The basic unit of this data model is a collection site. Sites at which one or more samples or specimens are collected receive an age determination and have an associated list of taxon occurrences. The resulting relational database will include new data such as the following:
(1) Biostratigraphic determinations (presently combined in a Comments field) will be kept in the AGE DETERMINATION table and combined in the AGE OF SITE table with reference numbers of reports that can eventually be scanned for the database.
(2) Sample age data will be kept as the original zone designation if the information is returned in this way by biostratigraphers. The ages of each zone will be kept in a lookup table (not shown in the model) and accessed by a function giving oldest and youngest ages for any combination of microfossil zones, so changes in zonal age determinations can be used to reassign the age of a sample. Actual interpretations of dates will be done manually and flagged.
(3) The ENVIRONMENT DETERMINATION table will record researchers' determinations of paleobathymetry and depositional environment and will be used in a manner similar to the age determination.
(4) The CORRELATED SITE table will aid in combining sites into larger groups. Because paleontologists work at a relatively large chronologic and geographic scale, we often wish to examine faunal patterns at the scale of all taxa from the same age and formation but different localities.
(5) The STRATIGRAPHIC SECTION table will put information about sections, sites and relative position in stratigraphic (= chronologic) order to get this data to researchers more quickly.
The model's entities (= tables in the database) and attributes (= fields in the database) are defined below.
The following contains precise descriptions of each entity and its
attributes. The entity names are in upper case letters and are preceded by a
number corresponding to the numbers on the boxes in the figure. Entity names
are followed by a description and then a short list of one or more attributes
which provides the primary key for the entity. Then the attributes, starting
with the primary key, are listed after each entity name, along with their
descriptions. The domain is the set of possible values an attribute may have.
The statement "not null" indicates that the field must have some value other
than blank or zero. In some cases, a default value for the attribute is given.
________________________________________
1.1 Project sample number: The number identifying each
SAMPLE collected by
a PPP participant. Numbers are assigned by the data manager in the order
in which they are inventoried at the Smithsonian Tropical Research
Institute (STRI).
Domain: PSN000001-PSN999999. Not null.
1.2 Site Visit Number: Tells on which SITE VISIT the
SAMPLE was
collected.
Domain: Same as SITE VISIT. Site Visit Number. Not null.
1.3 Collector Sample Code: The private sample code used
by each
collector
and recorded in his field notes. The codes are unique for each collector
and in many cases have been used for many years preceding this project.
The combination of Collector Sample Code and Collector ID is unique and
serves as an alternate key to SAMPLE. This key is not used within the
database, but will be useful for investigators needing to combine PPP
data with their own records. An assistant taking SAMPLEs assigns his
supervisor's code.
Domain: Numbers, characters, spaces and "-" up to 12 characters
long.
Not null.
1.4 Collector ID: The initials of the person collecting
the
SAMPLE. The
initials are unique for each person in the project and in case of
conflict are assigned by the data manager. SAMPLEs taken by an
assistant are assigned the supervisor's initials. Together with
Collector Sample Code, uniquely identifies the SAMPLE collected.
Domain: Same as PROCESSED SUBSAMPLE.Curator. Not null.
1.5 Sample Type: The type of SAMPLE collected. Types
are:
1.6 Number of Bags: SAMPLEs are usually put into one or
more cloth
bags in
the field.
Domain: Integers 1 to 99. Default is 1.
1.7 Collection Date: The date the SAMPLE was collected.
Sometimes,
collections are made at a SITE over a period of several days, so
different SAMPLEs may be collected on different dates from the same SITE
VISIT. Hence Collection Date is an attribute of SAMPLE, not SITE
VISIT.
Domain: All calendar days since the beginning of the project. Not
null.
1.8 Process Date: The date that either : 1) a specimen
or float
SAMPLE was
washed, glued, sorted, and boxed or 2) the date that a micro, basb, or
strib SAMPLE was cooked and washed. (A second processing step called
preparation appears as an attribute to PROCESSED SUBSAMPLE.) The date
can be approximate. If null, SAMPLE has not been processed or SAMPLE is
not of a type that needs processing.
Domain: True or false. Can be Null. Default is false.
1.9 Lithological Description: A description of the
lithology of
the SAMPLE
by the person who collected it.
Domain: Up to 80 characters. Default is blank.
1.10 Lost?: True if SAMPLE is lost.
Domain: True or false. Not null. Default is false.
1.11 Sample Comments: Includes information on
preservation, lost
SAMPLEs,
whether a SAMPLE was barren for calcareous nannoplankton, bryozoans,
etc.
Domain: Up to 80 characters. Default is blank.
________________________________________
2.1 Project Sample Number: Tells from which SAMPLE the
PROCESSED SUBSAMPLE came.
Domain: Same as SAMPLE.Project Sample Number. Not null.
2.2 Subsample Number: A unique number starting from 1
for each Project
Sample Number assigned by the data manager when the PROCESSED SUBSAMPLE
is prepared. In reports, the Subsample Number is connected to the
Project Sample Number with a dash, e.g. PSN000234-2.
Domain: Integers from 1 to 99. Not null.
2.3 Taxon Type: The code for a general group of taxa
are included in the PROCESSED SUBSAMPLE. Different SAMPLE.Sample Types have
different sets of Taxon Types that are allowable.
For SAMPLE.Sample Type = micro:
For SAMPLE.Sample Type = strib, basb, spec or float:
For SAMPLE.Sample Type = micro, strib or basb:
For SAMPLE.Sample Type = pmag:
2.4 Repository ID: The code for the current physical
location of the
PROCESSED SUBSAMPLE. Codes are:
2.5 Curator ID: The initials of the person responsible
for the PROCESSED
SUBSAMPLE. If a participant's initials are not unique, the data manager
will assign a code. The currently used codes are:
2.6 Transfer Date: The date that the PROCESSED
SUBSAMPLE was sent
to the curator.
Domain: Same as SAMPLE.Collection Date. Not null.
2.7 Preparation Date: The date a particular group was
picked from
washed
residue of a micro, basb, or strib SAMPLE; was picked for a particular
group; or the date a specimen or float SAMPLE was washed, glued, sorted,
and/or put in boxes. If null, SAMPLE was not prepared.
Domain: Same as SAMPLE.Collection Date. Default is null.
2.8 Barren?: True if a PROCESSED SAMPLE is found to
have no fossils relevant to its Taxon Type.
Domain: True or False. Default is False.
________________________________________
3.1 Project Sample Number: Tells to which SAMPLE the
AGE DETERMINATION applies.
Domain: Same as SAMPLE.Project Sample Number. Not null.
3.2 Subsample Number: Together with Project Sample
Number, tells which PROCESSED SUBSAMPLE was used for the determination.
Domain: Same as PROCESSED SUBSAMPLE.Subsample Number. Not null.
3.3 Zone/Age Determined: The age determined by
examination of a PROCESSED
SUBSAMPLE by a specialist. Usually, this is from calcareous
nannoplankton, planktonic foraminifera, or from a paleomagnetic sample
combined with previous biochronologic results. The format of the
returned age is variable. It can consist of a calcareous nannoplankton
zone (e.g., NN17), a planktonic foraminifera zone (N12), an absolute age
(3.5 Ma) or a range, consisting of any combination of these (NN16-NN17,
3.5 Ma-3.2 Ma, N12-3.5 Ma). Note that even a zone designation can
include an absolute age if the proper index fossil is found (or not
found) indicating that only a part of a zone is present in a SAMPLE.
This format for ages is well established and easily understood by the
users, but does not lend itself to SQL queries. Application specific
functions (Youngest and Oldest) use the appropriate lookup table to find
the currently established ages for zones and return either the youngest
or the oldest age for any of the formats above. These functions are then
used to fill in the derived attributes in the table corresponding to the
AGE OF SITE entity.
Domain: 11 characters and digits, the minus sign, blank, and
decimal.
The letters are NN or N which must precede a two digit integer (with a
leading zero if necessary), or Ma, which must precede a decimal number
from 0.0 to 9.9. The minus sign is used as a connector when a range is
given. Not null.
3.4 Documentation Code: The reference to the document
submitted by a
participant which contains his findings from a PROCESSED SUBSAMPLE. All
such documents are given a catalog number and stored as a paper record
at several institutions. Eventually these documents will be scanned and
stored as bitmaps in the database.
Domain: Catalog number or numbers used for documents from
participants.
3.5 Table Entry Date: The date that a value for
Zone/Age Determined was
entered into the database, or if corrected or updated, the date of the
last change. This information is used in conjunction with Interpretation
Date in the AGE entity to determine whether Youngest Age and Oldest Age
need to be re-interpreted.
Domain: Same as SAMPLE.Collection Date. Default is current date.
Not null.
3.6 Valid?: Whether an AGE DETERMINATION is considered
in error and not to
be used in interpreting the age of a SITE. This attribute is marked as
False in those cases.
Domain: True or false. Not null. Default is true.
3.7 Age Comment: Comments about the age
determination.
Domain: 80 characters or numbers
________________________________________
4.1 Project Sample Number: Tells to which SAMPLE the ENVIRONMENT DETERMINATION applies.
4.2 Subsample Number: Together with Project Sample Number, tells which PROCESSED SUBSAMPLE was used for the determination.
4.3 Environment Determined: The text of the ENVIRONMENT
Determination
returned by a participant. May be blank but only if Depth Determined is
blank.
Domain: Up to 40 characters. Default is blank.
4.4 Depth Determined: The paleowater depth
determination returned by a
participant. Is blank if nothing is returned.
Domain: Up to 40 characters. Default is blank.
4.5 Documentation Code: The reference to the document
containing the
findings from the SAMPLEs. (See note about these documents for
AGE DETERMINATION.Documentation Code).
Domain: Catalog number, or numbers, for documents from
participants.
4.6 Table Entry Date: The date that a value for
Environment Determined or
Depth Determined was entered into the database, or if corrected or
updated, the date of the last change to either. Both need to be
considered together in interpreting the ENVIRONMENT of SITE.
Domain: Same as SAMPLE.Collection Date. Default is current date.
Not null.
4.7 Valid?: Whether an ENVIRONMENT DETERMINATION
is
considered in error and
not to be used in interpreting the ENVIRONMENT OF SITE. This attribute
is marked as False if either Environment Determined or Depth Determined
is not considered Valid.
Domain: True or false. Not null. Default is true.
4.8 Environment Comment: Comments about Environment
Determination or Depth Determination.
Domain: 80 characters or numbers
________________________________________
5.1 Project Sample Number: Tells the Project Sample
Number in which this TAXON OCCURRENCE was found.
Domain: Same as SAMPLE.Project Sample Number
5.2 Subsample Number: Together with Project Sample
Number, tells the PROCESSED SUBSAMPLE in which this TAXON OCCURRENCE was
found.
Domain: Same as PROCESSED SUBSAMPLE.Subsample Number
5.3 Researcher ID: Tells the code for the researcher
who is using this Taxon ID.
Domain: Same as TAXON NAME.Researcher ID
5.4 Taxon ID: Together with Researcher ID, identifies
which taxon has
occurred in the PROCESSED SUBSAMPLE. This Taxon ID is not necessarily
the currently used code, but rather it will always match the code that
was used at the time the sample was analyzed. The currently used
Taxon ID, and that taxon's full name, is resolved by the many to one
relationship to TAXON NAME, and by that entity's many to one
relationship to itself.
Domain: Same as TAXON NAME.Taxon ID
5.5 Abundance Code: A collector specific estimate of
abundance in the SAMPLE, appropriate for the particular taxon and type of
SAMPLE.
Domain: 12 characters and/or numbers.
________________________________________
6.1 Researcher ID: Tells which person is responsible
for maintaining a
particular list of Taxon IDs. This code may represent several
researchers if they want to collaborate on maintaining a list. This
attribute allows each person to develop his own set of Taxon IDs without
having to ensure that they are different from all others in the
project.
Domain: Up to 8 letters. Not null.
6.2 Taxon ID: An abbreviation representing the
taxonomic name used at the
time a particular specimen is recorded. This name will never be changed
so that the name in the database will always refer to what is actually
written down on the original data sheet. This avoids confusion in case
the name currently used changes several times.
Domain: Eight letters, both upper and lower case, and digits 0 to
9.
These should be legal column (field) names for the most commonly used
databases.
6.3 Current Taxon ID: Tells which Taxon ID is
currently in use for a given
Taxon ID. Often, a researcher will change the name for a taxon, either
to correct an error in identification, to reflect a more precise
identification, or because of a change in the taxonomy. By recording the
currently used name for an obsolete name, the new name can automatically
be used when reports are printed, and when taxon abundance totals are
calculated. Merely substituting the new code for the old in the database
can cause great confusion and destroys information about the history of
names used for a particular taxon. Substitution like this is never a
good idea.
The rules for changing the Current Taxon ID are as follows:
Whenever Current Taxon ID is changed for an existing Taxon ID, a
new instance must be added to this entity. This new instance must
have the same value for both Taxon ID and Current Taxon ID. The
other information in the original instance, including Name1,
Name2, and Name3, is left unchanged to preserve the history of
changes to the Taxon ID and its full name. If yet another change
is made to Current Taxon ID, then another instance is added and
both previous instances must have Current Taxon ID updated. There
is a recursive relationship between this entity and itself which
allows a reference to the old Taxon ID to return the Current
Taxon ID, along with the current full name. All instances then,
where Taxon ID and Current Taxon ID are different represent
obsolete usages. To prevent ambiguity in archived species lists,
the combination of Researcher ID and Taxon ID, even for obsolete
usages, must remain unique. This means that a Taxon ID, such as
CoralSp, cannot be recycled once a more accurate identification is
supplied for the original usage.
Domain: Same as Taxon ID.
6.4 Name1: A genus name, a higher TAXON NAME, or a
short unstructured description.
Domain: Not Null. Up to 20 letters. Can include '?' .
6.5 Name2: A species name, the letters 'Sp.' possibly
with a letter or number after, or a continuation of a short description from
Name 1.
Domain: Up to 20 letters. Can include '?'. Default is blank.
6.6 Name3: A sub-species name, the letters 'Ssp.'
possibly with a letter or
number after, or a continuation of a short description from Name1.
Name1, Name2, and Name3 taken together are referred to in this paper as
the full name.
Domain: Up to 20 letters. Can include '?'. Default is blank.
________________________________________
7.1 Site Visit Number: The code assigned to the SITE
VISIT. Having one
number for all SAMPLEs corresponding to the same time range in the
section facilitates reference to the age ultimately returned by the
collectors of those SAMPLEs by providing a publishable number at an
early stage. It is possible that two SAMPLEs collected at exactly the
same time and place could receive different Site Visit Numbers because
of the way they were handled during collection and subsequent
processing.
Domain: PPP-000001 to PPP-999999
7.2 Site Number: Tells to which SITE the SITE VISIT
belongs.
Domain: The set of existing SITE VISIT numbers, but with the
prefix S instead of PPP.
________________________________________
8.1 Site Visit Number: Tells which SITE VISIT the
FORMER SITE VISIT NUMBER refers to.
Domain: 12 characters. Not null.
8.2 Former Site Visit Number: The "Default CJ number"
on some labels and in some field notes. No longer assigned.
Domain: 12 characters Default is blank.
8.3 Obsolete Site Visit Number: The code found only in
Coates' early field notes. No longer assigned.
Domain: 12 characters. Default is blank.
________________________________________
9.1 Documentation Code: An identifier for a written
note describing how the
current Site Visit is related to another. Normally, the note is from a
field notebook and the owner, volume, page, and line numbers are given.
This field must be unique, but is otherwise unstructured.
Domain: 20 letters or numbers. Not null.
9.2 Current Site Visit Number: Tells which current SITE
VISIT has entered into an association.
Domain: Same as SITE VISIT.Site Visit Numbers.
9.3 Referenced Site Visit Number: Tells which SITE
VISIT is referred to in documentation about a previous, or a concurrent, SITE
VISIT.
Domain: Same as SITE VISIT.Site Visit Codes.
9.4 Overlap Type: How the two SITE VISITs are
associated. The judgement of
how the collections are related is made by the person collecting the
SAMPLE. Sometimes a collection of macrofossils will be made from a SITE
visited the previous year and these will be considered "equivalent" and
an Overlap Type will be assigned indicating this. The codes are:
10.1 Site Number: Tells which SITE was visited. The
default indicates that
no Site Number has been assigned. Site Numbers are assigned in batches,
after the data for new SAMPLES have been entered.
Domain: Same as SITE VISIT.Site Visit Number except that the
digital part is preceded by 'S' instead of 'PPP'. Default is 'S000000'.
10.2 Map Locality ID: Tells approximately where on a
map a SITE is found.
Domain: Same as Locality.Map Locality ID. Not null.
10.3 Locality Number: Together with Map Locality ID,
uniquely identifies the LOCALITY in which a SITE is found.
Domain: Same as LOCALITY.Locality Number. Not null.
10.4 Stratigraphic ID: Tells from which STRATIGRAPHIC
UNIT a SAMPLE was taken.
Domain: Same as STRATIGRAPHIC UNIT.Stratigraphic ID. Not null.
10.5 Section Number: Tells the STRATIGRAPHIC SECTION in
which the SITE found.
Domain: Same as STRATIGRAPHIC SECTION.Section Number. Default is
0.
10.6 Correlated Site Code: Tells to which CORRELATED
SITE this SITE has been assigned.
Domain: Same as CORRELATED SITE.Correlated Site Number
10.7 Position in Section: The position of the SITE in
the composite
section, measured in meters from the bottom and adjusted for dip and
local differences in section thickness.
Domain: Numbers from 0.0 to 999.9. Not null.
10.8 Latitude: The latitude of the SITE, using decimal
notation, as
accurately as can be measured. Currently, location is measured to within
100m using a map or a GPS receiver. Latitude and longitude can be
expressed in degrees, minutes, and seconds where required by using a
function to make the conversion on the fly.
Domain: Numbers from 8.0000 to 11.0000 and 0. Default is 0.00000,
indicating a missing value.
10.9 Longitude: The longitude of the SITE, using
decimal notation, as accurately as can be measured.
Domain: Numbers from -86.00000 to -77.00000, and 0. Default is
0.00000, indicating a missing value.
________________________________________
11.1 Section Number: The number assigned to the
STRATIGRAPHIC SECTION.
Domain: Integers from 0 to 999. Default is 0.
11.2 Section Name: A name given to the STRATIGRAPHIC
SECTION
Domain: Up to 20 characters. Not null.
11.3 Depositional Basin: A geographic area with a
common river drainage.
Domain: Up to 20 characters. Not null.
________________________________________
12.1 Stratigraphic ID: A code identifying the Group,
Formation, and Member.
Since formation names are unique in the study area, the code consists of
an abbreviation of the formation name, and if used, the member name.
Includes a code for unknown.
Domain: Up to 12 characters.
12.2 Group: The established name of the group. Can be
'unknown'. Blank indicates that a group name is not used.
Domain: Group names. Default is blank.
12.3 Formation: The established name of the formation.
Can be 'unknown'. Cannot be blank.
Domain: Formation names. Not null.
12.4 Member: The established name of the member. Can be
'unknown'. Blank indicates that a member name is not used.
Domain: Member names. Default is blank.
12.5 Group Sequence: A decimal number indicating the
position of the group
in the geological column. It, and the following two attributes, are used
to display the names in stratigraphic rather than alphabetic order. The
smallest numbers correspond to the youngest rocks. Blank is 0, 'unknown'
is 99.9.
Domain: Integers from 1.0 to 99.9. Not null.
12.6 Formation Sequence: A decimal number indicating
the position of the
formation within the group. 'unknown' is 99.9.
Domain: Integers from 1.0 to 99.9 Not null.
12.7 Member Sequence: A decimal number indicating the
position of the member within the formation. Blank is 0, 'unknown' is 9.9.
Domain: Integers from 0.0 to 9.9 Default is 0. Not null only if
STRATIGRAPHIC UNIT.Member is not null.
________________________________________
13.1 Map Locality ID: A short code combining Map
Locality Name and the
Region together. It identifies a limited area on a 1:50000 map where one
or more sites exist. With Locality Number, it uniquely identifies the
location of the SITE.
Domain: 14 characters. Characters with diacritical marks are
excluded. Not null.
13.2 Locality Number: All of the Detailed Localities
having the same Map
Locality ID are assigned a Locality Number, starting with 01 for each
different Map Locality ID.
Domain: Two digits, 0-9. Not 00 and not null.
13.3 Map Locality Name: A name that can be found on a
1:50000 topographic
map (such as Isla Col¢n or R¡o Azul) which identifies a small area.
Domain: Any name on a map up to 20 characters.
13.4 Detailed Locality: Short directions on how to
reach the outcrop.
Examples are "300 meters north of the bridge over the R¡o Azul" or "50m
downstream from Site PPP000123".
Domain: Up to 80 characters.
13.5 Country: An abbreviation that tells the country in
which the SITE is
found. The abbreviations currently in use are:
Pan (Panama), CR (Costa Rica), Nic (Nicaragua) , Ecu (Ecuador).
Domain: The above codes. Not null.
13.6 Region: A subdivision of a country.
Domain: Established names of subdivisions of countries. Up to 12
characters.
13.7 Ocean: An abbreviation that tells into which ocean
the streams flow.
Domain: P (Pacific) or C (Caribbean). Not null.
________________________________________
14.1 Site Number: Tells to which SITE the AGE OF SITE
refers.
Domain: Same as SITE.Site Number. Not null.
14.2 Youngest Age: The youngest composite age in Ma
interpreted for a SITE by an experienced researcher.
Domain: Decimals from 0.0 to 9.9.
14.3 Oldest Age: The oldest composite age in Ma
interpreted for a SITE by an experienced researcher.
Domain: Decimals from 0.0 to 9.9
14.4 Person Making Interpretation: The initials of the
person who made the age interpretation.
Domain: Same as SAMPLE.Collector ID. Not Null.
14.5 Interpretation Date: The date the interpretation
was made. If this
date is earlier than the date that any AGE DETERMINATION was last
entered into the database for this SITE, the AGEs will have to be
reinterpreted.
Domain: Same as SAMPLE.Collection Date. Not null.
14.6 Interpolated?: Whether the AGE OF SITEs were
obtained by interpolation from other nearby SITEs.
Domain: True or false. Default is false.
14.7 Age Comment: Comments about the dating
process.
Domain: Up to 80 characters. Default is blank.
(The following attributes are derived from the AGE DETERMINATION entity and a zone/age age lookup table (not shown in the figure). The database fields will be filled in by the computer to aid the person interpreting the data.)
14.8 Nanno-Plankton Zone/Age: From AGE
DETERMINATION.Zone/Age Used if there is an AGE DETERMINATION from calcareous
nannoplankton.
Domain: All values of AGE DETERMINATION.Zone/Age Determined for
calcareous nannoplankton.
14.9 Planktonic Foram Zone/Age: From AGE
DETERMINATION.Zone/Age Used if there is an AGE DETERMINATION from planktonic
foraminifera.
Domain: All values of AGE DETERMINATION.Zone/Age Determined for
planktonic foraminifera. Default is blank.
14.10 Nanno & Foram Oldest Age: The oldest age possible
given the
available nanno-plankton and planktonic foraminifera AGEs. This
information is calculated by the computer from all available AGE
DETERMINATIONs and a lookup table (not shown in figure 1) with the most
recent ages of the zone boundaries.
Domain: Decimals from 0.0 to 99.9. Default is 99.9
14.11 Nanno & Foram Youngest Age: The youngest age
possible. See description of Nanno % Foram Oldest Age.
Domain: Decimals from 0.0 to 99.9. Default is 99.9.
14.12 Paleo-Magnetic Age: From AGE
DETERMINATION.Zone/Age. Used if there is an AGE from paleomagnetic data.
Domain: All values of AGE DETERMINATION.Zone/Age Determined for
paleomagnetic Taxon Types.
________________________________________
15.1 Site Number: Tells which SITE has this
environment.
Domain: Same as SITE.Site Number. Not null.
15.2 Paleo-Depth: The paleowater depth determination
for the SITE. This is
an uncoded attribute, reflecting concisely the best estimate of the
Person Making Interpretation.
Domain: Up to 20 characters. Default is blank.
15.3 Paleo-Environment: The depositional environment,
excluding depth, for the SITE. This is an uncoded attribute, reflecting
concisely the best estimate of the Person Making Interpretation.
Domain: Up to 80 characters. Default is blank.
15.4 Person Making Interpretation: The experienced
participant making the interpretation of both Paleo-Depth and
Paleo-Environment.
Domain: Same as SAMPLE.Collector ID. Not null.
15.5 Interpretation Date: The date the interpretation
of the ENVIRONMENT
was made. This information will be used in conjunction with ENVIRONMENT
DETERMINATION.Table Entry Date to determine if a re-interpretation is
necessary.
Domain: Same as Sample.Collection Date. Not null.
15.6 Environment Comment: Comments about the
interpretation of the ENVIRONMENT.
Domain: Up to 80 characters. Default is blank.
________________________________________
16.1 Correlated Site Code: A code identifying a group
of similarly aged SITEs.
Domain: Integers from 1 to 999.
16.2 Defined Youngest Age: The youngest age, in Ma, of
SITEs assigned to the CORRELATED SITE.
Domain: Decimals from 0.0 to 9.9. Not null.
16.3 Defined Oldest Age: The oldest age, in Ma, of
SITEs assigned to the CORRELATED SITE.
Domain: Decimals from 0.0 to 9.9.
________________________________________