Where is this immense gallery of scratched and polished carvings? Who was the sculptor? What was the clay?
Ideas, answers? Please add a Comment below. A post will follow, after I’ve recovered from Post Vacation Trauma.
Hayden Peak, constructed of sandstone and quartzite masonry on a Cyclopean scale.
“… the view of one of these mountain lakes, with its deep-green water and fringe of meadowland, set in a sombre frame of pine forests, the whole enclosed by high walls of reddish-purple rock, whose horizontal bedding gives almost the appearance of a pile of Cyclopean masonry, forms a picture of rare beauty.” —pioneering geologist Frank Emmons, after working in the Uinta Mountains in 1869 and 1871
Yellow sepals surround the pistil and stamens; petals are inconspicuous (source).
See the half-submerged brandy bottle?
Leaf stalks grow directly from large thick rhizomes firmly buried in mud. Blades can be a foot across.
“… there is one mountain range that commemorates early 19th century geologists and topographers who were influential figures in the geoscience field: the Uinta Mountains. More than 20 major geographic features in this mountain range (lakes, streams, and mountain summits and passes) bear the names of these important geoscientists.” [listed here]The sandstones and quartzites of Hayden Peak started as sediment in a rift valley back when the continent was being torn apart 750 million years ago (Late Proterozoic). The faults on either side of the peak are much younger—maybe created 65 to 40 million years ago when the range was being uplifted.
|The summit of Hayden Peak is 12,479 feet above sea level. Red lines mark faults.|
Next leg of the trip—down to the Green River, 2000 feet below the ridge crest.
The rock itself is far older than the mountain range. It began as sand in a deep rift valley, 700 million years ago.
The piles of sand, rock and dirt along the trail used to be part of a mountain range.
“This is what I love about geology, the opportunity to look far into the past and unravel a tiny bit of the surprising mysteries around us.” -- October 7, 2011
“For my knowledge and appreciation of the stromatolites of the Nash Formation, I thank one of the great legends of Wyoming geology, Dr. Samuel H. Knight. It was because of his “Precambrian stromatolites, bioherms and reefs in the lower half of the Nash Formation, Medicine Bow Mountains” (1968) that we were able to hike along Precambrian reefs, for Doc Knight drew a detailed map of reef locations (above, click on image to view).”
Samuel H. Knight, University geologist, a full century ago (source).
|Doc Knight in 1965, with phyllite and stromatolites (source).|
Before taking the tour, I plotted the tour stops in Google Earth.
Now stromatolites are restricted to harsh environments where predators can’t survive, for example the hypersaline waters of Hamlin Pool in Shark Bay, Western Australia (source).
Orange lichen highlights the laminar structure of fossilized stromatolites (pen points to original base).
These stromatolites are just before and upslope from Stop #1. The Snowy Range in the distance is a beach turned on its side.
|Sediments were tilted to vertical with continental collision (more info here).|
This famous stromatolite has been “affectionately named Big Daddy” by Boyd and Lageson.
|Entering the Valley of Stromatolites (looking south).|
Doc Knight’s map of the Valley of Stromatolites. He used a 4-foot protractor to accurately measure the arching layers (see Knight 1968 for details).
Note elongated stromatolite in center right of photo. Perhaps it was compressed before being turned to rock (original top is to right).
Close-up of glacially-polished digitate stromatolite, with alpine avens (Geum rossii).
Original top is on the right.
|View of opposite side.|
Looking upslope from road; original top is to the right.
|But why do domal structures give way to flat layers? Always so much to ponder!|
Water color painting of a stromatolite, by SH Knight. Doc Knight was an artist and a poet, as well as a pioneering geologist and beloved teacher.
My old friend Sparky, on an early Proterozoic beach in southeast Wyoming.
|Emmie is fascinated by early Proterozoic rocks.|
The Snowy Range is mostly Medicine Peak quartzite, which is highly resistant to erosion. That’s why the Range stands above the rest of the Medicine Bow Mountains.
Original beds (layers) are still visible (left of center, beyond lake; click on image for a better view).
On the west side of Mirror Lake, beds of sand-turned-to-rock are tilted to nearly vertical.
|Arrows point to a pebble layer in cross section.|
See that dark one?
It’s quartz pebble conglomerate!
An even better one!! It's so hard to quit searching ... just like in beach-combing.
|(10,847 feet above sea level)|
Snowy Range in the Medicine Bow Mountains. Arrow marks pullouts with geological signs (Google Earth).