Interview with a Living Gem; An Insight on the World of Rock with Geologist, Carla Kuhn

Christine Cauble | May 11th, 2012 - 2:47 pm|

Carla and her Grams - the one who helped nurture her love of geology.

What does rock climbing mean to you?  From the start, my love for climbing was ignited from several areas of the sport; namely, it was done outside.  As a little girl spending my summers on my grandparents’ ranch in Oregon where fields, forests and cow manure were all a part of my playground, there was nothing more appealing than continuing into my adult life to exist and play in a natural environment.  I’ve learned to love communicating with rock; to read its very edges with my toes, appreciate large huecos that give atrophied muscles rest.  I converse with cracks using fingers and hands and love a jug that enables me to ascend.  Rocks rock our world.

But how well do we know our environment?  One of the other exciting aspects about climbing is being able to physically see and learn about the ancient stories of our Earth’s past while on the rock.

After bombarding friend and geologist, Carla Kuhn, with my many questions whenever I travel to an area of beautiful geological formations, I decided to share some of her wit, character and knowledge on some of our climbing havens.  I also wanted her to share some of her views on global warming, a very serious issue that we are facing now; something that may affect mountaineers (more instability in ice/snowy conditions) and ice climbers at this moment but an issue that reflects us all as our home morphs into its next existence.

A big thank you to Carla for sharing her time on these interesting subjects…

RRRG:   What field of geology do you work in and for how many years now?  What inspired you to pursue geology as a career?   

Carla:  I worked in a sideways-hybrid part of geology….

My geologic fascination was in mining and gem materials; I planned to finish a doctorate in some aspect of mining or mineralogy.  Meanwhile, teaching began to beckon.  While an undergrad I worked with my husband, Matt McMackin–a structural geologist, mapping mineral resources in Arizona, assembling teaching  materials for the United States Geological Survey (USGS) and taught teachers how to teach geology.  I was very intent on moving into a professional position.  As Fate would have it, our son Aidan decided to show up.  I decided to switch my visual and finished my masters in education instead and was the first geoscience grad ever certificated by Stanford.  I taught middle school for the following twelve years, using geology as a platform on which a learner might better understand chemistry or mechanical physics or mathematics.   When possible, my alternative ed students met me at the rock gym which had a huge impact on their self-perceptions.  I was a total subversive teacher, which pleased me enormously, and all because Aidan couldn’t wait to get to Earth!

 My grandmother is my inspiration.  With two thermoses of water and two rock hammers, we’d “tootle” around Death Valley, Needles, Anza Borego…fearlessly, with an easy comfort in being outdoors – me in my Stride Rite stiff-as-steel shoes, and her, amazingly, in sensible heels and dress.  She’d pick up all kinds of rocks and tell me their stories and, later on, we’d putter around in her Rock Studio.  She encouraged me to explore whatever caught my eye.  And so I did.  I hounded a long while and many miles as I got older, almost everywhere in U.S. but deep South and northernmost Plains.  After university and various careers, I returned for a geology degree in honor of my grams!

RRRG:  What an amazing story on your grandmother’s influence.   Are there many women that work in geology?   Or are there a disproportionate number of men to women in this field?

CK:  I was in Edinburgh at a geo conference a while back, and met this energetic slip of a Scottish gal who was just home from her fourth traverse of Mt. Everest.  Well, it was more work than play, she said, and the tourists were a huge bother.  Mt. Everest was her PhD area of study and, and being a monolith of limestone, she was keen to correlate its entombed (and very ancient) critters with rates of uplift in other locations around the world with same critters.  Her biggest issue was not acclimation or Khumbu.  It was her advisors, who were NOT pleased that she picked something to study “that should be left to men.”  Not so long ago, I was counseled to give up geology for home and hearth—this in the 1990s!!  

A lot of that has changed.  The number of women in the geosciences is about equal now to that of men.  I’ve met or know all kinds of women (demure to pistol-packing) who tend gold and gem mines, natural gas drilling ops, and like the gal above, scrutinize Mt. Everest for it’s role in Earth’s history…and now, how it changes weather patterns.  They bring their version of organization, management, and social…er…decorum to this science that didn’t exist when The Man dominated this profession.

RRRG:   I’m sure our climbers would be interested in hearing some basic information on the rocks they love to climb on….can you please explain briefly some differences in regards to some of the rocks climbers ascend on such as granite, sandstone, tuff, limestone and conglomerate rock?  What are we seeing and grabbing on?

CK:  Climbing is perhaps the most Earth-intimate of ‘em all.  Each grip holds a story, and as they say in the biz, “can’t know the story until you get your nose on the rocks.”  You can ascend from proterozoic crystalized basement to pluton to roof pendant and watch a billion years go past your eyes in several pitches!!  So I’d bet a buncha stuff that climbers know their rocks far better than even some geos……  

Granite comes in all colors: mafic (dark green- or blue-black–lots of hornblend, biotite) to dove white (lots of feldspar, quartz).  Freshly spalled or fractured granite is not (yet) spoiled by time and the elements.  Maybe the hardest to find a place for safety, but affords a usable, mostly safe grip.  Yes, some of those great smooth grips can be  way ….over….there, off-route.  The worst granite, as you know, is the weathered stuff, decomposed granite or DG.  You know it already; you look at it or breathe on it and it crumbles.  Try to place protection and it pulls out with slightest tug.  Being a wise climber, you bail on the route and location, and figure out something else.  

Sandstone can be just as problematic.  Made of grains the size of rice to that of face powder from eons of erosion and off-shore or river deposition, it can take protection or a firm grip depending on how it’s all glued together: calcite or quartz.  Calcite is crummy glue and the sediments will fall apart in your hand or, if you’re already on-route, from any kind of compression (ie, from gear).  Quartz is far more stable.  The really, really old quartz-cemented rock is known as quartzite because its grains have been additionally melted into place by metamorphic activity—ie, a pluton has worked itself to the surface and the quartz-seds were in the way of its “diapiric rise”—some geo lingo for you!!  You climbers already know this, too.  It can provide a safe, useable grip if the particles can be seen, that is weathered, so your hands don’t slip on grip.  Sed rock as boulders, as in Joshua Tree is fun to scramble or free climb as high as you are willing to fall.   It can really chew up rope.

Tuff  is unconsolidated, ie, unglued, volcanic ash.  Volcanic ash is made of small siliceous particles, ie. volcanic glass urped out during a volcanic eruption.  It will shred your expensive rope to bits.  It will chew through your duct-tape wrapped fingers, and bloody your knees and knuckles.  It is savage stuff.  It is common in my area, the Eastern Sierras especially around the Mammoth area.  I tackle it gingerly only if slope is very gentle…ie, a trail!  There are other rocks with confusingly similar names: tufa and tuffoni.  Tufa is an evaporite rock.  Think Tufa Towers of Mono Lake.  Eerily beautiful.  You don’t want to climb this stuff  because it has no compressive strength whatsoever.  Tuffoni is another type of evaporite involving salt and iron oxides which cement at the outer edge of what looks like sandstone with irregular shaped bubbles.  The center part of tuffoni rock weathers out easily because it isn’t cemented.  Tuffoni is more of a textural kind of surface best to admire and snap a few pics.  

Conglomerates is, like, a larger kind of sed rock.  Its particles, or “clasts” in geo-speak, can be like little pebbles the size of marbles to huge boulders the size of VW bugs, or anything in between.  They’re quartz or calcite or volcanic “schmutz” cemented.  If quartz cemented you won’t be able to pickaxe the clasts out of the formation.  However because weathering forces operate 24/7  quartz-cemented congloms won’t always provide consistently reliable safe grips.  Calcite and volcanic “schmutz” (my own geo-speak for loose, crummy volcanic ash or pyroclastics) don’t do well under compressive loads.   There are some great LOOKING congloms along sections of the Tahoe Rim trail, but I like to marvel over them…not climb ‘em….makes me too nervous.  

Limestone…..one of my favorites.  This is where a teeny bottle of vinegar comes in handy.  Can’t tell if it’s limestone?  Take your bottle and put a small puddle of vinegar on the rock, give it a few moments, then watch to see if it fizzes, which if it does then you know its limestone!  

Limestone is mostly calcite (hence the fizzes) and flotsam remnants of organic animals (ie, corals, forams…).  The pale yellow white crystalline looking stuff you sometime see is the mineral Aragonite.  Cooked limestone is known as marble.  As for climbing on it, sometimes that can be an easy, stair-stepped kind of climb or, if steeper, will surely shred rope, skin, climbing shoes—–even hiking boots—into a merciless mess.  The Dolomites, in Italy, are a must-do climbing location.  However, upon return, climbers both marveled at their beauty and swore a streak about their viciousness, all in the same breath.  So, limestone can be as exciting as they can be problematic, where anchors and grips are plentiful, in the same pitch, they become flaky, risky, and cut like razors.  

RRRG:   Speaking of climbers, you met one of our interviewees, Lynn Hill before…..did you give her a lesson on rocks for a lesson on climbing? :)

CK:  Are you kidding? I was a newbie and way way too awestruck! I took a few climbing classes at a rock gym in Santa Cruz about 20 years ago.  That gym hosted a coffee-chat-demo session with Lynn one afternoon.  I didn’t know much about Lynn other than what my husband, Matt relayed to me: she was a Camp 4 regular (as was Matt ten yrs previous) and was amassing quite the rep among climbers for her agility and balance and, ahem, for a woman, her derring-do.  She was not what I expected: shy, quiet-spoken, not very muscular looking, and……very petite!   Once she began her boulder and overhang demos, what a transformation!  Lynn moved with the unbelievable fluidity of…a…spider!  She turned and shouted to the dumbstruck below that balance, not so much brute strength, and placement were key.  “Use your fingers and toes in the present to get your rhythm…Let your mind plan the future…don’t forget to enjoy your surfaces!”  So much easier said than done!

5.  Please give us some of your favorites in regards to areas of beautiful rock formations you have seen.  Explain your attraction or awe to these places.  Please also tell us some places you would really love to see but have yet to visit and why you would like to see them.

CK:  Great questions… but, er, how much space do you have??  A gorgeous rock formation can be found anywhere, in any size.  At the moment, some that come to mind….the towering chevron folds in the Eastern Sierras above Bishop, California…the vast, vast expanse of Valles Marineris of Mars (hard to visit, easy to see with good telescope)…Zion’s rocks–not so much the Grand Canyon’s…Maine’s rocky coast, especially the swash zone along its beaches…the massive rock face just above the town of Squamish in BC, Canada…there are great spalls of granite along Hwy 88 (between Nevada and California)…the road cuts just as one enters New Mexico…the “whale back” in Pennsylvania… ETC ETC ETC

Hmmmmm.  What I’d love to visit??  The mining side of me wants to sluice out placer gold from any “glory hole” in Alaska.  There’s diamonds to be had in southern part of Wyoming, feldspar “sunstones” in Oregon, and rubies of good quality in/around Franklin, North Carolina.  Internationally…Queen Maud Land…anything in New Zealand…Africa’s rift …Petra…retrace your trip, Christine, thru the Atacama (swing by to see the uber deep space telescope there)…and if I could talk Matt into it, the Oman Ophiolite sequence.   I find landforms—I don’t know how to put it in words exactly—these landforms are as mystical, inspiring, and visceral as twinkly gems.   If I stand on my front porch, I can take in a broad expanse of the eastern Sierra Nevadas.  These mountains soothe and keep me company. 
RRRG:  What do you think about global warming?

CK:  Overall, the scientific community is pretty frustrated, if not disgusted, with the persistent denial in media, among politicians and everyday people that no such thing really exists.  Global warming exists and it is, according to the data, overwhelmingly caused by our use of fossil fuels.  Period.  True, our Earth has gone thru periods of warming and cooling, however not by the exponential magnitudes we’ve seen over the past 100 years.  The most recent data is blunt:  Earth’s basal temp continues to rise, now for the 35th year!!  You know, it doesn’t matter much what I think about global warming .  But, consider what my students (165!!) and our son and his high school chums think of global warming:  they’re pissed off, really pissed, that my generation continues to waste and destroy the planet!  “We’ll die because you guys are leaving nothing for us!!”

RRRG:  As a scientist, how do you envision our planet’s future environment in the midst of global warming?  And when do you think we will really notice the most drastic changes happening….if they aren’t happening right now?

CK:  Sigh….The drastic changes are happening now, Christine!!  Island countries such as Azores, the Indonesian galapagos, and the Maldives are now flooding and their pleas for worldwide assistance continue to be ignored.  Evidence shows that polar bears, in spite of the political hoo-hah to the contrary, are endangered and may shortly become extinct because the ice floes on which they “camp” in order to hunt for food are disappearing, meaning they must swim exhausting distances from floe to floe.  Disrupted migration patterns, shifting insect and plant habitats, and frequency of extreme weather patterns—flood to drought—are happening now.  And, one only has to fly over Greenland or Antarctica to witness its profound loss of ice shelf and glaciers!  The window we have to repair our Earth is now down to 10-15 years, otherwise we permanently lose the Earth we know.

RRRG:   Also, to satisfy my own curiosity on this….being a bit geeky, I used to occasionally visit the us gov.’s earthquake site (for fun!) to see the number of earthquakes going on.  Do you think there are more earthquakes now than in the last few hundred years?  Or is it that there is better media coverage that is capable to inform the public on these events and other factors?  What is your theory/thoughts?

CK:  That’s OK, hon, geek away!   We notice earthquakes more because there are (1) more people on our planet to experience AND report them, (2) more people live on the cheap land on/near major faultlines (ie, Hayward, Calif.) b/c they are willing to risk it, and (3) more geos are available to correlate the subtle nuances of motion (ie, depth, location, direction, magnitude…etc), and (4) instantaneous media coverage.  A dear friend of mine is head of USGS press relations and sighs deeply when her phone rings late at night with a desperate reporter asking about earthquakes, especially the M1 to M3s.  S/he is up against a deadline and the only thing “tabloidy” enough is some EQ article to fill assigned program time or column inches.  Meaning, when there’s nothing else to sensationalize, why not catastrophize teeny earthquakes.  The public is at fault.  They allow themselves to be carefully trained in Fear by those who, when sex, scandal, or crime is nowhere to be found, rustle up the EQ fear….California sliding into the ocean, for example.  Many people choose to be science-stupid….don’t get me started!!!

Our Earth’s surface has cooled down and her heaviest atoms have sunk to her core.  The heaviest atoms, however, are the radioactive kind.  They are “overweight” and toss off particles from their nuclei (ie, “decay”) to achieve balance.  Atomic decay isn’t passive.  It heats up the lower mantle rock which, like a pot of bubbling oatmeal, causes the hot stuff to rise and the cooler/upper mantle rock to sink.  The mantle, then, is busy convecting, and it is this convection that keeps our planet “alive.”  I’ll say!!  Convection moves hot, young, and high (ie, buoyant crust) “earth” to the surface and subducts/recycles her cold, old, and low “earth” back into the mantle.  Because new crust is appearing while old crust is disappearing, her plates have to shift around to make room.  Some plates move past each other with ease, others do not and build up lotsa elastic tension—so pull on a rubber band = elastic tension, when it breaks = EQ).  When the elastic tension overwhelms the friction between the two plates, we feel that lurch of “release.”  I’m sure while Earth’s inhabitants freak out and, at times, suffer tremendous misery, Earth herself sighs in relief!!

Just thought I’d throw this link in.  From an acquaintance at USGS who studies earthquakes and has an AMAZING way of showing people what they are http://earthquake.usgs.gov/learn/listen/download.php

RRRG:   What is the most satisfying feeling about being a geologist?

Carla: Ah, c’est ma vrai passion!!  I am a jumble of earth signs, so geology is perhaps a fitting lifestyle-journey, n’est pas? 

RRRG:  Any shout outs?

Carla:  Ah yes… to my hubby Matt who has shared his adventures with mine…to my Grams for getting me going…and to you, Christine, for all your intrepid curiosity, that re-inspires my wanderlust when it starts to sag!!


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