Understanding Clasts in Physical Contact
In geology, conglomerates are sedimentary rocks composed primarily of rounded fragments, known as clasts. The way these clasts are arranged and supported within the rock provides important information about how the rock formed.
The question specifically asks for the term used when these fragments, the clasts, are touching each other directly, establishing physical contact throughout the mass of the rock.
Defining Ortho Conglomerate
The correct term for a conglomerate where the clasts are in direct physical contact with each other, forming the main supporting structure of the rock, is Ortho conglomerate.
Key characteristics of an ortho conglomerate include:
- The larger fragments (clasts) are tightly packed and touch their neighbors.
- These clasts bear the load, meaning they support each other.
- The finer material, known as the matrix, fills the spaces remaining between the clasts but does not primarily support them.
Imagine a jar filled with tightly packed marbles; the marbles are the clasts in physical contact, and any space between them could be filled with sand (the matrix).
Distinguishing Other Conglomerate Classifications
Understanding the differences between the given options is key:
- Para conglomerate: This type of conglomerate is characterized by its matrix-supported framework. Here, the matrix holds the clasts apart, and the clasts are not necessarily in physical contact with each other. The matrix plays a significant role in supporting the weight.
- Intraformational conglomerate: This term relates to the origin of the clasts. An intraformational conglomerate consists of fragments derived from the erosion of older sedimentary layers within the *same* geological formation. While its clasts might be touching, the name emphasizes its depositional context rather than the specific clast arrangement (like physical contact).
- Oligomict conglomerate: This classification focuses on the composition of the clasts. An oligomict conglomerate contains clasts made up of predominantly one or very few rock types. This term describes the constituents, not the supportive structure or whether the clasts are in physical contact.
Conclusion on Clast Contact Terminology
Therefore, when the defining feature is that the clasts in a conglomerate are in physical contact throughout the rock, the appropriate term is Ortho conglomerate.
Important Questions from Miscellaneous
A stone is thrown horizontally from the top of a 20 m high building with a speed of 12 m/s. It hits the ground at a distance R from the building. Taking g = 10 m/s2 and neglecting air resistance will give :
A sphere of volume V is made of a material with lower density than water. While on Earth, it floats on water with its volume f1V (f1 < 1) submerged. On the other hand, on a spaceship accelerating with acceleration a < g (g is the acceleration due to gravity on Earth) in outer space, its submerged volume in water is f2V. Then:
A railway wagon (open at the top) of mass M1 is moving with speed v1 along a straight track. As a result of rain, after some time it gets partially filled with water so that the mass of the wagon becomes M2 and speed becomes v2. Taking the rain to be falling vertically and the water stationery inside the wagon, the relation between the two speeds v1 and v2 is :
Consider the following statements:
1. Distance between the longitudes becomes zero on North Pole and South Pole.
2. Distance between the longitudes is maximum on the Equator.
3. Number of longitudes is more than number of latitudes.
Which of the statements given above is/are correct?
One block of 2⋅0 kg mass is placed on top of another block of 3⋅0 kg mass. The coefficient of static friction between the two blocks is 0⋅2. The bottom block is pulled with a horizontal force F such that both the blocks move together without slipping. Taking acceleration due to gravity as 10 m/s2, the maximum value of the frictional force is :
