Geology

John McCullagh March 14, 2005

Earth is about four thousand seven hundred million years old.  Rocks, the subject of geology, are regularly re-cycled and the oldest known surviving rocks (in Greenland) are some three billion years old. 

John McCullagh May 14, 2004

Imagine standing on Warrenpoint beach looking towards Greenore.  You may dip your toe in the water but from this experience alone you must deduce – without travelling on or over the sea – the nature of water, and of sea-water, of seas and oceans and currents, their total volume and extent, their composition, what plants, […]

John McCullagh April 23, 2004

The Quaternary Period of the last 1.6m years has been marked by Ice Ages which were punctuated each 100,000 years or so by inter-glacials like the one we are presently in. 

John McCullagh April 22, 2004

The ’tilt, wobble and stretch’ of planet Earth on its celestial path contribute to long-term variation in environmental conditions that determine whether and where on Earth life can thrive or even be sustained.  It was a Yugoslav scientist who first closely studied these variations and proposed a theory based upon them, and named for him, […]

John McCullagh March 5, 2004

The Ring of Gullion, an igneous, intrusive, granitic rock, dominates the south-east portion of this map.  What is perhaps more remarkable is the Newry Granite [white] that has intruded into the centre of the Ring! The North of Co Armagh, bordering Lough Neagh, is dominated by estuarine clay [tan].  This owes its origin to successive […]

John McCullagh February 9, 2004

This working quarry near Hilltown is interesting for a variety of reasons.  It contains a unique seam of rock that is currently very valuable in many aspects of the building industry.  Its rock is blocky, hard, sharp and slightly flinty in texture.  The homogenous blocks are contrasted with, for example, the fissilated [wafer-like] shales more […]

John McCullagh January 22, 2004

The origin, nature and conditions required for the proliferation of life forms remains one of the great unsolved mysteries of science.  One possibility receiving serious consideration is that the earliest life forms came to us from space – perhaps from a nearby planet like Mars (and hence the interest in the experiments on that planet […]

John McCullagh January 8, 2004

One hundred million years [100,000,000 years] is a small step in geological time, barely enough for mountains to ‘fold’ or erode, or oceans to open/close.  Yet it is possibly too great a time for the human mind to comprehend.