Final answer:
The early geologist inferred that strata near Edinburgh with ripple marks were shoreline deposits of an ancient sea.
Step-by-step explanation:
The subject of this question is Geology and the grade level is High School. The early geologist who observed waves washing onto the shores and produced ripple marks in the sand was studying the formation of sedimentary structures. He noticed that similar ripple markings found in strata near Edinburgh were indicative of shoreline deposits of an ancient sea.
By studying these ripple marks, geologists can infer information about the past environments and geological processes that shaped the Earth's surface.