Entity_and_Attribute_Overview:
In the data set for geologic units and faults, the entity type is a geologic unit as shown on
the 1980 state geologic map (Berg and others, 1980). Each geologic unit consists of a
sequence, group, formation, or member. The units are distinguished from each other by
geologic characteristics such as rock type, color, and texture, and are mappable at the scale
of 1:250,000. Units shown on the 1980 map are intended to be rock-stratigraphic (i.e.,
correlations shown or implied are rock correlations and may transgress time boundaries).
The polygon and line (arc) attribute items for the entity type of geologic unit are in
typical ArcInfo feature class format. Polygon attribute items (in table pageo.pat) are
as follows:
COLUMN ITEM NAME WIDTH OUTPUT TYPE N. DEC. INDEXED?
1 AREA 8 18 F 5 --
9 PERIMETER 8 18 F 5 --
17 PAGEO# 4 5 B -- --
21 PAGEO-ID 4 5 B -- --
25 UNITNO 4 4 I -- --
29 MAP_SYMBOL 10 10 C -- --
39 NAME 100 100 C -- --
139 AGE 50 50 C -- --
189 LITH1 35 35 C -- --
224 LITH2 35 35 C -- --
259 LITH3 85 85 C -- --
Please note that the shapefile for polygons (pagpoly.shp) has the same items, but the "#"
symbol is changed to "_" in the conversion from the ArcInfo file.
Definitions of user-defined polygon attribute labels are as follows. Please refer to
<A HREF="polyattrib.pdf">polyattrib.pdf</A> for a complete list of attribute domain values for each item, and to
<A HREF="changes.pdf">changes.pdf</A> for a list of changes and updates made in the data sets to map symbols,
names, and ages from those shown on the 1980 state geologic map (Berg and others,
1980).
UNITNO: A unique number assigned to each map unit in the data set. The number,
which is not derived from the 1980 map, places the units approximately, but not
completely, in a sequence ranging from those having the youngest ages (lower
numbers) to those having the oldest ages (higher numbers). In the data set for geologic
units and faults, there are 193 unique unit numbers ranging from 1 to 195 (unit number
6, kimberlite, and unit number 15, Quarryville Diabase, occur only in the data set for
dikes).
MAP_SYMBOL: The symbol used to label the unit on the 1980 state geologic map,
except where modified as indicated in <A HREF="changes.pdf">changes.pdf</A>. Please note that the "double-bar
P" shown on the 1980 map to indicate units of Pennsylvanian age has been changed
to "P," the special character for Triassic units (capital "T" joined to small capital "R")
has been changed to "Tr,"and the special character for units of Cambrian age ("C"
with horizontal bar) has been changed to "C" in the attribute table.
NAME: The name of the geologic unit in the explanation of the 1980 state geologic
map (Berg and others, 1980), except where modified as indicated in <A HREF="changes.pdf">changes.pdf</A>.
AGE: The age of the geologic unit as shown on the 1980 state geologic map (Berg and
others, 1980), except where modified as indicated in <A HREF="changes.pdf">changes.pdf</A>. Ages are at the level
of a geologic period.
LITH1: The dominant lithology, volumetrically, in the rock unit. Lithologies were
modified from the geologic description in the map explanation of the 1980 state
geologic map (Berg and others, 1980), based on reviews by PaGS staff geologists in
1998 and 2000. The lithologies are assigned based on the entire areal extent of the
geologic unit within Pennsylvania; thus, all lithologies listed (particularly in the
LITH3 item) may not be present in local areas.
LITH2: The secondmost dominant lithology, volumetrically, in the map unit. See
LITH1 above for source.
LITH3: Other major lithologies, volumetrically, in the rock unit. See LITH1 above
for source.
The arc attribute items (in table pageo.aat) are as follows:
COLUMN ITEM NAME WIDTH OUTPUT TYPE N. DEC. INDEXED?
1 FNODE# 4 5 B -- --
5 TNODE# 4 5 B -- --
9 LPOLY# 4 5 B -- --
13 RPOLY# 4 5 B -- --
17 LENGTH 8 18 F 5 --
25 PAGEO# 4 5 B -- --
29 PAGEO-ID 4 5 B -- --
33 CONTACT 5 5 C -- --
38 FAULT 5 5 C -- --
43 BORDER 5 5 C -- --
48 CONTACTLINE 30 30 C -- --
78 FAULTLINE 30 30 C -- --
108 BORDERLINE 15 15 C -- --
Please note that the shapefile for arcs (pagarc.shp) has the same items, but the "#" symbol
is changed to "_" and "CONTACTLINE" has been truncated to "CONTACTLIN" in the
conversion from the ArcInfo file.
Definitions of user-defined arc attribute labels and attribute domain values are as follows:
CONTACT: Indicates whether the line is a contact (y, yes; n, no).
FAULT: Indicates whether the line is a fault (y, yes; n, no).
BORDER: Indicates whether the line forms the border of the data set (y, yes; n, no).
CONTACTLINE: The type of contact line between geologic units shown on the 1980
state geologic map. The types of contact lines (i.e., the attribute values) in the data set
for geologic units are as follows:
Solid: A contact line between two geologic units that is shown as a solid line on the
1980 map. Quantitative locational accuracy values are not known.
Dashed: A contact line between two geologic units that is shown as a dashed line on
the 1980 map. The location of a dashed contact line is more approximate than that
of a solid contact line. Quantitative locational accuracy values are not known.
Arbitrary: A contact line between geologic units that is shown as a color break only
(i.e., no line is shown) on the 1980 map. This type of contact typically occurs where
two or more geologic units are mapped separately on one side of the contact line and
are grouped together as one unit on the other side of the contact line. The units are
grouped either because (1) their individual unit areas are too small to be shown at the
scale of 1:250,000; or (2) the geology of the area has not been mapped in sufficient
detail to allow the units to be distinguished separately. An arbitrary contact line may
also represent a facies change (i.e., a lateral variation between sedimentary rocks that
were deposited during the same time period but in different sedimentary
environments). In such cases, the approximate area of the change from one unit to the
other is indicated by the arbitrary line. An arbitrary contact line is also used to bound
the Valentine Member of the Benner Formation, which is generalized on the 1980
map as a line of uniform width, and which is included in the data set as a polygon of
uniform width.
Queried: A contact line between two geologic units that is shown as a queried line
on the 1980 map or source materials used for that map. A queried line indicates that
the location of the contact is uncertain or questionable.
FAULTLINE: The type of fault line shown on the 1980 state geologic map. The types
of fault lines (i.e., attribute values) in the data set are as follows:
Solid: A fault line that is shown as a solid line on the 1980 map. Quantitative
locational accuracy values are not known.
Dashed: A fault line that is shown as a dashed line on the 1980 map. The location
of a dashed fault line is more approximate than that of a solid fault line. Quantitative
locational accuracy values are not known.
Queried: A fault line that is shown as a queried line on the 1980 map or source
materials used for that map. A queried line indicates uncertainty about the
existence of the fault.
BORDERLINE: A term used to define the type of line that generally forms the outer
boundary of the data set. The types of border lines (i.e., attribute values) in the data
set are as follows:
State: The Pennsylvania state boundary.
Quad: The boundary of a 30-by 60-minute quadrangle within Pennsylvania.
Lake Erie: The shoreline of Lake Erie.
In the data set for dikes, the entity type is a dike as shown on the 1980 state geologic map
(Berg and others, 1980). Although dikes are tabular features, because of the scale, they are
shown as lines on the 1980 map and have been digitized as lines (arcs) in the data set. The
arc attribute items (in table padike.aat) are as follows:
COLUMN ITEM NAME WIDTH OUTPUT TYPE N. DEC. INDEXED?
1 FNODE# 4 5 B -- --
5 TNODE# 4 5 B -- --
9 LPOLY# 4 5 B -- --
13 RPOLY# 4 5 B -- --
17 LENGTH 8 18 F 5 --
25 PADIKE# 4 5 B -- --
29 PADIKE-ID 4 5 B -- --
33 UNITNO 4 4 I -- --
37 MAP_SYMBOL 10 10 C -- --
47 NAME 100 100 C -- --
147 AGE 50 50 C -- --
197 DIKELINE 15 15 C -- --
212 LITH1 35 35 C -- --
Please note that the shapefile for arcs (padike.shp) has the same items, but the "#"
symbol is changed to "_" in the conversion from the ArcInfo file.
Definitions of user-defined dike attribute labels are as follows. Please refer to
<A HREF="dikeattrib.pdf">dikeattrib.pdf</A> for a complete list of attribute domain values for each item, and to
<A HREF="changes.pdf">changes.pdf</A> for a list of changes and updates made in the data sets to map symbols, names,
and ages from those shown on the 1980 state geologic map (Berg and others, 1980).
UNITNO: See definition of "UNITNO" in polygon attributes for the data set for
geologic units and faults above.
MAP_SYMBOL: The symbol used to label the dike on the 1980 state geologic map
(Berg and others, 1980), except where modified as indicated in <A HREF="changes.pdf">changes.pdf</A>.
NAME: The name of the geologic unit in the explanation of the 1980 state geologic
map (Berg and others, 1980), except where modified as indicated in <A HREF="changes.pdf">changes.pdf</A>.
AGE: The age of the geologic unit as shown on the 1980 state geologic map (Berg and
others, 1980), except where modified as indicated in <A HREF="changes.pdf">changes.pdf</A>.
DIKELINE: The type of line symbol used for the dike on the 1980 state geologic map.
The types of dike lines (i.e., attribute values) in the data set are as follows:
Solid: A dike line that is shown as a solid line on the 1980 map. Quantitative
locational accuracy values are not known.
Dashed: A dike line that is shown as a dashed line on the 1980 map. The location
of a dashed dike line is more approximate than that of a solid dike line. Quantitative
locational accuracy values are not known.
LITH1: The dominant lithology, volumetrically, in the rock unit. See source for
lithologies in definition of "LITH1" in the polygon attributes for the data set for
geologic units and faults above.