Fern spike Refers to the graphical representation of a rapid increase in fern abundance following an event detrimental to the environment. Ferns grow quickly in environments where there is little competition for survival, but then decline as more advanced species take over. Techniques used to map subsurface geology, using fundamental laws of maths and physics. These include gravity and magnetic surveying. Global warming Increase in mean global temperatures due to gases in the atmosphere insulating the Earth.
Icebergs melt and sea levels rise.
Gravity survey A survey to measure differences in density between an area and its surrounding rocks. Impact breccia A rock consisting of angular fragments thought to have been broken up and ejected from the crater during impact. Impact glasses Glass-like rocks formed by a meteorite impact. Impact-wave deposit Strata formed from deposition from large waves that are formed when a meteorite lands in the sea. The deposit may be indirectly linked to an impact, since the force of an impact may trigger other events that will cause these deposits to form e.g. Submarine slumping or tectonic readjustments.