overburden
3
8.2
- noun
- /ˌoʊvərˈbɜrdən/
- Specialized
:
capa de estéril
- Oil extraction begins with mining techniques, specifically removing the layers of earth and overburden (a thick layer of clay, silt, and gravel) to expose the oil-laden sand.
Examples
-
Lava has made a channel for itself under the ground, and the overburden has collapsed, permitting us to see the course through which the lava flowed.
-
This beautifully preserved fragment of a kneeling figure on a curved base was found under 9 m of overburden in tin-bearing deposits in the main mine at Nok.
Academic text (1994) -
The top layer of river overburden contained considerable gold.
Fiction book (1997) -
After sorted wood and other organic fractions were processed, the overburden was taken to local projects as fill.
Academic text (1999) -
The crucial mining problem was to find a cheap, efficient method of stripping the overburden and sorting out the gold.
Academic text (1994) -
The river had a gradient of thirty feet per mile, ideal for placer gold, with only a six to eight foot overburden over slate-phyllite bedrock.
Fiction book (1997) -
But near the surface, under what farmers call dirt and miners call overburden, around where the rich veins used to run, there was plenty of low-grade ore.
Blog text (17) -
The miners used heavy machinery to remove the overburden before accessing the valuable minerals below.
-
Excavating the overburden revealed several ancient artifacts that had been buried for centuries.
-
Before mining could begin, the team needed to clear away the thick layer of overburden covering the site.
Surface Forms
Morphology
Etymology
The word overburden comes from over- 'above' and burden 'a load you carry', so it literally names the soil and rock lying 'above' a mineral deposit that must be removed to reach what is under it.