GEOL 1202 Plant Earth
My Pet Rock
The rock was picked up on Crystal beach, Halifax, nova scotia, Canada. Crystal beach is situated in Muskoka District municipality. The weather is mostly shinny with temperature ranging from 17 to 21 (degrees Celsius ) and windy ranging from 10 to 15 (Km/h w). The main entranced is characterized by fine sand particles which stretches to the far right hand side of the beach which contain several rocks (see image 1 below).
Image 1
Observation
An angular fragment rock with a smooth surface and beautiful outlook. The rock was a float with neighboring rocks looking similar although there were also slightly different rocks some two meters away. Some holes are visible on the upper surface of the rock which are likely to have been caused by harsh raindrops on the clay particles making up the rock. Besides these observable features, there are shinny pebbles firmly held together by fine sand particles which gives the rock a hard solid structure.
Mineralogy
The rock is composed of phaneritic angular grains of different sizes. The diameter of the rock measures about 85-95mm. The grains are tightly cemented with smaller particles that firmly holds all the particles making it relatively hard to break. Some grains are lustrous while others are brown due to the interlocked soil particles. In the outer surface, the brown soil particles are easy to break and washes off leaving small holes on the rock surface (see image 2).
Image 2
Structures
There are noticeable vesicles in the rock. These vesicles seemed to have been filled with clay which has gradually weathered leaving pebbles. Also, there are some traces of rain drops as can bee observed from the small holes on both the surface of the rock. Ripple marks are also present among the beautiful layers making the rock (see image 3)
Image 3
Rock Group
Based on the observable features above, this is a sedimentary rock. There are presence of different particles of sand, clay and pebbles that are firmly interlocked. These particles seem to have been cemented for a longer period which may have resulted from weathering process to give rise to the firm and beautiful rock of consisting of stunning layers of grain particles with a shinny particles that give it visibility among other rocks (See image 4). Hancock and Bilham-Boult (2005) posit that sedimentary rock are followed following a lengthy period of time whereby pebbles, clay and sand are gradually laid in layers which are then lithified to give rise to firmly held sedimentary rocks. There layer form reflects a sediment process leading to combination of fossils as well as minerals to give the rock a lighter color. These minerals also help in keeping the grain particles together. However, they argue that different sedimentation process give rise to distinct type of sedimentary rocks.
Image 4
Rock Name
This is Breccia sedimentary rock. It has grain particles that are greater than two millimeters, a typical characteristic of Breccia sedimentary rock. The particles are closely bound together with smaller particles that gives it a solid angular fragment structure. According to Hancock and Bilham-Boult (2005), Breccia sedimentary rocks contain grain particles which are over two millimeters in diameter. He also highlighted that this type of rock has an angular fragment with large grain particles cemented by smaller fine particles that gives them strong structures that are difficult to break (see image 5 below)
Image 5
References
Hancock, J., & Bilham-Boult, A. (2005). Geography. London : Letts Educational
