Evolution, now this is a hard one. But don’t let that dissuade you from joining. This word leads me to much thought and much history. But we start with the dawn over the Niagara River in images. A beginning of another day of evolution to start.
evolution |ˌevəˈloō sh ən|
1 the process by which different kinds of living organisms are thought to have developed and diversified from earlier forms during the history of the earth.
2 the gradual development of something, esp. from a simple to a more complex form.
3 Chemistry the giving off of a gaseous product, or of heat.
4 a pattern of movements or maneuvers.
Talking about the garden evolving over time seems like a given, because many gardens do change. Changes in lifestyle, change how we approach maintenance and care. We may decide to do entertaining and the original patio, too small for the needs, grows. Yet, the original concrete must remain. We adapt to change.
It can be the busy life of a growing family, or it can be the loss of physical abilities by an aging gardener. In the case of the design being shown, the one owner was resigned to a wheelchair and still wanted to enjoy the property, it was designed to accommodate his needs. Gardens change, but do they evolve?
Interests change over time or mature to include a whole new genre of plants. Change is deliberate, or inevitable. It can be accidental and fortuitous if we are given plants to start anew. We can create and change. We also preserve. The Magnolia below was saved and became a focal point to the circulation route. The brick was re-used and added for accent.
Weather changes terrain and wears on the landscape. This is the weathering process. Weathering can inhibit or instigate progress. And inherent in process and progress, is evolution. But notice in my garden descriptions it is not evolve, but change. Change over time, not evolve over time. Change seems more deliberate, whereas evolve seems more innate. Evolve by definition, requires lots of time and happens via processes. Unless we are talking natural landscape, change seems more fitting to our home gardens. So let’s go long in time and natural in process.
No where better for time and process to be seen than in that of a river. The river channel provides a clear and concise cumulative history of the past flows. History is carved in the banks and walls and is evident in the river beds.
- marine limestone
Throughout the ages, nature has worked in conjunction with the wind, water and ice to create stratified layers of rock and earth in the Niagara region. The Niagara Gorge provides a snapshot of those layers which would otherwise go unseen.
The image in the middle is Lockport Dolostone.
Approximately 425 million years ago, Niagara was the bottom of an ancient tropical sea. Today fossils from that era can be found deep in the layers of rock of Niagara.
Because of the depth of the Niagara Gorge, many of these fossils have been exposed along the walls of the gorge. Not only does the river record its past, but it constrains the river’s future as well. It is dynamic system, constantly changing the river flow, all the while, the deepening gorge walls are constraining the path it takes. The river is constantly changing its banks and deepening its channel.
Below is a Trilobite from the Cambrian or Paleozoic era. It is from my collection, not from the Niagara Gorge, although they have been found here since they lasted until the mass die off 250 million years ago.
Yet, like the small garden affected by man, humans work on a larger scale and are a major factor in fashioning this world in change. So our rivers can be diverted, slowed or made uninhabitable. They can be cleaned, protected and favorably engineered. People play in the process of change and affect how change exhibits over time.
The Niagara Falls region spans a deep and long history. Whirlpool State Park, which I have been showing lately, exhibits a number of geological features. It features post-glacial river terraces of the Niagara River on top of the escarpment. It exposes the buried St. David’s Gorge on the Canadian side, which was a channel of an ancient river.
The exposed Ordovician – Silurian rock succession with tectonic faulting in the Whirlpool Sandstone at the bottom of the gorge gives indications of the variability of the amount of water flowing through the gorge and carving it out.
The river basin is a mere 12,000 years old, yet the gorge walls, created by erosion, have fossils dating back millions of year. And when I say millions, it is like 425 million as mentioned above, older than the time that the dinosaurs roamed, (source of much of this info). Can you imagine what evolution occurred in that period of time?
Eons ago our area was at the bottom of an ancient tropical salt water sea. Ancient specimens are being found deep under the soils of Niagara that are still today found at the bottom of our oceans. This is amazing to think how and what precipitated these changes. But there is evidence of this in the rock strata.
The Niagara Escarpment was covered with a sheet of ice 2 – 3 kilometers thick or around 1.8 miles of the Wisconsin Glacier 23,000 – 12,000 years ago. Glacial Lake Tonawanda was created with the retreat of the last Wisconsin Glacier. The lake was located east of the Niagara River and covered most of the western New York area to Rochester. As the Glacier retreated, the upper Lakes began draining into the lower lakes at five to six locations across the Niagara Escarpment.
Twelve thousand years ago, the Niagara River ultimately became the main water outlet over the Niagara Escarpment. The waters of a much larger Lake Erie began to flow over the escarpment into a larger Lake Iroquois (Lake Ontario). As the water flowed over the escarpment to the water below, the water began eroding through the glacial material and the limestone rock of the Niagara Escarpment to begin the formation of the Niagara Gorge. This really is evolution of an area. Weathering and time creating and recreating.
Four thousand – five hundred years ago, the crest line of the Falls was located north of the Whirlpool Bridge. I am not sure how this was determined, but this area is one of the most studied areas by a multitude of professionals, from archeologists, geologists, engineers, paleontologists, historians, and the list goes on.
Today, through increased water diversion and anti-erosion remedial steps, the rate of recession at the Horseshoe Falls has been reduced to a fraction of what it used to be historically. Through continued remedial efforts and further water diversion, it is projected that the amount of erosion at Horseshoe Falls will be reduced to approximately 1 foot every 10 years.
Today, erosion of the American Falls is estimated at 3 – 4 inches every 10 years. The water flow which is regulated and is currently insufficient to cause major erosion. This is a remarkable reduction in the effects of water, weather and time. Erosion is the largest factor which will alter its appearance in the future.
The most realistic outlook is that the Falls will continue to erode southward for the next 8,000 years at which time it would reach the limits of Lake Erie. The Falls of Niagara could once again become one if the Horseshoe Falls, once it has eroded far enough south, cuts off the water flow to the American Falls.
But the greatest effect of change comes with what can not be completely predicted. This is rock slides, like that which have occurred at the American Falls, shown here, collecting at the base of the falls. Although this was addressed by the Army Core of Engineers, it is still in chance of occurrence. If it continues, the height of the Falls will diminish by the amount of talus collected at the bottom.
Enter your post in the meme for Evolution below. Join our fun. The word this week was provided by Experiments With Plants. Our thanks for this challenge goes out to b_a_g.
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And our next word for November 2 will be…. Ephemeral. So put on your thinking caps. And Lingering will move on in the next poll. Get in those words you want to see in Photos folks. I want to start the poll for the Nov 16, W4W.