From Wikipedia, the free encyclopedia
Solid rock under loose surface material
Soil with broken rock fragments overlying bedrock,
Sandside Bay
,
Caithness
,
Scotland
Soil profile with bedrock labeled R
In
geology
,
bedrock
is solid
rock
that lies under loose material (
regolith
) within the
crust
of
Earth
or another
terrestrial planet
.
Definition
[
edit
]
Bedrock is the solid rock that underlies looser surface material.
[1]
An exposed portion of bedrock is often called an
outcrop
.
The various kinds of broken and weathered rock material, such as
soil
and
subsoil
, that may overlie the bedrock are known as
regolith
.
[4]
Engineering geology
[
edit
]
The surface of the bedrock beneath the soil cover (regolith) is also known as
rockhead
in
engineering geology
,
[5]
[6]
and its identification by digging, drilling or
geophysical
methods is an important task in most
civil engineering
projects. Superficial
deposits
can be very thick, such that the bedrock lies hundreds of meters below the surface.
[7]
Weathering of bedrock
[
edit
]
Exposed bedrock experiences
weathering
, which may be physical or chemical, and which alters the structure of the rock to leave it susceptible to
erosion
. Bedrock may also experience subsurface weathering at its upper boundary, forming
saprolite
.
[8]
Geologic map
[
edit
]
A
geologic map
of an area will usually show the distribution of differing bedrock types, rock that would be exposed at the surface if all
soil
or other superficial deposits were removed. Where superficial deposits are so thick that the underlying bedrock cannot be reliably mapped, the superficial deposits will be mapped instead (for example, as
alluvium
).
[9]
See also
[
edit
]
References
[
edit
]
- ^
Jackson, Julia A., ed. (1997). "Bedrock".
Glossary of geology
(Fourth ed.). Alexandria, Virginia: American Geological Institute.
ISBN
0922152349
.
- ^
Allaby, Michael (2013). "Regolith".
A dictionary of geology and earth sciences
(Fourth ed.). Oxford: Oxford University Press.
ISBN
9780199653065
.
- ^
Price, David George (2009).
"The Basis of Engineering Geology"
. In de Freitas, Michael H. (ed.).
Engineering Geology: Principles and Practice
. Springer. p. 16.
ISBN
978-3540292494
.
- ^
McLean, A.C.; Gribble, C.D. (9 September 1985).
Geology for Civil Engineers
(Second ed.). CRC Press. p. 113.
ISBN
978-0419160007
.
- ^
Swinford, E. Mac (2004).
"What the glaciers left behind?the drift-thickness map of Ohio"
(PDF)
.
Ohio Geology
. No. 1. Ohio Department of Natural Resources, Division of Geological Survey. pp. 1, 3?5.
Archived
(PDF)
from the original on 2 October 2012
. Retrieved
12 September
2012
.
- ^
Lidmar-Bergstrom, Karna
; Olsson, Siv; Olvmo, Mats (January 1997).
"Palaeosurfaces and associated saprolites in southern Sweden"
.
Geological Society, London, Special Publications
.
120
(1): 95?124.
Bibcode
:
1997GSLSP.120...95L
.
doi
:
10.1144/GSL.SP.1997.120.01.07
.
S2CID
129229906
. Retrieved
21 April
2010
.
- ^
"Digital Geology ? Bedrock geology theme"
. British Geological Survey.
Archived
from the original on 13 December 2009
. Retrieved
12 November
2009
.
Further reading
[
edit
]
- Rafferty, John P.
"Bedrock"
.
Encyclopædia Britannica
.
Archived
from the original on 29 July 2019
. Retrieved
1 April
2019
.
- Harris, Clay (2013). "Bedrock". In Lerner, K. Lee; Lerner, Brenda Wilmoth (eds.).
The Gale Encyclopedia of Science
. Vol. 1 (5th ed.). Farmington Hills, MI: Cengage Gale. pp. 515?516.
External links
[
edit
]
Media related to
Bedrock
at Wikimedia Commons