ASBOG Practice Exam

Which of the following depositional textures can help in reorienting strata?

1. Chemical precipitates, igneous intrusions, fossil beds

2. Graded bedding, slump bedding, lateral facies relationships

3. Ripple effects, clastic textures, biochemical layers

4. Bioturbation, mud cracks, vegetative layers

The correct answer is: Graded bedding, slump bedding, lateral facies relationships

Graded bedding, slump bedding, and lateral facies relationships serve as key indicators in stratigraphy that can aid in the reorientation of strata. Graded bedding refers to a layering style where sediment size decreases upward in a single bed, which often indicates the processes of sediment transport and deposition within a specific energy regime. This can inform geologists about the dynamics of the environment at the time of deposition. Slump bedding occurs when layers of sediments become unstable and slide down a slope, creating deformed strata that can indicate past movements, further assisting in understanding the geological history and orientation of the layers involved. Lateral facies relationships help to establish the distribution of sedimentary environments over a horizontal plane and give information on how different sediment types transition in space. By analyzing these relationships, geologists can infer the orientation of the strata and the environments of deposition. The textures mentioned in the other options, while relevant to sedimentology and stratigraphy, do not offer the same level of direct insight into the reorientation of strata.