Table Name | Field Name | Begin Column | Definition | Valid Values | Descriptions
millpits.shp |  |  |  |  |
| Pit_q_id |  | Number, 6,0 | Ex: 1,2,3,4,5,6,7.... 341, 342, 343, 344 | Aggregate pit unique ID
| Source |  | Text, 16 | See Below | Construction aggregate pit data source compiled from or observed (ex: topographic map- found on the topographic map).
|  |  |  | ASIS | Minnesota Department of Transportation database called Aggregate Source Information Systems. If the location did intersect a gravel pit, the locations were interpreted off of existing gravel pit sheets to relocate the mines to as specified on the sheet.
|  |  |  | Air Photograph | Gravel mines were also located and some attributes were interpreted with air photography.
|  |  |  | Fieldwork | These pits were located while in the field.
|  |  |  | Topographic Map | These gravel pits are located from USGS 7.5 minute quadrangles.
| Type |  | Text, 16 | See Below | The type of pit or quarry observed
|  |  |  | Gravel Pit | Gravel Pit
|  |  |  | Sand Pit | Sand Pit
|  |  |  | Borrow Pit | Borrow Pit- is defined not by use but by material. If a pit contains significant clay and silt material, it was classified as borrow.
|  |  |  | Quarry | Quarry (Construction Aggregate or Dimension Stone, See field ‘Status_2’ for quarry type)
| Asis_numbr |  | Number, 9,0 | Ex: 0, 47035, 47036, 47070, -999 | Aggregate Source Information System Number (MN/DOT Database). An empty field means that it does not have an ASIS number. Use this field to join with milldotqual.dbf for the pits that list the Source as “ASIS”. (-999 value is null)
| Size |  | Text, 8 | See Below | Refers to the relative size of the pit.
|  |  |  | Small | Small pits are generally less than five acres. These pits are usually used by private landowners or for small jobs.
|  |  |  | Medium | Between 5 and 15 acres in size. These pits are used by landowners and for small construction jobs, They are generally used for short periods of time by contractors.
|  |  |  | Large | These pits are generally greater than 15 acres and are typically used by commercial aggregate operators.
| Thickness |  | Text, 15 | Ex: >10, ~20, >25, 10, 25, <20, NA | The thickness of the deposit expressed in combination with a modifier. ‘NA’ indicates not available
| Thick_mod |  | Text, 1 | Ex: ~, >, < | Modifiers to express numeric approximations observed for deposit thickness: ~ approximate < less than > greater than.
| Thick_val |  | Number, 4 | Ex: 5, 10. 15…-999 | Gives a value for thickness. (-999 is a null value)
| Overburden |  | Text, 15 | Ex: >10, ~20, >25, 10, 25, <20, NA | Expresses overburden thickness by possibly using one or both the modifier and value. ‘NA’ indicates not available
| Ob_mod |  | Text, 1 | Ex: ~, >, < | Modifiers to express numeric approximations for the overburden thickness at a gravel pit ~ approximate < less than > greater than
| Ob_val |  | Number, 4 | Ex: 5, 10. 15…-999 | Gives a value for overburden thickness. (-999 is a null value)
| Watertable |  | Text, 15 | Ex: >10, ~20, >25, 10, 25, <20, NA | The depth of the water table expressed in combination with a modifier. ‘NA’ indicates not available
| Wattab_mod |  | Text, 1 | Ex: ~, >, < | Modifiers to express numeric approximations for the depth to the water table: ~ approximate < less than > greater than
| Wattab_val |  | Number, 4 | Ex: 5, 10. 15…-999 | Describes the depth to the water table within a pit or quarry. If 20 feet of gravel was exposed and there was no water table encountered, then >20 were used. (-999 is a null value)
| Status_1 |  | Text, 20 | See Below | Refers to the status of the pit at the time of mapping.
|  |  |  | Active | Active indicates that the pit is either being actively mined or used for other mining related usage like stockpiling material.
|  |  |  | Inactive | Refers to a pit that does not appear to have been active for some time.
|  |  |  | NA | Not available
|  |  |  | Prospective Pit | Mine that has MN/DOT data but has not been developed.
|  |  |  | Reclaimed | The pit has been passively or actively reclaimed. Status_2 further describes type of reclamation
|  |  |  | Vegetated | Part or all of mine that has been re-vegetated.
| Status_2 |  | Text, 50 | See Below | Associated with the field Status_1. This field further explains the condition of a partially or fully reclaimed gravel pit. Additionally, it explains the type of active quarry, such as an aggregate or dimension stone quarry.
|  |  |  | Aggregate | Specifies that mine is an active aggregate producing mine.
|  |  |  | Agriculture | Mine has been reclaimed into an agricultural use.
|  |  |  | Commercial Development | Mine has been reclaimed into an commercial development like a strip mall, a store, etc.
|  |  |  | Dimension Stone Quarry | Mine is a quarry producing dimension stone (granite used for counter tops, gravestones, building facades).
|  |  |  | Field | Mine has been reclaimed into a field.
|  |  |  | Golf Course | Mine has been reclaimed into a golf course.
|  |  |  | Graded | Mine has been actively reclaimed and mine walls have been sloped.
|  |  |  | Grass | Mine has been passively reclaimed and re-vegetated with grass.
|  |  |  | Grassland | Mine has been reclaimed into grassland.
|  |  |  | Highway | Mine has been reclaimed or has been developed over by a highway.
|  |  |  | Lake | Mine has been reclaimed into a lake or a body of water.
|  |  |  | Meadow | Mine has been reclaimed into a meadow.
|  |  |  | NA | Not Available
|  |  |  | Naturally Vegetated | Mine has been passively, or naturally re-vegetated over time.
|  |  |  | Parking Lot | Mine has been reclaimed into a parking lot.
|  |  |  | Partially Vegetated | Mine has been partially re-vegetated and is partially unreclaimed.
|  |  |  | Residential | Mine has been reclaimed into residential development.
|  |  |  | Sloped | Part or all of mine has been actively reclaimed and mine walls have been sloped.
|  |  |  | Storage | Mine has been reclaimed into commercial development- mini storage.
|  |  |  | Transfer Station | Mine has been reclaimed into a transfer station.
|  |  |  | Trees | Part or all of mine has been actively reclaimed by natural re-vegetation of trees.
|  |  |  | Vegetated-Grass | Part or all of mine has been actively reclaimed by natural re-vegetation of grass.
|  |  |  | Vegetated-Trees | Part or all of mine has been actively reclaimed by natural re-vegetation of trees.
|  |  |  | Wetland | Part or all of mine is covered by a wetland.
|  |  |  | Wetland and Grass | Part or all of mine is covered by a wetland and grass.
| Dom_litho |  | Text, 30 | See Below | Dominant lithology of the pit
|  |  |  | Des Moines Lobe | Sand and gravel associated with a glacier called the Des Moines Lobe. These sands and gravels contain deleterious rocks (like shale, iron oxides, and soft limestones) that can degrade the quality of the deposit.
|  |  |  | Granite | An intrusive, felsic igneous rock that has a medium to coarse texture.
|  |  |  | NA | The source of the sand and gravel could not be determined. This is primarily due to the deposit could not be accessed and was not observed and the surrounding geology is too complex to extrapolate the source.
|  |  |  | Quartz Monzonite | An intrusive igneous rock that has a specific composition of equal portions of orthoclase and plagioclase feldspars.
|  |  |  | Rainy Lobe | Rainy Lobe is a northeastern sourced glacier flowing along the highlands of eastern Minnesota to the southwest. Rainy Lobe sediments tend to contain high percentage of granites and granitic rock types. Aggregate with Rainy Lobe rock lithologies generally are of high quality and durability.
|  |  |  | Superior Lobe | Superior Lobe is a northeastern sourced glacier flowing from the Lake Superior basin to the southwest. The quality of these deposits tends to be good to very good due to the rock types found within the deposits (basalt, granite, gabbro). Also, these deposits have undergone some degree of mixing with rock types associated the Rainy Lobe (granites).
|  |  |  | Superior/Rainy | Superior Lobe sediments stratigraphically above Rainy Lobe sediments.
| Dom_text |  | Text, 35 | See Below | The dominant texture of the pit
|  |  |  | Gravel | Rock fragments of specific particle size that is larger than 2 mm and less than 63 mm.
|  |  |  | Gravel and Till | Containing both gravel and till (unsorted sediment deposited by glaciers- contains a mixture of clay, silt, sand, gravel and boulders).
|  |  |  | NA | The texture of the gravel pit was undetermined due to lack of exposure or geologic evidence to make a determination.
|  |  |  | Sand | Indicates the deposit is composed of sand and has a fine texture.
|  |  |  | Sand and Gravel | Indicates the deposit has approximately equal or slightly more sand than gravel by percent weight.
|  |  |  | Sand minor Gravel | Indicates the deposit contains mostly sand with few gravel-sized rocks and has a fine texture.
|  |  |  | Sand with Gravel | Indicates the deposit has more overall more sand than gravel by percent weight and has an overall fine texture
| Comments |  | Text, 100 | Ex: Very sandy deposit with limited gravel | Geologist comments related to the pit
| GPQNAME |  | Text, 50 |  | If available, the pit name at the time of mapping