Shatter Cones

Definition

Shatter cones are distinctive rock formations that form during the initial stages of a meteorite impact event. They are characterized by a radiating, cone-shaped pattern of grooves and striations on the surface of rocks, indicating the immense pressures and shock waves generated by the impact.

5 Must Know Facts For Your Next Test

1. Shatter cones are the only known macroscopic evidence of shock metamorphism, a process that occurs during the initial stages of a meteorite impact event.
2. The formation of shatter cones is believed to be caused by the interaction of the shock waves generated by the impact with the pre-existing fractures and heterogeneities in the target rock.
3. Shatter cones are typically found in the central uplift or rim of a complex impact crater, where the highest shock pressures are experienced.
4. The size and orientation of shatter cones can provide information about the direction and intensity of the shock waves during the impact event.
5. The presence of shatter cones is a key diagnostic feature for identifying impact craters, as they are not produced by any other known geological process.

Review Questions

• Explain the formation of shatter cones and their significance in the context of impact craters.
  • Shatter cones are formed during the initial stages of a meteorite impact event, when the intense shock waves generated by the impact interact with the pre-existing fractures and heterogeneities in the target rock. The resulting radiating, cone-shaped patterns of grooves and striations on the rock surface are a macroscopic indicator of the high-pressure, high-velocity conditions experienced during the impact. The presence of shatter cones is a key diagnostic feature for identifying impact craters, as they are not produced by any other known geological process. The size and orientation of shatter cones can also provide valuable information about the direction and intensity of the shock waves during the impact event.
• Describe the relationship between shatter cones and the formation of complex impact craters.
  • Shatter cones are typically found in the central uplift or rim of a complex impact crater, where the highest shock pressures are experienced. The formation of shatter cones is a direct result of the interaction between the shock waves generated by the impact and the pre-existing fractures and heterogeneities in the target rock. As the shock waves propagate through the target material, they create a distinctive radiating, cone-shaped pattern of grooves and striations on the rock surface. The presence and characteristics of shatter cones can provide valuable insights into the mechanics of the impact event, such as the direction and intensity of the shock waves, which are crucial for understanding the formation and evolution of complex impact craters.
• Analyze the role of shatter cones in the identification and study of impact craters on planetary surfaces.
  • Shatter cones are a key diagnostic feature for identifying impact craters, as they are not produced by any other known geological process. The presence of shatter cones is a clear indication that a circular depression in the surface was formed by a hypervelocity impact event, rather than by volcanic or other geological processes. Additionally, the size and orientation of shatter cones can provide valuable information about the direction and intensity of the shock waves during the impact, which is crucial for understanding the mechanics of crater formation and evolution. This information can then be used to study the impact history of planetary surfaces, including Earth, the Moon, and other bodies in the Solar System. By analyzing the distribution and characteristics of shatter cones, scientists can gain important insights into the impact processes that have shaped the surfaces of these bodies over geological timescales.

Related terms

Impact Crater: An impact crater is a circular depression formed in the surface of a planet, moon, or other solid body in the Solar System, caused by the hypervelocity impact of a smaller body with the surface.

Shock Waves: Shock waves are intense pressure waves that travel through a medium, such as air, water, or rock, at velocities greater than the speed of sound in that medium, typically generated by explosions or meteorite impacts.

Ejecta: Ejecta refers to the material that is thrown out or expelled from an impact crater, including fragments of the impacting body and the target surface material.