{"id":119,"date":"2012-01-17T15:01:20","date_gmt":"2012-01-17T20:01:20","guid":{"rendered":"http:\/\/web.colby.edu\/extinctsouthafrica\/?p=119"},"modified":"2012-01-19T07:44:51","modified_gmt":"2012-01-19T12:44:51","slug":"it-may-not-be-snow-white-but-whites-the-right-color","status":"publish","type":"post","link":"https:\/\/web.colby.edu\/extinctsouthafrica\/2012\/01\/17\/it-may-not-be-snow-white-but-whites-the-right-color\/","title":{"rendered":"It may not be snow white, but white\u2019s the right color!"},"content":{"rendered":"

Debate continues about exactly when the \u201cMother of Mass Extinctions,\u201d the Permo-Triassic event, actually occurred on land.\u00a0 A team of scientists published a paper in the journal Science last November in which they reported on a large suite of radiometric dates from ocean sediments that bracket the extinction event.\u00a0 But, to date, there are no well constrained dates for when the event occurred on land.\u00a0 The problem lies in the fact that volcanic ash beds, in which datable minerals occur, are unknown from the sediments deposited on the Late Permian land surface.\u00a0 With only three days left to this year\u2019s field season, and following several grueling long days of 10-12 hours under the Karoo sun, and a hard night\u2019s sleep (see Dan below with Lulu), we\u2019ve hit pay dirt (no pun intended).<\/p>\n

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Earlier today we found a new volcanic ash horizon in the vicinity of Graaf Reinet that is close to the reported Permian-Triassic boundary.\u00a0 The photograph below may not look like much other than some crumbly rock of various olive-gray shades, but a close examination of the image will reveal a white interval that may look like snow.\u00a0 As an aside, it is hHard to believe, but true, that the mountain passes here often receive centimeters of snowfall during winter, and there are signs warning travelers of road closings….in Africa.\u00a0 The snow white layer in the picture is volcanic ash, which we collected and will have analyzed by our colleague, Sandra Kamo, University of Toronto, for datable minerals.\u00a0 This is one of the Rosetta stones for which we\u2019ve been looking.\u00a0 To date, the Karoo has been unrelenting in giving up its secrets, with teams of scientists searching for such a horizon.\u00a0 It now may be the time for breaking the locks on the rocks.<\/p>\n