The impact cratering record of Fennoscandia

Pesonen, L. J.; Henkel, Herbert

doi:10.1007/bf00117542

Cited by 24 publications

(6 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Geophysical signatures rank among the most prominent features that can be observed at terrestrial impact structures, and many of these craters have been initially recognized as local or regional, geophysical anomalies (e.g., Pesonen ). The nondestructive geophysical methods applied in the MEMIN project have similarities to geophysical methods used in field studies.…”

Section: Geophysical Surveying Of Experimental Impact Cratersmentioning

confidence: 99%

Experimental impact cratering: A summary of the major results of the MEMIN research unit

Kenkmann

Deutsch

Thoma

et al. 2018

Meteorit & Planetary Scien

View full text Add to dashboard Cite

This paper reviews major findings of the Multidisciplinary Experimental and Modeling Impact Crater Research Network (MEMIN). MEMIN is a consortium, funded from 2009 till 2017 by the German Research Foundation, and is aimed at investigating impact cratering processes by experimental and modeling approaches. The vision of this network has been to comprehensively quantify impact processes by conducting a strictly controlled experimental campaign at the laboratory scale, together with a multidisciplinary analytical approach. Central to MEMIN has been the use of powerful two‐stage light‐gas accelerators capable of producing impact craters in the decimeter size range in solid rocks that allowed detailed spatial analyses of petrophysical, structural, and geochemical changes in target rocks and ejecta. In addition, explosive setups, membrane‐driven diamond anvil cells, as well as laser irradiation and split Hopkinson pressure bar technologies have been used to study the response of minerals and rocks to shock and dynamic loading as well as high‐temperature conditions. We used Seeberger sandstone, Taunus quartzite, Carrara marble, and Weibern tuff as major target rock types. In concert with the experiments we conducted mesoscale numerical simulations of shock wave propagation in heterogeneous rocks resolving the complex response of grains and pores to compressive, shear, and tensile loading and macroscale modeling of crater formation and fracturing. Major results comprise (1) projectile–target interaction, (2) various aspects of shock metamorphism with special focus on low shock pressures and effects of target porosity and water saturation, (3) crater morphologies and cratering efficiencies in various nonporous and porous lithologies, (4) in situ target damage, (5) ejecta dynamics, and (6) geophysical survey of experimental craters.

show abstract

Section: Geophysical Surveying Of Experimental Impact Cratersmentioning

confidence: 99%

Experimental impact cratering: A summary of the major results of the MEMIN research unit

Kenkmann

Deutsch

Thoma

et al. 2018

Meteorit & Planetary Scien

View full text Add to dashboard Cite

show abstract

“…Geophysical signatures belong to the most prominent features recognizable in impact craters on Earth. Often crater structures are first recognized due to the discovery of geophysical anomalies (e.g., Pesonen 1996). This is because most impact craters on Earth are either heavily eroded and thus are not directly recognizable by their surface expression (typical impact crater morphology) or they are buried by sediments and therefore not directly accessible (e.g., Donofrio 1997).…”

Section: Introductionmentioning

confidence: 99%

Application of nondestructive testing methods to study the damage zone underneath impact craters of MEMIN laboratory experiments

Moser¹,

Poelchau²,

Stark³

et al. 2013

Meteorit & Planetary Scien

View full text Add to dashboard Cite

Abstract-Within the framework of the Multidisciplinary Experimental and Modeling Impact Research Network (MEMIN) research group, the damage zones underneath two experimentally produced impact craters in sandstone targets were investigated using several nondestructive testing (NDT) methods. The 20 · 20 · 20 cm sandstones were impacted by steel projectiles with a radius of 1.25 mm at approximately 5 km s )1 , resulting in craters with approximately 6 cm diameter and approximately 1 cm depth. Ultrasound (US) tomography and vibrational analysis were applied before and after the impact experiments to characterize the damage zone, and micro-computer tomography (l-CT) measurements were performed to visualize subsurface fractures. The newly obtained experimental data can help to quantify the extent of the damage zone, which extends to about 8 cm depth in the target. The impacted sandstone shows a local p-wave reduction of 18% below the crater floor, and a general reduction in elastic moduli by between approximately 9 and approximately 18%, depending on the type of elastic modulus. The results contribute to a better empirical and theoretical understanding of hypervelocity events and simulations of cratering processes.

show abstract

“…The Suvasvesi-North (5 km in diameter) and Suvasvesi-South (4 km in diameter) impact structures may form a doublet (Figures 1 and 6). The Suvasvesi-North is probably late Permian (260 Ma) in age, based on paleomagnetism and magnetic modelling (Pesonen et al, 1996), while the age for the Suvasvesi-South has not been determined. The Geological Survey of Finland drilled the Suvasvesi-North structure in 1992 in the center of a circular negative magnetic anomaly.…”

Section: Finlandmentioning

confidence: 99%

“…However, distal ejecta from the Siljan impact have not been identified; hence it is difficult to relate the impact event directly to late Devonian bioevents. Abels et al (1998;2002), Henkel and Pesonen (1992), Pesonen (1996) and Puura and Plado (2005). The table gives the age, the maximum present field diameter of the structure and information on crater morphology: C=complex crater, S=simple crater, e=exposed, m=submarine, l=lake, b=bay, tec=tectonically modified, bu=buried under sediment, r=rim exposed, u=central uplift exposed, f=crater field.…”

Section: Swedenmentioning

confidence: 99%

Impact structures and events – a Nordic perspective

et al. 2008

View full text Add to dashboard Cite

Impact cratering is one of the fundamental processes in the formation of the Earth and our planetary system, as reflected, for example in the surfaces of Mars and the Moon. The Earth has been covered by a comparable number of impact scars, but due to active geological processes, weathering, sea floor spreading etc, the number of preserved and recognized impact craters on the Earth are limited. The study of impact structures is consequently of great importance in our understanding of the formation of the Earth and the planets, and one way we directly, on the Earth, can study planetary geology. The Nordic-Baltic area have about thirty confirmed impact structures which makes it one of the most densely crater-populated terrains on Earth. The high density of identified craters is due to the level of research activity, coupled with a deterministic view of what we look for. In spite of these results, many Nordic structures are poorly understood due to the lack of 3D-geophysical interpretations, isotopeor other dating efforts and better knowledge of the amount of erosion and subsequent tectonic modifications. The Nordic and Baltic impact community is closely collaborating in several impact-related projects and the many researchers (about forty) and PhD students (some seventeen) promise that this level will continue for many more years. The main topics of research include geological, geophysical, and geochemical studies in combination with modeling and impact experiments. Moreover, the Nordic and Baltic crust contains some hundred suspect structures which call for detailed analysis to define their origin. New advanced methods of analyzing geophysical information in combination with detailed geochemical analyses and numerical modeling will be the future basic occupation of the impact scientists of the region. The unique Cretaceous/Tertiary boundary (K-T) occurrences in Denmark form an important source of information in explaining one of the major mass extinctions on Earth.

show abstract

The impact cratering record of Fennoscandia

Cited by 24 publications

References 21 publications

Experimental impact cratering: A summary of the major results of the MEMIN research unit

Experimental impact cratering: A summary of the major results of the MEMIN research unit

Application of nondestructive testing methods to study the damage zone underneath impact craters of MEMIN laboratory experiments

Impact structures and events – a Nordic perspective

Contact Info

Product

Resources

About