* Astronomy

Members Login
Username 
 
Password 
    Remember Me  
Post Info TOPIC: Loch Leven Crater


L

Posts: 131433
Date:
Loch Leven Impact Structure
Permalink  
 


The Ochil fault is associated with numerous subsidiary faults which extend across most of Scotland from eastern Fife to the Ayrshire coast. Despite more than a century of study by generations of geologists, the origin of these fault movements remains obscure. It is known, however, that the fault was active at the end of the Carboniferous period, approximately 295 million years ago.
The most interesting features, however, are revealed by microscopic investigation of some of the deformed sandstones of the fault plane. Under the microscope, the quartz grains in these rocks can be seen to contain minute defects in the crystal structure which are known as Planar Deformation Features (PDFs). These features are uniquely associated with a particular type of event in Earth history - Asteroid impact. They are produced by the extremely high pressure shock wave which is generated by the collision of an asteroid with the planet surface. No other natural process produces PDFs, although they have been found in rocks affected by underground nuclear explosions. Their discovery in rocks of the Ochil fault complex indicates that the cause of this episode of faulting was an asteroid impact in what is now central Scotland at the end of the Carboniferous period, 295 million years ago.

Source



__________________


L

Posts: 131433
Date:
RE: Loch Leven Crater
Permalink  
 


Title: A Triple Complex of Low-Angle Oblique Impact Structures in the Midland Valley of Scotland
Authors: B. J. Hamill

A linear chain of three elliptical impact structures has been identified in the Midland Valley of Scotland. These structures appear to have been produced by fragments of a large asteroid which disintegrated on impact. The primary impact site was the Loch Leven basin (56 12' N, 3 23' W), which is an elongated structure (18 x 8 km) with a central ridge and lateral terraces. Field evidence suggests an end-Carboniferous date for this impact, similar to that of several known North American craters and suggesting that this was a global event which may have been implicated in the disappearance of the forests of Laurentia and Laurussia.

Read more (PDF)

Google earth file: Loch Leven Impact Structure.kmz (2kb, kmz)



__________________


L

Posts: 131433
Date:
Permalink  
 

Title: The Loch Leven Crater: Anatomy of a Low-Angle Oblique Impact Structure
Authors: B. J. Hamill

The Loch Leven basin (56 12' N, 3 23' W) in the Midland Valley of Scotland has been identified as the site of the primary impact of a low-angle oblique impact event dating from the end of the Carboniferous. Together with two further downrange structures, it forms a chain of craters which appear to have been produced by fragments of a large asteroid which disintegrated on impact.

Read more (PDF)



__________________
Page 1 of 1  sorted by
 
Quick Reply

Please log in to post quick replies.



Create your own FREE Forum
Report Abuse
Powered by ActiveBoard