How Old is Buffalo Bayou? Where Does It Come From?

Geology Lessons on the Bayou

Want to learn about the geology and natural history of Buffalo Bayou?

Save Buffalo Bayou is partnering with board member and professional geologist Tom Helm, who also happens to be an outstanding naturalist and river guide, to offer floating classes on the geology of our 18,000-year-old mother bayou.

Paddle with Tom on a two-hour canoe trip down Buffalo Bayou and see some of our Pleistocene geologic history right here in the middle of Houston. Learn all about the formation of the bluffs and sandstone rocks during the last ice age. Find out why the banks are sandy and how sand moves downstream, why the river looks the way it does, and much more.

Geologist Tom Helm explaining 500,000-year-old sandstone on Buffalo Bayou.

Geologist Tom Helm explaining 500,000-year-old sandstone on Buffalo Bayou. Photo taken March 18, 2016

Where, When, Cost

The classes start at the Woodway boat launch in Memorial Park and float past the historic nature area of the park and the Hogg Bird Sanctuary. Multiple stops will be made along the way to examine features of interest. This is the stretch that the Harris County Flood Control District had planned to raze, dredge, reroute, and “restore.”

The schedule is weekends only. One to four persons can be scheduled with 72 hours’ notice. Groups larger than four persons (up to 30 persons maximum) need to schedule at least one month in advance.

Cost is $50 per person, which includes canoe and equipment, and light refreshments at the end. Discounts are available for academic faculty and students.

Note that the classes will be not take place if the flow of Buffalo Bayou is greater than 300 cubic feet per second (as measured by the Piney Point USGS gauge). At water levels above this, the sandstones are mostly obscured. If a trip is cancelled due to high water, students have the option of rescheduling or receiving a full refund.

For more information, contact Tom Helm.

Some Things We Learned Already: Why Mud Stinks

We floated with Tom recently for a preview of the geology class. Among the things we learned is why some of the mud stinks. The mud and the sand are filled with layers of organic matter, leaves mostly, and as the organic matter decomposes, it smells like … decomposing stuff. But it also builds soil for future vegetation. This process produces the mysterious oily sheen that you see floating on top of the mud sometimes.

We also learned to tell mud from sand from silt. (Hint: it’s a matter of the size of the grains.) Tom showed us how geologists rub the mud between their thumb and fingers to feel the size of the grains.

We studied the patterns in the sand, watched the grains of sand moving in the water, and learned about eddies and sediment deposition and transport. We saw a lot of animal tracks.

We learned to put the constantly changing bayou in the context of its natural process.

In every outthrust headland, in every curving beach, in every grain of sand there is the story of the earth.
Rachel Carson

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