Tuesday 27 March 2018

Geology of the north of Ireland

Geology of the North of Ireland

1. The limestone and basalt coast of County Antrim

During the past fifty years I have made many trips to Northern Ireland, as this is where my wife was born and where some of her family still live.

2. Ireland and the new Atlantic Ocean

It is a beautiful country, but even more interesting beneath the surface. The north-eastern corner, Country Antrim, is particularly interesting and the geology is readily visible along its coast. Until relatively recent times (65 million years ago) there was no Atlantic Ocean and the land structure of Ireland was in continuity with North America.

3. Fairhead, the cliff scenery of the coast of County Antrim

Geological time seems to have started with the supercontinent Rodinia, which was assembled about one billion years ago (the age of the Earth is 4.5 billion years). With continental drift, Rodinia split into two with the formation of Laurentia (which gave rise to the north hemisphere land masses) and Godwana (which gave rise mainly to the southern hemisphere land masses). The gap between the two became the Lapetus Ocean, about 480 million years ago.

4. The break-up of Rodinia

Then there was a reversal. Lautentia and Godwana started to move back together to form the super-continent Pangea, about 400 million years ago. The Lapetus Ocean disappeared completely about 250 million years ago, but a remnant of its seabed is found in Ireland. The collision of Laurentia and Godwana resulted in the elevation of the Great Caledonian Mountain Range. Today its fragmented remains can be found in Norway, Scotland, the north of Ireland, Newfoundland and further west in Canada. The Caledonian Mountain range is represented in Ireland by the Sperrin Mountains in  County Londonderry. Being mountains of such antiquity, gathering has caused them be much reduced in height and rounded.

5. The Sperrin Mountains, County Londonderry, part of the Caledonian Mountain range

Further continental drift lead to the break-up of Pangea, about 65 million years ago. The separation of the North America tectonic plate from that of Europe led to the creation of the Atlantic Ocean and the continental arrangement that we see today.

6. The continental origins of Ireland

One geological feature of Ireland is that the northern part is derived from Laurentia whereas the southern part originated in Godwana and the Lapetus Ocean bed. 

There was time when the island of Ireland was submerged beneath a warm tropical sea. This led to a thick limestone layer, derived from the deposit of vast numbers of minute calcium-containing sea creatures.  The land level rose again (or the sea level fell) so that the surface of the land became limestone, chalk of the cretaceous period. 

7. Limestone seen in Ben Bulben, County Sligo, west coast of Ireland

The limestone surface allowed the appearance of luxurious plant life. This was on the super-continent Pangea, before the opening of the Atlantic Ocean.

8. Antrim before the lava flows

After the elevation of the limestone landmass of Ireland (and much of the British Isles), there was a long stable period of almost 200 million years. Movement of the North American tectonic plate away from Europe brought this to an end.

9. The formation of the Atlantic Ocean, with volcanic activity in County Antrim

We are aware of the mid-Atlantic ridge as an indication of the volcanic activity of tectonic separation, extending into the volcanic island of Iceland. However this process started in Ireland, and evidence of this volcanic activity can be seen in County Antrim. It is seen today as an active process in Iceland.

10. Volcanic basalts erupting though vents in the underlying limestone, forming the basalt plateau

Country Antrim is a large lava plateau that has covered the limestone (chalk). The first major lava flows over the limestone came to an end, then followed by sufficient stability to allow plant life to reappear. But then there was a second series of major lava flow, giving rise to the basalt formations of the magnificent Giant's Causeway.  

11 Basalt columns of the Giant's Causeway

12 The "organ pipes", Giant's Causeway

Major geological activity then came to an end as the line of separation of the North American and Euro-Asian plates moved away from Ireland into the new Atlantic Ocean.

13. The Antrim coast road

The story of these geological  processes are readily visible on driving along the Antrim coast road, which was first constructed in 1830.

14. A geological fault-line is through the sand, basalt to the right, limestone to the left. Whitepark Bay
There has been additional geological activity with the occurrence of faults in the land surface. These have allowed the basalts and chalk to become adjacent, when sections of  basalt slipped down to the level of the chalk. 

15. Ballintoy Harbour, basalt to the left of the submerged fault-line, limestone to the right

Fault-lines can be seen well in Whitepark Bay and also at the picturesque and geologically fascinating natural Ballintoy harbour. One side of the harbour (north, on the left of the photograph) is basalt and the other side (south) is limestone.

16. Basalt and chalk pebbles

The action of the sea has resulted in a mixture of black (basalt) and white (chalk/limestone) pebbles.

17. "Salt and pepper sand"

Further sea action has resulted in remarkable and perhaps unique "salt and pepper sand".

There other geological features in Northern Ireland. To the south of Country Antrim lies Country Down. 

18. Northern Ireland relief map

On the coast of County Down, on the Ards Peninsula, folded mudstone rocks of the bed of the original Lapetus Ocean can be seen.

19. Remnants of the Lapetus Ocean sea-bed, Millisle, County Down

But the most important geological feature of County Down must be the Mountains of Mourne. These are granite, which after spending millions of years beneath the surface being heated and becoming crystalline, were pushed up to a great height. 

20. "Where the Mountains of Mourne sweep down to the sea"

At present the Mountains of Mourne rise to an elevation of just under one kilometre, but it is calculated that the maximum elevation in the distant past was four kilometres.

21. Mountains of Mourne from Dundrum Bay

The erosion of the high mountains by the weather has resulted in a profusion of large rounded granite boulders. It must have been with difficulty and considerable skill that the fields of County Down became characterised by perimeter walls of Mourne granite stones.

22. A typical Mourne wall, constructed from Mourne granite

Ireland in general, and Northern Ireland in particular, is remarkable for its geological interest. It is also possible to see many examples the use of stone by humankind during the past six thousand years.

23. Dolmen, of which many are found in Ireland
24. New Grange, on the banks of the River Boyne, to the north of Dublin

Friday 9 March 2018

The Coronary Heart Disease Pandemic in the 20th Century

In 2013 I wrote one of my first Blog Posts drawing attention to the epidemic of coronary heart disease (CHD) that occurred in the UK during the 20th century. 

The onset of the epidemic

This has been supplemented by a further Post describing in detail the onset of the epidemic, which occurred after about 1924.  Much of the original work had been published in the British Medical Journal in 1963, by Dr Maurice Campbell, a highly respected and pioneer cardiologist in the UK. As with all epidemics, that of CHD had to become well-established before its presence could be  recognised.

The peak of the epidemic

I also described the peak of the epidemic in about 1970. This was the time that I was heavily involved in emergency medicine, and experience of "heart attacks" was then so very different from what we see today. We would see people, mainly men, admitted via the emergency department (where I worked) every day, in whom the clinical features of severe myocardial infarction (MI, heart attack) were glaringly obvious. They had experienced severe crushing chest pain, and about had 50% died before they got to the hospital: sudden death was a major clinical presentation of CHD. Those who made it to the emergency department were usually very cold and clammy with low blood pressure – they were in cardiogenic shock with high risk of acute left ventricular failure and pulmonary oedema. Recorded hospital mortality was as high as 35%. Cardiac defibrillation had only just been introduced and coronary care units were only in a stage of development. The ECG was used in diagnosis and usually showed the appearance of Q waves, very rarely seen today, MI being a much milder condition than it was then. Cardiac enzyme testing was undertaken but it was not usually necessary for diagnostic purposes.

The decline of the epidemic

I have also described the unexpected decline of CHD deaths after about 1970. The decline was slightly earlier in the USA. The presence of an epidemic had been denied by most people, claiming that the data were unreliable and that the condition had always been present. Most of these people had probably never attempted to investigate the data and had never read the papers of Dr Maurice Campbell. 

However the rapid decline of CHD deaths could not be denied: it occurred at a time of good quality data collection in many countries and standardised by the World Health Organisation (WHO). When it was realised that CHD deaths were in sharp decline, the great surprise  was such that in the USA a Bethesda Conference was called by the National Institutes of Health (NIH) in 1978, the purpose being to explain this unexpected decline.

The result was the establishment of the MONICA  project (Multinational MONItoring of trends and determinants in CArdiovascular disease). After 20 years it concluded that the decline of deaths was mainly the result of a decline of heart events rather than more effective treatment. No conclusion was reached concerning either the specific cause of the epidemic or its decline.

The pandemic

My Posts were concerned with the UK experience, which had been very obvious to me. I have been puzzled as to why so few people had recognised that there was a very serious epidemic of CHD deaths in the UK. I find the lack of curiosity very disappointing, especially a lack of curiosity that deaths from CHD had spontaneously gone into sharp decline.

But it was in reality much more than an epidemic. It was a pandemic, occurring in all continents simultaneously, and in effectively all nations in the temperate zones of the planet.

Dr William G Rothstein

The nature of the pandemic is now described in a new book entitled "The 20th Century Pandemic of Coronary Heart Disease". Its author is Dr William G Rothstein, Professor of Sociology Emeritus at the University of Maryland, Baltimore County.

The book is clear and concise, easy to read but of course the reading of data is slow but essential to full understanding. 

The author explains the problems with classification during the onset of the pandemic. The terms used were "angina pectoris" in the years 1900 to 1930, and the new term "diseases of the coronary arteries" after 1930. The International Classification of Disease (ICD) was introduced in 1948, with later revisions, now revision 11. The new term "ischaemic heart disease" (IHD) ,which is the same as the now more commonly used "coronary heart disease" (CHD), was introduced in 1968.

Rothstein confirms that the emergence of the pandemic of CHD "did not receive the attention that it deserved". This is true as people did not appreciate that there was even a national epidemic. 

I have stated previously that the rapid decline of the pandemic has been effectively denied by the medical profession, probably because a reason for it could not be envisaged. Rothstein's states: "The experts' fatalistic acceptance of of coronary heart disease as the result of lifestyles in modern societies produced amazement and confusion among them when coronary heart disease mortality rates began to decrease steadily and substantially in the 1970s and 1980s in the United States and other advanced countries."

I mentioned above that the surprise was such that the NIH Bethesda Conference was assembled in 1978. Rothstein draws attention to the comment from a participant in the conference: "The announcement for this reversal in the long-term trend [of CHD deaths] was received with great astonishment, both in the United States and other countries." This "astonishment" was kept very quiet in the UK, if not in other countries.

The epidemic in North America

The author has assembled data mainly from the USA. These have come from national and state statistics, but also from Life Insurance organisations, which in the early 20th century have been more concerned with accurate cause of death data than national and state registries. 

A simplified presentation of these data are shown in Figures 4 and 5 below.

Rothstein describes the epidemic of CHD in the USA as having the same time characteristics in all states, but the highest death rates in the north-east states. 

He describes the epidemic in Canada as having the same characteristics as in the USA.

The pandemic in other continents

He continues to identify that there was a true pandemic. The sudden appearance and decline of CHD deaths occurred in three continents continents simultaneously, North America, Europe, Australia and New Zealand.

He describes the pandemic in Western Europe, the UK having by far the best data collection. He identifies that mortality rates from CHD were highest in countries north of the 51st parallel (north of 51 degrees latitude), that is Ireland, UK, Belgium, Netherlands, Denmark, Norway, Sweden and Finland. They were lowest in the southerly European nations, Portugal, Spain, France, Switzerland and Italy. Importantly Rothstein notes that the data indicate that the peak and decline of the pandemic was simultaneous in all European countries, for all age-groups and for both men and women. Reliable data are not available for eastern European countries.

The book also describes the pandemic in Australia and New Zealand, with good quality data indicating a peak and decline of CHD death rates simultaneous with Europe and North America.

The pandemic appears not to have occurred in Central and South America. The exception is Argentina, which experienced the pandemic but in a milder form compared other continents. Central and much of South America are effectively tropical, such zones having not experienced the pandemic of CHD. Argentina is clearly in the southern hemisphere temperate zone. 

Age differences

Rothstein indicates that there appears to be a background form of CHD that was present before the pandemic, and is now appearing in the present post-pandemic era. The background CHD was and now is a disease of the elderly. The characteristic feature of the pandemic is that it caused the deaths of millions of people (mainly men) in middle age. It is this that is coming to an end.

The "non-causes" of the epidemic

The purpose of the book is to describe the pandemic, not to explain its cause. However Rothstein looks briefly at suggested causes of the pandemic of CHD and finds them all inadequate to explain it. He emphasises that the simultaneous rise and fall of the epidemic in all continents indicates a single and world-wide cause.

Diet - No dietary factor has been show consistently to be a a causative factor of CHD, and there was no significant change in the American diet between 1920 and 1950. Rothstein states that it is inconceivable that a single dietary factor could explain the rise and fall of the pandemic in all continents simultaneously. The appearance of "fast food" (which many consider to be bad for us) was in the 1970s, at the time of rapid decline of CHD death rates.
Cigarette smoking Although an accelerating factor of CHD, cigarette smoking cannot be regarded as the cause as toward the height of the epidemic, similar proportions of smoking and non-smoking proportions of the population died from CHD. Rothstein indicates that the rapid decline of the CHD pandemic occurred at a time when there was no reduction in lung cancer deaths, a reliable measure of cigarette smoking death.  
Male sex  
In all nations experiencing the pandemic of CHD the incidence has been about three times higher in men than in women.
At the time of the decline of the CHD pandemic the prevalence of diabetes was unchanged. Diabetes could not have been a significant causative factor of the CHD pandemic.   
The decline of the CHD pandemic has occurred at a time of concerns about the increasing prevalence of obesity.

Changes in lifestyle risk factors were not responsible for the emergence or decline of the CHD pandemic.

Statin drugs were introduced after the major part of the decline of the CHD epidemic and had no obvious impact.


In a previous book that identified the epidemic of CHD in the USA, Rothstein similarly eliminated a reduction of known risk factors as responsible for the epidemic and its rapid decline. In a review he was criticised "for not providing an alternative explanation". This is a false criticism. It was and still is not Rothstein's responsibility to identify the cause that has eluded all of medical science internationally.  Just because he cannot identify an alternative explanation does not mean that one of eliminated "explanations" must be correct.

However it is probably true that once all known risk factors have been eliminated as the cause of the epidemic of CHD, people somehow seem to "switch off" and stop thinking, as though they do not want to know the truth.

The cause

And so it is in Rothstein's book The 20th Century Pandemic of Coronary Heart Disease. The identification of the cause is not offered. Rothstein's purpose is to identify what the vast majority of people (including medical professionals) are unaware of: that during the 20th century the world witnessed one of the most serious pandemics of all times.

Rothstein states that it is "....inconceivable that the many advanced countries on three continents that experienced the pandemic underwent identical changes in their diets and lifestyles at the same times before the emergence of the pandemic and identical reverse changes in their diets and lifestyles at the same times before the decline of the pandemic."

I have suggested in a previous Blog Post that the only plausible explanation of the pandemic of CHD death must be an environmental biological agent, in other words a micro-organism. Only this would affect all continents simultaneously, with a rapid appearance of the disease and then a rapid decline as inherited herd immunity developed. A specific organism has not yet been identified, but a search unlikely to have even started. It is always after the acceptance of an epidemic (or pandemic) being due to a micro-organism that this line of investigation occurs (for example, AIDS and HIV).

CHD in the 21st century

Rothstein indicates that in the 21st century, in the post-pandemic era,  CHD became primarily a disease of the very old, as it had been a century earlier.

He suggests that the need for restraints in health care expenditure in many countries necessitate the re-evaluation of methods of prevention of the condition in healthy persons, including accepted risk factors. 

He wonders if statin drugs currently used widely in healthy people are necessary in the post-pandemic era.

Data presented

William Rothstein presented a great deal of supportive data in his book. His descriptive data from the USA was divided into the groups White Men, White Women, Non-white Men, Non-white Women. 

During the CHD pandemic deaths rates were lower in women than in men. The development of the CHD pandemic was slightly later in non-whites compared to whites.

I would like to display some of Rothstein's data in a simplified graphical format, and in the interests of simplicity I will display only the data for white men in the USA, but for all men in the UK.

Figure 1 All cause mortality in white men in the USA
In Figure 1 we can see data from the USA illustrating all cause mortality. In all four age-groups the death rates were lower in the years 1931-35 than in the years 1911-15. Obviously there are more deaths in the older age-groups.

Figure 2 Deaths from angina pectoris in white men in the USA
In Figure 2 we see in contrast that in all age-groups, deaths from the heart disease angina pectoris (a manifestation of CHD today) increased very significantly during the same time periods. Death rates more than doubled in the younger age-groups.

Figure 3 Deaths from disease of the coronary arteries in white men in the USA
Figure 3 show the other classification category of what we now call coronary (or ischaemic) heart disease. Once again there was a major increase, more than doubling during the first half of the 20th century. This clearly the onset of the pandemic.

Figure 4 Deaths from CHD in white men in the USA
In the 1940s the introduction of a new international classification of disease (ICD) led to the term ischaemic (later coronary) heart disease. In Figure 4 the US data assembled by Rothstein shows clearly the pattern of the pandemic in the USA, similar in all age-groups but more deaths in the older age-groups. In this figure we see the percentage of deaths from CHD in each age-group and not absolute death rates.

Figure 5 Deaths from CHD in white men in the USA
Figure 5 shows the same data but presented by age-group. The same epidemic pattern can be see in each age-group. Once again we see the percentage of deaths from CHD in each age-group and not absolute death rates.
In Figure 6 we can see more recent data, again for simplicity just white men in the USA. Between 1970 and 2010 there was a reduction of all cause death rates in all age-groups, especially in those aged 65–74. It is this that has led to a great increase in the elderly and very elderly in the countries that experienced the pandemic of CHD.

Figure 6 Death rates from all causes in white men in the USA

Figure 7 Deaths from CHD in white men in the USA

We can see in Figure 7 that the reason for the reduction of all cause death rate was an even more dramatic reduction of deaths from CHD. This is the clear decline of the US epidemic. Please remember that statin drugs only came use in about 1990, and into widespread use after 2000. The decline of the pandemic was "spontaneous", meaning that it was not explained by a decline of known risk factors.

Figure 8 All cause death rates in white men in the USA
Figure 8 shows the decline of all cause death rates in the four age-groups in the USA. Once again this is numerically mainly in the older age group (65–74) creating a rapid increase in the number of elderly.

Figure 9 CHD death rates in white men n the USA
Figure 9 shows specifically the decline in the US epidemic of CHD in the four age-groups, responsible for the decline of all cause death rates shown in Figure 8.

Figure 10 CHD death rates in elderly white men in the USA
In Figure 10 we see Rothstein's data on the  elderly in the USA. There is a major decline in CHD death rates between 1970 and 2010. It is interesting to note death rates being greater in the 75–84 age group compared to those more than 85 years old.

Figure 11 All cause death rate in men in the the UK
In Figure 11 we see Rothstein's data illustrating the decline of death rates from all causes  following the peak of the CHD epidemic in men the UK.

Figure 12 CHD deaths in men in the UK
In Figure 12 we see the decline of CHD deaths in the UK following the peak of the epidemic in 1970.

Figure 13 CHD deaths in white men in the USA
Figure 13 displays the USA epidemic of CHD in white men in the USA.
Figure 14 CHD deaths in white women in the USA
Figure 14 shows the same, but for white women in the USA. The epidemic is clear but not as dramatic as in men in Figure 13. The effective the epidemic in the USA in younger women was minimal.
Figure 15 CHD deaths in white men and women aged 65-74 in the USA
In Figure 15 we can see the USA epidemic in white men and white women aged between 65 and 74 years of age. It shows the much greater impact of the epidemic in men compared to women.


I would like to thank Professor Rothstein for permission to present this review of his excellent and informative book, and also for his permission to present his data in a simplified graphical format.