Enchanted Rock
Enchanted Rock is located near Fredericksburg Texas. It is a granite rock that rises 130m (425 ft) to the top, 1825 feet above sea level, and covers 640 acres.
At the base there is a dry creek bed of granite that has been cut by a series of fractures. Fine black rock along these fractures is called gouge. Fault gouge is comprised of little pieces of rock that was ground upward when the fault moved. Once you go up the trail and climb past the trees to the large space of bare rock, you are on the exfoliation dome. At this point you can examine the “coarse-grained porphyritic granite that makes up the majority of Enchanted Rock”. As you examine the surface, you will see how the granite magma cut into the surrounding rocks. When this occurred over a billion years ago, the magma was a combination of very hot liquid and crystals. Once you reach the mid-point of the climb you can see to your right a boulder-covered granite hill known as “castle tor”. An area on the rock that looks like a line down the slope is called an aplite dike. Several of these cut the rock; these consist of fine-grained granite with a sugary texture and minimal biotite. Dike describes the crack where molten rock has been inserted. As you climb up the front, a section of rock has a texture change. This appears to be a Ductile Shear Zone, a long narrow change that has a more fine grain consistency.
From the top of the rock you can see gnamma pits. These are areas where the rock has weathered, leaving pits in the tock that soil builds into and plants hold it in
place. The deeper the pit and soil, the larger the plants can grow.
From the top of the rock looking north, you can see a line of pink hills or small castle tors. Looking to the east you notice a flat topped hill, this is the Edwards Plateau. This is composed of limestone, which at one time covered the top of Enchanted Rock but eroded back, exposing the granite. Our tour now heads downward and we pass a weathering characteristic that looks like a doughnut ring with a gnamma pit in the center.
Along the decent we come across a Tent Blister, a sheet of rock that breaks in the middle and the center portion of the rock elevates into a point.
The shelf-edge includes carbonate-to-clastic facies transition and tectonic uplift and erosion of the carbonates followed by deposition of the clastics. The Saint Peter Sandstone is a well-sorted, almost pure quartz arenite deposited during a major mid-Ordovician low stand. Clastics spread across an exposed carbonate platform by transportation. This is shown by the well-rounded, frosted texture of the quartz grains.
I believe that this drumlin is closely related to erosion and accretion hypotheses of drumlin formation. This is because of its location being close to a steep valley wall.
The Chthamalus branacles fell off of the rack face and the Semibalanus rock became much more plentiful in that area of the rock.
The Don Valley Brickwork consists of many different layers of geological deposits, allowing us to observe and have a better understanding of how the sediments we see today are formed. The most bottom layer in the Brickworks are from the Georgian Bay Formation, and consists of grey- shale bedrocks. Fossils are often found in this layer and it is estimated that this deposit of sediments is around 445 million years old. Above the bedrocks is a thin layer of grey clay sand and gavels left behind by the Illinoian Glacier. This layer is called the York Till and occurred around 135,000 years ago. The next layer consists of a sandy deposit called the Don Formation, which is formed by the Sangamonian Interglacial Stage. Many plant and animal fossils are found in this layer due to warmer climate around 120,000 years ago. Above it lies the Scarborough Formation, which consist of clay and sand. This sediment likely occurred 115 - 106,000 years ago. The next layer above is the Poetry Road Formation, and consist of sand and gravel. This layer is likely formed during the early Wisconsin glacial substage around 106- 75,000 years ago. Higher is the Sunnybrook Drift which was formed 60 – 75,000 years ago. And on the surface, is the Halton Till, which was left behind by the final push of the Wisconsin Glacier.
The site visited on this day was informally known as the Bedrock Knob (NTS grid reference: 120 342). It is in an area where patches of limestone and exposed bedrock are common. The bedrock is part of the Preca...
water is kept in by a rock ridge on the floor of the corrie called a
...e morphed it into the quartzite that is seen surrounding the butte (4). Rocks that undergo this process are called metamorphic rock, which is the same as the rock seen years ago by dinosaurs and other extinct creatures. The quartzite rocks were formerly seafloor sediment that was forced upwards, and then surrounded by lava basalt flows. Once erupted through fissures and floods through out most of the area, lava flow eventually created enough basalt to form a thickness of about 1.8 kilometers (1). All of this basalt flow eventually led to the covering of most mountains, leaving the buttes uncovered. The igneous lava flows and loess is reasons that the Palouse consists of such sprawling hills, and rich soil for farming (2). In result of the lava flows, the Precambrian rock Quartzite was formed. And lastly covered by the glacial loess, which were carried by the wind.
"NPS: Nature & Science» Geology Resources Division." Nature.nps.gov » Explore Nature. Web. 05 Dec. 2011. .
Soon after the sea reached longer distance westward and the sandy tidal deposits were converted to deep water deposits. Mancos Shale is the name given to represent these deposits, which are comprised of organic material and small particulates. Another interesting fact to note is that this type of sediment consists of fossils. These remains can include prehistoric shell fish, shark teeth, and many other types of organisms. The hills seen at the foundation of the mesa in the Montezuma Valley are comprised of gray
On the outside it looks like a stereotypical rock, but on the inside you don't really know whether it's actually a rock or a crystal. You need to be open minded and willing to find out.
This sedimentary rock has hardened over the many years with sand shells, small pebbles, grains of sand and rocks of various sizes. In comparison to our 4.5 billion year old Earth, these sand shells might as well be brand new, when in reality they could be up to 1,000 years old. If the sandstone were to be replaced with calcite it would completely change the subclass of rock, it would then be chemical & organic limestone. The variation in sand stone is due to different rates of deposition and change in patterns of the sediment movement (Mc Knight, p. 384). These tightly compacted varying stones and shells will be weathered away by wind and waves over time and could eventually be reduced to a rock the size of your hand.
Froede, Carl R. “Stone Mountain Georgia: A Creation Geologist's Perspective.” CRS Quartely 31, no. 4 (March 1995): 6.
PLOT AND SUMMARY: Fablehaven by Brandon Mull is the story of two siblings Kendra and Seth’s adventure through their Grandparent’s magical reserve. The story starts with the two of them feeling uneasy about being at their Grandparent’s for the summer, but after drinking the magical milk that lets them see what’s really around them, they start to like it more and more. As they venture through the reserve they encounter many magical and dangerous creatures, these include; two satyrs with an obsession with electronics, a dying demon Graulus, a fairy queen, and witch that lives in a shack. After they release the evil witch Muriel, by undoing the last of her knots that imprison her, she unleashes the demon Bahumat.
and Metamorphic rocks can be found. There are also a lot of crusted plates, and violent
This seemingly boring process came to fruition in one of the most beloved National Parks in the United States of America. The Grand Canyon National Park is located in the state of Arizona. It is over 270 miles long and, at some points, is up to 18 miles wide and deep (History.com Staff). Its deep walls help provide a geologic history of the earth, because the many layers contain artifacts and information about the climate at the time (History.com Staff).