The Cretaceous-Tertiary boundary at Gubbio revisited - Vertical extent of the Ir anomaly

Details The Cretaceous-Tertiary boundary at Gubbio revisited - Vertical extent of the Ir anomaly The Cretaceous-Tertiary boundary at Gubbio revisited - Vertical extent of the Ir anomaly

Aug 1990

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1990e%26psl..99..206r&link_type=abstract

Earth and Planetary Science Letters (ISSN 0012-821X), vol. 99, no. 3, Aug. 1990, p. 206-219.

Computer Science

17

Anomalies, Cretaceous-Tertiary Boundary, Iridium, Italy, Limestone, Magnetic Properties, Sediments, Stratigraphy

Scientific paper

The classical Gubbio (Italy) Cretaceous-Tertiary boundary section has been resampled for both magnetostratigraphy and iridium. Paleomagnetic samples were taken over 7 m in the Maastrichtian and 6 m in the Paleocene. Previous results obtained a decade ago are confirmed. The reversal sequence is well defined and the individual reversals are somewhat more precisely located. A noticeable difference is the location of the position of the 29N/29R limit which may be lowered by 20-30 cm in the stratigraphic column. This would imply that the KTB occurs near the middle of chron 29 R. Iridium measurements were made on samples from both shales and surrounding limestone beds from 2 m below to 3 m above the boundary: these measurements indicate that Ir is associated with clay minerals. Concentrations in the two types of samples are indeed compatible when reduced to a carbonate-free basis. Iridium concentrations stand above background over almost 3 m of section, corresponding to half a million years based on magnetostratigraphy. This is likely to indicate a protracted duration of the (external or internal) source of iridium, on top of which the main (short-lived) KTB anomaly proper stands.

Affiliated with

Also associated with

No associations

Rating

The Cretaceous-Tertiary boundary at Gubbio revisited - Vertical extent of the Ir anomaly does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with The Cretaceous-Tertiary boundary at Gubbio revisited - Vertical extent of the Ir anomaly, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The Cretaceous-Tertiary boundary at Gubbio revisited - Vertical extent of the Ir anomaly will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1126201