High prices at the pump this summer have Americans thinking about gasoline. So for a group of Brigham Young University geology students, the chance to ponder the particulars of petroleum was one they couldn’t pass up.
And even though their “mega” field trip to the Florida Keys and Andros Island in the Bahamas may sound like easy living, it was really an exhausting and exhilarating extension of the classroom designed to teach them all they could learn about carbonate rocks in one of the few places they are known to currently form.
These highly permeable and porous rocks, ideal for the underground migration and pooling of oil and gas, are of eminent interest to companies like ChevronTexaco and ExxonMobil — almost 50 percent of the world’s oil and gas reserves come from underground reservoirs in carbonate rocks.
Also of interest to the oil and gas world are up-and-coming BYU geology students, who, thanks to real-world experiences like this W. K Hamblin Global Geology field trip, are attractive hires in an industry eager to find the best and brightest capable of hitting the ground running — destination: oil reservoir.
So important are students who have been exposed to environments like the ones in Florida and the Bahamas, that Anadarko Petroleum Company, one of the world’s largest independent oil and gas exploration and production companies, helped subsidize the mentored-learning excursion.
“Wages are so good in the oil and gas industry right now that most people in the program are landing there,” said senior Riley Brinkerhoff from Vernal, Utah, adding that graduates of the program have earned as much as a $70,000 starting wage. “The money is tempting.”
And so for one week, Brinkerhoff and his fellow students (14 undergraduates and 12 graduate students in all) got dirty, sweaty, sunburned, seasick and extremely excited looking at countless samples of mud, sand and rock — and not just for the promise of a petroleum payday.
Spend any time with these students and you’ll quickly learn that their true motivation lies in the excitement of identifying a fossil in the bathroom tile of their motel room or seeing ripples form in the sand of the ocean’s floor during one of the trip’s many excursions.
“The ripples were amazing! And seeing them in real life makes a huge difference,” said Ashley Dalrymple, a senior from Glendale, Calif. “Before, I thought, ‘Great. Tides move sand.’ But I didn’t really know they could actually move things that fast. It never really occurred to me there would be that much movement of sediment because of tides — they are such a force!”
Two stops among many illustrate how students gained perspective on the trip — the first at Windley Key Fossil Reef Geological State Park in Florida and the other at an extensive, submerged sandbank off Andros Island in the Bahamas.
The park is home to a limestone quarry that supplied massive blocks for the overseas Florida East Coast Railway in the early 1900s. The clean cuts of the quarry machinery used to extract the blocks exposed the fossilized remains of a 125,000-year-old coral reef. Nearly every inch of the quarry’s flat, sun-bleached panels contains recognizable plant and animal ocean life — mollusks, sea urchins and corals of all shapes and sizes.
Upon arrival, the students grouped into pairs to map meter-wide cross sections of the rock wall at the rear of the quarry. As part of the exercise, they explained to one another what they think happened geologically — why that portion of the wall looks the way it does.
Peering over the shoulder at an undergraduate’s map, graduate student Carl Standley, a participant in the Graduate Mentoring in Applied Science Setting program funded by the College of Graduate Studies, encouraged him to “take a mental snapshot” for the upcoming portion of the trip — a snorkeling excursion over living ocean reefs.
“The ancient rocks here will help you understand the modern setting,” he said. “Then, you’ll take that information and figure out what the petroleum is doing.”
Sure enough, the very next morning the group — some members clad in wetsuits, others wishing they were clad in wetsuits — jumped from boats into the chilly ocean. For the first half of the day, professor Scott Ritter, lead faculty adviser on the trip, stopped in multiple locations around the Florida Keys to observe the composition of sand and mud on the ocean’s floor. At each point, students took measurements of the water’s salinity, acidity and temperature and gathered sediment samples for later classroom discussion.
Hours later, the group swam across a reef, comparing what they saw in the quarry to real life.
“When you’re snorkeling, you’re by yourself,” he told students. “You’re isolated with your thoughts. I want you to be thinking ‘geology.’”
After one more day of observations, students had a good idea of the sedimentology of present-day reefs, as well as the plant and animal life that inhabits them. Next, they traveled to Andros Island in the Bahamas
to fill in the last puzzle piece in their understanding of how carbonate rocks form.
Andros Island’s shoal, a sandbank roughly 15 miles by 10 miles across, is comprised of “ooids” — not the granite-based sand familiar to most North Americans.
As its name suggests, ooid sand is round, having formed around a nucleus of bone, fecal matter or shell particles. Organic material coats the nucleus over time, in a process similar to that of a pearl’s formation. Each granule is no larger than 2 millimeters, but in clumps and as a whole is porous and permeable, allowing fluid to quickly and easily migrate through it.
“Air bubbles in lava rock are nonporous and lack permeability. They are individually sealed chambers, unconnected to one another,” explained geology professor Tom Morris, another faculty adviser on the trip. “That type of rock isn’t a good place to look for oil. Carbonate rock, on the other hand, allows liquid to pass through it very easily.”
The site of the shoal is what Miami looked like 130,000 years ago. For that matter, it’s also what parts of Utah looked like anciently — sand as far as the eye can see. It is this ooid sand that settles and hardens between the plant and animal remains on reefs, forming carbonate rock.
The Andros Island shoal is one of three places where ooids are known to form, and Ritter guesses the most pristine. The crystal blue water, ankle-deep when the group first arrived, barely covered the smooth, white granules beneath. With the incoming tide, students were soon up to their knees.
They repeatedly scooped the flowing sand into their hands, looking at it through magnifying lenses to better appreciate its unique properties.
“I think these trips are priceless,” said Rachel Henderson, a first-year grad student from Grosse Pointe, Michigan. “Until I saw the ‘carbonate factory’ in real life, I didn’t really understand the expanse of it all.”
Ooid sand is the best friend of geologists working in the oil and gas industry. Using 3-D visualization tools, they are able to take “pictures” of geologic formations underground, like reefs buried in ooid sand — a feature that vastly increases the chance that oil and gas is present.
Near the end of the trip, Morris told students: “It’s really incredible what we’ve seen in the last few days. If you internalize it, you will have a great feel for carbonate sedimentation. You can talk the talk and walk the walk.”
Eager to do just that, Anne Dangerfield, a senior from Green Bay, Wisc., hopes a future employer finds the experience as invaluable as she did. “I kept saying to myself, ‘So this is what that looked like when it was alive.’ The trip has really given me a better understanding of size and scope, and I think the experience will help me land a job after graduation.”