Look at the photos below and what mineral comes to mind? Amethyst? Fluorite? Perhaps something Li-bearing? Lepidolite? Nope. It’s none of these.
In fact the masses above are a large aggregation of very small hexagonite crystals. Hexagonite? Yes, hexagonite – a Mn-rich variety of tremolite, in this case originating in the Adirondack lowlands near Balmat, New York.
Sexy enough for you? Well, at the very least, it’s “hexy” enough for me.
Just a heads up for any of you following this blog or using any of the other webpages on my outcrop.org domains, that these websites will be out of commission for a couple of days while I move the servers to a new location. I hope to be back up and running by the weekend, but at this time I cannot make any guarantees. With any luck this will amount to simply a diastem and not an angular unconformity, but only time will tell.
I’m sure there are many rocks I wish I’d picked up, certainly rocks I wish I’d taken larger samples of, and (especially now that I’m moving out of my office) more than a few I wish I’d taken better field notes about. And like many of the others who made the deadline, I greatly regret not taking many more photos (particularly since the dawn of the age of digital photography). For most of these regrets, though, there is a silver lining – a reason to go back and revisit the localities and collect more, and photograph more, and learn even more about the geology.
But when it comes right down to it, the thing that I genuinely miss the most, because I left it behind in the field, is my very first Estwing Rock Hammer. I didn’t mean to leave it behind, of course. Sadly, I don’t think I even have it’s picture to share with you. I got this hammer at the beginning of Colgate’s 6-week geology summer field camp as part of our standard field gear (along with an acid bottle, orange field book, and Silva Ranger compass). It served me well for the six weeks of camp, exposing the fresh innards of rocks and the cold innards of beer cans alike. And it came with me to Giant Mountain in the Adirondacks where I participated in my first geological field work for research, helping me liberate samples of the Roaring Brook intrusion breccia from the glacially polished banks of that cold mountain stream. But alas, somewhere in the bushes alongside that babbling brook it slipped out of my improvised rope belt and made itself a permanent resident of the Adirondacks. I suppose I can take a modicum of comfort knowing it will rust out its final days in the field, along with some of the nicest companions Nature has to offer.
Felix Bossert’s WoGE #298 was just oozing with the hues of the Sahara Desert. Since I’d previously posted WoGE #66 not too far away (as it turns out) and I’ve contemplated posting other WoGEs from this spectacular region, my search took on a fiercer urgency than I’ve felt in some time. Sometimes I really enjoy the flat out frantic academic sprint that searching for a WoGE without the Schott Rule can be.
And since I enjoyed it so much, I’ll return the favor and not invoke the Schott Rule for WoGE #299. That means it’s going to be a fanatic dash to see who can identify the latitude and longitude of the locality below and explain its geologic significance for the honor of hosting WoGE #300. On your marks… get set… Go!
For Accretionary Wedge #35 Evelyn Mervine asks “What’s your favorite geology word?” This is a tricky one, because there are so many great geology words – I’m seriously tempted to start flipping through the Glossary of Geology to avoid missing some great word that I’ve forgotten or never used, but I literally fear being sucked into an hours or days long sinkhole that would expand my vocabulary, but ultimately lead to frustration and gnashing of teeth at the plethora of possibilities.
Of course, one of the challenges in choosing a word for this Accretionary Wedge is trying to find one that is both interesting and not likely to be chosen by someone else. The most straightforward way to fulfill these requirements is to pick a word close to your own specialty, perhaps even one that figures into the title of your cleverly namedgeoblog. Since I named my blog in a decidedly (geologically) unclever way I’ve got no help there. My web domain “outcrop.org” was chosen with a definite nod to the place I’d rather be, but is it really my favorite word? I don’t think so. Part of my Ph.D. research involved geochronology, though its now over a decade since I’ve worked on that. Zircon? Xenotime? I like them, but they’re not my favorite words. One of the other aspects of my Ph.D. research was tectonics. During a Penrose Conference in the southern Sierras, while discussing the possibility of tectonic erosion (specifically subduction erosion) removing the larger mass of a geologic body, but leaving behind just the “head”, a colleague coined the wonderful term “decorpitation” (think decapitation, but from the head’s perspective) to describe this event. Unfortunately, I don’t think decorpitation has made it into the literature so I’m a little hesitant to make it my choice. Besides, these days I think of myself as a geology generalist, so choosing a word on the basis of a geologic specialty has less appeal to me.
There is also the strategy of choosing a word for its humor value as a word. The classic geologic word in this category is cactolith, defined by the venerable Charles Hunt as “a quasihorizontal chonolith composed of anastomosing ductoliths whose distal ends curl like a harpolith, thin like a sphenolith, or bulge discordantly like an akmolith or ethmolith.” Yes, it’s a real word, describing a real geologic feature, published in a real scientific report, but let’s face it, its the definition more than the word itself that’s the source of the humor. (Oh, to have been drunk around the campfire with Hunt and field crew in the Henry Mountains when they came up with that one!) Another word that I gave strong consideration to comes from my undergrad advisor, Art Goldstein’s Ph.D. field area. He worked on the Lake Char Fault in eastern Massachusetts. Lake Char is an abbreviation, however. The full name for the lake is Lake Chargoggagoggmanchauggagoggchaubunagungamaugg (spellings, as you might imagine, vary somewhat), and therefore that is the more complete name for the fault, too. (As a bonus of being Art’s advisee, I had the honor of learning to pronounce this monster – ask me sometime when you see me at a meeting.) While it’s definitely a winning word and a favorite, it’s really Art’s word, not mine.
That last example got me thinking along a slightly different line. What about choosing a favorite geologic word that described not a geologic process or general type of geologic material or landform, but rather a specific example? For example, the word Grímsvötn has a certain appeal to me both as a specific volcano and for the sound of the word itself – or more accurately, what I think the word itself sounds like. The fact is I can’t be sure how to pronounce any Icelandic word – I’d love to learn, but it’s just not in my native DNA. But that brings me to another volcano that I’ve always loved the name of: Tavurvur. I love the fact that it’s a very active volcano, part of an active caldera complex, a previous WoGE locality (where I foreshadowed my affinity for its name), but most of all I love just the sound of the word Tavurvur. And that’s good enough reason for me to name Tavurvur as my favorite geology word.
Towards the end of the spring semester I usually begin plotting all the great things that I want to get done once summer starts and the luxury of unscheduled time (not precisely vacation, in this case, but something very much like it) is at hand. I even hinted at this in a tweet at the beginning of the month, but alas, just as I was beginning to see the light of summer at the end of grading finals, another rather important appointment placed itself on my calendar and postponed the unscheduled bliss just a bit longer. So before I get to tilting at summer windmills, I figured I’d chronicle a few bits and pieces from the trip east and back to the high plains that occupied my past two weeks. Mainly, this post serves to force me to upload and share some of the electronic media I captured along the way, before it dissapears into the dustbin of my Drobo.
The business end of my trip occupied the first couple of days. I’ll spare you the details for now, but suffice it to say it ended up with an enjoyable meetup with @callanbentley at his academic home in northern Virginia. After that, I took a couple of days to visit my parents in northeast New Jersey. They wasted no time in getting my out-of-shape butt walking through some of the parks of my childhood. I captured one of these walks through Van Saun Park on my Droid. I know this technology has been available via dedicated GPS receivers for a while, but having it on the phone makes the phone the equivalent of a Swiss army knife; I’m definitely going to look into working this into future hikes. I love being able to capture something like this with technology – almost enough to motivate me to exercise more often… almost. Alas, we didn’t get to ride the train at Van Saun – I guess I’ll have to plan that into my next trip home to NJ.
After brief visits to both of my sisters places I proceed on a bit of a southern detour on my way back to Hays, KS. The first real geological stop on my way back was a visit to the Sideling Hill roadcut on I-68 in western Maryland. I got rather fortunate with the weather, catching the cut on one of the few relatively sunny mornings on this trip.
The first view is from the bench at the end of the paved trail. The gate there was locked so it was impossible to go further along the bench. Also, it was disappointing that the interpretive visitor center at the cut was closed – budgetary issues?
It’s hard to imagine a more “textbook” syncline. My only regret is that there’s no way to really get a GigaPan unit out to the optimal viewpoint to capture an on-axis view.
After a brief visit to a friend in southwest Virginia I continued southwest along the spine of the Appalachians. This leg of the trip brought me into some virgin territory (for me) – beginning with a first visit to Alabama, where I was greeted by a chorus of cicadas that practically drowned out the thunder of a nearby thunderstorm. Sound incredible? I pulled out the handy voice recorder and recorded about a minute of it – listen for yourself – if you listen carefully you can hear the swelling and ebbing of the cicadas (of at least two different types), cars on the interstate, and thunder. Otherworldly!
I was hoping to find a spot near Tuscaloosa, AL to GigaPan the tornado damage from last month, but though I saw some definite signs of wind damage, it appears the tornado paths didn’t cross I-59. (In fact, I had passed up stopping earlier in the day near Pulaski, VA for what was some very clear tornado damage visible from I-81.) Nonetheless, tornadoes fall outside the scope of what I usually teach about in geology classes, so I pressed on for Mississippi and the real goal of this “detour” – the flooding lower Mississippi River. (At the same time I was looking to GigaPan some tornado damage, my southern route was also keeping me clear of one of the more deadly tornado outbreaks this year.) By the time I’d finished the trip I’d added three of the five remaining US states that I hadn’t previously visited (AL, MS, LA) – all that I have left are North Dakota and Alaska.
Last Monday I arrived at my goal. I crossed the Mississippi at Baton Rouge, Louisiana and thence turned north to seek out the two great diversionary structures along the western mainline levee of the Mississippi at Morganza and Old River. Already at the bridge at Baton Rouge it was obvious that the Mississippi was at a high flood stage, but wow nothing quite prepares you for climbing up atop the levee just north of Morganza and seeing just how high the water is on the Mississippi side. Not that the water was especially low in the Morganza spillway, which by this time had been flooding for over a week.
US Army Corps of Engineers, State of the Lower Mississippi & Distributaries, May 23, 2011
Below is the video I shot as I drove along the crest of the Morganza Control Structure. I had hoped to be able to shoot a GigaPan of the structure, but as you’ll see, there was absolutely no place to pull over to set up and shoot one. I’m still pretty new at shooting video, and I wish I had cleared the dashboard of objects that reflect in the windshield (the shiny object is the Droid dock, in case you’re wondering). I also wish I had narrated my thoughts as I drove along – all you hear from me is a muttered “holy crap” as I get a good look at the discharge passing through the structure.
Of course, as a great fan of John McPhee‘s The Control of Nature, the highlight of this journey was crossing over the Old River Control Structure during the height of a flood comparable to the 1973 flood he described in Atchafalaya. Suffice it to say that the Army Corps of Engineers was considerably better prepared for the 2011 flood than the 1973 flood. That in no way lessens the impact of the current flood. There’s a huge amount of water in the Mississippi and the Atchafalaya remains poised to capture it if (or more likely in the long tern, when) the western levees or one of the control structures fails.
It’s hard to get across in pictures and words just how impressive it is to stand atop the mainline levee and see the Mississippi within a few feet of its crest, moving fast on one side, and cropland sitting some 20 feet lower and dry at the base of the levee on the opposite side. The 360 degree GigaPan below is my best effort to simulate this for you, but even with all the detail therein it’s hard to translate the impact of seeing it firsthand.
On the recommendation of Steve Gough, my next stop was Vicksburg, Mississippi. Vicksburg is one of the few places along the lower Mississippi where one can get real elevation above the river. Unfortunately even this does not get across the full extend of the flooding – only aerial or space views really seem to capture that well. I was also plagued by clouds and failing batteries, thus the GigaPan that was intended to look like this:
I, for one, am not displeased to see that the pace of recent Where on Google Earth challenge solutions has once again returned to something resembling normalcy. I’m just back from about two weeks travelling and once my own routine returned to some semblance of normalcy I was pleased to find that Péter Luffi’s WoGE #287 was waiting patiently to be solved. And solve it I did, though it took an hour or two of searching to polish off the rust that had built up while I was away. It’s good to be able to get the old blogging juices flowing in the traditional manner…
As always, it’s hard to guess whether my new locality will be easy to find or whether it will prove to be a needle in a haystack. In any case, I’m not putting any restrictions on those who wish to find it (no Schott Rule). Seek the spot in Google Earth, and when you’ve found it you can claim the right to post WoGE #289 on your own Geoblog by commenting below with the locality (latitude and longitude, please) and a brief description of the geologic origin and significance (if any) of the landforms seen in the image below.
… and since a river evidently runs through this challenge, I’ll wish you “Happy Fishing”!
[Hint added 6/3/11: In order to aid the weekend warriors who are willing to don their waders and seek out this river I think it’d be in order to offer an obtuse hint as to the location of WoGE #288. After all, this is meant to be a fishing expedition, not a wild goose chase.
So here it is: The location of WoGE #288 is closer to a different ocean than this river ultimately drains into. (So for example, the headwaters of the Amazon are generally closer to the Pacific Ocean than the Atlantic Ocean, thus would qualify.) Obtuse enough for you?]
[Final hint added 6/10/11: The first European to fish here was Dr. Livingstone, I presume.]
Since Dana asked so nicely (and persistently), I suppose I oughta break my blogging silence and contribute to Accretionary Wedge #34.
I refuse to find much “weird” about geology – the scientist in me cringes a bit every time someone describes a natural phenomenon as “crazy” – but there is one geologic phenomenon that does come to mind when the term “weird” is in play: quicksand. My first introduction to the phenomena came in my early childhood watching reruns of the Lone Ranger (the episode is “Quicksand”, Season 5, Episode 8). Sadly, I can’t find even a decent episode summary online, but the power of the phenomena was visual anyhow. It appears the studios haven’t gotten around to making this particular episode available, so I can’t relive my horror. Let me assure you, it was a traumatic introduction to discover that not all terra is firma, and it made a lasting impression.
Since then my encounters with quicksand have been few and far between. I recall a picture in the great 1960′s editions “America’s National Parks” from National Geographic of a hiker knee deep in quicksand in Zion National Park, being pulled out by his companions. That proved to me that this wasn’t just some movie/TV plot device, but a real geologic phenomenon. (Evidently hikers still do encounter quicksand hiking at Zion.) After that, I encountered Henri Charrière’s description (probably exaggerated) of killer quicksand on the South American coast in his novel Papillon. And there’s the moment in Lawrence of Arabia where Daud cashes it in. Of course, over the years I’ve learned plenty about how to save yourself if you ever do encounter real quicksand (movie quicksand being all but inescapable), but I’ve never had the opportunity to put it into action.
I understand the basic physics of thixotropy, and have certainly experienced the related phenomena of beach sands and certain muds that liquify when shaken, but none of these strike me as being genuine quicksand in the traditional sense of the phenomena. I suppose this is just one of those weird geologic phenomena that I’ll have to keep exploring to discover firsthand.
It’s been a quiet semester in Lake Wobegon… very quiet, as far as this blog goes. My inability to win “Where on (Google) Earth?” challenges has been no small part of the reason for that. There was a time when I could count on winning WoGEs to make up for a shortfall in my geoblogging, but it seems with the sharp new crowd of WoGErs and my seemingly interminable Schott Rule waiting period – now over 48 hours – it’s becoming harder and harder to cover my geoblogging defecit.
Fortunately last week Felix stumped the competition long enough for me to take a crack at a WoGE again and for a change I was able to distinguish his Damaran delicacy before my brethern had a chance to beat me to yet another. To repay all of these new WoGE experts, I’m sending you all to Davy Jones Locker to search for WoGE #283. I can’t begin to guess how quickly this one will be solved, but I’ll take a chance and NOT invoke the Schott Rule this time around. Thus, the first person to correctly identify the locality (latitude and longitude, please) of the seafloor below and to explain its geological significance will have the honor of hosting WoGE #284 on their own little home in the geoblogosphere.
It didn’t take me too long to find Cole Kingsbury‘s WoGE #260 on Alaska’s Seward Peninsula, but it turns out my thermokarst explanation of the geology was all wet. The lakes were, in fact, formed by two marvelous maars – though there was no real hint of that in the Google Earth imagery or layer data.
In order to dry off I’m choosing a location in a slightly warmer part of the world. And because everyone is too good at finding ye olde map view – as evidenced by the veritable Nantucket sleighride of WoGEs over the past three months – I’m going to try to mix things up a bit by offering an oblique view with some tasty geology. I don’t expect to bring things to a grinding halt with this scene, but I will attempt to slow down the regulars by invoking the Schott Rule. (Post time: 1/30/10, 21:25 USA CST – 1/31/10, 03:25 GMT).
Your mission, should you choose to accept it, is to identify the location (preferably by latitude and longitude) of the scene above. Then, to the best of your ability, describe the geologic significance of the scene. And let me tell you, there’s plenty of great geology to see here. (Somebody would absolutely make my day by breaking out Photoshop and annotating geologic units and relationships of the scene – after you’ve posted your ID of the location, of course). And winners take note: Don’t forget to post the URL of each new WoGE in the comments of the previous one as soon as its posted – some of you have been slacking recently.
If this view proves too challenging I’ll provide a map view in a few days. The clock is ticking…