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).

Thursday, October 9, 2014

Artisanal gold mining on the Loess Plateau (updated)

On the bullet train the other day, I caught a glimpse of an artisanal mining operation. I snapped several pictures of it as it flew past--not great pictures, as it is hard to capture something so close to the train when you are whipping by at 300 km/h.

I didn't know for sure that it was a gold mining operation, but there aren't too many other kinds of artisanal operations. However, this paper (pdf) confirms that artisanal gold mining is common in the Loess Plateau, at least near the border between Shaanxi and Henan provinces, which the route map confirms as the location of these photos.

The crew are just left of centre in this picture. They appear to be sucking up loess interbedded with gravels from the old river bed.

(Update: Now that I look more carefully, I think the concentrator has to be in that shack near the top of this photo. It makes more sense looking at its position relative to the tailings.)

"Tailings" pile (discarded fines from gravity recovery or just screening) of loess, which is composed of wind-borne silt-sized particles.

Gravel beds in the river channel--this river flows north, feeding the Yellow River. There are gold mines upstream on the river, according to the report in the above link. The equipment at the bottom is probably a concentrator, but the image isn't very clear.

Looks like there's been a lot of work down here too. All these photos overlap to an extent, but in some of them I am looking forward and in others I am looking back, so they are not easy to stitch together.


  1. Sweet, mercury pollution from budget gold extraction along the Yellow River tributaries. Hopefully the people living along that river get their drinking water from elsewhere.

  2. Don't worry, I'm sure they'll restore the environment after they are finished.

    And do you know how many millions draw their water from the Yellow River? At least the mercury is being divided up amongst tens of millions.