Monday, May 01, 2017

Spring Wildflowers and Rocks in Grand Canyon

I recently completed an 11-day Hiking and Geology Special Rafting Trip in Grand Canyon with Colorado River and Trails Expeditions. The wildflowers this season are excellent. We did some great hikes in perfect conditions - 80 degree days and 50 degree nights.

Our first hike was up inside North Canyon, famous to geologists for it exfoliated sandstone surfaces.

At the reflecting pool in the back of North Canyon.

Note how the exfoliation planes mimic the shape of the open space in the canyon. As the canyon becomes progressively opened through this massive sandstone (massive meaning that it lacks significant bedding features or fractures and so behaves as a coherent substance), the sandstone in the walls "pops out" parallel to the shape of the open space. On the walls, the exfoliated planes are vertical but they turn to horizontal on the canyon floor. It makes for striking forms.

Enjoying the solitude and stillness in a Grand Canyon tributary.

Dan enjoys looking at a conglomerate-filled channel that was cut into the underlying sandstone. Such channels are not uncommon in the Supai Group rocks. This happened in the Pennsylvanian Period, some 300 Ma.

Huge, cross-bedded sets of sandstone in there Supai Group in North Canyon. The cross-beds are very planar and might suggest a dune blowing across the floodplain.

We saw two Chuckwallas on the way back to the boats. I love the Latin name for this species, (Sauromalus obesus), the "Big bad fat lizard."

The second one was this little juvenile with its distinctive banded tail. Chuckwallas are strictly herbivorous.

The Marble Canyon section of Grand Canyon has wonderful springs that issue from the Redwall Limestone. Here trip participants observe a travertine encrusted spring on the wall of the canyon. Maidenhair ferns (Adiantum capillus-veneris) and Golden columbines (Aquilegia chrysantha) are often growing at these sites.

Inside Redbud Alcove at River Mile 39.

Slopes covered in yellow brittlebush (Encelia farinosa) downstream from the Eminence Break at River Mile 44.

The Sedesrt globe mallow (Sphaeralcea ambigua) was just beginning to bloom.

Desert fleabane (Erigeron divergens) was found up in Saddle Canyon at River Mile 46.

A typical day on the boats below Nankoweap Canyon. Both oar-powered trips and motor-powered trips have pluses and minuses. I used to strictly use oar-powered craft but have now switched to motor-powered. There are numerous reasons why and you'll just have to come on one of my trips to find out why.

Engelman hedgehog cactus (Echinocereous engelmanni) at the confluence of the Little and Big Colorado rivers.

Imagine 10,000 people a day coming down from the point on the skyline in a tramway. No way!

Part 2 to follow later in the week.

1 comment:

Gardner Cadwalader said...

Such a wonderful trip; great outfitters, excellent guides and food and great Grand Canyon.
Wayne's photos above are the best.
We all have been waiting for days for the second installment, Wayne, please.
Number 4