readers, looking to the west:
(And now we know why the Spanish called them Los Pechos de la Chola.)
Here’s hte USGS Google Earth geological layer and key.
Another shot got both towers of the Golden Gate Bridge fully lit (i.e. not shaded by a cloud).
Nice (though this is obviously a better shot).
UPDATE:
So it has come to my attention that the individual names for each Twin Peak, are, well, rather uninspiring. My initial thoughts:
- “Giants Peak” and “Seals Peak”
- “BART Peak” and “Muni Peak”
- “Gavin Peak” and “Willie Peak”
(OK, maybe not those last pairs.)
Please add your suggestions to the comments, and I will make a poll when we get a critical mass of names.
Burrito Justice 
Archaeological Side note: Chert is more or less the same thing as flint, and was far and away the most common tool-making stone for the Prehistoric natives in this part of California. However, it is much more easily workable once it has been “baked” in a fire. Essentially heating it changes the stone’s properties so that it is more easily knapped.
Thanks. I have learned more about chert (and geology) in the past year than I ever thought possible.
Did you know that when the BART tunnels were being built in 1972, they found 5000 year old human remains over 50 feet below Civic Center? (They were once at ocean level but the area filled with sediment as sea levels rose after the ice age.)
I hadn’t heard of that find, no! However, I can’t say that I am too too surprised, the geography of the Bay Area has altered radically since the end of the last ice age. If I am remembering correctly, for instance, didn’t the bay only fill with water about 5,000 years ago? Before that it was an inland valley, which means that most of human habitation sites from that period are now very much underwater. (Not that this is a phenomenon at all limited to here. Really it is more the Rule than the Exception when it comes to Meso- and Neolithic coastal sites)
Definitely check out the paper I referenced – it’s all about that.
Sea level rose 130m in 15000 years. The Farallons used to be big granite hills, etc. They estimate the ocean breeched the Golden Gate (the base is 70m down) 11,000 years ago which is when the Bay began.
As far as i can tell, anything that’s flat today is sedimentary fill and the “original” surface is way down. All the cool stuff was happening 15 miles out where the coast was at the time – SF would have been like Orinda.
Hmm, is it really that long? It’s been a long time since I studied it, but I thought that the Bay started to fill about 9,000 years ago, and finished about 5,000. Maybe I am confusing Years-before-present and Years B.C./B.C.E. in my memory, however.
Good call on the flat-terrain-as-fill. When you’re doing archaeological survey you basically learn that flat terrain is generally evidence of either having-been-underwater at some point, or the result of human action, or some combination of the two.
That paper was published in 1978 so the dates could very well have been nudged since.
I would like nothing more than to get a reader at Pixar or the like to do a digital fly through of a grassy Bay-to-be, and watch the creeks get subsumed by and encroaching pacific over 10,000 years.
They should be named Marian and Vivan of course http://en.wikipedia.org/wiki/Marian_and_Vivian_Brown
You know how tempted I am to actually start a band called Franciscan Complex Volcanic, considering I am a geologist with a music degree? SO TEMPTED.
I doubt I will be able to convince anyone to join me, though, so the world is probably safe.
(Actually, I would kind of love to have a band called “1906.”)
How about Emperor Norton Peak and George Washington II Peak?
Maybe Gumshan Peaks, 金山 for short, first because everyone knows how to pronounce either gumption or 金山, and it translates into Spanish as Los Picos Agallas, which counts as a near homonym to everyone’s favorite Mexican chutney. Plus we need more exposure on Fox news for tolerating and/or in some extreme cases enjoying the presence of foreigners.
Which is to say Gum Peak and Shan Peak
Ha, I like that. I was hoping for single character kanji for “joy” and “pain”, or “smug” and “better” but no such luck. (Assuming the same in Chinese.)
sweet fucking panos.