1: Title Page 2:Table Of Contents 3:Rock Layers Of The Region 4: Pikes Peak Granite(Layer 1) 5:Fountain Conglomerate(Layer 2) 6: Lyons Sandstone(Layer 3) 7: Lykins Formation(Layer 4) 8: Dakota Sandstone(Layer 5) 9:Niobrara Limestone(Layer 6) 10: Formation of Pikes Peak and Garden Of The Gods Overview 11: What Caused The Rock Layers To Emerge? 12: 3 Different Rocky Mountains 13: Formation of The Rocky Mountains/ Laramide Orgeny (continued) 14:Weathering and Erosion 15:Oxidation 16:Differential Weathering 17: Frost Wedging 18: Exfoliation 19: Ice Erosion 20:Faulting 21: Bibliography 22: End Slide/ Pictures of Us Slide # : Content

Pikes Peak Granite Fountain Conglomerate Lyons Sandstone Lykins Formation Dakota Sandstone Niobrara Limestone

The igneous Pikes Peak Granite was created approximately one billion years ago when a pool of magma 2 miles under earths crust worked its way to the surface and created many volcanoes and once the activity died, molten magma was left underground. Since the magma was miles underground it took thousands of years for it to cool. Once the magma was cooled it formed the coarsely grained granite we see today. Millions of years following the formation of Pikes Peak Granite, forces by the Pacific and North American Plates’ converging cause the snapping of the horizontal strata into diagonal an vertical positions.

The Fountain Formation is the complete layer including the Fountain Conglomerate. The formation was deposited around 295 million years ago. It is primarily made up of conglomerate and feldspar crystals, which make for a very non- cemented rock layer which crumbles easily. In between the Precambrian rocks and the Fountain Formation is an unconformity that represents a missing chunk of geologic history. The Fountain Formation was made by the sediments deposited by rivers and streams from the Ancestral Rockies compacting and creating the formation.

Lyons Sandstone is one of the sedimentary layers of rock that makes up Red Rocks, Garden Of The Gods and other spectacular formations in the region. The sandstone can be white, red or pink. This depends on the amount of oxidizing the rock has been through. Lyons Sandstone is one the thickest layers, created millions of years ago when the mile high sandstone was just sand at sea level. As time went on the ocean receded and the sand dunes were left and eventually packed down by the rock layers developing above. More recently( 65 mya) the forces of the Pacific and North American Plates’ convergent boundary pushed this and other layers of rock into a vertical position, projecting out of the ground.

This sedimentary rock formation made of calcium- magnesium carbonate is the second layer in the Garden Of The Gods’ rock strata. Lykins Formation contains siltstone, muddy limestone, and dolomite (Lykins Dolomite). In this formation you can find fossils of marine algae, as it was formed in a marine environment around 250 million years ago. The calcium carbonate eventually hardened to form limestone which is the main stone found in the formation. The layer today can be spotted by it’s wavy, light gray layers that are found between Lyons Sandstone and the Morrison Formation.

Dakota Sandstone part of the fifth layer in the rock strata of Garden Of The Gods. Dakota Sandstone makes up a large part of the Dakota Group(Purgatoire Formation, Lytle Sandstone, Glencarin Shale, and Dakota Sandstone). This sandstone was formed in a marine environment around 100 million years ago in the early to mid Cretaceous period. The sandstone was one sand underwater, with algae and other marine bacteria inside of it, this is why you can find the fossils of marine life in the layer today. When the water receded the sand was left and eventually packed down, much like the Lyons Sandstone.

Overview: About 65 million years ago stresses within the Earth pushed the Pikes Peak granite up, thus forming the mountains to the west of the park. As this mountain-building pressure increased it broke, bent, and tilted the overlaying sedimentary rocks into vertical positions that today are called the Garden Of The Gods. This exposed rock gives us a look into our earths geological history from millions of years ago up until present time.

Over time Pikes Peak and the rock layers surrounding it have rose due to tectonic uplift. This is the reason we have the opportunity to see rock layers over a million years old, above the surface of the earth. Tectonic uplift can be defined by, the raise of elevation due to converging plates. In this instance, the two plates causing uplift are the Pacific and North American plates. The convergent boundary caused the Pacific Plate to dive under the North American Plate, causing the continent to buckle, and uplifting the Front Range, giving us the Rocky Mountains.

Ancestral Rockies The Ancestral Rockies occurred approximately 300 million years ago. The erosion of these first Rocky Mountains formed the sedimentary Fountain Formation, conglomerate layers, and Lyons sandstone. These Rockies were uplifted from the seas by tectonic forces. Immediately, streams began to erode away the previously deposited marine sediments. As the land rose higher, the streams cut through the sediments and deeply into the underlying older granite, gneiss, and schist. They stripped away all of the marine rocks, about 300 feet thick, and 2,000 to 3,000 feet of the older rocks. Eventually, a range of mountains, the Ancestral Rockies, was sculptured in the uplifted land mass. Though the total uplift of the land may have amounted to 4,000 to 5,000 feet, the pace of erosion was such that the mountains were never very high. The Laramide Orgeny and the Laramie Rockies Less commonly known, the Laramide Orgeny was the series of tectonic events that created the second Rocky Mountains. The complicated processes started occurring in the late Cretaceous, around 75 million years ago. This created the Laramie Rockies which were eroded by a long time of erosion and weathering almost 40 mya. Many scientist find it hard to accept the theory that the Rockies were formed by subduction for two reasons they are considerably wider than most other mountain ranges that were formed by subducting plates. Instead, the major theory to explain the creation of the Rocky Mountains is divided into the following three parts: hot spots, mantle plumes, and shallow subduction zones. Pikes Peak and Present Rockies The Rocky Mountains we see today are also being eroded like the Ancestral Rockies and Laramie Rockies. They have been the height they are currently at for thousands of years.

First, it is believed that mantle plumes and hot spots were the primary contributors to the creation of the Rocky Mountains. Shallow subduction also contributed its part. Mantle plumes are columns of extremely hot rock that rises up through the mantle. Sometimes the magma will rise up and create a volcano, but in this instance it remains underground.(Walker 21) A hot spot can be defined as an active site of volcanism within the plate interiors. In this instance a mantle plume and a hot spot were located on top of each other. During the North American plate moving around the globe, this theory states that it moved over one of these hot spots, which was previously covered by an oceanic plate. This occurrence would have an influence on the way the mountains were formed. As the plate moved over the hot spot and mantle plume, the heat partially melted the continental crust. This made it less dense and allowed for the creation of the mountains over a greater width. This explains the observation that the Rocky Mountains cover such a wide area compared to other mountain ranges which have been formed by either continent-continent collisions, or through subduction zones. Subduction plays a role in this formation because resulted from a fast and very shallow angle of subduction. It was so shallow, that it did not create any volcanoes in the Western United States. Volcanoes did not occur because the zone where the melted rock was spread out was too large of an area. This prevented the concentration of enough magma needed in one place to penetrate the surface. When the spreading zone finally was subducted, the gap and its underlying magmatic plume continued to travel east under North America at a shallow angle, close to the root of the continental lithosphere. Thus all, forming the Rocky Mountains we see today.

Weathering and Erosion are always happening, but the different forms we see it in can be identified long after the erosion and/ or weathering have stopped. We know this by the clues we find in and around the rocks. While Garden Of The Gods has and currently is being shaped by many erosion and weathering processes, some of the very important and effective ones are Differential Weathering, Wind Erosion, and Oxidation. Today we see the beautiful structures with arches, red rocks, and pinnacles jutting out of the ground, but only these processes can explain why the park looks the way it does.

The form of Chemical Weathering, Oxidation of iron- bearing silicate minerals causes "rusting" of the minerals, this is what we see to left. The ‘rusting’ is what causes the red color of the rock. This chemical process can be represented by the equation 4Fe O 2 - > 2Fe 2 O 3 ‘Kissing Camels’

Differential Weathering is the result of hard, resistant rocks & minerals weathering and eroding more slowly that softer, less-resistant rocks & minerals. This presents beautiful plateaus, ‘steps’, and other rock structures. To the left we see Balanced Rock located at Garden Of The Gods, this is an excellent example of differential weathering because the surrounding rock and bottom was softer and more easily weathered than the rock we see today.

Frost Wedging is the process of freezing and thawing, causing the weakening/ fracturing of rock and eventually a piece of rock will fall off of the original place. The freezing and thawing happens within the cracks of the rock, as the water freezes it expands causing the rocks to separate, when it melt it leaves more room for water to come in, therefore spreading the rock more when it freezes.

As we can see to the left, Exfoliation the Mechanical Weathering process where the solid rock acquires fine cracks through pressure release jointing. More weathering opens up the joints further and loosened these slabs. A good visual representation of Exfoliation is peeling back layers of an onion. These slabs being loosened from the outside of the rock can be a hazard for hikers and rock climbers.

In the last Ice Age over 10,000 years ago, Glacial(Ice) Erosion carved out valleys and semi circles called cirques in Pikes Peak and throughout the Rocky Mountains. A cirque(as seen to the left) is where the glacier begins, leaving the semi-circle cutout in the mountain. As the ice mass moved down the mountain it left u-shaped valleys Pikes Peak’s form was greatly effected by the glaciers of the Pleistocene Epoch..

Faulting is the result of a fracture in the continuity of a rock formation caused by a shifting or dislodging of the earth's crust, in which two adjoining surfaces are displaced relative to one another and parallel to the plane of fracture.(Noblett 34) You can identify a fault by a place in rock strata doesn’t line up, the difference can be by a few centimeters(picture to the left) to multiple meters.

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