Table Name | Field Name | Begin Column | Definition | Valid Values | Descriptions
Renvagppy.dbf | Id |  | Integer,8 | Values from 208 to 660. | Unique identifier for the field mapping units
| Fieldudesc |  | Text, 70 | e.g., Colluvium - Slope Wash/Debris; Glaciofluvial Outwash Terrace - 50+ ft Sand w/ Gravel (Low); Holocene Alluvium - Sand (>5 feet); Ice Contact - Sand and Gravel - Low Potential; Granite/Gneiss, Till - Slope of Valley Wall. | A short, summarized description of the field mapping units.
| Sgeo_plb |  | Text, 80 | Listed below as Sgeo_plb (Sgeo_lab), youngest units to oldest units. | The surficial geologic unit shown on map Plate B. Mapping units may be bedrock material, a glacial sediment, or a modern Holocene sediment.
|  |  |  | Colluvial Sediments (Qcl) | Clay, silt, sand, and gravel, with occasional cobbles and boulders of varying composition, as well as angular fragments of limestone and sandstone of varying sizes. The sediment is moderately- to poorly-sorted, however, it occasionally contains thin (<6 inch) beds of well-sorted alluvial material. Colluvium is deposited at the foot of steep slopes where the bank material has collapsed and become slightly washed by sheetwash and alluvial processes. This colluvial sediment is primarily located at the base of the steep till and bedrock walls paralleling the Minnesota River.
|  |  |  | Alluvial Flood Plain Sediments (Qfp) | Silt, fine sand, coarse sand, gravel, and clay layers, overlying coarser sand and gravel layers and lenses. The sediment is generally moderately- to well-sorted and is interpreted to be alluvial overbank and stream bottom deposits. Within this unit, coarser sediment is typically found in abandoned and modern channels, point bars, and river bars. Alluvial sediments exist throughout the county in valleys, in low lying areas where drainage occurs as channelized flow, and within the current flood plain of the Minnesota River.
|  |  |  | Alluvial Fan Sediments (Qaf) | Stratified fine sand, coarse sand, and gravel, with thin layers of silt and clay. The sediment is moderately well- to very well-sorted. Coarser material is typically found at the base of the fan (that is, the bottom of the deposit) and near the mouth of the fan. The sediment is generally deposited at the end of tributary streams where they enter larger valleys, due to the change in slope and slowing of the water flow, forming a cone shaped deposit. Alluvial fan sediments primarily occur in the western part of the county where smaller tributary streams enter the Minnesota River valley.
|  |  |  | Alluvial Terrace Sediments (Qat) | Fine sand, coarse sand, and gravel, with occasional layers of silt and clay. The sediment is moderately well- to well-sorted with thin layers, lenses, and pockets of very well-sorted sands and gravels. The terraces are typically covered by 6 inches to 2 feet of silt, clay, and/or fine sand layers derived from flood plain sediments. Alluvial terrace sediments are found along tributary streams that enter the Minnesota River, where moving water has cut through the pre-existing till and glaciofluvial material and redeposited the sorted sands and gravels.
|  |  |  | Glaciofluvial Outwash Terrace Sediments (Qot) | Stratified coarse to fine sand, and gravel with occasional layers of cobbles and small boulders. The sediment is generally rounded to well-rounded and moderately well- to very well-sorted. Most of the sediment is associated with large distal, meltwater channels of Glacial River Warren and is observed protruding from Holocene alluvial sediment within the Minnesota River valley and along the bluffs paralleling the valley. Smaller terraces are also observed in some of the tributaries of the Minnesota River and are interpreted to be associated to outwash channels of glacial meltwater and drainage of glacial lakes.
|  |  |  | Glaciofluvial Outwash Channel Sediments (Qoc) | Stratified fine to coarse sand and gravel with layers of silt, fine sand, and cobbles scattered throughout. The sediment is rounded to well-rounded and moderately-well to very-well sorted. The sediment occurs in channels that were initially eroded proximal to glacial ice, marking recessional ice margins, then was deposited by distal glacial meltwater. Some of the sediment is collapsed and discontinuous, as a result of melting of buried ice blocks underlying the sediments.
|  |  |  | Lacustrine Sediments (Qlu) | Massive silt, clay, or fine sand with interbeds of sandy silt and fine sand. The sediment is associated with the ponding of glacial meltwater to form a shallow, short-lived lake (Glacial Lake Benson). The margin of the lake is not well defined and discontinuous, which is interpreted to be due to confinement of the lake by stagnant ice and subsequent scouring by the drainage of Glacial Lake Agassiz. The lake margin is located in the western portion of Renville County.
|  |  |  | Glacioacustrine Sediments over Till (Qlt) | Thin, discontinuous layers of sands, silts and clays mantling unsorted till sediments (unsorted clay, silt, sand, gravel, cobbles, and boulders). The sediment is interpreted to be till that has been modified by wave action of water. Thicker accumulations of lake sediment are found in the small depressions between till hummocks. This unit is interpreted to have formed during the initial phases of Glacial Lake Benson where the lake was confined by retreating ice and a large end moraine.
|  |  |  | Stream Modified Till Sediments (Qmt) | Thin, discontinuous layers of fine to coarse sand and gravel with occasional layers of silt, fine sand, and cobbles. The sediment mantles scoured, unsorted till sediments (unsorted clay, silt, sand, gravel, cobbles and boulders) which may have produced a pebble/cobble lag at the contact. The sediment is interpreted to be till that has been modified by glacial meltwater in or near outwash channels.
|  |  |  | Ice Contact Sediment Sediments (Qic) | Stratified silt, fine sand, coarse sand, and gravel with an occasional thick mantle of glacial till. The sediment is rounded to well-rounded and moderately-poor to moderately-well sorted. Ice contact sediments can be observed in long narrow, occasionally sinuous, ridges that are broadly interpreted to be eskers. Eskers form as water transported sediment at the base of glacial ice or within melting blocks of ice. Other landforms include ice supported stream sediments that are observed the along the edge of the east/west trending outwash channel. Some of the sediment is collapsed and contains lenses of glacial till.
|  |  |  | Stagnant Ice Sediments Sediments (Qtm) | Stratified silt, fine sand, coarse sand and gravel with frequent clay and washed till mixed throughout. This sediment is found in discontinuous patches and ridges; the sediment is poorly- to well-sorted, well-stratified to mixed, and is variable. The ridges are interpreted to have formed when glacial meltwater flowed on and between stagnant ice that later collapsed. The collapsing caused the deposit to be discontinuous and mixed with till. Stagnant ice sediment is observed in the eastern edge of the county.
|  |  |  | Till - Collapsed Sediment (Qcc) | Till sediment (unsorted clay, silt, sand, gravel, cobbles, and boulders) overlain with occasional, discontinuous and patchy accumulations of sand, silt, clay and organics. These sediments are observed in mostly elongated, segmented depressions and occasionally in singular amorphous depressions. The depressions are interpreted to have formed when subglacial meltwater channels eroded into the substrate, which were later filled in with till and/or ice blocks within till.
|  |  |  | Till - Ground Moraine Sediments (Qtg) | Unsorted and unstratified clay, silt, sand, gravel, cobbles with occasional boulders. This till sediment (also called unsorted drift) was deposited directly by and underneath the glacier without subsequent reworking by glacial meltwater. The random melting of ice and deposition of material produced a relatively flat to gently rolling, hummocky topography that is characteristic of ground moraine.
|  |  |  | Till - Ground Moraine Sediments (Grantsburg) (Qgg) | Unsorted and unstratified clay, silt, sand, gravel, cobbles with occasional boulders. This till unit contains parallel, semi-regularly spaced till ridges deposited in a "washboard" pattern. These ridges are too small to delineate at the map scale and are shown with line symbols. The ridges within this unit indicate a change of ice flow direction from the southeast to the northeast, which is interpreted as an indicator for the Grantsburg sub-lobe.This unit is observed in the northeastern corner of the county.
|  |  |  | Till - End Moraine Sediments (Qte) | Till sediment (unsorted clay, silt, sand, gravel, cobbles, and boulders) that has been deposited into multiple broad, arcuate, landforms. End moraines form at the terminus of active glacial ice and marks long standing positions of a retreating ice margin. Delineated moraines can be either very large to small in size. This unit is observed in the southern half of the county.
|  |  |  | Till – Cosmos End Moraine Complex (Qcm) | Till sediment (unsorted clay, silt, sand, gravel, cobbles and boulders) with discontinuous pockets of stratified silts, sands and gravels. This unit has been deposited into a large, arcuate landform that marks a single, long standing ice margin. An older till that is lithologically similar may be exposed western limit of the moraine. The presence of this till near the surface may be attributed to glacial thrusting of the older till or due to a thin mantle of the younger glacial sediments. This landform has been further modified by glacial meltwater that was ponded to the north of the county. Scalloped ridges and segmented channels are observed on the moraine, which is located in the northern part of the county.
|  |  |  | Clay/Kaolin Clay (Kc) | White, light gray, yellowish-brown, and dark green colored, thinly laminated clays. The clay layers typically range from 2 to 25 feet and can have a sharp to gradational contact with the underlying bedrock. Clays are exposed along the Minnesota River and near the mouth of its tributaries. Overlying the clays are thick layers of till and glacial outwash.
|  |  |  | Pisolitic Regolith (Kp) | Red, dark brown, tan to light green in color regolith with pisolite nodules. A resistant, iron-rich pisolitic layer overlies a less resistant pisolitic-bearing layer that has a fine-grained to medium-grained matrix. The regolith is exposed as a rock bench in the Minnesota River valley.
|  |  |  | Granite/Gneiss, undivided (Pg) | Dominant llithologies are pink and/or gray, black colored, foliated and banded granitic gneiss with granitiod intrusions and mafic dikes. The granitic gneiss exhibits bands and/or lenses of granular minerals alternating with bands and/or lenses of elongated minerals. The gneiss formed from regional metamorphism during which time the pre-existing granite was exposed to intense heat and pressure, which caused it to change or metamorphose into gneiss. The gneiss was later intruded by large granitic plutons and mafic dikes.
| Sgeo_lab |  | Text, 4 | Qcl, Qfp, Qaf, Qfp, Qot, Qoc, Qlu, Qlt, Qmt, Qic, Qtm, Qcc, Qtg, Qgg, Qte, Qcm, Kc, Kp, Pg | The label for the surficial geology mapping unit used on map Plate B.
| Sgeo_age |  | Text,30 | Precambrian, Cretaceous, Holocene, Holocene/Cretaceous, Holocene/Pleistocene, Holocene/Precambrian, Pleistocene, | Describes the age of the material encountered at the surface.
| Sgeo_proc |  | Text, 40 |  | The type of geological process that deposited these features.
|  |  |  | Alluvial | Modern stream processes
|  |  |  | Alluvial over Glaciofluvial | Modern stream processes overlying glaciofluvial (glacial stream) processes
|  |  |  | Bedrock | Material deposited by ancient seas during the Cambrian and Ordovician.
|  |  |  | Colluvial | Material that was deposited as slope wash or slump along steep banks.
|  |  |  | Glacial | Unsorted glacial material deposited in place.
|  |  |  | Glacial over Glaciofluvial | Unsorted glacial material deposited over glacial sediments that have been sorted by meltwater.
|  |  |  | Glaciofluvial | Glacial sediments that have been sorted by meltwater.
|  |  |  | Glaciolacustrine | Sediments deposited at the bottom of a glacial lake.
| Sgeo_feat |  | Text, 50 | Alluvial fan, Alluvial terrace, Bedrock, Collapsed channel, Colluvial slope, Flood plain, Glacial lake bed, Ground moraine, Ice contact, Outwash channel, Outwash terrace, Sand bar, Stagnant ice moraine. | The type of geological feature encountered at the surface (surficial geology). Surficial Geology is defined as the geologic units encountered within the top 5 to 10 feet of the surface.
| Sgeo_mat |  | Text, 40 | e.g., Clay, silt, and sand over till; Sand; Sand and gravel; Granite; Till with patchy sand and gravel. | The dominant type of material encountered in the surficial geologic unit.
| Sg_sigpot |  | Text, 50 | Potential Sand and Gravel Resources; Potential Crushed Stone Resource; Limited Potential for Aggregate Resources. | Significant Aggregate Resources Deposits are defined as those deposits most likely to be explored and evaluated for future commercial use. They include all the moderately and highly desirable sand, gravel, and crushed stone deposits as well as very large areas of finer sand and gravel that could be blended with coarser material to make more highly desirable deposits.
| Sg_potpla |  | Text,100 | e.g., Highly Desirable Sand and Gravel Deposits; Less Desirable Sand and Gravel Deposits/Moderately Desirable Crushed Stone Deposits; Limited Potential Aggregate Resources. | The aggregate resource potential, combined from the Sg_pota_sg and Sg_pota_cs fields.
| Sg_pota_sg |  | Text,50 |  | The aggregate resource potential for sand and gravel, as shown on map Plate A. From the legend on Plate A…. POTENTIAL SAND AND GRAVEL RESOURCES: Geologic units that are inferred to contain sand and gravel. These units exhibit the geologic characteristics that typically produce sand and gravel deposits. Existing gravel pit and MN/DOT aggregate sources lying within these units indicate identified or known resources. The geologic units having potential for sand and gravel include alluvial features (flood plains, terraces, and fans), glacial outwash features (channels and terraces), and ice-contact features (eskers and kames). These units typically contain sorted sand and gravel with little silt or clay.
|  |  |  | Highly Desirable Sand and Gravel Deposits | Glaciofluvial features, such as terraces and outwash channels. These deposits are very large in areal extent¹. These deposits consist of sand and gravel with thicknesses typically ranging from 15 to 40+ feet with less than 5 feet of overburden. The probability² that a potential sand and gravel deposit exists within this unit is high to very high. The texturalcharacteristics³ of these deposits are classified as good to very good. The quality is typically moderately high to very high relative to all deposits within Renville County.
|  |  |  | Moderately Desirable Sand and Gravel Deposits | Glaciofluvial features, such as outwash channels and terraces; ice-contact features, such as eskers and kames; as well as Holocene age terraces, floodplains, and fans. These deposits are moderately small to large in areal extent with sand and gravel thicknesses typically ranging from 10 to 20+ feet, with less than 10 feet of overburden. The probability that a potential sand and gravel deposit exists within this unit is moderately to very high. The textural characteristics of these deposits are moderate to very good, with the quality ranging from moderately high to high.
|  |  |  | Less Desirable Sand and Gravel Deposits | Glaciofluvial features, such as outwash channels and terraces; ice-contact features, such as eskers and kames; and alluvial features such as flood plains, terraces, fans, and sand bars. These deposits are moderately small to very large in areal extent and consist of sand and fine sand with thicknesses ranging from 0 to 15+ feet, with overburden thicknesses between 0 to 50+ feet. The probability that a potential sand and gravel deposit exists within this unit is moderate to very high. The textural characteristics of these deposits are moderate poor to good, with the quality ranging from moderately low to high.
|  |  |  | Limited Potential Sand and Gravel Deposits or Limited Potential for Aggregate Deposits | Units that include glacial features such as collapsed glaciofluvial channels, ground moraines, end moraines, colluvial slopes, and small alluvial features such as flood plains and streams. The probability that a significant aggregate deposit exists within this unit is very low to moderate. The aggregate deposits occurring in this unit are very small to moderately small in areal extent and typically consist of finer material (sand with some gravel). The thicknesses of these aggregate deposits are typically less than 10 feet, with overburden thicknesses sometimes reaching over 100 feet. The textural characteristics are poor to moderately poor with the quality ranging from low to moderate. These units also contain granitic bedrock units with an overburden thickness of greater than 25 feet (however, a dotted pattern on top of this color indicates crushed stone potential but limited sand and gravel potential).
| Sg_pota_cs |  | Text,50 |  | The aggregate resource potential for crushed stone, as shown on map Plate A. From the legend on Plate A… POTENTIAL CRUSHED STONE RESOURCES: Granite and other crystalline bedrock formations, (gneiss, monzonite, gabbro, amphibolite, basalt, and peridotite) that are suitable for crushing. These units are inferred to be relatively thick (10 to 100+ feet), with overburden thicknesses ranging from 0 to 25+ feet. Quarries located within these units indicate identified or known resources.
|  |  |  | Highly Desirable Crushed Stone Deposits | Granite and other crystalline bedrock formations that contain material suitable for crushed aggregate. These units are exposed at the surface, and the exposed thickness of bedrock knobs can range from 10 to 70+ feet (with the potential of extending 100+ feet below surface). Overburden thickness is typically less than 10 feet. These units have a very high probability of containing potential for crushed stone deposits. The quality of these units is potentially high
|  |  |  | Moderately Desirable Crushed Stone Deposits | Granite and other crystalline bedrock formations that contain material suitable for crushed aggregate. These units are found near or slightly below the surface and can have thicknesses greater than 100+ feet, with an overburden thickness typically less than 25 feet. These units have a high to very high probability of containing potential for crushed stone deposits. The quality of these units is potentially high.
|  |  |  | Less Desirable Crushed Stone Deposits | Granite and other crystalline bedrock formations that contain material suitable for crushed aggregate. These units are found below the surface or along the valley walls of small streams. The thickness of the unit is probably greater than 100+ feet, with an overburden thickness greater than 25 feet. These units have a moderately high to very high probability of containing potential crushed stone deposits. The quality of these units is potentially moderately high to very high.
| Sg_prob |  | Text, 20 | Very High, High, Moderately High, Moderate, Moderately Low, Low. | The relative degree of certainty that sand and gravel exists within a unit. Based on air photo interpretations, field observations, CWI, drilling, presence of gravel pits and quarries, etc. Each unit is relative to the other units and range from very high to very low.
| Sg_depsize |  | Text, 20 | Very large, Large, Moderately large, Moderate, Moderately small, Small | The relative size of the sand and gravel deposit
| Size_in_ac |  | Text, 7 | >50, 40-50, 30-40, 20-30, 10-20, 5-10 | The size of the deposit in acres.
| Sg_thickmn |  | Integer, 4 | 0, 5, 10, 15, 20, 25, 30 | Describes the minimum thickness of the sand and gravel unit.
| Sg_thickmx |  | Integer, 4 | 5, 10, 15, 20, 25, 30, 40, 50, 75 | Describes the maximum thickness of the sand and gravel unit.
| Sg_thickmd |  | Text,1 | + | The sg_thickness modifier indicates that the thickness of the unit exceeds the value listed in the Sg_thickmx field.
| Sg_overmin |  | Integer,4 | 0, 3, 10, 20 | Describes the minimum thickness of the overburden covering the sand and gravel.
| Sg_overmax |  | Integer,4 | 1, 3, 5, 10, 15, 20, 30, 40, 50 | Describes the maximum thickness of the overburden covering the sand and gravel.
| Sg_overmod |  | Text,1 | + | The sg_overburden modifier indicates that the thickness of the overburden exceeds the values listed in the Sg_overmax field.
| Sg_texture |  | Text, 20 | Very Good, Good, Moderately Good, Moderate/Good, Moderate, Moderately Poor, Poor/Good, Poor. | A relative scale of the textural quality of the sand and gravel resource (sieve analysis). The coarser the material the higher the rating. Fine sand material would have a poorer rating. See MN/DOT Pit sheets for more detail.
| Sg_quality |  | Text, 20 | Very High, High, Moderately High, Moderate/High, Moderate, Moderately Low, Low/High, Low | A relative scale of the quality of the sand and gravel (soundness, durability, and mineral makeup). Determined from MN/DOT pit sheets.
| Sg_thick |  | Text, 15 | e.g., 0-5, 5-30+, 20-40, 25-75+ | The assumed range of thickness of the sand and gravel deposit (in feet). A combination of the Sg_thickmn, Sg_thickmx, and Sg_thickmd fields.
| Sg_overbdn |  | Text, 15 | e.g., 0-1, 0-20+, 10-20, 20-40+ | The assumed range of overburden thickness of a sand and gravel deposit (in feet). A combination of the Sg_overmin, Sg_overmax, and Sg_overmod fields.