What is an unconformity?
Q: What is an unconformity?
A: An unconformity is a gap in the sequence of rocks in a geologic column, which separates two rock strata of different ages.
Q: Why does an unconformity occur?
A: An unconformity occurs because sediment deposition was broken for a time, usually because the land was above sea level at that time.
Q: How is an unconformity formed?
A: An unconformity is formed when the older layer is exposed to erosion for some time before deposition of the younger layer.
Q: How long can an unconformity last?
A: Many millions of years may separate the rocks above and below the discontinuity.
Q: Who discovered examples of unconformity in Scotland?
A: James Hutton discovered examples of unconformity in Scotland, at Jedburgh in 1787 and at Siccar Point in 1788.
Q: What does an unconformity represent?
A: An unconformity represents time during which no sediments were preserved in the region, and the local record for that time interval is missing.
Q: What is a hiatus?
A: A hiatus is the interval of geologic time not represented by an unconformity, also known as a 'gap'.
