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GEOLEX
- Search for lithologic and geochronologic units -

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Search Criteria
HELP is available for using this database! There is a Quick Search version of this form.

1. Select any number Geologic Age(s) (Help)
(definitions are available to help you):
ERA PERIOD EPOCH

C
E
N
O
Z
O
I
C
Quaternary Holocene
Pleistocene

T
e
r
t
i
a
r
y
late
(Neogene)
Pliocene
Miocene
early
(Paleogene)
Oligocene
Eocene
Paleocene

M
E
S
O
Z
O
I
C
Cretaceous Late
Early
Jurassic Late
Middle
Early
Triassic Late
Middle
Early

P
A
L
E
O
Z
O
I
C
Permian Late
Early

C
a
r
b
Penn. Late
Middle
Early
Miss. Late
Early
Devonian Late
Middle
Early
Silurian Late
Early
Ordovician Late
Middle
Early
Cambrian Late
Middle
Early

P
R
E
C
A
M
B
R
I
A
N
Proterozoic Late
Middle
Early
Archean
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2. Type of Unit (Help)
Lithologic Geochronologic Both
3. Unit Name (type "Dakota Sandstone", "Dakota", "Dak", etc.) (Help)
4. Citation Title (Help)
5. Citation Author (e.g. Smith, J) (Help)
6. State, Territory or Country (Help)

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Your are welcome.
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GEOLEX is a component of the National Geologic Map Database.
The National Geologic Map Database is managed by the USGS's National Cooperative Geologic Mapping Program in cooperation with the Association of American State Geologists.
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Project personnel.
Last modified: July 22, 2013
URL http://ngmdb.usgs.gov/Geolex/geolex.html

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