The principle of original horizontality actually helps geologists, not causes them problems. It's a fundamental principle in geology, stating that sedimentary rocks are originally deposited in horizontal layers.

Here's why it's helpful:

* Understanding geologic history: When we find sedimentary rocks tilted or folded, we know they were disturbed after their initial deposition. This helps us understand the geological events that occurred in the past, like mountain building, faulting, and erosion.

* Determining relative age: The principle helps us determine the relative age of rocks. If one layer is tilted or folded on top of another, the tilted layer is younger.

* Predicting rock formations: The principle helps geologists predict the arrangement of rock layers in a region based on their understanding of how sediments are deposited.

Where it can be tricky:

* Complex geologic structures: In highly deformed areas, the original horizontality may be difficult to decipher. This requires careful analysis of the rock layers and other geologic evidence.

* Metamorphic rocks: Metamorphic rocks have been subjected to intense heat and pressure, altering their original structure. In these cases, the principle may not be directly applicable.

Overall, the principle of original horizontality is a powerful tool for geologists. It helps them understand past events, determine the relative age of rocks, and predict the arrangement of rock layers.