Metadata of the Coal Bed Mapping Project GIS Coverages
West Virginia Geological and Economic Survey expects that these data will be
utilized only within your organization and will not be given or sold to others
outside your firm or organization except as results in appropriate conventional
research reports and maps. These data may not be used in computerized or other
databases made available to third parties.
Acknowledgement of the West Virginia Geological Survey is expected in
products derived from these data.
These data were geo-referenced at 1:24000 scale, and therefore may not be
appropriate for use at more local scales.
Each coal bed has the following coverages/themes:
1) mining/remaining resources polygons
2) coal map boundaries
3) the elevation contour arcs
4) the control point location coverage for the elevation models.
5) net coal thickness polygon coverage with 6 inch intervals.
6) the control point location coverage for the thickness model.
7) percent parting polygon coverage with 5% intervals
8) total coal bed thickness polygon coverage with 6 inch intervals
Optionally, several coverages may also exist to provide supplementary
information about the mining. These include
1) a vector coverage of coal discontinuities
2) a vector coverage delineating mine boundary extents that are
questionable or unknown
3) and a point coverage showing additional maps identifiers that were
used to create a particular mine polygon.
Further explanation of each of these coverages/themes and how they were created
is given at the end of this file in the 'METADATA' section. Fully FGDC
compliant metadata for these data sets is being developed.
In some rare occasions, the three thickness models may not be calculated due to
insufficient data control but an elevation and overburden grid always exist.
****METADATA****
Projection information for all data sets:
Grid_Coordinate_System_Name: Universal Transverse Mercator
UTM_Zone_Number: 17
Longitude_of_Central_Meridian: -81.0
Latitude_of_Projection_Origin: 0.0
False_Easting: 500000
False_Northing: 0
Planar_Distance_units: meters
Horizontal_Datum_Name: North American Datum of 1927
Ellipsoid_Name: Clark 1866
Time Period for creation of the data:
The coal bed modeling was based on the stratigraphic point data available to
the geological survey as of a particular time period. Thickness and elevation
models were created during the time period of 2000 - 2001 for Raleigh County
and during the time period of 1997 - 1998 for Fayette County. Thickness and
elevation models were created during the time period of 2000 - 2001 for Hancock,
Brooke, Ohio, Marshall, Wetzel, Marion, Harrison and western Monongalia counties.
These models were created during the time period of 1999 – 2000 for eastern
Monongalia County. Mine compilations for all coal beds were updated in 2003
using maps current as of January 1, 2003.
Information pertinent to multiple coverages/themes/grids:
Coal Stratigraphic Database
West Virginia Geological and Economic Survey's Coal Stratigraphic Database
contains location and stratigraphic data for approximately 100,000 points.
Data has been obtained from a variety of sources over the last 100 years.
Some data points were collected in the field by Survey geologists.
Frequently, drill hole data has been obtained directly from coal companies
and from permitting files at the WV Department of Environmental Protection.
Other data points were taken from mine maps.
Thickness Models
A "coal bed" may be composed of multiple, interbedded layers of coal and
subordinate layers of non-coal lithologies, such as shale or sandstone.
Therefore, a data point for a specific coal bed may contain multiple
stratigraphic records, one for each layer. The net coal thickness value is
the sum of the thicknesses of each individual stratigraphic record
designated as "coal" within a specific bed. This value is calculated for
each data point for each specific bed.
The subordinate, non-coal layers in a coal bed are referred to as
"partings". The parting thickness value is the sum of the thicknesses of
each individual, non-coal stratigraphic record within a specific bed. This
value is also calculated for each data point for each specific bed.
These calculated parting thickness and net coal thickness values are the
basis for the grid thickness models for each coal bed which are calculated
by interpolation between the discrete data points. (The total bed thickness
grid model is calculated from the sum of the parting thickness and net Coal
thickness grids.)
Surface III mapping software was used for the point interpolation. This
mapping program was researched and developed by the Kansas Geological
Survey and Surface III is a marketed by Interactive Concepts, Inc. Standard
interpolation methods were employed, however the actual interpolation
parameters vary somewhat for each coal bed. The individual parameters are
not provided within this document, however, they are available upon request.
These parameters will be included in the FGDC compliant metadata being
developed.
Mine Maps
Mine Maps are the primary source for compilation of the underground mined
areas. The sources of these mine maps are:
1) U.S. Office of Surface Mining(OSM) Mine Map Repository
The repository contains aperture cards for all historic mine map documents
received and microfilmed by OSM. West Virginia Miner's Health Safety and
Training forward final paper copy mine maps for closed mines to the OSM
Mine Map Repository. Also, paper mine maps acquired by the WVGES from
outside sources that are not represented by an existing aperture card are
sent to the OSM Mine Map Repository. Each map is assigned a unique
identifying number by OSM. Copies of the aperture cards for maps in West
Virginia are maintained at WV Geological Survey. The scales of the
original (before shot with camera) mine maps range from 1:1200 to
1:100000.
2) West Virginia Miner's Health Safety and Training (WVMHST)
Maps of current mining are obtained by WVGES through the appropriate
regional office of the WVMHST. Paper copies are made and filed at WVGES.
The originals are returned to WVMHST. The scale of these maps typically
range from 1:1200 to 1:4800.
Apcard Identifier
An identifier to the source of a spatial feature from a mine map. If the
map was obtained from the Office of Surface Mining's (OSM) Mine Map
Repository, then OSM has assigned a 6 character identifier between 300000
and 500000 to the map. Maps obtained from WV Miner's Health, Safety and
Training are assigned a 6 character identifier between 900000 and 999999 by
WVGES. Since there is frequently more than one mine on a single map, an
alphabetic suffix was added to uniquely identify each underground mine on a
map. Since some maps contained more than 26 mines, the alphabetic suffix
is two characters, from "A " to "ZZ" (always in caps). Other spatial
features, such as geologic discontinuities, are not uniquely identified and
only have the 6 character identifier to the source mine map.
Information for each type of coverage/theme/grid:
Mined and Remaining Coal (ALLMNG)
Description
This coverage divides the mapped area of each coal bed into polygons of
mined areas and un-mined (remaining resource) areas. The mined areas are
further differentiated by the method of mining - underground, surface, or
auger. The outer boundaries of this coverage are described in the COALBNDS
coverage.
Polygon attribute names:
typ
apcard
mine_name
comp_name
permit
comment
year
Attribute description:
typ (binary)
A code defining whether the polygon represents a remaining coal resource
or mined-out area. If the polygon represents a mined-out area, then this
code indicates whether it was undergound, surface or auger mined. Codes:
0 : Eroded
1 : Remaining Coal
2 : Surface Mined
3 : Auger Mined
4 : Underground Mined
apcard
An identifier to the Aperture Card source of a mine polygon; 8 characters long. Only
underground mine polygons and auger mine polygons have a value for this
attribute. Auger mine polygons only have the 6 character identifier
without an alphabetic suffix. The apcard value for auger mine polygons
are not unique and no other attributes (mine_name, comp_name, etc.) are
filled in for auger mine polygons.
mine_name
A text field (50 characters) containing the name of the mine represented
by this polygon . Only Underground Mine polygons have a value for
this attribute. It may contain the value of "UNKNOWN".
comp_name
A text field (50 characters) containing the company name for the mine
represented by this polygon. Only Underground Mine polygons have a
value for this attribute. It may contain the value of "UNKNOWN".
permit
A text field (10 characters) containing the permit number for the mine
represented by this polygon. Only recent underground mine polygons
have a value for this attribute. All others contain the value "NDE"
(no data entered). There have been many naming conventions for permits
throughout WV's history. For a more comprehensive discussion of these
naming conventions, contact WV Miner's Health Safety and Training.
comment
A text field containing a comment that the project geologists found useful
when researching the mine maps. Only Underground Mine polygons have a
value for this attribute.
year (binary)
Year of the mine map from which the mine polygon was obtained. An unknown
year value if represented by a zero. Only Underground Mine polygons have
a value for this attribute.
Lineage
Underground, augered, and surface mined areas and attributes are
obtained from mine maps. Surface mined polygons are also extracted from
geo-referenced tifs of 7.5" topographic maps and from air photos.
Documents are visually examined for verification of location and are
selected to best represent (construct) an entire mined area polygon
and/or to capture coal bed elevation and/or thickness point data.
These are scanned and a vector coverage of each mine image is created
by on-screen digitizing the outside edges of the mine. Internal
polygons of remaining coal are preserved and assigned a different
polygon type.
Coal Map Boundaries (COALBNDS)
Description
This coverage outlines the area of the bed as mapped to date and describes
the type of each boundary. Boundary types include the outcrop line (surface
trace representing the intersection between the coal bed and the land
surface); stratigraphic edge of the bed (where the bed becomes absent in the
rock column); the temporary extent of mapping to date, the final extent of
mapping (for example, near a state line); and the adequate data control
boundary (beyond which data is too sparse for mapping).
Arc Attribute Names
boundtyp
Attrubute Description
boundtyp (binary)
Code denoting type of boundary. Codes:
1 Coal Outcrop
2 Stratigraphic Termination Boundary
3 Temporary Mapping Extent
4 Final Mapping Extent
5 Adequate Data Control Boundary
Lineage
The 1:24000 hypsography, point hypsography and hydrography coverages from
Digital Line Graphs provided by WVU GIS Technical Center were used to
generate a 10 meter surface elevation grid of topography for each 7.5'
quadrangle using Arc/Info's 'topogrid' program. An elevation grid of each
coal bed was subtracted from the topography grid to obtain an overburden
grid for each coal bed. This overburden grid was then contoured to connect
zero value grid cells which produced an outcrop line for each 7.5'
quadrangle for the coal bed. Outcrops by coal bed by quadrangle were
edge-matched to form an outcrop vector coverage for the extent of each coal
bed. A polygon defining the mapped extent of each coal bed was then
constructed by adding the lines representing the other boundary types.
Structural Contours (ELVCNT)
Description
This coverage contains the coal bed elevation (structural) contour lines.
These lines depict the variation in elevation of the base of the coal bed in
relation to sea level. Units are in feet. The contour interval used is
either 20 or 40 feet, matching the 7.5-minute topographic map (published by
US Geological Survey) of the area. The elevation of a coal bed is one
component used to delineate the geographic area underlain by the coal bed.
The elevation of a coal bed is used to determine the intersection of the
coal bed and the land surface; which is defined as the outcrop line of the
bed. The elevation of the coal bed also defines how deep a coal bed is
beneath the land surface. Elevation contour lines delineate the tectonic
folding, or geologic structure of a coal bed. Knowledge of the geologic
structure of a coal bed is very important in mine planning and in
investigating such environmental problems as mine drainage. Coal bed
elevation is represented by two models 1) vector contour lines, and
2) grids.
Arc Attribute Names
elev
Arc Attribute Descriptions
elev (integer)
The elevation value of the line.
Lineage
West Virginia Geological and Economic Survey's Coal Stratigraphic Database
contains location and stratigraphic data for approximately 100,000 points.
Data has been obtained from a variety of sources over the last 100 years.
Some data points were collected in the field by Survey geologists.
Frequently, drill hole data has been obtained directly from coal companies
and from permitting files at the WV Department of Environmental Protection.
Other data points were taken from mine maps. The elevations of the bottom
of the coal bed are taken from the Coal Stratigraphic Database and used to
make a computerized elevation model that is adjusted by geologists to
reflect information about surface mining or to make the contours for
vertically adjacent coals beds better conform to each other.
Elevation Control Points (ELVPTS)
Description
This point coverage shows the location of data points used in the
construction of the coal bed elevation models. This coverage provides the
user with the density of data control points used to construct the model so
that one can judge the relative reliability of the map throughout its
extent. The locations of control points for the elevation and thickness
models are not necessarily the same. Some points have only an elevation or
a net coal thickness value. No data (attributes) are provided for the
control points.
Lineage
Extensive time is spent by project geologists validating and correlating the
many data points in the stratigraphic database. Elevations are looked at in
relation to adjacent data points and vertical relationships. This requires
several sweeps through the entire data set for a study area. This coverage
reflects the state or instance of the stratigraphic database when the CBMP
elevation model was created. Since the stratigraphic database is
continually being updated, it was necessary to preserve the control point
locations as they existed at the time the model was generated.
Net Coal Thickness (ISOPOLY)
Description
The purpose of this coverage is to illustrate the variation in the thickness
of coal in a bed. Each polygon has a value of average thickness. For
example, An area with a net coal thickness between zero and six inches would
be assigned an average thickness value of 3 inches, and an area with a net
coal thickness between six and twelve inches would be assigned an average
thickness value of 9 inches, etc. Average thickness values are also
calculated in 12 inch intervals. Net coal thickness is also represented by
a grid model which is more appropriate for detailed analysis. The polygon
model is better for display and cursory analysis purposes.
Polygon Attribute Names:
avgthk6
avgthk12
Attribute Descriptions:
avgthk6
The average thickness of the area covered by the polygon assigned in 6
inch intervals.
avgthk12
The average thickness of the area covered by the polygon assigned in 12
inch intervals.
Lineage
The net coal thickness values are calculated for all valid data points and
Surface III software creates 30 meter grids for each 7.5 minute quadrangle.
These are converted to ArcInfo grids (ISOGRD). An ArcInfo AML was developed
to create a polygon coverage from the individual 7.5 minute ISOGRDs. First,
each grid is re-classed into 6 inch intervals and then converted into
polygons. These individual coverages are then combined into one single
coverage and are dissolved where average values are the same for adjacent
quadrangles. Then the arcs are generalized and splined. Some smaller
polygons are eliminated due to the simplification of the arcs. Topology is
rebuilt and then each new polygon is assigned average thickness attributes
by referencing back to the original grid.
Thickness Control Points (THKPTS)
Description
This point coverage shows the location of data points used in the
construction of the net coal thickness, total bed thickness, and percent
parting models for a coal bed. This coverage provides the user with the
density of data control points used to construct the model so that one can
judge the relative reliability of the map throughout its extent. The
locations of control points for the elevation and thickness models are not
necessarily the same. Some points have only an elevation value or a net
coal thickness value. No data (attributes) are provided for the control
points.
Lineage
Extensive time is spent by project geologists validating and correlating the
many data points in the stratigraphic database. Elevations are looked at in
relation to adjacent data points and vertical relationships so the elevation
and net coal thickness models will be as consistent and correct as possible.
This requires several sweeps through the entire data set for a study area.
This coverage reflects the state or instance of the stratigraphic database
when the CBMP thickness models were created. Since the stratigraphic
database is continually being updated, it was necessary to preserve the
control point locations as they existed at the time the model was generated.
Percent Partings (PRTPOLY)
Description
The purpose of this grid is to illustrate the variation in the volume
percent of non-coal partings in a bed and provide an approximate measure of
the amount of reject material that could be expected from a mining
operation. A volume percent of 30 is equal to approximately 50% by weight.
Each polygon has a value of average percent parting. For example, an area
with a percent parting between zero and five would be assigned an average
percent value of 2.5, and an area with a percent parting between five and
ten would be assigned an average percent value of 7.5, etc. Percent parting
is also represented by a grid model which is more appropriate for detailed
analysis. The polygon model is better for display and cursory analysis
purposes.
Polygon Attribute Name
avgprt
Attribute Description
avgprt
The average percent parting of the area covered by the polygon assigned
by intervals of 5 percent.
Lineage
The net coal thickness values and percent partings values are calculated for
all valid data points and Surface III software creates 30 meter grids for
each 7.5 minute quadrangle. These are converted to ArcInfo grids (ISOGRD,
PRTTHK). A percent partings grid is calculated in ArcInfo from the
net coal thickness and parting thickness grids using grid math:
PRTGRD=((PRTTHK/IOSGRD+PRTTHK)*100). An ArcInfo AML was developed to create
a polygon coverage from the individual 7.5 minute PRTGRDs. First, each grid
is re-classed into 6 inch intervals and then converted into polygons. These
individual coverages are then combined into one single coverage and are
dissolved when the same average percent occurs in adjacent quadrangles.
Then the arcs are generalized and splined. Some smaller polygons are
eliminated due to the simplification of the arcs. Topology is rebuilt and
then each new polygon is assigned average percent parting attribute by
referencing back to the original grid.
Total Bed Thickness (BEDPOLY)
Description
The purpose of this grid is to illustrate the variation in the total sum of
coal and in-bed, non-coal partings, often referred to as bed or seam
height. The bed height generally represents how high the face would be in a
mining operation and is an important consideration in evaluating the
minability of a bed. Each polygon has a value of average thickness. For
example, an area with a total bed thickness between zero and six inches
would be assigned an average thickness value of 3 inches, and an area with
a total bed thickness between six and twelve inches would be assigned an
average thickness value of 9 inches, etc. Average thickness values are
also calculated in 12 inch intervals. Total bed thickness is also
represented by a grid model which is more appropriate for detailed
analysis. The polygon model is better for display and cursory analysis
purposes.
Polygon Attribute Names:
avgthk6
avgthk12
Attribute Descriptions:
avgthk6
The average thickness of the area covered by the polygon assigned in 6
inch intervals.
avgthk12
The average thickness of the area covered by the polygon assigned in 12
inch intervals.
Lineage
The net coal thickness values and percent partings values are calculated for
all valid data points and Surface III software creates 30 meter grids for
each 7.5 minute quadrangle. These are converted to ArcInfo grids (ISOGRD,
PRTTHK). The total bed height or thickness is the sum of the net Coal
thickness value and the parting thickness. The BEDGRD is calculated with
grid math by adding together the two grids (BEDGRD=ISOGRD+PRTTHK). An
ArcInfo AML was developed to create a polygon coverage from the individual
7.5 minute PRTGRDs. First, each grid is re-classed into 6 inch intervals
and then converted into polygons. These individual coverages are then
combined into one single coverage and are dissolved when the same average
percent occurs in adjacent quadrangles. Then the arcs are generalized and
splined. Some smaller polygons are eliminated due to the simplification of
the arcs. Topology is rebuilt and then each new polygon is assigned average
percent parting attribute by referencing back to the original grid.
Geological Discontinuities (DISCNT)
Description
This coverage is comprised of vectors representing various types of coal bed
discontinuities encountered in underground coal mines. These are features
that disrupt mining such as stream channeling (washouts) contemporaneous or
penecontemporaneous with peat deposition, geologic faults, areas of
uncontrollable roof or floor, excessive parting, or other local features.
These features are captured as a GIS coverage because many are local in
nature and may or may not be reflected in other coverages such as the net
coal thickness grid. To an experienced coal geologist or mining engineer,
these features serve as a warning sign as to what sorts of discontinuities
may be encountered in mining operations in that bed elsewhere in the region.
Arc Attribute Names
apcard
type
reported
Attribute Descriptions
apcard
An identifier to the source map of a discontinuity arc; 6 character field.
type (binary)
A code indicating the general type of discontinuity. The purpose of this
code is to be able to draw different linetypes on a map since another
attribute contains the actual text used to describe the discontinuity on
the mine map. Codes:
1 : bad top
2 : bad bottom
3 : channel feature
4 : seam split
5 : geologic fault
reported
A text field (25 characters) containing the actual text from the mine map
describing the discontinuity.
Lineage
Discontinuities are obtained from mine maps. In addition to mined area
outlines, vectors are digitized that represent discontinuities shown on
the mine map. These are compiled by coal bed.
Mining Extent Unknown (EXTUNK)
Description
The vectors in this coverage indicate where a map of underground mine
workings has been truncated. It should be used in conjunction with the
mining/remaining resource coverage to completely understand the mine polygon
boundary. On some mine map documents, it is obvious the mine workings
continue beyond the edge of the document, but are cut off. The "extent
unknown" vector delineates the edge of such incomplete mine maps. This
coverage serves to warn the user that additional mining almost certainly
exists beyond the "extent unknown" vector, but unfortunately a map of the
additional mine workings is unavailable at this time.
Arc Attribute Name
apcard
Attribute Description
apcard
An identifier to the source map of 'the extent unkown' arc; 6 character field.
Lineage
These arcs are obtained from mine maps. Once satisfactorily geo-referenced,
a vector coverage of each mine map image is created by on-screen digitizing
of the outer edges of the mine, including the edges where the mine workings
have been truncated. If no other mine map is located that includes the
missing works, a vector is created to delineate the truncated boundary.
These vectors are compiled by coal bed and can be drawn with a map symbology
to let the user quickly see that a mine is not entirely represented.
Aperture Card Label (APCDLBL)
Description
This point coverage is comprised of identifiers for additional mine map
documents (besides the primary one used for the polygon attribute) That were
required to
assemble the complete boundary of some underground mine polygons. When used
in conjunction with the corresponding mining/remaining resource coverage,
all the points within an underground mine polygon will provide identifiers
to all the map sources for the mine polygon. The complete area covered by
an underground mine is frequently assembled from multiple documents. The
identifier for the document contributing the most information to the entire
mine polygon is used for the attributes of that polygon. The source of the
remainder of the polygon is documented with identifiers within this
coverage.
Point Attribute Name
apcard
Attribute Description
apcard
An 8 character field containing an identifier to an additional source
document (in addition to the primary one used in allmng.pat) used in the
construction of the mine polygon in which this label is located.
Lineage
These points/labels are obtained from mine maps. In some cases, a single
mine can only be portrayed by a compilation of pieces from several mine
maps. When this occurs, only one aperture card/source document number is
assigned to the polygon; the number from the map that showed the largest
portion of the mine. The location of the label is approximately in the
center of the mine polygon's area that was obtained from that source.