Farallon Plate Part 2

Next in my hall o' fame of geoscience images is the Farallon Plate - North American Plate animtion put together by Tanya Atwater (UCSB). This is one of a series of excellent earth science animations available at this site. This cartoon continues last week's theme, the fate of the Farallon plate, and follows (in map view) the evolution of the western U.S. plate boundary from 38 Million years ago until present. I have long considered this to be one of the best and most useful geoscience illustrations ever produced.

I've seen this animation in a wide variety of talks and lectures. As someone who went to graduate school in California, every discussion of the San Andreas fault would begin with this movie. But I've also seen it used when discussing general plate tectonics, basin and range extension, or this history of magmatism in California.

The movie was made primarily using plate reconstructions. Basically you "unspread" the oceans, using the time and velocity constraints provided by sea-floor spreading anomalies to step things back in time. This is augmented and checked using terrestrial records of deformation. Although it is slightly simplified, it is a fantastic view of the development and evolution of the western U.S., especially California, and the development of the San Andreas Fault.

In the movie you will see a number of things. First off, the thick red lines are the plate boundaries. Separating the Pacific Plate from the Farallon Plate is a divergent plate boundary, where sea floor spreading is making new oceanic crust. The toothed red line separating the Farallon Plate from the North American Plate indicates a subduction plate boundary, where the Farallon Plate is being subducted underneath North America. This plate configuration begins at roughly the same time as the Humphreys figure I blogged about here. The big white arrows are plate velocity vectors relative to a stable north america. The thin black lines on North America are rough outlines of the state boundaries, prior to Basin and Range extension.

So at the beginning of the movie, the western plate boundary of North America is a subduction zone. Beginning in southern California (at about the latitude of Santa Barbara) at ~30 Ma, the divergent plate boundary (or spreading ridge) separating the Pacific and Farallon Plates is subducted. This results in in the formation of a strike slip boundary, the margin we now refer to as the San Andreas Fault.

As more of the spreading ridge is subducted, the transform San Andreas fault gets longer and longer. You also see the initiation of significant extension throughout western North America. These regions are colored a salmon color in the movie. This extension roughly doubles the present width of the western U.S. This extension leads to the formation of the Basin and Range province.

As the San Andreas continues to form, you can watch parts of southern California rotate (the transverse ranges) and/or be translated northwards. Finally, the movie finishes with the modern plate set up.

As simple as the cartoon now looks, it represents a great deal of effort to put together. And, if you are looking to discuss any geologic event in the western U.S. in the past 40 Ma or so, this cartoon provides a fantastic framework.

I've used this movie every time I've TA'd or taught a course, or given lectures to audiences unfamiliar with Cordilleran geology. The figure has the rare ability to talk to all levels of earth scientists. People with no background can really see the development of a very complex plate margin.

Now a quick disclaimer. The website that hosts these movies says they can be used for free for educational purposes. My blog is non-profit and I consider it to be primarily an educational endeavor, which is why I am posting the video. If anyone connected to the video does not appreciate that, please just email me.

Enjoy! And check out the site I reference for a whole boatload of geoscience movies.

Angus MacGyver, Patron Saint of Noble Gas Labs

I'd like to nominate MacGyver as the patron saint of noble gas thermochronology labs. I had originally thought that perhaps he could represent all labs, and perhaps I need to expand my definition, but I have my reasons. Let me explain. For those of you who don't know, MacGyver was one of the greatest television action heroes/good guys of all time. Like most TV heroes, he almost never failed, but what made him unique were three important characteristics.

1. He hated guns. Except in one early episode, he never touched them. This leads directly to point number 2, but also explains why my mom let me watch the show. I like this, noble gas thermochronologists are a peace loving bunch.
2. "Mac" was resourceful, and often called upon his vast background in "science" and "engineering," crafting weapons, picking locks, breaking through security systems, opening doors, and in general saving the world using his Swiss Army Knife, duct tape, and whatever pieces of junk happened to be lying around. I'll get to this later. Oh, and for the record, I don't care if most of what he did was BS, it was still sweet. And, allegedly the producers made things slightly impossible so stupid kids in places like Sacramento didn't try to replicate his bombs and booby traps, just an idea.
3. He was supposed to be Canadian. Seriously, how many other Canadian action heroes were huge on American TV? Richard Dean Anderson, the actor who played MacGyver, is a Minnesotan who only took to acting when his hockey career was put on hold, which in my opinion is the best training an American can have for playing a Canadian.

MacGyver is the patron saint of noble gas labs because of his resourcefullness. On TV, MacGyver destroys a laser using smashed up binoculars and cigarettes, plugs a leaking vat of acid with a chocolate bar, and made a bomb out of cold medicine. In the time of need, he has no budget, and has to work with what is around. Doesn't that sound familiar! How can I fix this with the half broken old lab equipment that is lying around ? I summon my inner MacGyver all the time, clamping together 3 different size KF flanges so I don't have to order the proper reduction fitting, using the brackets I had made for the pneumatic valves for every structural support need except the pneumatic valves, the old UHV gauge controller with the "warning, may produce lethal shock" sticker that I "rescued" and used for 2 years. The list goes on. Not as impressive as the real MacGyvers, but hey..

In addition, MacGyver just looks like a geochronologist.


Check it out, here he is checking on his LMT heavy fraction. Ooooooh, lots of heavies, yes!


And here he is at the power source for the magnetic sector mass spectrometer. Hmmm, I think the problem is with the z-deflector, maybe the accelerating voltage is low...



This is when he was trying to figure out which integrated circuit blew during the power outage, man this takes forever. Thank god I have my leather bomber jacket


OK, I think the tube is ready for the reactor. And, let me add, that is obviously a paleontologist in the background, they probably want MacGyver to tell them how old some ash beds are, that's all they ever want from us.



Check out my LMT lights, I can totally get enough kspar out of this for an Ar MDD analaysis. But first, let me have a drink from my NHL water bottle, go Sabres!


And he even does field work. On the Colorado Plateau! Must be a detrital zircon thing. Let me guess, there's a Grenvillian Peak. By the way, polar fleece long before it was popular. Mac was a trendsetter.

So in conclusion I am trying to think of all of the random things that were commonplace in my lab. Aluminum foil, of course, rolls and rolls of Reynolds Wrap, Q-tips, unwaxed dental floss for the cryogenic cold trap, binder clips, balloons, cinder blocks, toothpicks, the little radioactive source from a film duster....Nothing compared to the great one, but a start. I'm interested what other non-traditional lab supplies are in use out there.

And, by the way, his first name was Angus, at least according to the infallible oracle of all knowledge. It only came out in the last episode, the same one where he found out he had a long lost son.

Apparent Dip Music Club #5 - Townes Van Zandt

This song became famous thanks to a cover by Willie Nelson and Merle Haggard, but I think the original Townes version, or the one found on this amazing posthumously released album, really capture the sadness of the song. Townes is one of those artists I never knew I liked until long after he had died. Like Stevie Ray Vaughan, his death came a t a time when he had turned his life around. Those of you interested, I highly recommend the documentary Be Here to Love Me, it chronicles Townes's life and music, complete with live performances and interviews.

Apparent Dip Music Club #4 - Stompin' Tom Connors

Today's music club offering might be new to those of you from south of the border. I first came across Stompin' Tom Connors, and this song, while I was in the field checking out what I thought would be my thesis field area (project never worked out, but that story is for another post; its a good one, I almost killed us). My office mate (we will call her Dr. Swartpuntia) and I had spent a great week and a half in southern British Columbia, near the beautiful town of Revelstoke, and were on our way back south listening to the CBC. They were announcing the results of this contest, where they had asked the listeners to call in with "the best trucking song ever written". Dr. Swartpuntia and I threw out our guesses, mainly "Truckin'" and a few others she knew of. The DJ came on and said, "while we received many good candidates, far and away the winner is Bud the Spud, by Stompin Tom Connors." What?!? This blew us away; as music snobs we both thought we would have at least heard of the song, if not already spent hours discussing the true meaning of the lyrics (hello "Tangled up in Blue" and "Last Trip to Tulsa"). Anyways, when we got back to school I was able to collect some Stompin' Tom, and now love a lot of his songs. This is perhaps his most famous, but please check out the rest of his catalog. Incidentally, I was also given a great gift related to this song, something that has a place of pride on my bookshelf. Youtube has some fantastic Stompin' Tom videos, mostly concert film, but one excellent video for Margo's Cargo that almost made me understand what the song was about (a cow-dung clock?).

Apparent Dip Music Club #3 - Gillian Welch, David Rawlings, and the Old Crow Medicine Show

Here is music club offering #3, a bunch of people I like singing a song I like, a song that if I could play an instrument and/or sing I would totally cover, especially when I opened for more popular acts like Reach of Imagination.

Apparent Dip Music Club #2 - David Francey Again!

I decided to do another David Francey concert clip for a couple of reasons. First, I am really excited that I received a positive comment on the first post, from his wife no less! That made my week. Second though, the weather here in the snowy northeast has finally turned wintery and cold, and I have been listening to David Francey nonstop. It just seems to fit perfectly. In addition he is someone everyone should know about, and what better place to find out about good music than a geology blog. There, three good reasons, more than enough. Enjoy.

Apparent Dip Music Club #1 - David Francey

Song 1 on my music club (shamelessly ripped off from the good people at crooks and liars), this is David Francey, a Canadian folk singer I ran into about a year ago. Only one of his albums is available in the US right now, but I fortunately have a Canadian geologist friend who supplied me with the rest. Now just to get him to tour in the states. If you listen to enough David Francey you definitely hear hints of Stan Rogers, more the spirit of Rogers, not some kind of rip off, because who could duplicate Stan, more the sensibility of Rogers. One hell of a lyricist.