Tuesday, 22 January 2013

Blog update #3

I’m getting a bit slack with new blog posts at the moment. The biggest problem I’m having is staying focussed enough to write a small spiel on a single topic. The 34th International Geological Congress in Brisbane last year resulted in a lot of new material relevant to the New England and Northern Rivers areas. So much so that I don’t know where to start!

Looking into the coming weeks (and months) I’d like to provide comments on research by Gideon Rosenbaum on Oroclines of the New England Orogen, Ben Cohen on Cenozoic intraplate volcanism and specifically information on the Main Range Volcanics and its implications south of the Queensland Border, David Branagan on Australias geologist history, plus others.

The above topics are additional to ones I really want to get to as soon as I can such as the Demon Fault, Quaternary sedimentation in the Richmond River Valley, the Tooloom gold fields as well as historical alluvial tin mining in the same area. I need to continue to discuss further aspects of the stratigraphy of the Clarence-Moreton Basin, I also really want to discuss the Mount Warning Central Complex. There just does not seem to be enough time in the day to write about all the geological things this region has to offer.

I'm also pleased that I've been able to be involved, albeit on a mainly strategic level with a local groundwater study, hopefully, in time I'll be able to write something on that... assuming we actually discover something of interest. 

As well as all of the above, the Bigscrub Landcare Group is also about to publish an article which I wrote on the volcanic geology of the region, nice to see how many different groups seem interested in what I'm keen on and are very complimentary about my writing. People are too kind!

Since starting this blog in 2011 I’ve had nearly 25 000 page views. I also vainly ‘google’ a few generic terms and find that the blog frequently comes up quite high in the search results. I’m sort of pleased with that. Of course please feel free to post a comment... especially if I'm wrong about something!

Well… I’ll get started on some more blog posts soon! In the mean time I just want to thank you for reading . I hope that people continue to find it interesting and useful. 

Sunday, 13 January 2013

Brown Under and Green on Top

A few months ago I took this photograph at a site I was working on (located mid-way between The Channon and Dunoon). It was a cold spring day with strong cold winds and rain threatening. I love the cold weather, it seems to make you feel more alive! Anyway, I thought it would be a good photo to share since it shows several attributes of our landscape and how  it was formed.

The south side of the valley between The Channon and Dunoon
Firstly the background geology. Where the photo is taken from is on a hill made from rock of the Walloon Coal Measures within a larger steep sided valley. The sides of the Valley are two rock formations more resistant to erosion which is the Miocene aged Lismore Basalt (not visible in the picture) and the Kangaroo Creek Sandstone (Cliffs of which can be in the picture). Here the Lismore Basalt overlies the Late Jurassic aged Kangaroo Creek Sandstone which in turn overlies the Jurassic Walloon Coal Measures. I’ve done some earlier posts which describe the nature of the Kangaroo Creek Sandstone and Walloon Coal Measures, just click on the respective link for more.

Rocky Creek runs through the valley today and it is the action of that creek that formed the valley. The creek must have cut through the lavas of the Lismore Basalt and eventually cut through the Kangaroo Creek Sandstone. Once it was through these hard layers it had an easier task of cutting into the softer and finer grained sediments of the Walloon Coal Measures. It is also possible there is some underlying structural control such as folding or doming but I’m not confident of the extent of this.

The top of the ridge in the photo shows a wet sclerophyll vegetation type, an open forest which contains many Eucalypt species reflecting the Kangaroo Creek Sandstones poor nutrient soils and rapid drainage. Also the ridge is quite exposed to direct sunlight and desiccating winds. Below the cliffs the Walloon Coal Measures start and here is found dry rainforest type vegetation reflecting the better, more nutrient rich and finer grained soils that are developed on the Walloon Coal Measures. The nearby Basalts also have the same vegetation type and in places approach wet rainforest especially in gullys and protected places.

In addition the picture shows the indirect and direct effect of Australians on the environment. The indirect effect is weeds. Many of the bright green trees in the middle of the picture are Camphor Laurel (Cinnamomam camphora) loving the dry rainforest environment. Right in the foreground is Wild Tobacco Bush (Solanum mauritianum) overtaking some of the grazing country. But you will also see a line of dead trees which is part of a successful effort to reclaim the weedy forest into quality native vegetation. The dead trees are poisoned Camphor Laurel with many hectares of forest in this area regenerated by staff working for the local water authority in an ongoing rehabilitation project.

Note that the stratigraphy of the Kangaroo Creek Sandstone has been recently revised since this blog post. See the this post for details.

Friday, 4 January 2013

A geological top 100

There seems to be a proliferation of variation to the theme of 100 things to see before you die. Geotripper did a geologists version back in 2008, it can be found here. Andrew Alden did a review of the list on 1 January which can be found here. I thought they were a little to USA centric so I've modifed theirs to include famous natural features that have a bit more of an Australian favour while maintaining the best ones from around the world. The ones I've managed to do are in bold text 40/100 - what is your score... or what do you want your score to be? Those that you can see in the northern rivers or very close by are underlined.
  1. See an erupting volcano
  2. See a glacier
  3. See an active geyser
  4. Visit the Cretaceous/Tertiary (KT) Boundary
  5. Observe a river whose discharge is above bankfull stage
  6. Explore a limestone cave
  7. Tour an open pit mine
  8. Explore a subsurface mine
  9. See an ophiolite
  10. An anorthosite complex
  11. A slot canyon
  12. Varves
  13. An exfoliation dome
  14. A large layered igneous intrusion
  15. Coastlines along the leading and trailing edge of a tectonic plate
  16. See the out of place palm trees of Palm Valley, Northern Territory
  17. Stromatolites
  18. A field of glacial erratics
  19. A caldera (no the Mount Warning “erosion caldera” does not count)
  20. A sand dune more than 100metres high
  21. Visit a fjord
  22. A recently formed fault scarp
  23. A megabreccia
  24. An actively accreting river delta
  25. A natural bridge
  26. A large sinkhole
  27. A glacial outwash plain
  28. A sea stack either an active one or a preserved one 
  29. A house-sized glacial erratic
  30. An underground lake or river
  31. The Great Dividing Range
  32. Fluorescent and phosphorescent minerals
  33. Petrified trees standing in place
  34. Lava tubes
  35. The Grand Canyon
  36. See a meteor impact crater on a scale that is comprehensible
  37. Swim on the Great Barrier Reef
  38. The Bay of Fundy, to see the highest tides in the world
  39. See a preserved sedimentary dyke (preserved liquefaction from an earth quake)
  40. Banded Iron Formations, in the Pilbara, to better appreciate the air you breathe.
  41. The snows of Kilimanjaro, Tanzania
  42. Lake Baikal, Siberia, deepest lake in the world with 20 percent of the Earth's fresh water
  43. Ayers Rock (Uluru), the classic inselberg.
  44. See a cliff face of classic columnar jointed lava
  45. The Swiss Alps
  46. Seeing rock cores being drilled
  47. The Li River, China, to see the fantastic tower karst that appears in much Chinese art
  48. The Dalmatian Coast of Croatia, to see the original karst
  49. The Gorge of Bhagirathi, one of the sacred headwaters of the Ganges, in the Indian Himalayas, where the river flows from an ice tunnel beneath the Gangatori Glacier into a deep gorge
  50. Visit Antarctica
  51. Climb Mount Warning, one of the most imposing volcanic ‘plugs’
  52. Land's End, Cornwall, Great Britain, with fractured granites that have feldspar crystals bigger than your fist
  53. Tierra del Fuego, to see the Straits of Magellan and the southernmost tip of South America
  54. Visit an active stratovolcano
  55. The Giant's Causeway and the Antrim Plateau, Northern Ireland, to see polygonally fractured basaltic flows
  56. The Great Rift Valley in Africa
  57. The Matterhorn, along the Swiss/Italian border, to see the classic "horn"
  58. Visited the Coorong and the lakes at the mouth of the Murray River
  59. Stood on the fossils of Maria Island, Tasmania
  60. Siccar Point, Berwickshire, Scotland, where James Hutton (the "father" of modern geology) observed the classic unconformity
  61. The moving rocks of Racetrack Playa in Death Valley
  62. See a lava lake
  63. See some the twelve apostles (well, some of them)
  64. The Burgess Shale in British Columbia
  65. The Channeled Scablands of central Washington
  66. See the Pinnacles in Western Australia (or even better, visited Cappadocia in Turkey)
  67. Grand Prismatic Spring at Yellowstone National Park
  68. Visited (or lived) in an underground house in Coober Pedy
  69. The San Andreas fault
  70. The dinosaur footprints in Lark Quarry, Winton Queensland
  71. The volcanic landscapes of the Canary Islands
  72. The Pyrenees Mountains
  73. The Moeraki Boulders on the East Coast of Southern New Zealand
  74. Denali (an orogeny in progress)
  75. A catastrophic mass wasting event
  76. Stood at the base of the Bread-Knife, Warrumbungle Mountains
  77. The black sand or the green sand-olivine beaches beaches in Hawaii
  78. Walk or climb through an Aa lava flow
  79. Looked inside The Superpit at Kalgoorlie
  80. Visited a waterhole in the Macdonnell Ranges
  81. The Tunguska impact site in Siberia
  82. Feel an earthquake with a magnitude greater than 5.0
  83. See dinosaur footprints in situ
  84. Find a trilobite (or a dinosaur bone or any other fossil)
  85. Find gold, however small the flake
  86. Find a meteorite fragment
  87. Experience a volcanic ashfall
  88. Experience a sandstorm
  89. See a tsunami
  90. Witness a total solar eclipse
  91. Witness a tornado firsthand
  92. Witness a meteor storm, a particularly intense (1000+ per minute) meteor shower
  93. View Saturn and its moons through a respectable telescope
  94. See the aurora borealis or Aurora Australis, otherwise known as the northern and southern lights
  95. View a great naked-eye comet
  96. See a lunar eclipse
  97. View a distant galaxy through a large telescope
  98. Experience a cyclone
  99. Burn your shoes on not-quite-cooled lava
  100. See the green flash

Tuesday, 1 January 2013

Do Geologists Fossick? (Happy New Year)

Oh dear, I thought I'd do better than I did in this quiz:


Andrew Alden put too many tricks in there for me to do very well at all. I'm so ashamed of how badly I won't even share my score!

The answers to the quiz can be found here:


I did however, get question 14 right...

Which of these would professional geologists probably not do: fossicking, frolicking, rimrocking, rocklicking?

When I was actually a professional geologist I would occasionally do some frolicking and almost certainly rocklicking, if I was looking for Uranium (I never got the chance) I might even be doing some rimrocking, but I technically could not be a fossicker. However, since my current profession is a step away from geology I don't consider myself a professional geologist and I can now go fossicking.

Just one of those weird things that has confused my Christmas. Speaking of Christmas, I hope all my readers had a lovely Christmas day. At least you don't have to be a professional to experience Christmas because thankfully Christmas represents a time where everyone who wants to can be freed by the actions of a person on our behalf.

Anyway, happy 2013 to all.