[meteorite-list] Article on Hypothesized Scottish Precambrian Impact Crater

From: Paul <etchplain_at_meteoritecentral.com>
Date: Sat, 15 Oct 2016 17:40:00 -0500
Message-ID: <155214b6-a004-266c-5cc8-45dd3a072a21_at_att.net>

Massive crater under small Scottish town could be the
crash site of the first meteorite to hit the British Isles
Thought to be under the small town of Lairg, northern
Scotland, it be one of the 15 largest known craters.
By Press Association and Libby Plummer, Mail Online,
September 21, 2016
http://www.dailymail.co.uk/sciencetech/article-3800595/Massive-crater-small-Scottish-town-crash-site-meteorite-hit-British-Isles.html

It is certainly not the "first" meteorite impact in British
Isles, as there undoubtedly have been older ones.
Instead, it might be simply the oldest known impact in
the British Isles. (Presuming that older impacts certainly
have occurred and not be either preserved of found.)
Like all news articles, some of the substance of the
science has gotten either lost or misinterpreted in
translation to lay English.

An interesting observation is that the impact crater lies on a
piece of crust composed of Lewisian Gneiss that was part of
Rodina. At the time that impact occurred, Rodina was being
rifted apart to form Laurentia (prehistoric North America).
This piece of crust ended up as part of the Laurentian
continental margin. It was this rifting that created active rift
basins, in which the Stoer and Sleat Groups accumulated and
the ejecta blanket was buried and preserved. Thus, at the
time the impact occurred, it hit within what became
prehistoric North America and only much later ended up
on the opposite side of the Atlantic.

A recent abstract is:

Simms, M. J., 2016, A Buried Impact Crtare in Scotland.
79th Annual Meeting of the Meteoritical Society (2016)
abstract no. 6090.
http://www.hou.usra.edu/meetings/metsoc2016/pdf/6090.pdf

An older paper is:

Simms, M. J., 2015, The Stac Fada impact ejecta deposit and
the Lairg Gravity Low: evidence for a buried Precambrian
impact crater in Scotland? Proceedings of the Geologists?
Association. vol. 126, pp. 742?761
http://tinyurl.com/StacFadaImpact
http://tinyurl.com/StacFadaImpact002

Yours,

Paul H.
Received on Sat 15 Oct 2016 06:40:00 PM PDT