Distinguishing deposits from andesitic eruptions

Telling apart different kinds of deposits associated with volcanic eruptions isn't always easy. There are a lot of factors that can affect their appearance: the location and type of eruption, the magma/lava type, where they're emplaced, etc. On Montserrat, volcanologists are lucky to have both ancient and modern deposits; they can look at what's currently being erupted and compare it to the older volcanics on the island. We did quite a bit of this on our field trip, and one of our assignments was to summarize the characteristics of andesitic eruption deposits on Montserrat. (I emphasized that because the characteristics we saw are not necessarily going to be the same for all volcanic eruptions, or even for all andesitic eruptions. I've tried to generalize a bit, but apply these cautiously if you're going into the field to look at other volcanic deposits; things may look very different in your field area.)

Block and ash flows are a kind of pyroclastic density current. "Pyroclastic flow" is a kind of catchall term, but there are more specific ones that better describe the makeup of one of these currents. "Block and ash flow" implies that the flow is composed of blocks (either of denser lava or pumice or both) and ash; "pumice flow" means that the contents are mainly pumice and ash, "ash flow" that there are few blocks and mostly ash in the current.

Faint reverse grading in a block and ash flow deposit at Old Road Bay

Block and ash flows contain a range of clast sizes from mm-sized ash to m-scale boulders. The clasts are usually somewhat angular and tend to be a combination of lithics (lava) and pumice. The matrix of these deposits (what larger clasts are embedded in) is generally ashy and may be crystal-rich. The deposit may be clast or matrix supported (which describes whether there is enough matrix that the clasts are not touching) and poorly sorted (clasts are not separated by size). Oxidation and alteration of clasts as well as fractured blocks (including radially jointed clasts) may occur if the flow is deposited into water and cools quickly. Sometimes you can see grading in the deposits (i.e., a change from small to large clasts, or the reverse), which has to do with the energy of the pyroclastic current and the conditions under which clasts are being deposited from it.

Pointing out matrix in a deposit on the side of the Belham River Valley

Debris avalanches form from older volcanic material that's unstable enough to collapse, either because of erosion or alteration or both. They form "hummocky" deposits that are very obvious in aerial photos, but in cross section they're also fairly easy to identify.

Panorama of a debris avalanche deposit near Jack Boy Hill. Different colors mark chunks of preserved stratigraphy.

Debris avalanche deposits contain mm to m sized clasts (or larger), as well as chunks of material from older deposits that retain their original stratigraphy. These clasts and chunks are poorly sorted, and rounded to angular in shape. Clast compositions are almost always mixed, and the matrix is often clayey and highly altered. Jigsaw jointing is apparent in individual clasts, with clast fragments separated by matrix material but orientation with respect to neighboring clasts preserved. Clasts or deposit blocks may be "smeared" out into trains or show internal faulting.

A "jigsaw" fractured block in a debris avalanche deposit

Lahars form when water mixes with volcanic material and flows downslope. These can have the consistency of soup to concrete, and they're a major concern even when a volcano isn't erupting (especially if the volcano is located in a tropical area that gets lots of rain.)

House buried in lahar deposits in the Belham River Valley

Clasts in a lahar deposit range from mm to multi-meter size. They are matrix supported, poorly sorted, and often contain clay or silt in the matrix. The clast shapes vary from rounded to angular and may be either monolithologic (all one rock type) or mixed rock types, depending on the source material. Sometimes the deposits show bedding features such as cross-bedding. There is one absolutely diagnostic feature for lahars: preserved voids where bubbles of air were trapped in the matrix mud. The voids are spherical and usually pretty tiny, but they don't form in pyroclastic currents. (The lack of these voids does not, however, mean that a deposit is not a lahar, so this feature is only useful if it's present.)

Cross-section of a fairly recent lahar deposit. There's not much in the way of sorting or grading here.

A fourth type of pyroclastic current, called a surge, also shows up on Montserrat, but they're not often preserved because they consist of a blast of ash and hot gases (sometimes derived from block and ash flows), and they leave very thin deposits. I don't have any good photos of them, but they tend to be fine-grained (mm to cm sized clasts at the most), and sometimes show cross-stratification. It's rare that they're preserved, especially in a tropical environment, because the fine material washes away very easily.

Little Rock City

Long time, no writing! I hate dropping the ball, but schoolwork has to come first. Anyway, I spent part of this weekend exploring the geology of Western New York - specifically, south of Buffalo in Cattaraugus County.

Cattaraugus County moves away from the carbonate sequences that you see around Buffalo and into Late Devonian sandstones and shales. On the map to the left, they're shown in a sort of pistachio green, while the limestones that I live on are in dark green. (You can find a copy of this map on the UB Library's map collection website - the resolution isn't great, but it's a pretty general map to begin with.)

The weekend was a combination geology and beer-and-wine-tasting trip, but Saturday was a lovely day for hiking, so we went for a visit to Rock City State Forest (roughly near the red arrow on the map). Cattaraugus County has a number of "rock cities" - places where the Salamanca conglomerate caps hills and breaks up into large blocks along joints. According to a K/H Geology Field Guide series book on Upstate New York, "where the rock cites occur, a conglomerate ledge forms a level, ribbon-like outcrop that follows the contour of the hill for a way and then seems to just fade out."

The rock cities are really fun, and look to be prime bouldering locations; the cracks between the blocks are anywhere from inches to feet wide, so there are lots of alleys and cracks to explore.

The conglomerate is really cool; it has some beautiful cross-bedding, normal and reverse grading sequences, and imbrication in the flat pebbles that make up the largest clasts. The pebbles are mostly white quartz or quartzite, but every so often there are little bits of shale.

I'm too out of practice to be bouldering without a spotter and the right shoes, but the crack climbing was just fine for some of the folks on the trip...

The conglomerate retains water very well - I guess you could consider the blocks "perched aquifers". There are little dripping springs all over the sides of the blocks, and the water tends to pool at the bases. It makes for muddy hiking, but somebody went to the trouble of putting down wooden walkways in some spots.

Luckily, it was a nice day for hiking; it's all too easy to get so caught up in the research part of geology that you forget to go out into the field. (The crazy weather up here right now also helped; we should probably be getting snow at this point, but it was warm enough yesterday to go outside in short sleeves! I'm betting this means we're going to get dumped on this winter.)

I'd recommend a visit to anyone who's in the WNY area; this is a small but probably underappreciated park that many people would probably overlook in favor of the larger parks (or the ski areas, which I'm sure are lovely when they have some snow...)

Accretionary Wedge #21: Earth Science Outreach

Happy Halloween! I hope you all are having a fun day of candy-and-costume-filled spookiness. And speaking of playing different roles, Earth scientists wear one hat in particular that's very important: the Outreach Hat!

That's why the subject of this month's Accretionary Wedge was Earth Science Outreach. This October has been a big month for Earth science: we've had Earth Science Week (a yearly event), a national Geological Society of America meeting in Portland, OR, and a DonorsChoose challenge on ScienceBlogs (Geobloggers Giving Kids the Earth), sponsored by geobloggers Kim Hannula, Anne Jefferson, and Erik Klemetti.

But individual Earth scientists do just as much to show others why our work is important. Read on to find out what!

To start with something I've already mentioned, we have Earth Science Week, a campaign for Earth science awareness and education that's been run by the American Geological Institute for more than a decade now. Silver Fox of Looking For Detachment wrote about some Earth Science Week activities in Nevada this year, and has plans to get even more involved next year. I've had some experience with Earth Science Week myself - before I started grad school, I worked for AGI for a year as their Outreach and Education Assistant. Part of my job was to help run the Earth Science Week program, so I'll admit I'm a bit of a biased advocate. But one of my favorite parts of the job was getting to visit classrooms and talk about what it's like to be a geologist; the photo at left is from one of those visits to my old elementary school in Virginia, where I'm trying to convince the students that scientists spend a lot of time writing. (I hope they believed me!)

Geobloggers spend time in (and out) of other people's schools as well as their own. Dr. Ian Stimpson (AKA Hypocentre) at Hypo-theses has written a lot about his Seismology for Schools project in the UK, which is is "coordinated by the British Geological Survey (BGS) and involves the donation of seismometers to schools to help promote geology and geophysics in the classroom". This is a great way to get students (and their teachers) directly involved in geoscience research - and who doesn't like to jump up and down next to a seismometer once in a while? (The US has a similar program run through Incorporated Research Institutions for Seismology [IRIS]). Garry Hayes of Geotripper writes about his own experiences with a program at Modesto Junior College called Science Educational Encounters for Kids, where local fifth graders visit the campus every Friday to get "an experience in science. Budget cuts in school systems across the country have made it difficult for teachers to give their students even a basic introduction to the sciences, and volunteering is a great way to make sure that students don't go through school without the tools to understand their world. Florian Jenn of EffJot has posted about a similar program being run by the Brandenburg Technological University in Germany, where the Environmental Geology department holds practical courses for secondary school students. FJ's students have done some projects in environmental geochemistry and hydrology - have a look!

Earth science outreach happens outside of a school setting as well, whether it's through a visit to a museum, field trips, short courses, or teaching others to teach geoscience. Pascal of Research at a snail's pace spent time trying to make the University of Wisconsin Geology Museum - and specifically its Burgess Shale exhibit - a little easier to visualize. (A good thing, since most of them were so hard to figure out that they got stuck in a genus called Hallucigenia!) Over at Geology Happens, we get to hear about opportunities for K-12 teachers and students to explore the Colorado Plateau. Since the Colorado Plateau was where I had my first real introduction to field work, I totally agree with the closing comment in that post: "You can't beat walking the mountains with a bunch of kids and just let the rocks tell their story." Lockwood of Outside The Interzone agrees - he's been leading field trips for years! I've heard over and over that the way many people get hooked on the Earth sciences is through field trips - there's just nothing to beat the sensory and intellectual experience you get in the field.

Finally, it's important to remember that Earth science outreach isn't just about showing people how wonderful the geosciences are - it's about providing opportunities to those who wouldn't necessarily have them. There are schools all over this country (and others) where teachers are incredibly dedicated to their students' education, but just don't have the means to teach them about science. Good tools aren't cheap, as anyone who's ever swung a rock hammer will know. That's why the ScienceBlogs Donors Choose Challenge was such a hot topic this month. Kim Hannula of All of My Faults Are Stress Related was part of the team who sponsored a challenge for geobloggers and their readers, with the goal of funding geoscience-related projects for classrooms in need. And it was a resounding success! Kim's post says it all: "October's over tomorrow, and the geobloggers' challenge has raised more money than any other challenge here at Science Blogs. $8,288. 40 donors. 1218 students reached. Last week, I had to go searching for new geoscience-related projects to support, because so many of the original projects had already been completely funded." Bravo, geobloggers! And remember, just because the ScienceBlogs Challenge is over doesn't mean the projects still don't need funding - go check out the geobloggers page and see who still needs help!

Thanks for everyone who contributed to this month's Accretionary Wedge - and thank you again for all the Earth science outreach you do, no matter how you do it! (Even through blogging...) As always, if you've got a late contribution or I've missed anything, leave a link and I'll add you on.

There's still no one hosting the Wedge for November, so if you have an idea, leave a comment at Who's hosting the next Accretionary Wedge? (and step up and volunteer some more, if you feel like it!)

The "Breached Dam Overlook" Field Trip at GSA: perspectives from a participant

Apparently my post on the Steve Austin field trip at GSA caught the attention of quite a few people, although it was already an issue that had come to the attention of the GSA field trip organizers. I chose not to go on the trip myself (for monetary and scheduling reasons, mostly) but have heard from one geoblogger who did (Pascal of Research at a Snail's Pace). He has kindly allowed me to repost his thoughts and observations on the trip, and I've included them below. He has also written several additional posts on the subject, with some thoughts on some interesting talks and posters that popped up at the meeting; you can read the whole collection here:

Part 1
Part 2
Part 3
Part 4
Part 5

And now, for those of you who wanted to see how the field trip actually turned out, on to the trip summary:

Introduction

"First, let me talk about what this post is not:
It is not a discussion of Dr. Steven Austin's character as a person. In fact, I found him to be very cheerful and enthusiastic despite the poor weather. The same could be said of all the people on the trip; people were generally quite upbeat and positive even if our boots still have not dried out completely.

"It is not a discussion/rant about religion - I find the parts of religious teachings that say we should be nicer to each other rather spiffy. There are plenty of other places to attempt some kind of cost/benefit analysis of belief/non-belief in any particular deity.

"My intention with this post is to describe the trip in terms of how it was laid out, where we went, what we saw, and what was said by the trip leaders as it pertained to the field trip. I will save posts related to implications of the trip and discussion of some of the abstracts submitted by other authors who were on the trip for the future."

The Trip

"We boarded the bus at the convention center and started up I-5 towards MSH. Along the way, Steven described the general purpose for the trip and handed out a reprint of the Guidebook [published as part of the GSA meeting field trip guidebook - more on this later]. It appeared that at least half of the people on the trip were familiar with the leader or co-leaders [I am still not sure how many actual "co-leaders" there were - at least four]. One of my friends from grad school was also on the trip, but I did not know any one else aside from the background research I had done to familiarize myself with the writings of those involved in planning the trip.

"While we were making our way north, Steven described scuba diving in Spirit Lake, some of the work he had done for his dissertation at Penn State, and mentioned several times how the people attending this trip could learn from it and lead their own tours in the future. He described the eruption as a seven or eight step sequence of events from initial quake and landslide, to steam explosion and ashfall, finally ending with the breach of the new spirit lake and rapid outlet of the Toutle River once it overtopped the debris damming the valley two years later. A great deal of emphasis was put on the time of each event and the quantity of material removed from the mountain and depth of erosion from the Toutle River. Oddly, he described the basal movement of the mountain side as "laminar flow."

"He spent some time describing "long-runout landslides" and the various mechanisms by which they can travel [there was nothing that seemed obviously wrong with his summary of primary concepts - although I have not double checked his reference yet]. He also spent some time describing hyperconcentrated mudflows along the Cowlitz River, which he described as turbulent, making bedforms. Traditional mudflows, he stated, had laminar flow and left massive, lacking bedforms/structures [which was confusing, since turbulence is largely a function of flow thickness, velocity, and bed interference, and even laminar flow can form sedimentary structures].

"He made some comment about these landforms being a result of "self-organized criticality," but I'm still not sure to what he was exactly referring [the eruption, the landslide, the breaching of the dammed material?] We got out at JRO to spend some time in the center to look at the displays and look at the [really cool] topographic model of the area with fiber optic lights to show the extent and pattern of eruptive events on the mountain. [I should really talk about JRO and MSH itself in a separate post].

"The group was split into groups of four [to help ease congestion on the trail and stops]. We then proceeded to wind our way down Truman Trail and into the valley. That's when it started to rain. Not a sprinkle or even a simple cloudburst, but sideways and nonstop for about four hours. This driving rain forced the trip leaders to postpone the first stop (on the ridge) to the return trip, so we continued on our trip. Down into the debris field, with Spirit Lake visible to the East, and the base of MSH occasionally visible. However, we didn't have much opportunity to gaze at the vista, since it was raining so hard [very few photos, either, since I wanted to keep my lenses dry for a while].

"We continued down the trail, eventually reaching the bottom of the valley, where we veered off the trail and toward the new channel canyon. Steven had obtained an off-trail permit for our group, and we plodded through the rain-soaked clay, ash, and volcanic rock debris towards the overlook. I kept my hood over my face to try and keep the rain from draining down the inside of my jacket. By this time my pants, boots, and socks had become completely saturated. Because I was moving, I wasn't feeling cold, however, and the rest of the group also appeared to take the weather in stride.

"Our arrival at the "breached-dam overlook" allowed us to see some of the more prominent erosional features of the Toutle River Valley. Here Steven picked up his narration, describing the landforms as a result of specific processes that had occurred at specific "moments" in time [my wording].

"After his description of the various landforms [basically: 1) debris hummocks, 2) ash-fall, and 3) erosional valleys], Steven mentioned again, that this landscape was a result of "self-organized criticality" [his wording]. There were some questions and comments from the attendees regarding past volcanic events and landscape processes, even a statement about something that happened "100 million years ago" to which Steven did not react or criticize. But then he left us with some oddly phrased question about how much of this landscape was a result of "catastrophic" change versus "gradual" change. To which another person [I do not know if they were co-leading or attending] added that "both types have occurred. I was still trying to parse his catastrophism comments, so I only asked one question about this particular landscape in the future: "what would you expect to see in this landscape in the distant future?" I don't think he quite understood what I was asking, but he did address the fact that this particular landscape was anthropogenically altered, therefore some changes would not take place [which was entirely correct]. But as a summary, his statement was "more erosion." Nothing about changes in stream power, or sediment load, or base-level fluctuations. Just "erosion."

"Because of the rain, his stop was likely cut short. As a parting comment about future eruptions, he made some comment about a similar 1980-style event unlikely [I'm not sure if he was talking about never again, or just in the relatively short-term]. But he made some passing comment about eruptions occurring as a result of the interaction between water, crystallization of magmas [my impression was he thought crystallization was near-instantaneous], and "self-organized criticality" allowing for this pressure to be released [his wording again]. I didn't have a chance to follow-up on that and ask him what he meant, since everyone had started to hike back to the ridge [I still need to do that].

"When we got up towards the ridge, the rain let up and I concentrated on taking photographs. Most of the group had started to spread out, such that I only saw the same four or five people at any given time. Arriving back at JRO, the overlook stop had apparently been cancelled, so I stood on the observation deck and took lots and lots of pictures.

"The return trip to the Convention Center was unremarkable, except that when we got off the bus, they handed a nice 60" wide panoramic photo of MSH to each of the attendees [this was pretty cool]."

So...

"Ultimately, the trip was not as embarrassing or intellectually painful as I had feared. If a GSA member had signed up for the trip, they may not have realized that the trip leader was a YEC [my grad school friend didn't know about Steve Austin until I mentioned something on the bus when we left for MSH]. The people sympathetic to his views were obviously happy. I took away some nice photos and memories of the volcano itself along with a clearer picture of what these YEC-ers are up to and what they are thinking.

"I want to thank Steven Austin and his colleagues for taking the time and effort to organize the trip. I have some concerns, but these are more appropriate for a letter to the GSA Field Trip Committee Chairperson.

"I also want to commend GSA for their decision. It wasn't a tough one, and understandably, there was a great deal of internal discussion related to the trip and whether to allow it. As written, the description of the trip makes no statements regarding a "Young Earth" or other sentiments anathema to the GSA mission. In addition, to deny a proposal on the "possibility" of something coming up is a big step down the slippery slope of guilt by association.

"Yes, the YEC crowd will put this as a shining feather in their caps [ironic, since they claim all of our work is wrong yet they view interaction with us as "proof" that their ideas have merit]. But, there are always unintended consequences. Thanks to the hard work of Jessica at Magma Cum Laude, I was aware of the situation prior to the event, and I've been able to share my experiences with sufficient prior knowledge to report on the event. I also have gained valuable insight into the YEC community, and a new lesson plan to teach about deep time - using Austin's work to show why it's completely wrong."

To finish up, here are a few thoughts from Pascal's last post about why using social networking for the sake of science can be really beneficial:

"This brings up an important point about social networks. The conference at GSA held a special session on the use of social networks in teaching and research. I think the use of social networking tools such as blogs, tweets, and facebooks is vital to help make the geologic community aware of what's going on. Without it, I would not have been able to be aware of the nature of the field trip: both in its implications, but also in terms of its "science" content. In addition, I might not have pursued the background research and stumbled upon these abstracts. The activities of the young-Earth community clearly are part of a larger strategy to gain "scientific merit" for their views (this is related to the "Wedge" strategy as described by the Institute for Creation Research). Without social networking, this behavior might not have been discovered until later - at a point where response and criticism would be more complicated.

"As geologists, we ignore people like Steve Austin, John Witmore, and Timothy Clarey at our peril. However, our response must be both thorough and united. Social networking can provide the first line of notification. I want to thank Jessica at "Magma Cum Laude" for her first note: without it, I - and others - would have been duped."

A geology geek to the core (Accretionary Wedge #18)

Sitting here in Zion National Park, one of the last spots I visited on my first geology field course, I feel like I'm coming full circle to some of the reasons that I'm still doing geology. (I also feel like I could receive wifi through my teeth. Twenty plus wifi points? Really?) Anyway, it's a perfect chance for me to answer Volcanista's question:

So July’s topic is about your inspiration to enter geosciences. Was it a fantastic mentor? Watching your geologist parents growing up? A great teacher, or an exciting intro field trip? How did it happen?

I first became interested in geology as a little kid - that rock and dinosaur phase that so many of us go through. Fortunately, living in the DC area meant that I could go see the Smithsonian Natural History Museum pretty much any time I wanted to, and I did. I remember my dad lifting me up over the rail so I could pet the fake tyrannosaur skull, and driving the video camera that looked in on the fossil prep lab, and peering at the fluorescent minerals in the gem and mineral exhibit. My parents let me dig giant holes in the backyard, and the one time I found a fossil (a shell mold), I remember asking if the Smithsonian might want it for their collection.

I pretty much knew I wanted to do geology all through primary and secondary school, and especially volcanology. Some Saturdays I would watch tapes of the old Planet Earth series (the one narrated by an Attenborough, not this Sigourney Weaver stuff they redid recently), and I would always skip to the plate tectonics and volcanoes episode. (Yes, I was pretty much an uber-geek from the start.) When I got to high school, the "geosystems" class was mostly meant for non-AP-track students, so I took AP Chemistry and, somehow, found out about a volunteer position at the Smithsonian instead, helping edit the Bulletin of the Global Volcanism Network . Two summers of that and I was hooked on volcanoes for good; I literally couldn't imagine having any career other than geology, and volcanoes were especially fascinating.

When I went looking at colleges, the geology program was a big factor, and I pretty much knew that I was going to go to William & Mary the moment I set foot on campus. When I started classes, I was so excited to be taking intro geology that I sat front and center the whole semester (although the instructor, who was a visiting prof, didn't even recognize me when I met him at GSA a year or so later). I was lucky enough that my freshman advisor turned into my permanent advisor, and that he took a chance on letting me into his Regional Field Geology course with nothing more than Intro and Historical Geology under my belt.

And that's how I ended up in Zion, and a lot of other places on and around the Colorado Plateau, after my freshman year. I didn't know much about minerals, or field mapping, or structures, or petrology, or pretty much anything at the start of that trip - but boy, did I learn. After three and a half weeks in the field I was pretty much hooked for life, even though I spent a good chunk of it being sweaty and tired and sleeping on rocks and generally being upset with my own lack of experience.

I was also hooked on the field work, which turned out to be a good thing - my senior research project, and some mapping I've been helping with the last couple of years, grew out of one stop on that first long field course. My advisor played a huge part (and I've written about it before), and the fact that he pushed me to work hard and take risks is one of the reasons I'm still in the field. It's invaluable to have someone who believes in you, after all. (He's also one of the reasons I became a better writer, and boy, has that paid off!)

I think the moment that I knew without a doubt that I wanted to be a volcanologist was when I scooped a blob of molten rock out of a Kilauea lava flow and watched it cool. My field notes for that hike say "BEST DAY EVER!" even though I know I was tired and hot and had a twisted ankle at the end of the hike. Handling the lava - seeing it up close for the first time - was just addictive, and every time I see a volcano I get the same sort of rush, to varying degrees.

So, I guess my answer is a mixture of things. I feel like to some extent the geology just got hardwired in there, although I have no idea how. But experiences and mentors were a huge part of it as well - and now that I'm in grad school for volcanology, and have even more great mentors to work with, I hope I'll want to stick with it for a long time to come.

An interesting field trip at the Portland GSA

While I was at the Toronto AGU, I happend to be looking at GSA's website for their annual meeting, which is going to be held in Portland this year. Naturally, I'm excited for the chance to get closer to some volcanoes (which are noticeably lacking in Toronto), and I was even entertaining the idea of going on a field trip. So when I saw this title, I perked up a bit:

425. Breached Dam Overlook at Mount St. Helens
Sat., 17 Oct. US$95 (L, R).

It's even affordable for a poor grad student. Then I looked at the field trip leader:

Leader: Steven A. Austin, Austin Research Consulting.

Usually, I expect to see people from the USGS or local universities leading a field trip - although the name sounded strangely familiar. So I did a little research...and all the hits that came up were from creationism websites. Namely, the Institute for Creation Research.

It appears that Steven Austin has degrees in geology (they're listed as B.S. Geology, University of Washington, Seattle, WA,1970; M.S. Geology, San Jose State University, San Jose, CA, 1971; Ph.D. Geology, Pennsylvania State University, University Park, PA, 1979), but that he is also the person who introduced the Mount St. Helens/Grand Canyon/Flood and Mount St. Helens "old" lava dome dacite arguments for the Flood and a young Earth. (Links to the debunking of these arguments can be found here and here on the Talk Origins website.)

Stuff like this just makes me twitch. I can't say whether or not Austin knows the recent geologic history well enough to lead a good trip. But what I do strenuously object to is the fact that the field trip description very carefully gives no indication that Austin works for the ICR, and that he has been very vocal in promoting what many geologists would consider to be extremely bad science.

Here's the trip description:

This six-hour hike follows a 13-kilometer-round-trip route to an extraordinary geologic location called “Breached Dam Overlook” just seven kilometers north of the crater of Mount St. Helens. The trail leads us from the Johnston Ridge Observatory onto the largest landslide deposit to have accumulated during human history. This debris avalanche deposit of May 18, 1980, forms one of the earth’s newest landscapes of 45 square kilometers area within the headwaters of the North Fork of the Toutle River. The objectives of the field trip are (1) to identify, classify and name individual landforms within the upper North Fork Toutle River landscape, (2) to relate the landforms to the sequence of events and processes that have occurred next to the volcano, and (3) to ponder questions about how the landscape at a volcano changes through time. Landforms on the debris avalanche landscape are relicts that have been impacted significantly by geomorphic processes that exceed a certain minimum energy threshold. Following the debris avalanche of May 18, 1980, the most significant event was the mudflow of March 19, 1982. That mudflow event breached the natural debris dam, caused adjustment within the drainage basin, and derived the present landscape. Now that the power of geomorphic processes has diminished, finer sediment is what is being moved. Channels are incised and armored with coarser clasts, and valleys are now plugging with sediment. Hikers can observe the new landscape from two selected overlooks. Johnston Ridge Observatory on the west side of Mount St. Helens Volcano National Monument is the staging area this roundtrip hike of 13.6 kilometers (8.4 mi).

Knowing Austin's background puts this into an entirely different light, and it's not one that I like. I'd say the odds are pretty good that his Grand Canyon and argon arguements are going to pop up on the trip, and unless the attendees know what they're getting into (and like to debate creationists for fun), people will probably be shocked and disappointed that they spent money and time only to be a captive audience for someone's bad pet young Earth theories. It's a pity; I would have liked to spend some time at St. Helens with a legitimate geologist (someone from the CVO, say; why aren't they leading any MSH field trips?)

Bottom line? I'm kind of surprised that GSA is allowing someone who so blatantly goes against their position statement on evolution and creationism to lead a field trip. I don't know what the vetting process is for field trip leaders, but if I were a GSA official, I wouldn't allow someone like Austin to potentially use GSA as an avenue for promoting theories that directly contradict the geological science that GSA works so hard to promote. (Then again, this may be a recurring thing - does anyone know if Austin has led other GSA field trips? Perhaps GSA just doesn't care.)

If you know of anyone who's thinking of attending the Portland GSA, please let them know about the background of this particular trip leader before they sign up and fork over their money - if they don't already recognize him.

A Big Island Geology Tour

Callan suggested that I post the advice I gave him for his recent trip to Hawaii, and since I haven't had time to write anything really meaningful lately (darn you, end-of-semester crunch time!) I think I'll do just that. You can follow along with his fantastic photos and discussion of the locations he visited - I'll link to each of his blog entries as they go up. (Those links are bold.)

These notes are the result of two trips to the Big Island, one that I made for an undergraduate field course, and one for a vacation and to take the Center for the Study of Active Volcanoes (CSAV) Field Methods in Volcanology class. (I highly reccommend that - where better to train to be a volcanologist than on an active volcano?) In addition, I've put all of these locations and some notes on a Google Map, and some of my own photos here. Enjoy!


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Kona area:

• About two miles south of Kona on Alii drive is the best snorkeling beach I've been to. It's a public park whose name escapes me, but it's a right turn off Alii before you get to Royal Poinciana Drive. They have snorkel gear rentals, so you don't have to bring your own, and it's an awesome place to see all sorts of fish and sea turtles, which come right up to the beach.

• Two miles north of the Kona Airport on Rt. 19 is the 1801 Kaupulehu lava flow on the Hualalai volcano. If you're coming from the airport, a large lava tube entrance will be visible on the right side of the road. This is a fantastic exposure of mantle xenoliths - really big chunks of dunite and (I think) websterite - and you can hike a short distance into the lava tube.

Southern Big Island:

• In addition to the green sand (Mahana or Papalakoa) beach, you should definitely try to get to South Point (Ka Lae), the southernmost point in the US. The cliffs make for a great view, and there's a sea cave to look into. (Some people jump into this thing, which I think is nuts.)

• The Punaluu Black Sand Beach is another great place for sea turtles, although the waves are too rough for much snorkeling; there is also a resident population of scruffy stray kittens. I also highly recommend stopping at the Punaluu Bake Shop in Na'alehu for some malasadas (Portuguese doughnuts) and lunch.

Hawaii Volcanoes National Park:

• I don't know if they're letting people near Halemaumau Crater anymore, but if you can get down there, on the other side of Crater Rim Drive from the overlook is the Halemaumau trail, which is a great place to see ballistic blocks from the 1920s eruptions, as well as an old airfield that got plowed up when the Japanese attacked in WWII.

• The Kilauea Iki hike is a great way to see the crater from the bottom, and you can look into the vent of a fire fountain that erupted in the 60s.

• If you can hike the caldera, there are great spatter ramparts along the Halemaumau trail.

• Devastation Trail, which runs behind Pu'u Pu'ai (the cone that formed from the Kilauea Iki eruptions) is a good place to look for Pele's tears, and get a good look at local flora and fauna (we saw lots of birds along here, and the ohia trees and ohelo bushes are pretty common). You can eat ohelo berries along the way, if you want - they get dark red when they're ripe, and make delicious jam. (Be sure to leave an offering for Pele to say thanks, though - she's kind of a touchy goddess.)
  

• Thurston Lava Tube is definitely worth a visit, and if you bring a headlamp (a good one, and maybe an extra flashlight), you can hike all the way to the back of the unlit section, where most of the tourists don't go.

• Along Chain of Craters Road, before you get to the active flow fields, there's an overlook and parking area next to a collapsed lava tube. If you follow the tube over the flow fields to the north, it leads all the way back to the summit of Mauna Ulu. (It's a long hike and you either have to go back the same way or have someone meet you along one of the other roads afterwards, though, and sometimes the access roads are closed.)

Hilo:

• Coconut Island in Hilo Bay has records of tsunami inundation heights posted on trees; it's also a good lunch and swimming spot.

• The Boiling Pots are a neat series of waterfalls and plunge pools that the locals go to for swimming (and for launching themselves off of cliffs). There's a public parking area and picnic tables, but this is a good place to keep a close eye on your stuff. (Be careful to stay out of people's backyards, too, because some of them grow marijuana and they're a bit touchy about trespassers...)

Mauna Kea:

• Definitely drive up to the summit. It's probably best to do this from the Hilo side, since there are no gas stations in the center of the island and you'll need a full tank to get up and down. There's an unpaved stretch of road between the ranger station at 9000 feet and the summit (13,000 feet) which is pretty grueling, but it's worth the drive if you take your time. When you get to the observatories at the summit, be sure to hop over the railing and climb the small cinder cone with the shrine on top - that's the real summit, and where you'll find the Mauna Kea benchmark. Be sure to spend at least an hour at the ranger station, though, and chug a few nalgenes of water before you try to go to the top - you'll be less likely to get altitude sickness. It's also a great place to see silversword plants, which are very rare.

• The ranger station has astronomy sessions in the evenings where students from UH Hilo help set up telescopes for moon and planet viewing. It gets extremely cold, but they sell coffee and tea and ramen that you can heat up in their microwave.
  
• Below the summit of Mauna Kea, around mile 6 of the access road, there's a small pulloff (on the right as you're driving up). If you hike out a bit over the scoria, there are some flat-topped rocks. Have a look at the top of these - this is the closest point one of the closest points to the equator that you can find evidence of glaciation! There are glacial striations here, and the debris surrounding the outcrop is supposed to be remnants of a glacial moraine. (There are a lot of glacial features up there, but I didn't get to see them all - the rangers will probably be able to steer you to them.)

Kohala Coast:

• Laupahoehoe Beach Park has a monument to the people who were killed in the 1946 tsunami. It's a beatiful place to camp, and they've installed tsunami warning sirens since the 40s.

• Waipio valley is absolutely worth the climb down the ridiculously steep road to get to the beach - some people will drive down, but I'd recommend not risking a rental car on it. Great saprolite exposures at the top of the road. If you make it to the far end of the beach (it takes a little stream-fording), you can see cliffs that expose a number of the lava flows that make up the ancient Kohala volcano. There are also boulders of some really funky lavas here; we found one piece that was chock full of huge plagioclase phenocrysts. Watch out for the donkeys that live in the area - they bite - and pay attention to the "kapu" signs; this used to be a burial ground for Hawaiian kings. I wouldn't recommend much swimming - the surf is very rough and the area is known for sharks.

Other:

• Off Rt. 137 (Kapoho-Kalapana Rd), which you have to approach from the east or north (since the current flow field took out the ocean road), there is a black sand beach and breadfruit/palm tree molds. This is the remains of the Kalapana Gardens subdivision; the people who still live there planted hundreds of coconut palms along the newly formed beach here.

• On Rt. 250 (Kohala Mountain/Hawi Road) north of Waimea (the north end of the island), there's a lava dome of benmoreite associated with late-stage, secondary melts from the Kohala volcano. I'm not sure of the exact location, but it's a light-colored roadcut with a bit of an overlook down on the Waimea valley. The benmoreite is probably one of the most felsic rocks on the island, so it's a bit of a novelty. (There are other benmoreites on Mauna Kea, but this is the only one I've seen.) *Sadly, I don't have a photo of the outcrop, but this website does.
  

For those of you who want more detailed geological descriptions than I've been providing, the USGS has some good Open-File geologic maps of the islands, and Hawaii Volcanoes National Park sells more detailed ones (as well as topo maps with trails marked).

A few safety reminders: If you're going out hiking on the lava fields (or anywhere else in Hawaii, for that matter), make sure you have the right gear, enough water and lots of sunscreen. Hawaii is much closer to the equator than most people realize, and it is very easy to get dehydrated and sunburned there (a really bad combination). I saw far too many people on both of my visits without proper hiking gear (sturdy shoes, long pants, hats, sunglasses, etc). Thick work gloves are also important for hiking on lava - when you fall, you tend to break your fall with your hands, and believe me, you don't want to grind volcanic glass into them. Also, if you'll be anywhere near hot lava, don't wear thin synthetic clothing. Picking melted nylon off your skin is not a fun exercise, no matter how great your new bug-zapper button-down is. Natural fabrics (cotton and linen) will scorch but not melt.

For a short hike (no more than a mile or two), bring at least two Nalgenes of water. For a long hike, bring a least a gallon - that's at least four Nalgenes. It's heavy, but you'll drink all of it, because it gets darned hot out there. Follow the same rules you would if you were in a desert - there is nowhere on those lava fields to get water, and rainwater that collects in hollows is often filled with nasty microscopic critters. Don't ever go hiking off-trail without an experienced guide, and certainly don't do it in flip flops. (I have seen people do this, and it is truly shocking.)

That said, Hawaii is a truly awesome place to explore, and even better if you do it safely. Watch out for yourselves!

Wild (and not so wild) animals in the field

I don't want to miss out on the domesticated or wild fun, so here are my contributions to the recent animal memes.

New and creepy insects are always turning up on field trips:




Fortunately, there are birds to take care of them - when they're not trying to steal your food.





Of course, why worry about birds when there are four-legged critters to watch out for?





Some are cute...



Some you wouldn't want to hug, but they could still qualify as cute...



Some definitely aren't cute or cuddly...


And some are are just so utterly comical that they require long breaks before any meaningful field work can get done.