Wedge Geology Dragon

All Things Rock

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These massive ash layers were formed from pyroclastic flow from a neighbouring volcano. The variation in the layers is indicative of separate eruption events, were there was a base surge and then settling of finer particles in the atmosphere. 

If you look closely, you can see ‘lapilli’, which are the small circular formations inside the ash layer. These are formed when there was rain at the time of the ash cloud, causing particles to condense together in spherical shapes with the water droplets. 

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These caves are called lava tunnels. They are not like limestone caves, as they often close up to dead-ends after a mostly direct straight line. They are formed when a lava flow hardens at the surface, where it is in contact with the air, but the lava underneath continues to flow underneath. Once the flow has ceased, the shell of basalt remains, leaving a tunnel. Sometimes, as in the case of the second photo, the roof of the tunnel collapses and exposes the chasm below. 

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Plates of Planktonic (top) and Benthic (bottom) foraminifera (micro organisms that make carbonaceous skeletons) I drew to include with my project. I did a study on the forams of the North West Shelf of Australia (modern) to correlate the percentages of each found at certain depths, so that my supervisor had a modern analogue for paleodepths in his research.  Planktonic forams are so fragile, but look mostly the same. The benthic ones are so varied and pretty! 

Here is the poster I made; showing just because I like to visualise data and so I made a pretty cross section. As you can see, the percentage plankton data flips with the depth values at the 200m mark: 200m is the end of the “photic” zone, and so benthic forams don’t live further down than that (meaning the percentage of plankton, which fall to the ocean floor as they die, increases). 

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A salt lake. It’s red coloured because of the high concentration of iron in the soil. The first image shows the shoreline. The second shows the nucleation of halite crystals on a twig that had fallen into the lake. The final image shows the deposition of salt from the evaporating hypersaline lake... it encrusted the ground and preserved the ripples from the water. 

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Stratigraphy! There’s four distinct layers here. A freshwater aquifer is draining into the ocean between layers three and four (where the greenery is growing). Layers two and three are similar, they are both sandstone however layer two is finer grained and contains more magnesium deposition (darker parts). The first layer is unconsolidated material. 

Cliffs are wonderful for observing geology. They aren’t so wonderful to climb back up, though. 

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Anyone want to see what gold deposition in a quartz vein looks like? Yeah this isn’t it. That’s some pyrite, but there was plenty of gold excavated from that mine. 

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Deformed limestone strata exposed on a cliff face. It’s so cool to be able to see it like this in so much detail. 

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Speleothems! 

I love how different the calcite appears in different formations. The flow stones in this cave were remarkably shiny and glittery, but the other forms were really smooth. 

Top to bottom: - Stalactites and Straws (thin developing stalactites) - More developing stalactites and straws - Cross-section of a stalactite, seeing the deposition variations - Drapery (ear-like bands/folds) with the calcitic banding shown in the light - Stalagmites and Columns at the base of a pool - Flowstone - Detail of the flowstone - so sparkly!

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Megalania skeleton. 

Essentially, a dragon-sized lizard. It was an Australian megafaunal varanid (monitor lizard) of the Pleistocene. It’s actual size is still fairly debatable, based on the tail, but think about 7 metres. 

This guy’s my favourite megafauna... it’s cool to be able to visit the model and stand in awe of it. 

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One of my favourite minerals, because it makes things sparkly ~ 

It’s also so fun to play with. 

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Geology Dragon hoards all the samples.