During the given time period, the same type of sediment is deposited throughout a basin. The strata deposited during one period of time are thus laterally continuous.

This statement is explaining a principle in geology known as the Principle of Lateral Continuity. This principle, proposed by Nicholas Steno in the 17th century, suggests that layers of sediment initially extend laterally in all directions; in other words, they are laterally continuous. This means that they spread out in all directions until they thin out or hit a barrier.

Here's a step-by-step breakdown of the statement:

1. "During the given time period, the same type of sediment is deposited throughout a basin." This part of the statement is setting up the scenario. It's saying that, over a certain period of time, the same kind of sediment (or small, broken-down pieces of rock) is being laid down across a large depression in the Earth's surface, known as a basin.

2. "The strata deposited during one period of time are thus laterally continuous." This part of the statement is applying the Principle of Lateral Continuity to the scenario. It's saying that the layers (or strata) of sediment that are deposited during this time period spread out in all directions across the basin. They continue to spread out until they become too thin to continue, or until they hit some kind of barrier, like the edge of the basin.

So, in simpler terms, this statement is saying that when sediment is deposited in a basin over a certain period of time, it spreads out to form a continuous layer that extends in all directions.