Geologists use sketches such as this to determine what tectonic forces have shaped the landscape in this area part d making observations i simple yet thoughtul observation exposes the history of an outcrop. the sedimentary rocks in the gigapan image were formed as sediment accumulated as layers that stacked atop older layers. as layers became lower in the stack sequence and imestone, a rock that cant be identified visually but can be identified using field-based tests underwater movement of sediment may also create mixes of fine and coarse grains. this sediment becomes conglomerate, a rock clearly identfiable given its combined coarse and fine grains over time, some layers would have become exposed as the water retreated and the rock layers above them were eroded. additionally, some layers would have been tited by tectonic forces. covered by newer layers. they became rocks. if this area had been under water, the shells of organisms would have become if this area had been under water, the shells of organisms would have become limestone, a rock that cant be identified visually but can be identified using field-based tests. underwater movement of sediment may also create mixes of fine and coarse grains. this sediment becomes conglomerate, a rock clearly identifiable given its combined c0arse and fine grains. over time, some layers would have become exposed as the water retreated and the rock layers above them were eroded.