Dust flux, Vostok ice core

Dust flux, Vostok ice core
Two dimensional phase space reconstruction of dust flux from the Vostok core over the period 186-4 ka using the time derivative method. Dust flux on the x-axis, rate of change is on the y-axis. From Gipp (2001).

Wednesday, February 24, 2016

Karst features of Guilin, part 2

In our last installment, I showed you some images of karst terrain near Guilin.

That is what is above the surface. Today let's look at what lies beneath.

Karst topography arises from dissolution of carbonate rock. But most of this dissolution does not occur at the surface. It occurs at depth. Today's feature concerns spelunking.

There are numerous caves in and around Guilin. Now, one of the charming things that the Chinese like to do in their natural parks is to "improve on nature" a little bit. In the caves, this was mainly in the form of strange lighting, but I suspect in a couple of areas, there was a little bit of construction as well.

Okay, I get it. You are trying to attract tourists to the caves, and they really aren't that interested in actual geology. Instead you talk about how this group of stalagmites over here resembles the Buddha giving a talk before the assembled monks, and this formation over here looks like ice cream, and this column over here resembles a dragon, and this one looks like Orlando Bloom smoking a joint (ok, I made up the last one).

The dissolution of rock makes the hole. If it is entirely underground, we call it a cave. Some of these features from holes or tunnels through masses of rock, like the examples above--most people don't think of these as caves.

On the flip side, once water levels fall, and the cave is dry, you start to get precipitation of minerals in existing spaces at all scales.

Stalactites, stalagmites, columns.


The caves above include Seven Star Cave in Guilin, and the Silver Cave in Yangshuo.

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