The word on playa dust and links for the newbie -

[Snow]

you know what I find the most with a metal detector. My steel toed boot. DOH! does that ever happen to anyone else?

They actually published that guy?

[Bob]

Um, no, wasn't making a crackpot science reference, there really are tons of meteorites out there.

And you won't look like a dork dragging a metal detector around, I promise, but you might dress it up with some raver fur and blinkylights.

[^Rhino!]

Glad to hear you weren't making a crackpot science reference.

So tell me, Bob, do you have a reference? Are there chondrites or troilites?
I'm now curious.

[Sail Man]

Sometimes epa or osha or someone else with a lab will run these for you.

Can we have a show of hands for people who want more government agencies involved? And um, I don't know about OSHA, but EPA is not swimming in cash.

Ohh! Ohh!!!

I'd like to see if project Blue Book is still active as I think they really oughta get out there and research all of those weird lights I see at night, plus I coulda sworn I seen me an alien or fifty.

[Sail Man]

Damn I missed out on the stake regulation fun and the t-shirt!?!?!

Neener neener neener, got mine Well, except for the steak thingy, we had gator instead.

What meat this year Rhino?

[Bob]

Rats, misplaced my collection. Just small fragments, dark with rusty oxidation, fine grained, bumpy/pitted surface, denser than the local basaltic country rock, slightly magnetic, and like totally special.

[^Rhino!]

I hear Bob fuming....."Why?, Why?" he cries. "Are you calling bullshit on ME?"

No, I'm not, Bob. I'm just very skeptical of a LOT of meteorite claims. With chondrites, it takes an expert to tell if they're different from the country rock. With metallic meteorites like troilites, you actually have to have it sectioned to expose a strange crosshatched pattern called "Widmannstatten lines."

Example of those lines is here:

http://en.wikipedia.org/wiki/File:Widma ... erns-3.jpg

There are lots of fresh and leached mineral deposits which exhibit slight magnetic character. The Black Rock Desert is chock full of all kinds of mineral deposits, as you well know.

Sail Man, good to see you in on this conversation. I'm bringing pork spare ribs this year!

[bm_cricket]

Random question #412:
I'm a Geology undergrad and I'm thinking it would be an interesting and unusual use of my energy to create a little senior thesis involving the playa. I've wondered this since 2008 when I first got out there. Since I only thought of studying this 2 minutes ago I haven't really had a chance to think it through but I would like to know your thoughts. Here is what I thought of doing...

Compare chemistry and particle sizes of:

-Wind blown dust.
-Surface dust.
-Near surface crunchy stuff
-Deeper playa (presumably deep enough that it's been unchanged by burners in the last ~20 years)

I would hope to discover:

-What chemical differences there are in wind blown vs. surface vs. deeper dust.
-What particle size differences there are in wind blown vs. surface vs. deeper dust.

I would like to do this for 3 simple reasons:

-It requires minimal processing!
-I'm interested!
-I would love to have a thesis in addition to Senior Field Mapping!

Oooookay, Why am I telling you all this? I want your advice. What else can/should I ask/study that seems reasonably simple given the fact I still plan to go out and have fun all week!

[Snow]

Well it looks quite interesting to me, I'd like to see such data, and would answer some of the questions brought up in this thread. Some things to think about:

for the wind data I'd want to know the local wind velocity, how and how long the sample was collected, and the height above the ground (idealy a few heights). I've never sampled airborn dust, I'm not sure what sampling equipment this would take.

Care must be taken not to contaminate samples with windblown dust.

Sample multiple locations and samples for each type at each location.

I'd like to see a gradation curve below the standard geotech 200 sieve (assuming you have such sieves avail. to you)

Will you be testing for raver sweat or hippie tears in any of the samples?

[Bob]

Dude, I'm an engineer, not a rock sniffer. I'd start with a few cone penetrometer and seismic surveys on grids transecting the lakebed, then think about actual sampling.

[Snow]

When I was in field camp in Ruth Nevada. There was a local kid who would ride his bike back in forth in front of our field station, taunting us "ROCKLICKERS-ROCKLICKERS-ROCKLICKERS" We thought it was hilarious and I've been using that term ever since.

leave it to a bunch of rocklickers to fill 4 pages with discussion about dust.

[bm_cricket]

Well it looks quite interesting to me, I'd like to see such data, and would answer some of the questions brought up in this thread. Some things to think about:

for the wind data I'd want to know the local wind velocity, how and how long the sample was collected, and the height above the ground (idealy a few heights). I've never sampled airborn dust, I'm not sure what sampling equipment this would take.

Care must be taken not to contaminate samples with windblown dust.

Sample multiple locations and samples for each type at each location.

I'd like to see a gradation curve below the standard geotech 200 sieve (assuming you have such sieves avail. to you)

Will you be testing for raver sweat or hippie tears in any of the samples?

Well, I was already planning for multiple sample sites (located by GPS and marked on each little baggy with standard sampling sharpie) all around the playa, probably 50 sites for air (I doubt they would all make it back with me, thus the high number), 10 sites X surface, near surface, deep, so 80 max samples.

I hadn't considered multiple heights for wind blown dust. I assumed I could just find camps all around the city and ask to stick a 10' wooden pole with an opened zip-lock bag someplace in the camp. Each pole would have a ziplock bag on the end that's forced to stay open. I would just collect the bag at the end of the week. My only real concern would be with having the wind blown samples either grossly contaminated by people messing with them, or having them not make it back to me for some reason.

What would the geologic significance be for raver sweat and hippy tears. Good idea anyway!!

I'm not sure what sized sieves are on hand but I'm pretty confident I could get my hands on what I need with a little begging to the rock sampling gods.

And with regard to contamination... yes. I would plan to use zillions of ziplock bags each labeled with their location. I am pretty confident that the samples I collect won't be contaminated but I would want as many air samples as possible since I'm relying on 1) plenty of dust, 2) people not messing with them all week, 3) getting enough dust to be useful, 4) I could use that to create two curves, one of samples people dicked with and one with real samples.

[bm_cricket]

Dude, I'm an engineer, not a rock sniffer. I'd start with a few cone penetrometer and seismic surveys on grids transecting the lakebed, then think about actual sampling.

If I could study subsurface features of the playa I would! ... However I was trained in rock sniffing, feeling, licking, and other lowly visceral methods. That and I'm spending my budget this year on more important things, like doodaads and hoohaas for my camp!

[^Rhino!]

I am gratified to see that the thread I started actually stimulated the gray matter of an undergrad at UC Santa Cruz, one of the premier geology schools in the US, according to US News and World Report.

cricket, here's my thoughts for you:

First off, for the particle sizes of windblown dust you're going to be looking at sieves might not be what you're looking for. I'd definitely suggest the use of a hydrometer set up. Use the sieves to take off the coarsest fractions, and then a hydrometer for the rest.

The next thing you'll need to think about is methods of collection, and establish a repeatable protocol for sampling. For the surface dust you don't have a problem, but for the windborne stuff you could. Remember that shales and the sediments that comprise them are approximately 75% of the sedimentary rocks in the overall geologic column exposed at the surface in the world. Study of shales and comparisons that can be made with other playas that have evaporite minerals. For the dust collection, get from your geology library a book that was edited by Bruce Purser some time back, a scientific work entitled "The Persian Gulf". In it, you'll find an article by some Iranian scientists named Kukal and Sadallah who talk about doing something very similar to what you're going to do and the results they got.

Don't forget to characterize the presumed source rocks at the surface, too. We spoke of halloysite that MAY have come from the Tertiary-aged rock units in the area, and montmorillonite that may have also. Also, since halloysite is dehydrated kaolinite, think about kaolinite formed in the playa sediments,too. The source for this may have been also the granites in the area in the Granite Range. Gypsum from the Selenite range. Another question - is there any anhydrite (dehydrated gypsum) out there?

Your chemistry is best accomplished with an inductively-coupled plasma atomic absorption mass spectrophotometer. Energy dispersive X-rays added on to SEM photomicrography will nail the clay minerals.

Put it all into spreadsheets, make your comparisons, answer what questions you've started with (if it's possible) and then ask yourself (as any good scientist should) what other things do you know or need to know about the area, and mention what questions you still have and possible avenues to pursue.

And if you're interested, there's always a Masters' thesis for you somewhere.
I wish you the BEST of luck. And I'll share any further analyses I get here.

Work for you?

^Rhino!

[Bob]

Please define "shale" in a Black Rock Desert context.

[bm_cricket]

^Rhino,

I am pretty pleased with UC Santa Cruz too! I'm not sure if it belongs on the top of the heap but it's definitely a great program at a wonderful community.

Thanks for the suggestions. I'm trying to make the sampling as simple and repeatable as I can. I think that if I really do this I'll probably also look into the sampling done over the years on Owens Lake. I could try to compare the composition of the air born dust between the two sites. Owens Valley has a problem with arsenic, among other things, in it's dust. I wonder how Black Rock compares.

I will look into the the book/author you mentioned. Could it possibly be this? http://www.amazon.com/exec/obidos/tg/de ... 0412734907 We have a copy of that but not of the book "The Persian Gulf" but that name seems to bring up a text from the 1980s that relates to geology. It seems to only be available on Ebay....

I think that Monday I'll stop by the person most likely to accept letting me on this sort of project. He's a fossil guy but I think Sed/Strat is up his alley. I'll see what he has to say and if he has any suggestions.

I think that working out the chemistry of the actual playa dust will be possible. I know we have a few different pieces of equipment that could be employed by a lowly undergrad. Making broader relationships to interpret a source is probably beyond my ability or resources but you are right, I should at least discuss what is already known. I think of this as a good excuse to spend more time on the playa while "giving" to the community. Everyone seems to wonder what they are breathing. Maybe I can answer that question? I just hope I don't find anything that's really, truly bad for us!!

Thanks for the heads up on all this and I'll look forward to any info you can throw my way. Naturally I'll let you know how this all pans out.

[bm_cricket]

Please define "shale" in a Black Rock Desert context.

I'm going to assume "shale" in this context to mean what the playa will be in a few million years. Clays are basically the makings for one sort or another of shale. It's just a question of particle size, temperature, pressure, and time. Time, to a geologist, is something of an odd thing. I guess that's what drew me to studying it in the first place. You need to have an eye for seeing everything as what was and what will be. It's all the same mess when you get down to it.

[Bob]

Funny how clay magically turns into shale when you hire a geologist.

[bm_cricket]

Funny how clay magically turns into shale when you hire a geologist.

Geologists aren't the only ones. I've had doctors turn "sprained ankle" into a 8 word, 32 syllable mess.

[theCryptofishist]

Funny how clay magically turns into shale when you hire a geologist.

Geologists aren't the only ones. I've had doctors turn "sprained ankle" into a 8 word, 32 syllable mess. :shock:

You should see what they did with my ankles.

[bm_cricket]

Funny how clay magically turns into shale when you hire a geologist.

Geologists aren't the only ones. I've had doctors turn "sprained ankle" into a 8 word, 32 syllable mess.

You should see what they did with my ankles.

Mine too. March 23th I had an FDL/FHL transfer with FDL reconstruction, calcaneous osteotomy, and a hardware extraction from a previous botched surgery. Ain't modern medicine great?!

[Snow]

Shale wah?

[bm_cricket]

Shale wah?

Best guess I can think of. Was I way off?

[Snow]

No you were right on, I'm just not sure what Rhino was talking about. I assume he meant what you said? Shale would require lithification. There are some lacustrine shales around reno-ish, not sure about black rock.

This site SUCKS to search but it has some really good stuff for nevada, reports, maps and more. Near the bottom are preliminary geologic maps.
http://www.nbmg.unr.edu/dox/dox.htm

This was all that I saw for Gerlach or the general area. I haven't even looked at it yet. I'm going to check the main site and see if they might have added a search function. http://www.nbmg.unr.edu/dox/of8503.pdf

[ygmir]

that German, electric, whatever it is group, (Kvon, et al),has been looking into what the playa is made of?..........

[bm_cricket]

that German, electric, whatever it is group, (Kvon, et al),has been looking into what the playa is made of?..........

Do you mean the Ein Hammer people?

[Snow]

I would also think that the source rocks for the silts and clays of the playa sediments (and dust?) would encompass much more than just the surrounding units. Much of the fine sediments would have been brought into the lake via stream flow (with an upstream source rock) and also to a much lesser degree transported via currents. Lahontan covered a very large area and very fine sediments may have been transported a suprisingly far distance. There is evidence in Lahontan and most NV pluvial lakes for currents.

[ygmir]

that German, electric, whatever it is group, (Kvon, et al),has been looking into what the playa is made of?..........

Do you mean the Ein Hammer people?

Power to the playa, from Germany.......
http://eplaya.burningman.com/viewtopic.php?t=32690&highlight=

[Snow]

No he means that German company wanting to do a test out there. I do not think they will be very forthcoming with thier data (I think they did get some samples), they seem to want to remain shrouded in a viel of secrecy. I offered to help them with BLM permits they may need as I have quite a bit of experience in this area. I got them in touch with the right state and fed people and they contacted them themselves. Completely leaving me out of the technical loop. I was quite dissapointed as I am quite intersted in what they are trying to do. I'm sure I will get a first hand look at what they are up to since I'm part of the Ein Hammer project. They aren't even really cluing us in on their technology, but we are told we will be recieving some kind of power recievers on the playa, they did NOT want us to get one before hand. I'm intrigued.

[bm_cricket]

No he means that German company wanting to do a test out there. I do not think they will be very forthcoming with thier data (I think they did get some samples), they seem to want to remain shrouded in a viel of secrecy. I offered to help them with BLM permits they may need as I have quite a bit of experience in this area. I got them in touch with the right state and fed people and they contacted them themselves. Completely leaving me out of the technical loop. I was quite dissapointed as I am quite intersted in what they are trying to do. I'm sure I will get a first hand look at what they are up to since I'm part of the Ein Hammer project. They aren't even really cluing us in on their technology, but we are told we will be recieving some kind of power recievers on the playa, they did NOT want us to get one before hand. I'm intrigued.

Sounds paranoid and weird. Maybe somebody's trying to build a tesla style wireless power? http://blog.ted.com/2009/08/wireless_electr.php

I look forward to seeing what the playa is like this summer.