Drunk on Geomorphology - Castle Creek Winery Cabernet Sauvignon

 

The next Drunk on Geology is for the Castle Creek Winery Cabernet Sauvignon out of Moab, UT. 

Located in the heart of the red rock region of Utah, Moab is spectacular place to catch some gorgeous scenery. We picked up this bottle just prior to moving away from Utah in 2021 and it does not appear that the winery is not open anymore but we will celebrate it nonetheless. 

The front label offers a lovely artistic rendering of the red rock cliffs surrounding the town of Moab. The rocks cliffs surrounding Moab are made up of several rock units including the Navajo Sandstone. The Navajo Sandstone is Jurassic in age, ~180 million years old, and is a preserved prehistoric desert that used to cover large parts of the American west. Although it can be red in color, it is generally a tan to light brown color. The Navajo Sandstone can be found in abundance in the nearby Canyonlands National Park. 

The area known as Park Avenue in Arches National Park

The rocks on the label though look more like the ones seen in another neighboring National Park, Arches National Park. The rocks structures in Arches NP are composed of arches and tall pinnacles called hoodoos. It is this hoodoo and other cliffs that appear to be the focus of the artwork. The rock structures in Arches NP are comprised of the Entrada Sandstone. The Entrada Sandstone, overlies the Navajo Sandstone and is therefore a bit younger. It is a Jurassic age (~150 million years old) sandstone, formed from a coastal dune environment. 

The reason that the Entrada Sandstone forms these fantastic structures is because of a variety of regions. There being that this is the desert. It is very dry here and not enough precipitation falls to erode away the rock structures. Another reason is that the Entrada is very porous, allowing for the rain water to easily soak into the rock. As the water filters its way down into the sandstone it eventually reaches the base of the sandstone at the contact with the lower rock unit, the Carmel Formation. The Carmel Formation is a slightly older, Jurassic age, series of mudstones, siltstones, and sandstones, formed in a tidal flat environment. The much higher percentage of mud prevents water from flowing through it, so as the water flows through the Entrada, it eventually pools at the base of the sandstone on top of the Carmel Formation.

The third feature is the cement in the Entrada Sandstone. Many sandstones are cemented by silica, which is basically a dissolved type of quartz, a very hard mineral. Those types of sandstones are incredibly difficult to erode. The Entrada Sandstone, however, is cemented with calcite, a mineral that easily dissolves in slightly acidic water, such as the calcite in caves. As the water sits at the base of the Entrada, it slowly dissolves away the calcite cement. Then as the water freezes and thaws over the winter months, the expansion and contraction of the water breaks apart the rocks and carries away the sand. Leaving an ever widening hole at the base of the rock formation.

The text on the back of the bottle:

Castle Creek Winery overlooks the mighty Colorado River at the foot of dramatic red rock cliffs. It's a classic, rugged Western landscape. Our lush, green vineyards are a standout among the sapphire sky, red rocks and mesas. A combination of hot summer days, cool evenings, and Moab's dry climate are optimum for growing many of the best varietals. Using locally grown grapes, the winery has produced over 30 award-winning wines.

There are many rocks units in the region and not only these two rock units, but many of the other rock units within the Moab area, are also red in color, producing the name the "Red Rocks Region". The red coloring comes from differing amounts of iron oxide in the rocks, also known as rust. Varying amounts of iron oxide can tint a rock from a light yellow/tan color to a very deep-dark red. And it doesn't take much iron oxide at all to produce this effect. The iron oxide within these rocks is from when the rocks were originally deposited as sandstones and mudstones millions of years ago, forever staining them for all time.

References

https://www.nps.gov/arch/learn/nature/arches.htm