Titlebook: Impacts in Precambrian Shields; Jüri Plado,Lauri J. Pesonen Book 2002 Springer-Verlag Berlin Heidelberg 2002 Impact Craters.Impacts.Petrop

Confess

Geophysics and Petrophysics of the Popigai Impact Structure, Siberia,s overlying Archean crystalline basement. The structure is characterized by a gravity anomaly low of ?35 mGal amplitude, one of the largest magnitude gravity anomalies associated with a terrestrial impact structure. Superimposed on the gravity low is a concentric ring-shaped high, ~45 km in diameter

朦朧

U-Pb Analyses of Zircons from the Popigai Impact Structure, Russia: First Results,ted in ages of 1982 Ma for two of the zircons and younger ages for the other two grains. Minimum age estimates of the younger grains can be derived from their 912 and 306 Ma .Pb / .Pb ages. No shock features are obvious in these grains; thus, the Pb loss could be recent. The older ages represent age

amphibian

Impact-Generated Hydrothermal Systems: Data from Popigai, Kara, and Puchezh-Katunki Impact Structurssian impact structures — Popigai (diameter: 100 km), Kara (65 km), and Puchezh-Katunki (80 km). The dominant hydrothermal assemblages at all craters are clay minerals (smectites, chlorites, and mixed-layered smectites-chlorites), various zeolites, calcite, and pyrite; in addition, cristobalite, qua

TEM

flimsy

食道

LATE

Dictation

PATHY

Notorious

,Seismic Correlation of the Mj?lnir Marine Impact Crater to Shallow Boreholes,f the crater and another ~30 km outside the crater periphery. This correlation provides a detailed seismic stratigraphy for the impact-related deposits and post-impact strata. The biostratigraphic 142 ± 2.6 Ma age for the event determined earlier at the base of the post-impact succession should be c