Welcome to this issue of Stumped by Nature, where we notice nature lurking just beyond our screens, curate a list of outside-y events in Austin, and build community with other folks in the thick of the startup ecosystem.
In this week’s issue:
🪨 Limestone
🌤️ Upcoming outdoors events
Let’s dig in!
-Nicole
PS. ATX Outsiders is our community where people get to know each other IRL outside each month. Join us!
Upcoming events:
Sunday, August 30: Reverse Brain Rot: We’re sprawling with books and notebooks at Barton Springs
Monday, August 31: Austin Reading Club. Get those pages in
Saturday, September 12: Bat-Watching and Bat Q&A: It’s happening. Skip Hobbie will join us!
NATURE SPOTLIGHT
My primary experience with Geology, beyond the mandatory elementary school overview back in the 1900s, was a 2011 OkCupid date with a geologist who made me realize I’d rather Google rocks.
But when I sit in construction on my way to/from my Westlake office, I’m surrounded by my absolute ignorance.
So I decided to finally Google.
And oh boy.
Views from my scenic Loop 360 commute
Today, we’re digging into limestone.
What is limestone?
Limestone is a type of rock
Rocks, as you may know, can be really old
Technically speaking: limestone is made of calcium carbonate in the form of mineral calcite, formed over millions of years
Limestone rocks are sedimentary, which means the detriment of the world is pressed down as new layers of the weight of the world accumulate, and some minerals in water act like glue so time + weight + adhesive minerals = hard rock
Limestone is biologic sedimentary rock, which means it’s made from the remains of living things
For Central Texas limestone, those living things were alive during the Early Cretaceous period, born of ancient seas
This means limestone contains both imprints of things that decayed away AND the physical remains of ancient clams, snails, and marine organisms
Translation: limestone is full of ghosts
Measuring the gouges of bottom-dwellers scraping their bellies across the prehistoric ocean floor
Limestone occurs where the world was once covered by warm, clear, shallow ocean water teeming with marine life, which is to say many places.
Himalayas and Alps? Even at the top, with a tectonic plate boost
Limestone is the primary construction material for the Egyptian pyramids. Mummies + prehistoric marine bones? No wonder it’s a world wonder.
Speaking of construction material, remember the Alamo? Limestone, baby. Folks can chop it up, smooth it out, and make steps, decks, blocks, pale facades, and sculptures
So here we are in Central Texas
The seas receded.
The layered, condensed graveyard of the dead remained.
And in Austin, we find ourselves at the edge of the Edwards Plateau, a large, elevated limestone region that includes our deeply eroded Texas Hill country.
On this limestone-y plateau, history also brought us European settlers in the 1800s. Some ecological yikes ensued: the fall of the bison and the people who depended on them, a shift from high biodiversity through oak-juniper woodlands/mesquite savannas/native grasses, to overgrazing + not crop-rotating. The Texas Parks and Wildlife Department breaks down the swift descent with a bleak explainer of the current Edwards Plateau ecology: a cedar monoculture where deer munch down all that is good in the world and droughts have no reason to lessen.
The region’s shallow, solid limestone nether-regions are unsuited for heavy crop farming, but quite suited for ranching, and we historically ignored this geographic reality. The geography held a firm boundary for what it’d tolerate. Yeehaw.
📸 Bill Davis
Side note: you can see evidence of parallel wagon tracks at Bull Creek from the commerce highway of the 1800s—the combo of high volume of heavy wagons with iron-rimmed wooden wheels + water + soft limestone = rock ruts.
Austin, Divided
Ever notice that the roads in East Austin can feel like a ribbon wand?
Limestone-based Edwards Plateau meets its regional end in Austin. To the east: Blackland Prairie.
The geologic meeting point is the Balcones Fault zone, which is roughly tracked by I-35.
The east side of town’s clay grasslands is where you buy real estate if you’re excited to learn about transferrable foundation warranties and how to patch drywall.
The Balcones Fault zone along I-35 in Austin also happens to have been the dividing line for segregation. The city’s 1928 Master Plan engineered institutional segregation, and included withholding infrastructure, zoning for hazardous industrial sites like fuel tank farms, and providing a foundation for 2020s east side to continue to have food deserts and intense gentrification. Yeehaw?
Ok. Limestone. Back to limestone.
A NW Austin trail where toddlers (or adults) can stuff their pockets full of fossils
Organic Hobby Tunneling
Thanks to things like the microscopic skeletal remains of algae, limestone is porous.
When water flows consistently and over the expanse of time, the grit of sand and pebbles act like sandpaper and it mechanically carves deep grooves.
Add mildly acidic rain, and we get a chemical reaction with the calcite in the limestone, called the karst process. Mildly acidic rain + porosity means the limestone absorbs water and traps the acid more easily, so acidic water moves deep into the stone. Chemical dissolution weakens the stone, and water enlarges cracks to form underground caves, sinkholes, and channels.
Karst may be uttered like a bad word in some circles—when new roads or buildings are being dug out, a crew puncturing into an underground void triggers a temporary work halt, and requires a process of environmental review for endangered species, water quality concerns, and sensitive cave ecosystems. MoPac construction enjoyed two surprise caves in 2015 at Enfield, 40 feet below the Expressway, and again in 2019 at La Crosse and Slaughter, where 72 karst features paused the TxDOT project for months.
In 1963 during core-drilling testing for I-35 overpass foundations in Georgetown, the Texas Highway Department discovered Inner Space Cavern. Now it’s an option for your 9-5 time span, advertising that it’s not affected by rain, it is 72 degrees year round, and has Ice Age animal bones for your viewing pleasure. BTW: if you’ve ever wanted to ensure a Vitamin D deficiency, Inner Space Cavern is hiring tour guide(s).
And so we commute:
In a previous life, my work commute was through Blackland Prairie, through a food desert, through the high school cafeteria and down C-Hall.
Now, the passageway to Westlake work: millions of years of condensed timelines, retaining and filtering water.
A corridor that’s fitting for stewing over Entrepreneur Operating Systems, the vision, how to protect the rocks.
And back home, garden steps made of smooshed sea creatures, standing on piles and piles of the fleeting lives lived, absolutely not having a full existential crisis at the reality of what bizarre blip of the world to be in, physically and timeline wise, and to have things on my to do list like look at the bees and complete the 87-part back to school forms for both kids, buy caffeine.
UPCOMING EVENTS
🗓️ August 20: Offshore Austin: You could still catch a yacht midday for a great Thursday afternoon
🗓️ August 20: Festival Beach Food Forest Celebration: live music, a chance to make an impact, and a take-home sprout kit await
🗓️ August 21: Pitch and Run ATX: Running buddies at the ready
🗓️ August 21: Carpenter Hall Co-Work: For a Friday change of scenery
🗓️ August 22: The Board Walks: talk it out
🗓️ August 22: Austin Ruck Club: fitness looks good on you
🗓️ August 22: Kayak Trash Cleanup: row row row your vessel
🗓️ August 22: Landscape Painting: tap into what you’re seeing
🗓️ August 25: Early Birds in the Garden: Have your binoculars at the ready
🗓️ August 25: Hill Climbers Tuesday Ride: roll into a good Tuesday
🗓️ August 26: Barton Springs Tree ID Walk and Sunset Swim: easy yes
🗓️ August 26: Bat Boat Cruise for Merlin Tuttle Day
🗓️ August 26: Merlin Tuttle Day Celebration: See and learn about bats from the Bat City crew
🗓️ August 27: Bat City Film Night: Excellent panelists for a very Austin effort
🗓️ August 27: SporeCorps: Mushroom Cultivation 101: for your new inoculation hobby
🗓️ August 30: Reverse Brain Rot: An ideal Sunday morning
🗓️ August 31: Austin Reading Club: Fun fact: you’ll love it
That’s all for this week!
In the meantime, I hope the only ghosts you encounter are friendly prehistoric sea creatures.
-Nicole
OPTIONAL SIDE QUESTS
🪵 Need to metabolize something? I help people write. Let’s chat.
🪵 Are you looking for a community of people in the startup ecosystem who go outside together? I’ve got you.
🪵 Speaking of, I chatted about local community building on this thing called a podcast
🪵 Are you sitting on a misogi-esque story? Spill.
🪵 Follow my calendar to know when we’re rallying.
🪵 I also write essays: this one is about witnessing a bison harvest.
🪵 Is this newsletter not your vibe? Forward it to your enemies to make them suffer too.
💰It’s safe to assume there are affiliate links, and I’ll monetarily benefit from any purchases you make. Hooray, capitalism! So far, this newsletter has generated $4.48 of cold hard cash. 💸