The purpose of this standardization is to allow all SGMC
covers to be seamlessly joined without any additional effort to form regional or
national level digital maps. Note that for Alaska, the state is being compiled as
blocks of 1:250k quadrangles that will ultimately be used to compile a new state map.
Douglas Stoeser and Ric Wilson are co-coordinators for the overall SGMC effort, with
Stoeser coordinating work on the mainland states and Wilson coordinating work for
Alaska and Hawaii.
Process Date: 2003 - 2004
C.L. Dicken obtained the digital geologic map of Florida from the following website:
http://www.dep.state.fl.us/geology/gisdatamaps/state_geo_map.htm
Dicken re-projected the coverage into the following:
projection: Lambert Conformal Conic
units: meters
datum: NAD27
standard parallel 1: 33 0 0.000
standard parallel 2: 45 0 0.000
central meridian: -100 0 0.000
reference latitude: 0 0 0.000
false easting: 0.00000
false northing: 0.00000
All attributes were deleted except FORMATION_.
(Note: Attributes associated with the generation of the coverages were not deleted.
PAT - shape, area, perimeter, coverage#, and coverage-id
AAT - shape, fnode#, tnode#, lnode#, rnode#, length, coverage#, and coverage-id)
The values from FORMATION_ where then calculated into a new field called orig_label.
Process Date: 20041102
The relevant state outline (arcs) was removed from the coverage and replaced
with the arcs from the 1:100,000 Scale State Boundaries of the Conterminous United States.
This allows for a seamless fit of each state to a standard state boundary base.
Process Date: 20041103
The following attributes were exported from Filemaker as a .dbf:
orig_label, map_symbol2, unit_link, reference_id, unit_age, rocktype1, and rocktype2.
orig_label reflects the original map symbol used on the source map
map_symbol2 reflects map-symbol1 with the addition of a province number
unit_link is an auto generated field based on map-symbol2 and the state
abbreviation (e.g. IN001) that produces a unique identifier for each map unit
reference_id was populated with an alphanumeric code (e.g. US001) that
designates the source used for the linework and other references used to describe
the age or lithologies of the unit.
unit_age was populated with general age assignment
rocktype1 records dominant lithology (must be >50% of unit), using standardized
data dictionary
rocktype2 records second most dominant lithology, using standardized data dictionary
The attributes were then converted using the following structure:
item name: orig_label
width: 12
output: 12
type: c
item name: sgmc_label
width: 16
output: 16
type: c
item name: unit_link
width: 18
output: 18
type: c
item name: source
width: 6
output: 8
type: c
item name: unit_age
width: 60
output: 60
type: c
item name: rocktype1
width: 40
output: 40
type: c
item name: rocktype2
width: 40
output: 40
type: c
Process Date: 20041110
Once the .dbf was in the correct format with standardized
column widths and data structure, it was converted into a lookup table (.lut) in
Arc/Info. Then a joinitem was performed to join the look-up table to the polygon
attribute table. orig_label was used as the merge item.
Process Date: 20041110
Next, in preparing the uniform .aat file, the following items were added to the table:
item name: arc-code
width: 3
output: 3
type: i
item name: arc-para1
width: 3
output: 3
type: i
item name: arc-para2
width: 3
output: 3
type: i
item name: source
width: 6
output: 8
type: c
Process Date: 20041110
Arc-code was populated using the paper map source to tag the lines using the
AAT line type data dictionary (see Chapter A in this series).
Arc-para1 was populated when additional information was available such as
identifying the upthrown side of a fault or direction of thrusting on a fault.
(see Chapter A)
Arc-para2 is a scratch field that is used mostly in Alaska.
Source was populated with an alphanumeric code (e.g. US001) that designates
the source used for the linework.
Process Date: 20041110
Once the .aat and the .pat were populated with the correct attributes, the
coverage was exported as an .e00 file (flgeol_lcc.e00).
Then it was unprojected into geographic coordinates and exported again
(flgeol_dd.e00).
Process Date: 20050118
Florida does not have any faults in their coverage so no
fault extraction was performed.
Process Date: 20050118
Finally, the geology lines and geology polygons were
converted into shapefiles; in both geographic coordinates and in Lambert Conformal
Conic projection.
Process Date: 20050118
GeoPlan Center received this data from USGS via download at
http://tin.er.usgs.gov/geology/state/state.php?state=FL on 7/22/2010.
When received the data was in shapefile format and was in the following
projection: North American Datum of 1927. GeoPlan, during the QA/QC
Process included the following aspects:
- Reprojected the dataset to FGDL Albers HGPN Projection. The projection file
was in Decimal Degrees Nad27. The data appeared to be reprojected incorrectly
when compared to existing Surficial Geology (SURGEO) and imagery. Changed
the source projection file to WGS84 and the data appeared to project correctly
- Deleted the area and perimeter fields and internal cov fields
- Upcased the UNIT_AGE, ROCKTPE1, and ROCKTYPE 2 Fields
- Added a descript field based on the actual definitions of orig_label
- Added a FGDLAQDATE field based on the date FGDL acquired the data
Process Date: 20100208
Data imported to ArcSDE and exported as a shapefile.
Process Date: 20100723
|