Friday, March 19, 2010

It's the beer..

Came across this and had to laugh... thought my fellow geologists would enjoy.

Destructive collecting

This past weekend I took Little Guy to find a carnelian. One of the iphone apps I have gave directions to the site, which took us about an hour and a half to reach. It was a nice drive and to my surprise Grim and Mandy had decided to tag along. Upon reaching our destination we were confronted with signs that made no bones about how the property owners (a tree company) felt about looking for said rocks. I was pretty surprised, until I started to take a look around. Almost very bend I could see in the creek had huge areas dug out along the banks. The hills beside the gravel road also showed massive amounts of destruction from individuals digging away the sides. Further up the creek piles of rock and mud were evident from screening and dredging for these rocks. Since when is mining activity attributed to a "hobby"?

I came across two locals on horseback and they told me that the area used to be a madhouse on the weekends with groups of people who identified themselves as being from rock clubs. While not all bad behavior can be directly attributed to these types of clubs, I do think they bear a big part of the responsibility for the site being closed. To overtax an area with too many people can take a huge toll on the locals who live in the area and want to enjoy some peace and quiet over the weekends. Not capping arranged trips to a certain amount of members can result in chaos and possibly bad behavior due to competition for getting that "rock". I've seen it happen before at other sites when there is too little room, too many people. Total madness.

In addition, if you are using mining techniques to get said rock, you are no longer a hobbyist- you are a miner! Buy a plot of land and mine it, but don't ruin rock collecting for those who like to casually walk streambeds and pick up rocks already exposed. At the very most, only digging out a rock that is half in/half out with a rock hammer. But to tear away a creekbed, adding to the sediment load.. bad! If you can remove a rock and it makes little to no visual difference, then that is a hobby or getting a rock sample. But if you are removing massive amounts to the point an entire bank is cut away, you are destroying the environment!
So thank you very much greedy people- you just effectively ruined one of the few FREE & educational activities I enjoyed with my children. At least for that area. I'm sure if this continues unchecked, more and more sites will become off-limits.


Sunday, March 14, 2010

Subduction styles/EQ magnitude

Strong Earthquakes in Latin America can be attributed to a greater release of seismic energy associated with flat slab vs.steep slab segments. The geometry of these flat slab regions allow for more stress to build up between the plates (Gutscher, et al.,2000).

Flat Slab segments lack the arc volcanoes which are prominent in western America from subducting young oceanic lithosphere, as depicted in the image above of Normal slab subduction. Normal slab subduction is characterized by maintaining a distinct low viscosity and high temperature melt in the boundary between the slab and overriding plate. Flat subduction occurs when a distinct decrease in the dip angle of the slab results the slab tip flattening underneath the plate overriding it. The wedge corner is subject to high stresses as the slab-tip is pushed into the mantle thereby constricting the corner flow above the slab.

Flat slab segments are attributed to the high magnitude earthquakes in LA, and one possibility behind the differing slab geometry is the buoyancy between the two slabs with the younger buoyant slab resisting subduction. The subduction of young buoyant lithosphere can be modified when encountering denser older lithosphere changing the thermal structure at the margin and displacing the asthenosphere away from the trench. The cooler temperature at the forearc predicts a larger locked zone therefore increasing the risk of great interplate earthquakes.

While Earthquakes occur all along the subduction zone, those in the ‘Seismogenic zone are most destructive. This is because they occur near the surface. The earthquake cycle in the Seismogenic Zone can be said to occur in two stages, the Interseismic Period and the Coseismic Period as described below:

The Interseismic Period Time between earthquakes: (10’s to 100's of years) where plate convergence continues at approximately 8cm a year (between Nazca and S. American plates) with the two plates are locking over a portion of the subduction plate boundary. This results in not only uplift, but also a horizontal shortening of the overlying plate margin.

The Coseismic Period/Earthquake rupture occurs over a few minutes. Once the accumulating stress exceeds the strength of the fault,  failure occurs in the locked zone and great earthquake occurs. During this episode stored elastic strain is released which in turn results in subsidence and horizontal extension where slow uplift and horizontal shortening had previously accumulated. In addition, the underwater displacements can cause tsunamis. Once the stress is relieved, the cycle resets and stress begins to build again.

In Latin America there is a combination of Steep slab/Flat slap segments, with the greater earthquakes occurring along the zones of flat slab subduction.  (Fig. below shows a run down of where earthquakes of greater magnitude occur as opposed to those of lesser magnitude).

Note: I couldn't find a comprehensive enough image to suit my purpose for this blog post so I created my own from a variety of figures (upper two images of steep slab/flat slab), with the principle source being from Gutscher, 2002.

Gutscher, MA., 2002. Andean subduction styles and their effect on thermal structure and interplate coupling. Journal of South American Earth Sciences 15: 3


Monday, March 8, 2010

Meteorite Men

I am so addicted to this show! I think I like it so much because the two guys showcased on the show, Geoffrey Notkin and Steve Arnold, remind me a lot of those I have been in the field with before. There is always a quirky person in every group, you know the one- he is chasing butterflies (or gathering tree sap- yes, tree sap) instead of measuring strike and dip on the outcrop you just climbed 200 ft to find and have yet another ridegback in the distance to conquer. It's tough to keep your temper at them, but they are just so darned puppy-ish you can't chastise them for fear your temper will boil over so you keep it all inside to protect his feelings. (Or at least for me). Then you have the guy who dresses like Charles Darwin (not sure what to say about that one) but he was smart so you don't really care how he dressed, you just wanted him on your team because he got things done. And then there is the loner who works on the outskirts of the group, but once you get to know them you find out they are a MENSA member and while not really as well-versed in geology as you would like, their sharp wit and sense of humour make you laugh at yourself. It's always a good thing to remember to laugh at yourself. :)

So as I watch this show, I see little nuances of the quirky things I have seen exhibited from people out in the field before and I feel strangely comforted. I think perhaps it is because I miss my motley group of friends that I have gathered. It's always tough to move away from people you admire and conspire with, especially for me when it comes to geology. When I watch this show it just flat out makes me laugh. The two of them [Geoff and Steve] banter at one another just as I have done with my friends out in the field, and they enjoy busting on one another as friends tend to do. (I would have had a field day teasing them about the snake boots- the only person I have ever seen wear a pair of those was the Charles Darwin guy, so yeah, um... yeah.). Not saying it's a bad thing to wear them, it just hasn't been a common practice in my experience so I would find it a bit funny. Plus Geoff takes forever to get ready once they arrive at the spot. Every geology trip I have ever been on we pile out of the van as if  we were told it was about to explode. If anyone lagged as Geoff does to get ready they would find themselves quickly alone wondering where everyone had gone off to. Unless it was an outcrop stop, at which point by the time he was finished everyone would be piling back INTO the vans. ha ha. So I enjoy watching him fiddle with getting his snake boots and gloves on as Steve is off and running. 

While the meteorites they find are pretty cool too, once they make their finds I usually prefer the part when they take it to the guy to put in the mass spec. I have to say they are quite talented in finding their treasures, and they are pretty clever in how they go about choosing sites to explore. 

If you haven't had a chance to see this show, I really encourage you to check it out


Saturday, March 6, 2010

Best Blog Post Eva!

I just read the absolute best blog post ever! It was written by Garry Hayes over at Geotripper and it pertains to the impact of certain groups rejecting evolutionary theory because of their religious belief. As a result, a recent poll in Texas revealed that an appalling amount of students were under the erroneous impression that dinosaurs and humans co-existed. In fact, there is a museum in Texas ran by creationists that actually claims a fossil they have is of human AND dinosaur footprints (together), so this poll does not surprise me. However, I firmly believe religion has no place in the classroom and I have covered this issue in previous posts.

What I love about Garry's post is how he brilliantly presents the issue by turning the tables and giving them what they [Creationists] want. The thought of the earth being 6000 years old has been so preposterous to me that I had never even considered what that actually would mean geologically if one were to entertain the idea. Garry paints a very colorful picture that opens up so many holes that had this creationist-based theory been presented by someone in anything other than a religious venue they would be made a laughingstock. How is it that religion can muddy the waters so much a reasonable person is wont to cry foul? This is why I think it should be taken out of the equation. I am all for anyone practicing whatever religion they see fit in the privacy of their own home, but when I send my child to school I want them to be very clear in the manner of which science is presented. There is no "other" side to the story as far as the science applies, and Garry demonstrates that aspect amazingly in his post. Kudos to you Garry!


Rock paper scissors...

After some thought, I feel I have been a little (or rather more than a little) unfair to Husband in regards to invading most of our closet territory. As I walked about the house and garage, I came to the startling conclusion that I have more than invaded most areas around the house with small-ish piles of rocks. This is not to include the rocks I collect and keep in the living room as a quasi display. I can't really call them decorative because most women who enter my home are unimpressed, as not all of them are what they would see as pretty- but I keep what interests me. Such as black calcite. From all outward appearances it is probably quite ugly to the average person, but to me it is absolutely lovely.

I figured I'd swallow my embarrassment and show you what my coffee table and "little" messes look like because I am curious if other geologists have these small piles of rocks around their home too. I know I need to defenestrate a lot of what I have gathered, as not all of the rocks I have are keepers. I just grab what I see of interest at the time and look later, as there have been numerous times I've kicked myself for NOT grabbing a piece. Such as the greenschist I came across on a field trip. I didn't grab it because I hadn't realized I already had a piece of corbin gneiss in my pack from the weekend before and hence by the time I had hiked in I was too tired to put anything more in my pack, and I wasn't about to dump the corbin gneiss.

Now I wish I had just sucked it up and grabbed the darned greenschist! It was perfect- all shimmery and a stunning shade of green. At any rate, there are times when you intend on returning to a spot but it just never happens, so it is best to grab the piece then and there. Especially when you know they are nice pieces. (Sometimes I grab leaverites just because I am curious, although usually only when I'm not packing long treks:).
To get back the subject about my messes... I went into the garage and noticed that Husband had put my hiking boots next to my rocks because I had failed to put them away last week when we went out.

All my rocks were neatly off to the side of the garage from the first trip and the rocks from the second trip were in a pile at the front of the garage. I had once mentioned to Husband that I didn't like the rocks mixed until I had sorted through them and labeled the ones I intended to keep, but I guess I hadn't specified that it didn't matter when we collect from the same area if the rocks are mixed. Especially when it isn't formal (if it were they would be labeled out in the field or immediately thereafter) and furthermore, we got the rocks from a stream bed. So I kinda chuckled, but was touched by his efforts. I REALLY need to sort through these and eliminate the leaverites.

Despite my best efforts, I am never able to keep everything organized for very long before rocks start spilling out onto the floor. At some point I guess I will have to put some away or have a room to just put them in in order to establish some form of organization, but with moving so often I find that more of an idea for the far off future. I have tried to slim down the rocks I decide to keep, but for some reason or another I cannot bear to part with them. Some I found during Field Camp, some were given to me by peers, some just are too interesting.... sigh. What do you guys do to thin down your piles of rocks? Or do you even bother? Is it really an issue? Maybe I'm just normal and I have nothing to worry about. As long as we aren't over our weight limit for the military to move us it's all good there. And we are far from that, amazing as it is! I think we are allowed around 24K and last move we only had 16K so I have plenty of rock room there :)

But with it all said and done, I should be ashamed of myself for even questioning why Husband invaded my side of the closet, especially since I have infested the house with my rock piles. Granted, he has never complained, but perhaps that is because rocks are cheaper than Pier One. Oh, I used to love that place- but as you can see from the pictures, I have little room for decorations without giving up rock space. What to do... pretty rock, Pier One candle. Rock wins every time.

Maze of distractions

Today (er, make that yesterday- just saw the time) was nothing but one distraction colliding into another. It began quite productively by registering for next terms class, but when I returned home it just went down the tubes. The lady at the registrars office said I should apply for special services due to my ADHD, and while I cringed at even the thought of it Husband talked me into at least looking into what they have to offer. The way I see it, if I can't hack being in classes and taking exams like the rest of my peers then perhaps I don't have any business in my field. Nobody ever claimed Geology was easy. However, while I may not have a 4.0 it is still above a 3.0 and this was accomplished without any special accommodations. In addition, I managed to successfully get through classes with a B or better where I hadn't as of yet taken the prereqs.

 But I digress.. To appease Husband I went in search of the paperwork from my original diagnosis of ADHD. In locating this paperwork (finally found it in the master closet) I realized Husband has slowly but surely taken over the closet. I'm not sure what first caught my attention to this fact, as I generally don't notice such things, but it was so obvious I stood there and laughed. Then went and got my iPhone to take pictures for proof! The two pictures were taken of opposite sides of the closet. The upper one is "his" side, but the picture to the right is supposedly "my" side. The ONLY thing that is mine in either of those pictures is the black trunk on the upper left is filled with geology gear I use when I go to the field. Everything else is his. LOL. This just cracks me up! I thought girls were the closet hogs?!
After that was accomplished I spied an old box with all the letters I had sent off to Husband while he was in Iraq. I started reading through a few but had to quit after awhile, as it wasn't really a place I wanted to return to in my mind. I mainly just looked at the script and remembered how I had used pen and ink to write to him during that time. It was easier because you didn't have to apply as much pressure and as prolific as I was about writing to him I was starting to get blisters. I generally wrote a letter a day, and they averaged about 5-7 pages. It was a run-down of everything we had done for the day and anything else I could think of -even to the point of movie reviews. We would email as well, and he called once a day around 11am (most days unless he was on a convoy). I felt quite lucky compared to most wives at the time who rarely heard from their husbands. Even though we had both venues to communicate (email & phone) I always wanted him to have something from the mail guys when they came around. I know when I received one of his letters in the mail my heart would jump a beat and I would cloister myself off to a quiet place (usually the backyard with the lulling ocean waves in the backdrop) to read.

We sent packages back and forth to one another and in the ones he sent to me were beautiful marble vases. One of them, a covered bowl, arrived crushed but it had been wrapped in bubble wrap so well it still held the original shape. So I bought some super glue and pieced each of the little parts together until it was whole again. It took a few tries because it would collapse when I started getting to the concave portion of the bowl, but in the end I managed to get it to work and the glue-job wasn't very noticeable. The lid didn't fit as nicely, but I didn't care. I still have that bowl- which surprises me because it has survived 4 moves since then. After I was finished upstairs I brought the paperwork down to my office (at least that is still all mine:) and began to wonder what I had done with the letters Husband had sent to me. I had to dig around through a few boxes I still have yet to rummage through from the move here last summer (hey- after 4 moves in 4 years you'd be a little unmotivated to unpack too, trust me! :) but I located the box of all the letters Husband sent to me. They are so like him- all the same envelope, ordered, structured, tidy. Everything I am not.

I looked about my office and had to sigh to myself for still having boxes on the floor with books I haven't unpacked and put away. My bookshelf is a total mess because I pulled out a bunch of books when I was researching my latest finds - I'm too embarrassed to take a picture of my living room coffee table with all the rocks and books strewn about. Even my rock hammer sits there next to a rock I cracked open on the living room floor (but vacuumed up the evidence before Husband could tell what I had done). Usually I do that outside, but it was late. And dark. And cold. And inconvenient. He doesn't ever get angry with me, but I feel bad when I've let my rocks cause such a mess of things. Which brings to the point that I had wanted to get them put away today, but obviously, despite my best intentions, that did not transpire. I am not even going to try and project when I may get all these tasks in my mind to completion, all I can say is I'll get to it when I get to it. Hopefully sooner than later. :)


Wednesday, March 3, 2010

Badlands road trip 2007

In 2007 I took a special topics course on fossils in the Badlands. This required a road trip across a few states to Interior, SD., and accommodations/travel were the responsibility of the student. A few people were those who made the jaunt every year it (class) was offered, some bringing their older kids, so I arranged for my daughter Brittney to come along with me. She had never been on any previous geology trips, and when I posed the suggestion to her she was very excited about the idea.

The trip out there was a lot of fun. Britt took tons of pictures, as the scenery was far from boring! We passed giant sculptures of dinosaur bones and bulls in pastures, beautiful lakes and hills, and the weather was absolutely lovely. Upon reaching our destination there is an astonishing change in geology. My breath was taken away by the effect. I can only imagine what the early settlers thought when they came upon the barren landscape that I found so beautiful. It was surely the antithesis of what I felt upon seeing the colorful layers of earth exposed from years of erosion.

The town itself made me smile. It reminded me of my little village back home in Alaska. What really made me fall in love with the place was when we stepped into the little cafe and everyone stopped talking to turn and look at us. My daughter was horrified, but I belted out the biggest smile before I could stop myself. I felt so at home! It was all I could do to keep from chuckling at poor Britt, as she is a through and through city girl and wasn't used to their curiosity; instead interpreting their behavior to mean they didn't appreciate strangers. I had to explain to her that when you live in a small town and someone new arrives, you cannot help but stare. It's like drinking a cold glass of water after being parched. After getting directions to the campsite from them (and once they knew what I wanted they were pretty much falling all over themselves to offer help and were very chatty:) we were on our way to the campsite. I love small quirky towns!

I had reserved a cabin at the campsite the class was meeting at and it much nicer than we had anticipated! It was a bit secluded, so we weren't really included with the rest of the group a lot, but this also allowed for us to just enjoy our time together. The itinerary began with heading out early the next morning towards Wall. Speaking of Wall, this is another cool town- a MUST see for anyone! Britt and I had so much fun there, I think my side was splitting from laughing so hard. There is a big "Triassic Park"- like dinosaur that appears innocuous at first, only to light up growl and charge towards you. The normal person wouldn't have been bothered by it, but I about peed my pants because I was just standing there and didn't expect it to move. LOL. It was so silly of me I think the two of us laughed about that for a good 10 minutes. There were a lot of fun shops to browse through, and it was just generally a lot of fun. Very tourist-laden, but worth the trip!

Now back to that first morning in the field.. it was very cold and it had started to rain, so we had to park the vehicles at the top of the hill, limiting us to a small area. The rain saturated the upper crust of the hills (which were deceptively steep) so when you took a step and lifted your foot, a 3 inch rim of mud was clinging to it and increased with each step you took. While I didn't slip, quite a few others did, prompting the professor to cut the day short. Our second day out proved to be much more fruitful. It was still cold, but the rain stayed off in the distance. The earth dried into a crumbly texture, so care still had to be taken when walking up the steep slopes. Again, they were deceptive in how steep they were. It didn't seem steep until you were up on top of them looking down.

Britt stayed close to me, and helped me brush away dirt when we found a fossil here and there. (She pretty much just stayed crouched in one spot watching me work, re: picture, left).  At one point I had spied a tooth, but when I went to reach for it I started to slide down the embankment prompting her to yell at me "Use your rock hammer!", which I did, in order to stop myself. Once I came to a stop I just stayed there for a second, but looked over at that darned tooth! Knowing me as she does, Britt says in her best deadpan manner, "Don't do it." LOL. I had to chuckle to myself when she said that. I wouldn't have grabbed for it, but can't deny the thought hadn't run through my mind. The drop was a good 80-100ft. and were I to fall we were in a remote area that wasn't easily accessible. So I just scooted back up to where the ledge evened out a bit and then sat back up and forgot about the tooth.

During this trip, we were also able to visit a rose quartz mine, see a pegmatite, and a quick trip to Mount Rushmore. Additionally, we were able to browse through the SD School of Mines museum which had beautiful displays of rocks, minerals, and fossils. It was a trip we both really enjoyed, despite the wet and cold conditions. Since then Britt has become quite talented at knowing what types of outcrops I like pictures of, and she will click away as I drive. In fact, she took the picture of the main rock outcrop I used in the title logo of this blog. If you look closely you can see a bit of the reflection from the window (on the right). Being as I was driving 50-60 mph I thought that was a minor issue. :) Esp. since it (picture) was taken with an iPhone!

Monday, March 1, 2010

Wrapped around his finger

During the weekdays there is about an hour when everyone has already gone on their merry way for the day while me and Brae have a few extra moments before I take him to the bus stop. We generally spend this time talking about how he is doing (socially) in school, what he is feeling, and just general chit chat. I try to keep it light because it isn't a time for lectures or a forum in which I want to dominate. I like to hear what he has to say about his life in general, and anything that is troubling him. Some days we just talk about rocks. He likes rocks, and is always bringing me what he finds in the schoolyard during recess. He has brought me some very interesting, albeit small, rocks in the past and is quite excited to show them to me at the end of the day. I do my best to tell him what they are, but sometimes I am at a loss. Instead of getting upset with me, he usually tells me he will try and find a better piece for me to look at. This makes me smile.

Well this morning I was washing off a piece of shale when he came over to watch me. I asked him if he thought his teacher may like it, since it had some pretty nice impressions in it. His eyes lit up and he said he probably would, so I went to grab some plastic baggies to wrap the rock up. Before I knew it, Brae was bringing me paper and a pen. I was a bit puzzled, and asked him if he was wanting me to write a note to accompany the rock. I hate writing notes, but he was pretty insistent upon it, so I complied. I didn't quite know what to write, but I did my best and tucked the note in with the rock. Funny how the smallest of things can make children so happy. Brae was positively beaming. Honestly, that smile of his is worth writing a thousand notes and giving my entire rock collection away. He certainly has me wrapped around his little finger. But then, they all do at one time or another

(note: His teacher mentioned to him that they would be learning about rocks soon, hence my suggestion for sending a rock to school. I thought shale would be a good choice because the sample had an enormous amount of plant impressions and could be used in showing what happens with heat and pressure etc etc. It's a 2nd/3rd grade class.)