Overview: Rock (and sediment) terms that represent the prevailing composition of each geologic map unit have been assigned (See Dominant Lithology Map link). Prevailing compositions are the dominant lithologies that most affect the unit's land-use and geotechnical behavior. This assessment was made by reviewing descriptions from existing geologic maps and published reports. Some map units are made up of more than one rock unit; in those cases the dominant lithologic term is a composite of the member units. The basic character of each lithologic term is described below, along with additional properties that are known to be associated with similar materials.
- Clay and silt: Unconsolidated to semiconsolidated, fine-grained sediment. Associated with surficial deposits in the Jackson Purchase region and glacial, lacustrine (lake) deposits in the Ohio River Valley and tributaries of the river. May contain lenses or thin layers of chert. Additional properties : Clay-rich deposits may have swelling properties.
- Eolian loess: Silt and clayey silt deposited by wind; typically unconsolidated, homogenous, nonstratified, and friable. Commonly covers uplands adjacent to alluvial valleys of the Ohio River and its tributaries. Additional properties : Reported to be most stable in near-vertical exposures.
- Eolian sand: Very fine-to fine-grained sand deposited by wind, such as sand dunes; mainly quartz grains. Unit commonly concealed by loess.
- Gravel: Mainly consisting of pebbles or cobbles of quartz, chert, limestone, sandstone, or siltstone. Matrix is commonly fine to coarse sand.
- Mixed sediments: Unconsolidated material containing mixtures of gravel, sand, silt, and clay. Lithology mainly occurs in surficial units such as Alluvium and Terrace deposits.
- Sand and gravel: Coarse-grained variety of unconsolidated, mixed sediments.
- Sand, silt, and clay: Fine-grained variety of unconsolidated mixed sediments.
- Artificial fill: Man-made compacted rock debris from highways, railroads, and earthen dam construction.
- Black shale: Fine-grained, organic-rich sedimentary rock formed from the compaction of clay silt or mud. Clayey to silty texture; commonly splits along irregular bedding planes. Gray to black. Commonly contains fractures. Additional properties: Prone to extensive weathering, plastic clays can present poor foundation conditions and unstable slopes. Possible pyrite expansion in some areas.
- Conglomeritic sandstone: Coarse-grained sedimentary rock consisting of large quartz pebbles in a sandstone matrix.
- Dolomite: Sedimentary rock, more than 90 percent of the mineral dolomite (CaMg(CO 3 ) 2 ) and less than 10 percent of the mineral calcite (CaCO 3 ). Generally has a sugary texture, but lacks visible, individual grains as in sandstone.
- Dolomite and limestone: Sedimentary rock units of interbedded dolomite and limestone (see definitions of dolomite and limestone).
- Gray shale: A fine-grained sedimentary rock formed from the compaction of clay, silt, or mud. Clayey to silty texture; commonly splits along planar or irregular bedding planes. Additional properties: Some units may have high percentage of swelling clay, slopes can be unstable and susceptible to landslides.
- Limestone and minor dolomite: Mainly comprised of limestone with few interbeds of dolomite. Unit may have thin interbeds of shale as well. Limestone varies from fine-grained argillaceous to coarse-grained crystalline varieties.
- Limestone and shale: Mainly composed of approximately equal parts limestone and shale. Both sedimentary rocks, limestone is primarily composed of calcite and varies from fine-grained argillaceous to coarse-grained crystalline varieties. Limestone is commonly fossiliferous. Shale is fine-grained and formed from the compaction of clay, silt, or mud. Clayey to silty texture; commonly splits along planar or irregular bedding planes. Additional properties: Areas underlain with this unit commonly have high karst potential.
- Limestone and minor shale: Mainly comprised of limestone with few interbeds of shale. Limestone varies from fine-grained argillaceous to coarse-grained crystalline varieties. Additional properties: Areas underlain with this unit commonly have high karst potential.
- Limestone, coarse-grained: Sedimentary rock primarily composed of calcite. Coarse-grained limestone can range from coarsely crystalline to bioclastic (fossiliferous) or oolitic. Additional properties : Areas underlain with this unit commonly have high karst potential.
- Limestone, fine-grained: Sedimentary rock primarily composed of calcite. Fine-grained limestone can range from argillaceous lime mud to finely crystalline varieties. Additional properties : Typically well suited for foundation material and construction aggregate. Areas underlain with this unit commonly have high karst potential.
- Lithic sandstone: Coarse-grained sedimentary rock containing visible grains of quartz (up to 90 percent), other minerals, and rock fragments. Commonly contains abundant amounts of mica minerals. These sandstones are typically light to dark gray in color.
- Mixed clastics: Interbedded shale, sandy shale, sandstone, fireclay, and coal; associated with coal-bearing rock sequences in the Eastern and Western Kentucky Coal Fields. Additional properties : Fine-grained rocks in these sequences, especially those associated with marine units, are susceptible to landslide development on steep to moderate slopes. Light-colored and red or green, fine-grained rocks found in northeastern Kentucky are highly slaking and do not form stable slopes.
- Mixed clastics and carbonates: Sedimentary rock sequences including detrital clastics and marine limestones. Lithology mainly represents combined rock units within the Mississippian and Pennsylvanian.
- Peridotite: A coarse-grained intrusive igneous rock. Some outcrops may be weathered areas of soil containing igneous mineral crystals. Green to black.
- Quartzose sandstone: A light-colored, coarse-grained clastic sedimentary rock in which quartz is the primary constituent (more than 90 percent). Commonly well-sorted, "clean" sandstone. Usually tan to white. Additional properties : Quartzose sandstones are often very hard and form cliffs or resistant caps to ridges and plateaus. Porous varieties may be hosts for petroleum reservoirs in the subsurface.
- Reddish green shale: Shale is a fine-grained sedimentary rock formed from the compaction of clay, silt or mud. The distinctive color is mainly a result of the carbon content and oxidation state of iron in the shales. Lithology may contain minor amounts of siltstone and sandstone. Additional properties: lithology tends to weather rapidly, slopes can be unstable at low angles.
- Sandstone and minor shale: A coarse-grained clastic sedimentary rock composed of grains of sand (primarily quartz) in a matrix of silt or clay. Sandstone is commonly interbedded with shale.
- Shale and limestone: Interbedded shale and limestone. More than 50 percent of the shale layers. Shale is a fine-grained sedimentary rock formed from the compaction of clay, silt, or mud. Additional properties : Thick accumulations of weathered shale on steep slopes can become unstable. Shale tends to slump when overly saturated with water.
- Shale and minor dolomite: Mainly consists of shale interbedded with minor amounts of dolomite. Shale is a fine-grained sedimentary rock formed from the compaction of clay, silt or mud. Additional properties : Thick accumulations of weathered shale on steep slopes can become unstable. Shale tends to slump when overly saturated with water.
- Shale and sandstone: Interbedded shale and sandstone. Unit has more shale than sandstone. Shale is a fine-grained sedimentary rock formed from the compaction of clay, silt, or mud. Additional properties - Thick accumulations of weathered shale on steep slopes can become unstable. Shale tends to slump when overly saturated with water.
- Siltstone and shale: Interbedded siltstone and shale. Unit has more siltstone. Siltstone is similar to shale but commonly lacking fissility and thin laminations. Additional properties - Thick accumulations of weathered shale on steep slopes can become unstable. Shale tends to slump when overly saturated with water.
- Brecciated or deformed: Breccia is a clastic rock composed of angular or broken rock fragments held together by a fine-grained cement or matrix. Deformation may be many any type of folding, faulting, brecciation, or shattering in the rock.
Geologic Map Service Tutorials:
Overview of Map Functionality
Most of the map functionality is provided in the tabs on the right-side of the map interface:
The tool tab contains standard tools for zoom and pan control of the map. In addition there are several custom tools:
- The button opens a tool which allows the user to search by and zoom to a
geographic area in Kentucky. The types of geographic areas which a user can search by include county name, coordinate location, stream or road name, etc...
- The button opens a table of links to other internet map services or
databases in Kentucky. Selecting a service from the table will open it in another window, zoomed to the same extent of the geologic map.
tool will return a quick popup window that provides information about visible features from the "Geology" and "Data"
layers (e.g. geologic faults, contacts, faults, oil and gas wells, water wells, etc). When used, the feature(s) will be highlighted and basic attribute
information displayed in the popup. Be sure to use the left and right arrow icons at the top of the window to scroll through the identified features if
more than one is found at a location.
- The tool is a query tool that returns information about features on the map at a point.
Clicking on a geologic unit provides lithologic descriptions and, in some cases, economic, geotechnical, hydrologic, or other descriptions. Clicking on an overlay feature
(e.g., oil well or quarry outline) provides summary information about the feature with links to additional data.
returns the same information as the point id tool, but for a rectangular search area drawn by the user.
- The tool is an id tool that returns all the information about a selected point layer (layer selection can be
made when the tool is activated, and include layers such as coal boreholes, wells, photos, etc.) within a buffered area around the selected point on the map.
- The will return photos taken at locations on the map which are designated by the images symbols. For this tool to function and to view the photo icons on the map, the "Photo Locations" must be turned on as a map layer.
- The tool is a measuring tool which returns the distance in feet and miles for a line drawn on the map.
- The tool is a measuring tool which returns the area and distance in feet and miles for a polygon drawn on the map.
- The tool is a click tool that returns the coordinate and descriptive location for a point on the map.
- The print tool creates a formatted print page for the map window.
- The print tool creates a formatted pdf page for the map window.
A note about map printing:
For best results, use the latest version of Internet Explorer, Firefox, or Google Chrome browsers.
NOTE: In older versions of Internet Explorer (8.0 and below), the topography or imagery may not print. You will need to either
upgrade your browser, use a different browser (Firefox or Chrome), use the "print to pdf" tool, or use your computer's screen capture functionality.
- The print tool creates a formatted legend for printing.
This functionality allows you to search the Kentucky Geological Survey database for geologic descriptions from KGS publications, maps, and field notes and highlight those units on the map.
Follow the instructions on the tab for more information about using this feature.
This tab provides explanations of symbology for the map layout. The map unit colors display the map colors for the units in the viewed extent. Other map symbols
are displayed below the colors and are also displayed with each map layer on the "Layers" tab.
This tab provides controls for changing the layout of the map. There are three main sections in this tab:
- Base Layers:
The map service has a basic basemap which includes mostly line features such as roads and streams. Using the buttons at
the top of this section, users may turn on topography with hillshade, topography without hillshade, an aerial photo base, or just
display the basemap. The basemap (roads, rivers, etc..) transparency can also be adjusted with the slider. Other basemap-type layers, including
various index maps for quadrangles and milepoints for roads and streams, can be turned on/off in the menus below the transparency slider.
- Quick Map Layouts:
Clicking the buttons within this section will refresh the entire map service to a standard map layout. The webpage will refresh and the map will zoom to the same location and
layers are selected/deselected based on the layout design. The "bookmark" link allows the user to save the currently selected map layout and extent.
- Customize Map:
In this section, the geologic map and data layers can be turned on/off, their transparency can be altered, and, in some cases, the user can select how features are labeled.
Simply turn on and off layers by selecting and deselecting the checkbox next to each layer name. The "Geology" layers are bundled within one service and have the same transparency settings.
The "Data Layers" are mostly point features of geologically-related data. Each data layer has their own transparency setting and, if applicable, labeling.
Also displayed under each activated data layer are the map symbols for that layer. Clicking the icon that is
next to each data layer will open the ArcGIS Server service info and metadata for that layer.
You can also bring these layers into your own GIS (e.g. ArcGIS) by following the instructions at this link.
There are two ways to get information about geologic units or other features on the map. The identity tool
, described above, is used to gather information about specific features. It works by clicking on the map
and the results are sent to a pop-up window. The identity tool only returns descriptions from the 1:24,000-scale GQ's. Be aware that the sensitivity of the tool is scale-dependant. Clicking at
small scales may return descriptions for multiple map units or features.
The Geologic Information tab provides comprehensive searches for all information that pertains to the map extent. Because of the larger amount of information that is accessed, the searches
are provided from individual links. The results are grouped by type of source and then by the individual source title. The source title is a link to the KGS online list of publications, where
many publications can be viewed. For lithology descriptions, a portion of the graphic stratigraphic column is provided for context, and the full stratigraphic column is accessed from a link.