Tuesday, March 09, 2010

Geologic Journey to Death Valley National Park

Our trip began in Las Vegas on February 22 and on the way out to Death Valley we drove through the Red Rock Conservation Area. Here, gray Cambrian limestone (the darker hills with snow) has been thrust over the reddish, Jurassic Aztec Sandstone. Total horizontal displacement on the Keystone Thrust is about 65 miles from west to east, although it took many millions of years for this displacement to occur. The snow made an unusual scene for this normally dry area.

We needed to find protection from the windy conditions this day and found it at the Amaragosa Opera House and Hotel. This was our "worst" weather day and it was manifested only as 30 mph wind.

The northeast entrance to the largest national park outside of Alaska

View of the Furnace Creek Formation near Zabriskie Point. These fine-grained deposits erode easily in the "flashy" runoff conditions of the Great Basin Desert.

Our first hike on February 23 was over alluvial fan deposits to the mouth of Fall Canyon in the Funeral Mountains

These are the narrows in Fall Canyon. The rocks are part of the Cambrian Bonanza King Formation, a western equivalent to the Bright Angel Shale and Muav Limestone in the Grand Canyon.

Admiring a large horizon of breccia in the Bonanza King Formation. This breccia likely formed during one of the mountain building episodes that occurred in the area.

The narrows in Fall Canyon

Scotty's Castle is an interesting diversion in a small canyon northeast of Fall Canyon

February 24 - We took the scenic Artists Drive and hiked in a canyon that was quite steep. A colorful mixture of rock types gives the area the name "Artists Palatte". The greenish rocks result from reduced iron and the brown colors are from oxidized iron.

Jim's arms span the walls of this narrow canyon, cut into sandstone and shale of the Artists Drive Formation

A close-up of these shales and sandstones, deposited in the initial pull-apart basin in Death Valley about 8 Ma

The sedimentary rocks (lower 2/3rds of photo) are overlain by dense welded tuff (obvious cliff on top). During the creation of this initial basin, volcanic eruptions blanketed the area with hot ash.

The Natural Bridge in a canyon in the Black Mountains of Death Valley. Note the original course of the stream bed to the left of the bridge. These relationships document very fast incision as the valley floor is lowered relative to the canyons that issue from the mountains.

View downstream of the Natural Bridge

Howard inspects the lower plate of the Badwater Turtleback. His hands and camera are on the surface of this fault. The upper plate rocks are not present here - they were faulted farther down into Death Valley. Lying on the turtleback surface are recent gravels from the modern stream.

Steve and Carol admiring the view of Badwater and Death Valley during lunch.

Photo by Steve Keagy of his benchmark, placed on salt deposits at Badwater. This is the lowest spot on the North American continent, -282 feet.

Photo by Mary Clark Capito. Wayne and Howard high on oxygen below sea level. Or is it the geology exposed in this gem of a park?

Badwater and the floor of Death Valley

Chaos! We heard about the Amaragosa Chaos named by Levi Noble in 1941. These are rocks that have undergone four distinct periods of deformation, and thus looked like chaos to early geologists. We had to admit that the rocks looked very tortured and were glad we were not the ones who had to describe this mess.

The Confidence Hills in southwest Death Valley

February 24 - A hike up Mosaic Canyon is always an interesting trip. The Precambrian Noonday Dolomite is partially covered here in cemented gravel from Mosaic Wash. Gravel from a flood filled and covered the rock, then was cemented by calcium when it was still buried, and then partially eroded to give this exposure.

Deformed rocks in the Noonday Dolomite in Mosaic Canyon. We had much fun finding the many areas where these rocks had been faulted, folded, squeezed, stretched and generally messed up.

Look at this chert-rich "augen" in the canyon wall. During deformation (perhaps many miles underground when it occurred) this piece of rock was "rolled" into this position. Note that the augen is faulted as well.

Yes - this is Death Valley too. It's called Darwin Falls and is located only a short distance from Panamint Springs

Photo by Mary Clark Capito of Wayne at Darwin Falls

Telescope Peak (elev. 11.049) and the Panamint Range from the Panamint Springs Resort. The weather was awesome.

View southeast towards the Black Mountains and the floor of Death Valley at Badwater. This was taken from Aguerberry Point in the Panamint Mountains. The ridge in the middle distance exposes Cambrian and Ordovician strata.

Howard in Heaven! Traveling to this high point was one of the highlights of the trip for all members of our group.

Looking northeast from Aguerberry Point towards the Mesquite dune field in the valley floor. We had walked in the dunes earlier in the day.

February 25 - The Harmony Borax Works north of Furnace Creek

Great view of the Furnace Creek Formation in Golden Canyon. These gravels were derived in fans from the western side of Death Valley about 6 million years ago. This means that the valley was not as deep as it is today. How else could the gravel travel to these east side exposures?

Ripple marks in the Furnace Creek Formation document shallow water conditions at times on the valley floor

An outcrop of borate mineral in Golden Canyon

Our group hiking to borate mines near Mt. Blanco on the Twenty Mule Team Road

A final look of Death Valley from Dante's View. Badwater is visible on the valley floor and Aguerberry Point can be seen on the crest of the Panamint Mountains across the way.

Goodbye Death Valley! From Left to right, Wayne Ranney, Steve and Carol Keagy, Mary and Howard Capito, Janie and Jim Randall. We all enjoyed our geologic and scenic discovery of Death Valley and will return again!

2 comments:

Russell Ownby said...

Great post Wayne! This coincided nicely with a documentary we watched not long ago...Amazing how much water is in the area. Thx for sharing!

Beamer said...

Carol and I totally loved our trip to Death Valley with you and our gang! The geology and history associated with Death Valley make it a must-see for everyone. Great weather, great food, great memories and great friends!! Thank you Wayne for a fantastic adventure and learning opportunity!!

Steve:)