[meteorite-list] K/T boundary-- Correction

From: E.L. Jones <jonee_at_meteoritecentral.com>
Date: Thu Apr 22 10:14:08 2004
Message-ID: <3EADC3DB.1050503_at_epix.net>

I err again but at least I caught it myself. The K/T boundary is the
Cretaceous/Tertiary---not the Triassic...DUH I was researching The
"Triassic Dinosaur Track Ways Corridor" in New England and Pennsylvania
when I paused to answer this mail.


In case anyone wants to know why "C" wasn't used in K/T. C is
carbonaceous. I believe €(Euro Symbol with only one tittle aka line) is
Cambrian.

In case anyone wants the rest of the story.....
To smplifiy nomenclature on geological maps a convention of
abbreveations are used to identify rock formations on geological maps
the first letter of the code for a rock formation (map unit) is its
geological time period. An Example would be "KMns" for the Cretaceous
Monach Formation, sandstone.

Several letters such as "P" were needed for other periods and so an
additional line was used to indicate which period it was refering to. A
plain "P" is Pennsylvanian A "P" with a tittle( top of a "T") across the
leg is Paleogene, An "IP" but conected so that the P has two legs is the
Paleozoic... rather than me explain take a look at
<http://srmwww.gov.bc.ca/risc/pubs/earthsci/bedrock/assets/fig-11.gif>
or the whole page on nomenclature and symbols at
<http://srmwww.gov.bc.ca/risc/pubs/earthsci/bedrock/bedrock-chap3.htm#bedrock.chap3.7>

Enough for me this week--runaway, go hide!...<sigh>
Elton


>
> "K/T" boundary means Cretaceous/Triassic(sic) boundary ...
Received on Mon 28 Apr 2003 08:14:19 PM PDT