271 D4. Geochemistry

Wednesday, 7 November 2018
1:30 PM - 5:30 PM
Room 138-139

THE OCCURRENCE OF IRIDIUM IN AMBER: A NEW DISCOVERY

Paper number: 271-7
Program: Technical Sessions
Time: 3:00 PM – 3:15 PM

Authors

Abstract

Amber from a collection of Cretaceous specimens containing inclusions from Myanmar was tested for elemental constituents using a Niton XL3t 950 GOLDD+ hand-held analyzer by Thermo-Fisher Scientific in September, 2017. Iridium was detected in the first sample and confirmed in each of the specimens in the collection. Confirmation was achieved through repeated testing employing manufacturer recommended procedures and strict preliminary decontamination and analysis guidelines. The results were consistent with an Iridium concentration of between 10-15 ppm ±2σ, in ~25 samples, with differences in major elemental constituents remaining within concentrations considered to be negligible. Additional samples from the general locality were acquired and tested confirming consistency in results. Following that series of analytical results, samples differing in age and locality were acquired. These samples have not yet been tested. Of the new samples acquired, approximately a third are of the Miocene in age from Mexico, while the remaining samples are from Colombia, apparently much younger and more appropriately identified as copal rather than amber. These samples are pending radioisotope age dating. Work progresses as additional samples from different localities and ages are acquired for testing to determine whether Iridium is present only in the samples from Myanmar or whether it may be detected in amber from additional localities and ages. Further study is required to ascertain possible origins for this anomalous occurrence of Iridium in amber.

Geological Society of America Abstracts with Programs. Vol. 50, No. 6

doi: 10.1130/abs/2018AM-320027

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