<abstract>The Assessment Unit is the fundamental unit used in the National Assessment Project for the assessment of undiscovered oil and gas resources. The Assessment Unit is defined within the context of the higher-level Total Petroleum System. The Assessment Unit is shown here as a geographic boundary interpreted, defined, and mapped by the geologist responsible for the province and incorporates a set of known or postulated oil and (or) gas accumulations sharing similar geologic, geographic, and temporal properties within the Total Petroleum System, such as source rock, timing, migration pathways, trapping mechanism, and hydrocarbon type. The Assessment Unit boundary is defined geologically as the limits of the geologic elements that define the Assessment Unit, such as limits of reservoir rock, geologic structures, source rock, and seal lithologies. The only exceptions to this are Assessment Units that border the Federal-State water boundary. In these cases, the Federal-State water boundary forms part of the Assessment Unit boundary.</abstract>
<purpose>The purpose of these files is to define and illustrate the geographic limit and geologic boundaries of the Assessment Units within the defined Total Petroleum Systems, as required for the USGS National Assessment of Oil and Gas Project. The Assessment Units were used as the fundamental units for the assessment of undiscovered oil and gas. The assessment unit boundaries define the combined geologic limits of each Assessment Unit and are described and defined in the text portions of this assessment publication.</purpose>
<supplinf>Oil and gas assessment units within province 065 (Black Warrior) are listed here by assessment unit number and name:
>Number Name
>50650101 Pre-Mississippian Carbonates Gas
>50650102 Carboniferous Sandstones Oil and Gas
>50650281 Black Warrior Basin Coalbed Gas
The following is a description of the Online Linkage URLs:
http://certmapper.cr.usgs.gov/noga/servlet/NogaGISResultsServ?subtheme=65&page=gis&vintage=2000 - GIS Data Download Page for Province 65
http://pubs.usgs.gov/dds/dds-069/dds-069-?/ - Petroleum Systems and Geologic Assessment of Oil and Gas in the Black Warrior Basin, USGS DDS-69-?
<placekey>50650102 = Carboniferous Sandstones Oil and Gas</placekey>
<placekey>50650281 = Black Warrior Basin Coalbed Gas</placekey>
</place>
</keywords>
<accconst>none</accconst>
<useconst>none</useconst>
<ptcontac>
<cntinfo>
<cntperp>
<cntper>Christopher J. Schenk</cntper>
<cntorg>U.S. Geological Survey, Central Energy Resources Team</cntorg>
</cntperp>
<cntpos>Geologist</cntpos>
<cntaddr>
<addrtype>mailing and physical address</addrtype>
<address>U.S. Geological Survey, Box 25046, MS 939, Denver Federal Center</address>
<city>Denver</city>
<state>Colorado</state>
<postal>80225</postal>
<country>USA</country>
</cntaddr>
<cntvoice>(303) 236-5796</cntvoice>
<cntemail>schenk@usgs.gov</cntemail>
</cntinfo>
</ptcontac>
</idinfo>
<dataqual>
<attracc>
<attraccr>The main attribute for the Assessment Unit coverage is the eight digit number that identifies the USGS-specific Assessment Unit. The first digit of the code indicates the World region number (5), the following three digits (065) are the North America province number, the following two digits (5065xx) are the Total Petroleum System number, and the last two digits (506501xx) are the Assessment Unit number of that particular Total Petroleum System.
The assessment results attributes have been rounded to two decimal places. For more detailed assessment results data, refer to the tabular information for the Black Warrior Basin Province that is available at NOGA Online (the URL is listed in the Online Linkage). The fractile estimates for the largest oil or gas accumulations are calculated for conventional accumulations and are defined as character fields because they may be blank (not zero) if the accumulation is less than the minumum undiscovered field size used in the assessment. Assessment units that contain no assessment results attributes are those that were not quantitati
