An unconformity exists between two rock layers when which geologic processes has occurred?

Unconformities: Geologic Evidence for Time and Process

Unconformity refers to an inter-section between rock layers that has experienced erosion or nondeposition. Unconformity is a disruption in rock records. Geologists can use it to understand geologic processes over time. Geologists look at the properties of rock layers to determine if there is an unconformity. They also examine for erosional surfaces or changes in lithology. Angulous discordance is when the rock layers of two are not in line. This indicates that the first layer was tilted, or eroded before being laid. Erosional surfaces can be flat surfaces caused by erosion. Leeder (2018) defines a change of lithology as any difference in physical characteristics between two rock layers. Unconformities are evidence of omissions in the rock records for a time period. This time frame is called the “unconformity gap”, and events occurring during it can either be classified as diastrophic (or epeirogenic).