Tuesday, 17 May 2016

Science, Philosophy and Politics

It is popular these days to start with a narrative and make the data fit in. Rarely do we think about alternative hypotheses other than our own already established professional narrative. Because researchers today rely on their reputation they must defend their theories or apparently loose credibility. Ironically, the most credible scientists are those willing to admit they may be incorrect.

Scientists today often delve into the areas of political intrigue. When this happens the scientists pet narrative becomes a fortress that must be protected. No one can criticize it because the scientist will see it as a personal affront since his whole credibility has been placed on the line. This in turn turns peers off from suggesting alternative hypotheses because they know if they make such a suggestion the whole thing will become a fight. Even suggesting an alternative that is not as popular as the politically expedient one can result in aggression, ostracism and public ridicule. No wonder scientists often find hiding in their laboratories the most rewarding experience!

When scientific concepts are backed by politics you know that you are onto ground that is not necessarily scientific. So with that in mind, here is a diagram that covers all the issues today that arise during scientific inquiry. This includes the moral, philosophical and political reasons for undertaking scientific research.
As a geological example that was publicized a couple of years ago in Nature on the problems with the mantle plume hypothesis. Even though the article recognizes many problems with the theory it demeans a group of scientists who have proposed alternatives that fit a wider range of data. It gently denegrates an alternative hypothesis by suggesting only a small number and therefore fringe group have advanced the hypothesis:
"No matter what the RĂ©union study finds, its results are unlikely to convince the few critics of the plume hypothesis."
Essentially, it is the anti-scientific idea of "consensus science" that is beginning to pervade all areas of inquiry. Some of these scientists responded  here is a link to a letter to the journal Nature. Unfortunately for the general public even to view this correspondence requires $18 just to read it (such is the nature of journals these days).

Saturday, 7 May 2016

Geology of the 'Big Scrub Rainforest' (Part 2)

The story of the 'Big Scrub' s preserved in the rock unit known as the Neranleigh-Fernvale Beds. The first post in this series is about this rock, the foundations of the region. This post deals with the period of big sedimentary basins which corresponds with the age of the dinosaurs. Some 50 or 60 million years elapse from the Neranleigh-Fernvale Beds until we come to our next period of rock formation.

The Big Basins

Walloon Coal Measures overlain by Orara Formation at Bexhill
This period begins in the age of the dinosaurs during the end of the Triassic Period. During this time tectonic forces became extensional, that is, the east coast of Australia was pulled and twisted apart, very little compression occurred. The crust became thinner as the once colliding continental plates began to relax and lowland basin-shaped regions formed. The thin crust allowed more volcanism to occur and the first geological units of the Ipswich and Clarence-Moreton Basin were formed. The Chillingham Volcanics consisting of lavas and volcanic ash was laid down in after 229Ma and this was subsequently overlain by units of lake and river deposits including the Evans Head Coal Measures, Laytons Range Conglomerate, Walloon Coal Measures and many other layers. By the height of the age of the dinosaurs, during the Jurassic great river valleys spread out from the mountains of the New England over our region. These rivers laid down great expanses of alluvial sand which were further overlain by other units. The great expanses of river sand are called the Orara Formation.

Today, like the Neranleigh-Fernvale Beds the sediments of the Clarence-Moreton Basin in the ‘Bigscrub’ area are mostly obscured by younger rocks. However, some of the Chillingham Volcanics seem to present in the Blackhall Range behind Wardell though this is difficult to identify. Rocks of the Orara Formation are present at the edge of Meerschumvale but are most obvious at Bexhill, indeed at Bexhill the Walloon Coal Measures are evident in the old brickpit. The Walloon Coal Measures are overlain by a sub-unit of the Orara Formation called the Kangaroo Creek Sandstone. This Sandstone forms nutrient very well-draining but poor soils. Lovely examples of the Kangaroo Creek Sandstone can be seen at Bexhill Open Air Cathedral or in the creeks near The Channon. This means that the vegetation on these areas consists of different plants to that of the rest of the ‘Bigscrub’. The soils in these areas cannot support the lowland subtropical rainforest that is the biggest component of the ‘Bigscrub’ unless they are well sheltered in a gorge.

Even though the units of the Ipswich and Clarence-Moreton Basins are dated from the age of the dinosaurs (the Triassic, Jurassic and Cretaceous Periods) no one has yet found fossils of dinosaurs preserved in any of these units in our ‘Bigscrub’ area. However, abundant fossils of plants and fish do exist in many units of the Clarence-Moreton Basin and dinosaur footprints have been seen in rocks of the Walloon Coal Measures in the Queensland part of the basin. Some fossil fish have been observed in the creeks near Nimbin. Along with the abundant coal during the Jurassic shows there was a very large quantity of organic matter and plants growing at the time. This was a time rich in life.

Sunday, 1 May 2016

Geology of the 'Big Scrub Rainforest' (Part 1)

Later this year it is intended that the Big Scrub Landcare group and many other contributors will release a book on people's connection with the 'Big Scrub'. It will be a multi-faceted book that introduces the emotional connection that people can have with a lovely part of the world. The book will even help picture the geological events that contributed to the formation of the amazing region. I understand that the book is intended to be launched in September at annual Big Scrub Rainforest Day. For those that would like some background information on the geology of the 'Big Scrub' I have provided a detailed outline of the rock types and events that went into building the foundations of this forest. There is a fair bit of information so I've broken this history into a series of blog posts. The book will have a different emphasis to this series of posts and will be a high quality visual feast. So I'll let everyone know more details about the book closer to the release date.

The oozy beginning

The history of the ‘Bigscrub’ starts a very long time in the past, yet it may be a surprise that by Australian standards the geology of our region is comparatively young. The oldest parts of Australia are 4400Ma (4400 million) years old but our little part of the Australian continent did not exist back then. It was not until 363-320Ma that the foundation rocks of our region were formed. These rocks are called the Neranleigh-Fernvale Beds

The Neranleigh-Fernvale Beds at Broken Head National Park near Byron Bay
The Neranleigh-Fernvale Beds are derived from the deep sea. In the Devonian Period sediments settled to the bottom of the deep sea crust. The sediments were at first very fine and mainly consisted of the microscopic silica based skeletons of algae called pelagic ooze. The amount of sediment was only slowly deposited but over a long time a great thickness accumulated. Occasionally thicker layers of mud would be deposited from submarine landslides which occurred at the edge of the far away continental land masses, rarely submarine volcanoes laid down lava that was quickly solidified by the deep, cold ocean water.

The process of plate tectonics means that oceanic plates move slowly under continental plates. Gradually, as this process continued during the Carboniferous our area came closer to the continental landmass as the oceanic plate was subducted (is pushed under) under the Australian continent. Tall active volcanic mountain ranges existed along the edge of the continent much like the mountain ranges of the Andes Mountains in South America today. As our area approached the continent it meant that the size of particles increased. Erosion of the mountain ranges and continuing submarine landslides created layers in the sediments called turbidite sequences. These are sequences where the bottom is coarse grained (usually sandy) and the top is fine grained (mud). This is because fine sediments take longer to fall out of the water. Subsequent nearby landslides would start a new layer with coarse grained sands followed by finer grained mud and so on.

Neranleigh-Fernvale Beds are quarried at many locations this is an old face at Teven
Eventually our part of the oceanic crust with its mass of deep sea muds and turbidite travelled to the zone of subduction where the collision with the Australian plate forced the oceanic plate under it. In this process the sediments that are on the oceanic plate are squashed and stuck onto the continent. Australia’s size grew as the process of accretion built up a thick wedge of submarine mud and turbidite. The pressure of the crustal plates sliding past each other squashed the sediments together and bent the layers into a complex arrangement of folds and faults. These are what we now know as the Neranleigh-Fernvale Beds.

As mentioned before, the Neranleigh-Fernvale Beds are the foundation rocks of our region. Today they form the ‘basement’ of the coastal Australian landmass from Gympie in Queensland to Broadwater on the Richmond River. However, in our region they are mostly obscured by younger rocks (discussed below) though it is possible to view outcrops of turbidite in several areas. These include on the Wilsons River at Laverty’s Gap, at Tintenbar and on the escarpment at Uralba between Ballina and Alstonville. Quartzite (from the silica rich sediment) is present on a hill near Nashua.

At the earlier stages of the carboniferous period the collision of the oceanic and crustal plates in our region stopped. The Neranleigh-Fernvale bed formation had been completed. The continent with its new additions ‘relaxed’ as compression eased and eventually stopped. Many more millions of years passed and what happened during that time is lost to history. No rocks are preserved in our region from the next time period known as the Permian. It is probable that the ‘Bigscrub’ area remained stable for a long time with only erosion being the most significant geological process.

Part 2.

Wednesday, 27 April 2016

Geology dance moves

I'm moving on from my job hoping for more opportunities in the future. I was disappointed with many aspects of my position, not in the least the resistance from bureaucratic processes to fit in with geological reality! This was particularly disappointing with the search for groundwater resources which I felt seemed encumbered by the processes rather than where water could actually be found. I guess that is government, but it is sad when you feel that the public money your organization is entrusted with is poorly spent. I could have paid for my salary many times over if my advice was taken in the first place. After two years they discovered that exactly what I had said was the case! several hundreds of thousands of dollars later my top two recommendations were identified by expert consultants as the best two recommendations and we hadn't even drilled yet! A lesson for all those people that think they can understand what the environment without actually going out from behind their desk.

So it is with relief that I move on to other things. Time will tell what will happen but in the mean time I might learn some dance moves courtesy of the Amoeba People .

'The Alluvial Fan' is my first starting move:
"We think you'll agree that few things are more dance-inspiring than cone-shaped deposits of sand, gravel and silt."

Monday, 18 April 2016

History Snippet: Drake

I noticed that the Northern Star Newspaper has an interesting snippet about historical copper mineral exploration near Drake. I thought It would be worth directing readers to the article.


I've been meaning to do a detailed post on the geology outlined by Grace Cumming who in 2011 did a very detailed survey of the region and put together an interesting model which illustrates that the mines and prospects just north of Drake are actually the remnant of a very large 400 square kilometre volcanic caldera. I will get to that soon! There is always a million interesting things in our region that I seem to never get the chance to cover them all. In the mean time I can only point you to one post I've done about the 'Drake mines'. http://nrgeology.blogspot.com.au/2012/12/drake-mining-managing-muddy-mess.html

If you are interested in the current explorer and operator of the mines just to the north of Drake here is the link to White Rock Minerals Mt Carrington project overview.

Monday, 11 April 2016

Most important movie of the year?!

An excellent song by the Ameoba People. I will be featuring some of their exceptional work all this month. Keep a look out for the Geology dance moves... and give them a go! 

Friday, 1 April 2016

A Brand New Month and a Brand New Eruption at Mount Warning

This morning started in a very interesting way. I wasn’t sure but there was some shaking of my house. I just thought it was a garbage truck going by so I thought little more of it. That was until I drove to work and looked out at Mount Warning. The clouds that hang around the peak in the morning (often to the dismay of tourists watching the sunrise from its peak) looked just a little odd shaped and darker. Again, I thought nothing of it.

What I didn’t know I had just experienced was one of the many small earthquakes that struck the region last night and continue today. You can see the latest seismic readings from geoscience Australia here. The clouds were actually not morning clouds but small amounts of ash and steam rising from the peak as a new vent opened up (the first in a very long time). Australia has not had a volcano erupt on the mainland since pre-colonial times and even those volcanoes erupted in Victoria and South Australia, no-where near our pretty part of the world.

The news websites are going very busy and I know that there are some interesting Instagram and facebook pictures going around already. I should have one of my own pictures up shortly. By all accounts there is little danger away from the mountain but people intending to visit the national park should be aware of the dangers present and not attempt to climb if they see any evidence of Holocene lava.