Geology of Angel Island

This year we're doing a change: Rather than circling the island, we'll hit the good geology stops in the first couple miles circling the island, then we'll head on up to the summit. This should give us breathtaking views of the Bay.

Distance: About five miles.

Elevation change: The summit is 788 feet, and we're going all the way up this time. With the ups and downs along the road, we'll probably climb about 1,000 feet total.

Map: Check here for a Google map (http://goo.gl/maps/FQ3h).

Finish time: We usually finish around 2:00, which is in time for the 2:55 ferries (Tiburon folks can catch a 2:20 ferry). See ferry schedules below.

Note: This is Pride Day in SF (http://www.sfpride.org/parade/). The parade kicks off at 10:30, so public transit into the city is highly recommended, as parking will be hard to find.

Angel Island is Trip 3 in Geologic Trips -- SF and the Bay Area (chapter title: Metamorphism and Blue Schists). I'm working on collecting a few web sites with more information, so folks can do a little reading before we embark on our trip.Low tide is at 9:15, and high tide not until 4:34, so we should be able to see some of the sites early in the hike that are best at low tide.

From the book:Most Franciscan rocks have not been metamorphosed; that is, the pressures and temperatures in the subduction zone were not high enough to alter the rocks significantly. However, the Franciscan rocks that make up Angel Island are metamorphosed. They have been altered by extreme high pressure in the subduction zone. These rocks mus have been carried to greater depths in the subduction zone than most Franciscan rocks.

We did this hike in August 2009 (https://www.meetup.com/SF-Bay-Area-Geology-Hiking/calendar/10934974/?from=list&offset=0) and October 2010 (https://www.meetup.com/SF-Bay-Area-Geology-Hiking/events/14879784/); you can see photos and reviews on those pages.

Notes:

This time, rather than circle the island we're going for the summit. We'll hit the three best rock sites in the first two miles, then hike all the way from the bay to the summit. Layer your clothing: it can be breezy out there in the middle of the bay. Bring food and drink. There are food concessions at the start, but not when we'll be at lunch time. Dogs are not allowed except for service animals. You'll need to take a ferry to Angel Island (you can park your own boat, but I don't know the docking fees), so check the times below because we're leaving from the Ayala Cove area of the island at about 10:30 (boats arrive 10:10 & 10:20). Be sure to get to your ferry terminal a bit early, we had a few people miss the boat last year.

More information about Angel Island
I'm starting a page with links to Angel Island geology pages (including books you can buy ahead of time): Angel Island (https://www.meetup.com/SF-Bay-Area-Geology-Hiking-Club/pages/Angel_Island)

Attendance limit:

I set no limit, but we usually get 15-30 people, even if 50-70 sign up (yes, I'm old-fashioned and a bit bugged by all the no-shows, but have given up on fighting it).

Ferries:
Prices are round trip and include park admission.

From Oakland or Alameda, take a ferry to Pier 41
Ferry from East Bay (http://www.eastbayferry.com/when/angel.html)
Oakland: 9:00 am
Alameda: 9:10 am
Pier 41: 9:20 am (transfer to ferry coming from Ferry Building, so you'll join the SF people)
Pier 41: 9:40 am
Angel Island: 10:05 am
Price: $15.50 adult; $11.25 13-18, 62+; $8.50 disabled, 12 and under free.

For many East Bay folks, it may be just as quick/simple to take BART to Embarcadero and load the 9:20 Blue and Gold Ferry at the Ferry Building. Unfortunately, they have discontinued the return ferry to the East Bay, so if you come over on the ferry you'll have to return on BART (which includes a bus ride or walk from Pier 41 to Embarcadero BART).

SF
Blue and Gold fleet (http://www.blueandgoldfleet.com/Ferry/Angel/angelislandsummerfall2010no51.cfm)
Ferry Building: 9:20 am
Pier 41: 9:40 am (where East Bay folks will transfer onto this boat)
Angel Island: 10:05 am

Return trips
2:55 pm to Pier 41 at 3:25
4:30 to Pier 41 at 5:25 and Ferry Bldg at 5:50

Ticket prices online have $1.50 service charge each way. The online price seems to be $18 for adults and $11.50 for kids 6-12. I've never seen the ferry sell out, so online tickets should not be a problem.

Tiburon:
Angel Island-Tiburon Ferry (http://www.angelislandferry.com/FerryServices/Schedule.aspx)
Leaves Tiburon at 10:00, arrives Angel Island at 10:20.
Adults (ages 13 and over) $13.50
Seniors $13.50
Children (ages 6 - 12) $11.50
Small Children (ages 3 - 5) $3.50
Toddlers (ages 2 and under) Free*

Return trips at 20 minutes after the hour; last boat at 5:20.

Vallejo
Blue and Gold, transfer in SF (http://www.blueandgoldfleet.com/Ferry/Angel/angelislandsummerfall2010no51.cfm)
Depart Vallejo at 8:30 am, join the SF group on the ferry from Pier 41
Adults (ages 13 and over) $30.50
Seniors $23.00
Children (ages 5 - 12) $21.00
Children (under 5) Free*

One return trip: 4:15 - 6:30.