MAP LAYERS

LAYER NAME:

KEGEOLOGY

AUTHOR/CREATOR:

United States Geological Survey (USGS)

ORGANIZATION:

United States Geological Survey (USGS)

LINK URL:

http://energy.cr.usgs.gov/energy/WorldEnergy/WEnergy.html

CREATION DATE:

June 29, 1999

MODIFIED BY:

DATA AND INFORMATION MANAGEMENT UNIT

UNDP_SOMALIA

MODIFICATION DATES:

23/04/2001

ABSTRACT:

The purpose of digitizing the geologic map was to allow us to have a geologic base on which we drew the boundaries of the geologic provinces.

The World Energy Assessment created geologic maps of 7 regions. These regions were joined with edge matching or checking for feature description by the Global GIS team. The user is warned there will be discrepancies on bordering features. The regions are described in the Geologic Provinces of the World full metadata files. The geologic maps were digitized so that we could use the geology as a general guide to draw the boundaries of the geologic provinces.

CONSTRAINTS:

 

Portions of this database covering coastline and country boundaries contain intellectual property of Environmental Systems Research Institute, Inc.(ESRI), and are used with their permission. End users are permitted to use these data sets for their own internal use, including derivative work, but are prohibited from using and redistributing these data individually or in a derivative work to third parties.

DATASET SIZE:

544KB

STATUS

BOUNDING COORDINATES

 EAST:        43.9431                        NORTH:        8.8044

 

WEST:        31.9862                        SOUTH        -5.9274 

POSITIONAL ACCURACY:

It is not possible to calculate a definitive measure of the horizontal positional accuracy of this coverage because it is a composite data set compiled from a variety of sources using a variety of methodologies. Positional accuracy is dependent upon the extent of geologic knowledge available about the area delineated for each assessment unit. This includes the density of oil/gas field center points and well locations in the Petro-consultants Exploration and Production Database (1996). The maximum possible accuracy is twice the fuzzy tolerance of 500 meters, or 1000 meters.

COORDINATE SYSTEM:

DECIMAL DEGREES

DATUM:

WGS 84

MAP PROJECTION:

GEOGRAPHICAL

FORMAT

ARCVIEW 3.1, SHAPEFILE.

 

TABLES

SOURCE:

United States Geological Survey (USGS)

SOURCE  PUBLICATION DATE:

June 29, 1999

CONSTRAINTS:

 

DATASET SIZE:

24KB

ATTRIBUTE RELIABILITY:

UNKNOWN

STATUS:

COMPLETE

FIELDS:

SEE ATTACHED FORM

 

CONTACT NAME:

Alex Lugadiru

ORGANIZATION:

DEPHA PROJECT

POSTAL ADDRESS:

c/o UNDP DDC

P.O. BOX 30552,

NAIROBI,

KENYA.

EMAIL ADDRESS:

alex.lugadiru@unep.org

TELEPHONE NO.:

254-020-7624186/95

 

GEOGRAPHIC INFORMATION SYSTEMS (GIS) SPATIAL OUTPUT FORMAT

 

 

Field Name and Description

 

 

Field Name

 Field Description

AREA

 Area of the polygon/region in square coverage units.

 Computed.

PERIMETER

 Perimeter of poly/region in coverage units.

 Computed.

AGE

  Specific age of source rock.

GLG

 abbreviated geologic age various geologic rock units of the geologic map (If the abbreviated name was unknown it was copied into the description column):

Q, T, K, JK, J, TrJ, Tr, PZMZ, P, CP, C, D, S, OS, CmO, Cm, AD, PZ, APZ, Qv, Cv, Mv, Pv, PZv, MCi, PMi, Mm, PZm, pC, H2O, Ice, U

Description: Explanation of “Glg” code:

Q - Quaternary (undivided)

T - Tertiary

K - Cretaceous (undivided)

JK - Cretaceous and Jurassic

J - Jurassic (undivided)

TrJ - Jurassic and Triassic

Tr - Triassic

PZMZ - Paleozoic-Mesozoic

P - Permian

CP - Permian - Carboniferous

C - Carboniferous

D - Devonian (undivided)

S - Silurian

OS - Silurian - Ordovician

CmO - Ordovician - Cambrian

Cm - Cambrian

AD - Precambrian - Devonian

PZ - Paleozoic

APZ - Precambrian - Paleozoic

Qv - Quaternary volcanics

Cv - Creteceous - Tertiary volcanics

Mv - Mesozoic volcanics

Pv - Permian volcanics

PZv - Paleozoic volcanics

MCi - Mesozoic - Cenozoic intrusives

PMi - Paleozoic - Mesozoic intrusives

Mm - Mesozoic metamorphics

PZm - Paleozoic metamorphics

pC - Precambrian (undivided)

Ice - Arctic areas covered by Ice

H2O - Lakes and wide rivers

U - Unmappedd area

"" - "unlabeled"