Tuesday, September 25, 2012

Images From My 2012 10-Day Geology Rafting Trip

Wow! I just concluded another great 10-day geology rafting trip in Grand Canyon. The trips just keep getting better and better. I'm off on another Grand Canyon adventure soon, this time on a Rim to Rim hike with the Grand Canyon Field Institute. But I thought I would at least post some of the pictures from the rafting trip. Highlights include seeing some brand new deposits from the intense runoff events that occurred during the summer monsoon. Look at these below!

I didn't take any pictures on the trip until river mile 76 at Hance Rapid, where a large debris flow entered the Colorado River in August.

The rock in the middle of the picture used to sit out in the channel of the river. But the new debris flow constructed a rocky pathway so that it is now part of the left bank.

New debris near the river's edge.

Looking upstream in Red Canyon where the debris flow originated.

While standing on the new debris fan, we got an excellent view of the Hance Rapid dike cutting across beds of the Hakatai Shale, a Precambrian red bed deposit of the Grand Canyon Supergroup.This is likely the unit that failed in the monsoon rain causing a cliff of overlying Shinumo Quartzite to collapse.

The vast majority of the boulders are Shinumo Quartzite suggesting that the debris was let loose close to the river and not within Paleozoic rocks up higher in the canyon walls.

Cruising through the Upper Granite Gorge above Phantom Ranch.

We talked a lot about metamorphic foliation, displayed vividly here.

Pt. Sublime on the North Rim of the canyon. Helen and I visited this viewpoint just three weeks previous to the river trip and I include a view from the point below, that looks back to this point on the river.

Looking back at the river from Pt. Sublime on August 12, 2012

A bighorn ram wanted to check us out at one lunch stop near Elves Chasm.

Evening on the river....

A time to reflect on the days sights....

A typical river camp. I did not set up a tent even once.

Barbara getting close to the Great Unconformity in Blacktail Canyon at river mile 121.

This years flooding left a large pool of clear water at the base of the chockstone cliff

A view downstream near Stone Creek of the angular unconformity that exists between the Tapeats Sandstone and the Grand Canyon Supergroup rocks. Can you see it?

If not, here is a close-up with all of the layers labeled. The yellow line represents the angular unconformity where more than half a billion years of earth history is missing in the rocks.

Near Tapeats Creek, there are huge landslide deposits that have filled former channels of the Colorado River. Can you spot the one here?

If not, here is the same photo with all of the labels.

Sunrise on the 6th morning below Deer Creek.

A quiet camp scene.

A huge fan of debris came down National Canyon at river mile 166 in July. The new material extends all the way to the rivers edge.

Wow! This view is of the upstream portion of the fan.

Here is a view of the downstream portion of the fan. The entire beach was inundated with rocky debris and rumors of 15,000 cfs coming down National Canyon are floating around.

No place to be in a flood.

The Grand Canyon

Alan and Carol

Cynthia and Tim

A volcanic dike cuts through the Bright Angel Shale just upstream from Lava Falls at river mile 179

Lava Falls as it looked on the morning of September 19 at just over 8,000 cfs.

Ready for the run of the Falls. Brandon did a great job getting us through.

I've never stopped at river mile 214 where the Bundy jars are located. The Bundy's are a local ranching family up on the Shivwits Plateau.

The jars are in an overhang of Tapeats Sandstone in front of numerous mescal pits. Here the group surrounds one of the pits.

Ripple marks in the sandtone

The summer rains really watered the desert in western Grand Canyon and I have rarely seen it so lush.

Green, green, green!

A lava remnant stands tall along a desert trail.

Mojave Desert vegetation in the western Grand Canyon.

Boatmen call this place "alien eggs."

Joe examines one close up. They appeared to be limestone blocks that were rounded and polished, then stained red by iron oxide.

This lava remnant is part of the Black Ledge flow that extends 84 miles down the channel of the Colorado River.

From the mouth of Three Springs Canyon at river mile 215.


Looking downstream along the Colorado River at Three Springs Canyon.

Aliona or rounded pinwheel carpeting the desert floor.

Our final attraction stop was at Travertine Canyon at river mile 229.

The grotto is spectacular.

Final shot of our group.

Brandon and Tom, our crew for the trip.