The meaning of `abruptnessʹ in the geological past

Some palaeoclimatic changes—and consequently also some environmental changes—were geologically abrupt, sometimes even fairly abrupt from a human point of view. One might question whether such abrupt changes in the global (or regional) climate are reflected, in one way or another, in the sedimentary record. It seems to be a simple and logical question, but it was never asked explicitly by geologists—until June 1998, when a conference at Stockholm University was devoted to the topic. One of the points discussed was: what does `abruptʹ mean in a geological context?