Welcome to our galleries page: Geovisions
The study of geology is the study of how our planet works and why the lands upon which we live and depend are the way they are. But it is also so much more. It is also the study of nature's beauty, the art-work of Mother Earth and Father Time combined. In our photographs we try to capture some of this time dependent beauty, and while we hope the images alone evoke in each viewer a sense of their own interpretation of the image, we realize that not all viewers are geologists, and a little commentary might be helpful and informative. We hope this works for you.
As many people know, there are three types of rock: igneous, sedimentary and metamorphic. Igneous rocks originated literally in fire and were the first form of rock in the planet's history. The granite rocks we described in the Eastern Sierra Nevada and Owens Valley sections are prime examples of these. Sedimentary rocks in contrast are made of fine grains of sand or clay or lime that are generally weathered and eroded from pre-existing rocks and are then transported by some aqueous or aeolian means to locations where they are then "deposited" either under the sea, in a river, in a lake, or even on land. Metamorphic rocks are any rocks that have been changed and transformed from their original state into something else because they have been subjected to very high heat and pressure while being buried deep in the earth's crust.
We confess to having a bias towards sedimentary rocks!! In our view they are the most varied - at least visually - and create the most interesting photographic subject matter. So we start out here with sedimentary rocks.
One of the most basic and fundamental principles of sedimentary geology - and most studies of sedimentary rocks - is the notion of "strata". Strata are layers of sedimentary rock which geologists often call "beds". As in this image, it is easy to see that strata are stacked one upon the other, each layer having its own set of physical characteristics that distinguish it from others. Each layer is separated from another by what geologists refer to as "bedding planes". The study, description, recognition and distinction of important beds and bedding planes is the study of "stratigraphy". Stratigraphy, for the most part, organizes around the concept of "superposition and original horizontality", notions first proposed in the 17th century by a Danish scientist: Nicholas Steno, who proposed that younger beds, or strata, sit vertically above older beds and that all sedimentary rocks, as those shown here in GEOV-001, were originally laid down in a horizontal disposition. In this image of a cliff face in southern Utah, it is not difficult to see that there are scores of strata, all laying near horizontally in what is often casually called "layer-cake" geology. It is also easy to see that different beds show different colors, thicknesses and respond to atmospheric weathering in different ways, some forming steep cliffs and others forming boulder strewn slopes. This is because different layers have different physical characteristics and erode at different rates. It is the interaction between these stacks of different rock types and the processes of weathering and erosion that creates the landscapes we see. Sometimes landscapes can be rugged with steep cliffs and canyons, as in southern Utah, sometimes they can be soft and rolling or sometimes they may even be completely flat. All landscapes result from some form of interaction between the underlying rocks and the overlying atmosphere, a process that is never static. It is a process that goes on all the time, everywhere. Sometimes the rate is so slow you may not see any significant change for millennia, but other times you may see dramatic changes over days and weeks, especially so where hillsides are steep and unstable and the weather severe. It is this interaction that provides photographers with a limitless resource of subject matter. The interaction of light and rock, color and texture, shape and disposition. Below are some of our attempts to creatively image the beauty of these processes.
First Rock Type: Sandstone
Sandstone is generally deposited by moving sea, river and lake water, or by wind. These moving media cause loose sand grains to move in waves, either at a small (ripple) scale or much larger scale in the form of dunes. Dunes, as we know from the modern day desert land forms, can be large, and for the most part, they are almost always in motion to some degree or another. The sandstones that wall the slot canyons in these images and in the cliff shown below were all deposited as large wind caused desert sand dunes ("aeolian" dunes). Today, we see the form of those preserved ("fossilized") dunes as stacked sets of beds that are "cross bedded". In the image below (GEOV-009), the viewer can see preserved in the rock face, five stacked dunes. The dune form is not complete because each one has been truncated by the following (overlying) dune. The four distinct, dark dividing lines sloping down from right to left are bedding planes and between each are what remains of the five dunes. The steeply dipping lines between each of the bedding planes are the remains of the so-called dune faces. In this example the dunes were migrating from right to left and each "cross-bed" is what remains of the migrating dune faces. These "cross-bed" forms when carved and shaped by modern erosional forces create all kinds of wonderfully photogenic forms and shapes that can be observed all over the desert south west of the United States.
In these images we focus on sandstone, a rock made up of many, many sand grains. Sandstones are some of the most common sedimentary rocks and can be deposited in a wide range of marine, fluvial, lacustrine and even terrestrial environments. The great states of Utah and Arizona have some of the most spectacular exposures of red sandstones in the world and some of the greatest networks of canyons in the world, including of course the Grand Canyon. Our canyon images are taken in what are known as "slot" canyons (their narrowness makes the name self explanatory) usually tributaries that lead to much bigger canyons further down-stream. They are so severely down-cut in such narrow galleries because of the highly energetic and violent nature of the torrents that rush down them during the severe storms this neck of the woods experiences during the monsoonal type rainfall of the summer months. These torrents flow through these narrow galleries at high speed and carry with them an abundance of boulders, pebbles and suspended sand grains that scour out the rock in a variety of forms. During dry spells, the sun-light shining down through these same galleries cast shadows in multiple directions and "warms" itself (making it redder) by bouncing back and forth from wall to wall. On the camera this effect is enhanced by using Fuji Velvia film, which is a saturated color film, and also by adding a 1A warming filter. In the digital world we can make equivalent corrections using Photoshop or Lightroom filters.
Next Rock Type: Mudstone
In complete contrast to sandstone is mudstone. Just as sandstones are predictably made up of sand, mudstones are made up of "mud", which to most people's way of thinking is a pretty messy, gooey, sticky, plain 'ol plain 'ol kinda stuff. Sticks to yer boots and can be a health hazard if you step in a wet pile of it and find yourself on your kiester!
But "mud" can be much more complex than one might imagine, especially chemically, and when it is buried in the subsurface it can transform into many other forms of multi-colored and multi-textured rock from mudstone to shale to slate to phylite and schist.
"Mud" is basically clay in water. That is, very fine fragments of many different clay minerals and possibly fine organic matter that come together initially in the form of a slurry which after deposition is progressively buried such that it is increasingly de-watered until the clay minerals become bound together at first in "laths" or "booklets" and then ultimately in fine laminae and ultimately beds of strata. It is a general rule of thumb that the harder and more severely bedded or cleaved the rock is, then the older it is and the more deeply it has been buried.
The amount and nature of the various clay minerals and organic matter in the mudstone, dictates what the clay becomes. Arguably, organic rich mudstones and shales have proven to be THE most important rocks we know of. The reason for this claim is that it is organic rich shales and mudstones that ultimately source all the oil and gas on which we have depended for petrochemicals, all forms of plastic and synthetic fabrics, and of course, energy supplies and most forms of modern transportation. In the oil and gas industry they are referred to as oil and gas "source rocks" and It is also these rocks that produce so prolifically when subjected to hydraulic fracturing.
In the image to the left we see mudstones and sandstones juxtaposed in dramatically contrasting poses. The mudstones form the back-drop.
Almost all rocks, but especially sedimentary and metamorphic rocks can be and almost always are to some degree, deformed. There are many forms and origins of deformation of solid rock, but the end result is invariably the same: a rather mind-blowing, seemingly impossible, frequently beautiful confluence of geology and physics. In the images that follow we illustrate different forms of brittle, plastic and soft sediment deformation.
Much more on this to come....