The importance of being cratered: The new role of meteorite impact as a normal geological process

Abstract

Abstract-This paper is a personal (and, in many ways, incomplete) view of the past development of impact geology and of the newly recognized importance of impact events in terrestrial geological history. It also identifies some exciting scientific challenges for future investigators: to determine the full range of impact effects preserved on the Earth, to apply the knowledge obtained from impact phenomena to more general geological problems, and to continue the merger of the once exotic field of impact geology with mainstream geosciences. Since the recognition of an impact event at the Cretaceous-Tertiary (K-T) boundary, much current activity in impact geology has been promoted by traditionally trained geoscientists who have unexpectedly encountered impact effects in the course of their work. Their studies have involved: 1)

Geological overview and cratering model for the Haughton impact structure, Devon Island, Canadian High Arctic

“…It is now widely recognized that impact cratering is a ubiquitous geological process that has played an important role in the evolution of the terrestrial planets as well as the rocky and/or icy bodies of the outer solar system (e.g., French 2004). The number of recognized terrestrial impact structures continues to rise each year (see Earth Impact Database 2005), with estimates on the order of several hundred more still awaiting discovery (e.g., Grieve 1991).…”

“…However, the majority of these structures will likely be buried and/or deeply eroded. As noted by French (2004), "simply finding new meteorite impact structures is no longer enough." In terms of furthering our understanding of the impact cratering process, it is probable that the existing database of terrestrial impact structures offers the best candidates for study.…”

“…This paper summarizes the current state of our knowledge of the geology of the Haughton impact structure based on articles in this issue, together with other recent results published elsewhere, in addition to previous studies carried out prior to the HMP. To borrow a few words from a recent paper by Bevan French (French 2004), these recent studies at Haughton demonstrate the value of "new and closer looks at the existing terrestrial impact cratering record….and looking at once-studied rocks again and seeing them in new ways. "…”

Morphological, structural and lithological records of terrestrial impacts: an overview

“…These studies need to apply systematic approaches such as those adopted by field geology and mapping. However, it has been recently pointed out that comprehensive approaches are still lacking (King & Petruny 2003a;French 2004;Grieve & Therriault 2004). Some papers applying standard geological methods to the investigation and mapping of impact structures, based on studies of large impact structures such as Popigai, Puchezh-Katunki, Kara and some others, were published in Russian (Masaitis 1983;Masaitis et al 1980, and references therein).…”

“…The data obtained from specific regions has been summarised, among others, by Koeberl (1994), Glikson (1996), Masaitis (1999), Abels et al (2002), Dence (2002) and in the present issue. Although significant results have been achieved, the geological exploration of terrestrial impact structures continues, and many problems remain to be resolved by future research (French 2004). These studies need to apply systematic approaches such as those adopted by field geology and mapping.…”