Talladega Springs Geologic Map Project

Concept StatementIn this project you will be provided with two starting raster files:

1. Talladega Springs 1:24,000 topographic map georeferenced into the UTM NAD1927 zone 16 coordinate system.

2. A scanned field map containing penciled geologic information obtained from geologic mapping. This map is not georeferenced.

The goal of the project will be to create a geologic map of the Talladega Springs quadrangle area based on the scanned field map, and based on data collected at many outcroppings in the area. You will use essentially the same methods as used in the first project to create the fundamental map elements (i.e. point symbols, geologic line work, and geologic polygons), but in addition you will post on the map geologic orientation field data already entered into an Access database (geodatabase.mdb) using methods integral to ArcGIS.

Step 1- Create Project file.Create a new ArcMap Project file in the folder \ArcGIS_Data\TalladegaSprings\”. Set the following parameters :

Title: Geologic Map of the Talladega Springs, AL, 1:24,000 Quadrangle

Coordinate System: UTM NAD1927 zone 16

Reference Scale: 1:24,000

Also make all file references “relative” rather than “absolute” in the document properties. Add the georeferenced USGS topographic raster (O33086A4.tif) to the project file and check to make sure the UTM reference marks on the base map match the cursor coordinates. Save the new project file into the working directory as “TalladegaSprings.mxd”.

Step 2 – Georeference Talladega Springs Geologic Field Map.The geologic field map is not georeferenced so you need to use the same procedures used in the Project 1 exercise to georeferenced the map. Because you are working with a field map your RMS value will be somewhat larger- probably in the 7-20 meter range. If your RMS strays over 60m let your instructor check out the georeferenced procedure. As with project one you should generate the georeferencing information in these steps:

1. Create a spreadsheet containing the 16 lat-long reference points2. Import the spreadsheet reference points into your project file.3. Use the “Georeferencing” toolbar to generate the georeferencing file.

When done delete the field map, and then “Add” it to your project. It should align reasonably well with the USGS base map.

Step 3- Create Geodatabase File for Talladega Springs Project

Using ArcCatalog create a new personal geodatabase file named “TalladegaSprings.mdb”. Within this database create the following features classes:

Name Geometry Additional Field Alias

Lithology Polygon Lithologic_Code Lithologic Type

WaterBodies Polygon Type Water Body Type

Contacts Line Contact_Code Contact Type

Border Line N/A N/A

Lithofacies Polygon LithoFaciesType Lithofacies Type

MegascopicStructure Line Type Structure Type

The “Lithology” field will have the following values that correspond the hand-written codes on the field map:

Value Lithology RGB

Mf Floyd Shale Formation 179,204,235

Dfm Frog Mt. Sandstone Formation 128,153,255

On Newala Limestone Formation 255,179,255

-C-Ok Knox Group undifferentiated 255,179,204

hgs Hillabee Greenstone Formation 0,51,0

Dtjc Jemison Chert Formation 255,102,153

S-Dtbr Butting Ram Sandstone Formation 153,0,102

S-Dtld Lay Dam Formation undifferentiated 51,102,0

S-Dtldss Lay Dam Formation, sandstone facies 51,102,0

S-Dtldst Lay Dam Formation, siltstone facies 51,102,0

S-Dtldd Lay Dam Formation, diamictite facies 51,102,0

-C-Osgbc Gooch Branch Chert Formation 153,51,0

-C-Ossrc Shelvin Rock Church Formation 51,51,0

-C-Osf Fayetteville Phyllite Formation 153,153,0

-C-Osj Jumbo Dolomite Formation 153,153,103

-C-Osjc Jumbo Dolomite Fm., metachert facies 153,153,103

-Ckwc Wash Creek Slate Formation 102,0,102

-Ckwck Wash Creek Slate, Kalona sandstone facies 102,0,102

-Ckb Brewer Phyllite Formation 153,102,0

-Ckwx Waxahatchee Slate Formation 204,102,255

-Ckwxc Waxahatchee Slate Fm., metaconglomerate facies 204,102,255

The “Lithofacies” polygons are subunits of the formations in “Lithology” – symbolize them via patterns. Use the following patterns in “Geology 24k” for corresponding labels:

Lithology Attribute Lithofacies Attribute ESRI Pattern (background=no color)

S-Dtldd diamictite Geology 24K: 502 Periglacial

S-Dtldss sandstone Geology 24K: 607 Sand

S-Dtldst siltstone Geology 24k: 616 Siltstone

-C-Osjc chert Geology 24K: 724 Massive igneous rock

-Ckwck sandstone Geology 24K: 607 Sand

-Ckwxc conglomerate Geology 24K: 602 Gravel, closed

The “Contacts” line feature class should be classified as below:

Contact Symbol type

Contact Geology 24K: Contact – certain

Approx. Contact Geology 24K: Contact – approximately located

Unconformable Contact ESRI: railroad {modify manually}

Approx. Unconformable Contact ESRI: railroad {modify manually}

Thrust Fault Contact Geology 24K: Thrust Fault, 1st gen., certain

Strike-slip fault Geology 24K: Strike-slip Fault

When sketching the contact line work note that a specific contact type, such as a regular “contact” may change to “approximate contact” as you follow the contact. In this situation you should sketch the line as a single entity, then edit it later after cutting polygons with the “split tool” into 2 units, and then attribute the contacts appropriately. Once again, to emphasize, if a contact is to be used as a cutting edge later with the “cut polygons” tool, do not split the contact until the polygon cutting operations are complete.

The “Megascopic Structures” feature class consists of large map-scale fold traces. There are only 2 on the Talladega Springs quadrangle in the northwest corner of the map area. If you can’t identify them have your instructor point them out. Both folds are “F3” or third generation folds, one is an overturned anticline (arrows point away from fold trace line), the other is an overturned syncline (arrows touch the fold trace line). Note that the fold trace line does not separate different lithologies- you can use that to distinguish fold traces from contacts :

Fold Name Symbol Type

F3 overturned anticline Geology 24K: overturned anticline- certain (Red)

F3 overturned syncline Geology 24K: overturned syncline - certain (Red)

The “Mesoscopic Structures” feature class is created from the Access database. When classifying these outcrop-scale structures use the following table (all symbols are 18 points size):

Structure Name Geology 24K Name Color

Bed, S0 inclined bedding Black

S0_90 vertical bedding Black

S1 inclined foliation,-layered gneiss Black

S1_90 vertical foliation- layered gneiss Black

L1 lineation Black

F1 minor folds Black

F3, C3 minor folds lt. green

F3_S, C3_S minor folds, sinistral lt. green

F3_Z, C3_Z minor folds, dextral lt. green

AP3 inclined cleavage lt. green

AP3_90 vertical cleavage lt. green

Note that AP3 refers to third generation axial planes but we are using the cleavage symbol from Geology 24k for it. S0 compositional layering and bedding are the same structures so we can use the same symbols for each.

Step 4- Create the Quadrangle BorderUsing the exterior 12 latitude-longitude control points draw in the quadrangle border in 2.5 minute segments. Add the “Border” feature class to the project file. Start “Edit Mode” in the editor toolbar, and then select “Create Features” from that toolbar. Make sure the “point” snap mode is set, and then proceed to sketch the border by snapping to the 12 exterior 2.5 minute points. Don’t forget to snap to the start point to completely enclose the quadrangle.

Step 5- Create the Water Bodies Feature Class With the project file loaded in ArcMap, add the “WaterBodies” feature class to the project. Make sure that the border feature class is turned on. Start edit mode, and set a snap mode that uses “edge” only. Proceed to sketch water polygons from the USGS base map (not “ts-geo.tif”). Sketch only the polygons that have significant area. Small farm ponds do not need to be digitized. If you are not sure about a water body feature ask your instructor. Sketch only streams and rivers that have a measurable area (i.e. not single line streams). Remember to use vertex/endpoint snap modes when sketching segments that will be merged later. If you prefer to sketch a boundary line for the water body polygon you can do so in a line feature class and then use the “autocomplete polygon” tool to create a water body polygon. If you do this be sure to erase the boundary line since it is not needed after autocompleting the polygon.

Step 6- Create the Contacts Line Feature ClassAdd the “Contacts” line feature class to your ArcMap project file. Start edit mode, and select “Create Features”, and select a “line” construction template. Also set an appropriate snap mode. If the contact starts from the quadrangle boundary, use a “snap to edge” so that the starting end of the contact begins exactly on the border. This is very important- if you don’t do this correctly when you later try to use the contact as a cutting edge to “cut polygons” it will not work properly. On the other hand, if you are sketching a line segment that you want to snap to the “end” of an existing line, then set “endpoint” snap

mode. This will allow you to merge the 2 segments later. Be sure to plan how you are starting and ending the vertices of the sketched segment before you start.

When you finish sketching contact immediately proceed to the next step to use them as cutting edges to create the lithologic polygons. When you complete that task, you can then use the “split” tool to separate line segments and attribute them (i.e. “Contact”, “Approx_Contact”, “Thrust_Fault_Contact”, etc.). Some of the line symbology is asymmetric – thrust fault teeth for example. If the thrust fault teeth are on the wrong side of the fault contact simply select the line, then use “flip” from the right-click popup menu.

Step 7- Create Lithologic and Lithofacies PolygonsAdd the “Lithology” polygon feature class to the ArcMap project. Start “edit” mode, and set the “snap” mode to “point”. Create the starting lithologic polygon by snapping to the 12 exterior latitude-longitude points along the margin of the quadrangle border. As soon as the polygon is created, make it 50% transparent so that you can see the underlying base maps.

Proceed to use the “Cut Polygon Features” tool to cut-up the stating polygons using the contact lines as cutting edges. Note that you must first pre-select the polygon you want to cut with the edit tool, and then move the cursor to the cutting edge contact, right-click, and then select “replace-sketch”. Immediately follow this action with a right-click and select “finish sketch”. This should dissect the selected polygon along the contact cutting edge. The two new polygons will be selected after the cutting operation. If this operation does not work the reason is probably that the cutting edge contact is not snapped to the edge of the selected polygon at both line endpoints.

As soon as you create new polygons you can attribute them with labels. Select the polygon with the edit tool, right-click on the selected polygon, and then select attributes. As you add attributes you may also want to add entries to the symbology table to have the polygons take on their final color. To do this right-click on the “Lithology” label in the TOC window, select “properties”, and then the “Symbology” tab. Make sure “Categories” are selected, and then “add value”. Select the attribute(s), and then “OK”. When the attribute appears in the category list, you can double-click on the color square to set the color.

Remember that if there are islands of significant area in water bodies you need to “cut a hole” with the “Cut polygon features” tool so that the underlying lithologic polygon and base map shows through.

When the lithology polygon features are complete the lithofacies polygons are ready to be constructed so add the “Lithofacies” polygon feature class to the project. You do not want to construct the lithofacies polygons as you did the lithology polygons because they are exact copies of a subset of the existing lithology polygons. The “easy” way to make them is with the OS clipboard with the “copy and paste” cycle. Make sure you are in edit mode and then try this with one of the lithology polygons that is also a lithofacies polygon (e.g. S-Dtldd):

1. Use the select tool to highlight the target lithology polygon. Right-click on the selection and choose “copy”. A copy of the polygon geometry is now in the OS clipboard.

2. Click the “Create feature” button on the “Edit” toolbar.3. In the “Create Feature” window select “Lithofacies” and then “Polygon” template.4. Your cursor will now be the familiar “cross” that signals that ArcMap is ready to “digitize” a

polygon. DO NOT LEFT-CLICK. Right-Click anywhere and choose “Paste”. You should see a dialog verifying that you want to paste the polygon into the “Lithofacies” feature class. Click “OK” to accept.

5. To verify that you now have a new polygon in lithofacies turn off “Lithology” and see if you can highlight the new polygon with the edit tool.

Proceed to create all of the lithofacies polygons as indicated. Note that they should be attributed as “sandstone”, “conglomerate”, etc., depending on the nature of the lithofacies.

Step 8 – Create the Megascopic Structures Line Feature ClassCreating the megascopic structural features is a simple matter of sketching the line feature, attributing the line, and then assigning the proper symbology to the line. Remember to sketch vertices close enough to preserve a smooth curve. All of the megascopic structures on this quadrangle are overturned fold hinges, therefore, the line symbol marking these structures is asymmetric. You may have to use “flip” to align the symbol properly. Don’t worry if the fold symbols appear too small on the screen- they generally work well when plotted on a large-format plotter.

Step 9- Post Station Data from DatabaseOn any geologic map the locations where orientation data were measured should always be posted on the map. The station locations are stored in an Access database file named “Geodatabase.mdb”. In this database a menu system is already setup to automate the process of querying the Talladega Springs location data. This will be demonstrated in class, and will produce an Excel spreadsheet file that begins as below:

Longitude Latitude Station_ID Lithology Notes-86.438387 33.0785 AM0017 -Ckwc metachert-86.439564 33.0757 AM0018 -Ckwc silver seri. phyll.-86.442091 33.073411 AM0019 -Ckwc silver seri. phyll.-86.38986 33.119599 AM0170 S-Dtld silver & red phyllite

In this form the station locations can be easily posted on the map with the “File > Add XY Data” menu option. Do this for the Talladega Springs data with the following symbology:

Station marker : red cross (+) symbol of size 5 points.

Station labels : Labels centered over the location symbol at 5 points size.

The station data is numerous – numbering over 500 for this quadrangle. The data should be in your digital map for reference, however, do not try to plot it on the paper map. The station markers will obscure the attitude data created in the next step.

Step 10 – Post Structure Data from DatabaseThe data measured at each station consists of orientation data that must be correctly rotated at the station location. To fully understand the operation you will have to see the data plotted, however, the Access database file has a automated query that will generate the appropriate spreadsheet file for importation into the ArcMap project. This will be demonstrated in class, so make sure to note the steps and the name of the query in the database (BuildArcGISstructureSymbolTable). The USGS code to use for Talladega Springs is "O33086A4". After running the query and producing the table, export it to your working directory as “ts_structure.xlsx”.

After adding the structure points with “File > Add XY data”, set the following:

1. Set the name of the new feature class to “Mesoscopic Structures”.2. Set the symbology of the feature class to use “categories” grouped by the “Structure” field.3. In the symbology tab use the advanced tab to set a symbol rotation using the

“Symbol_Rotation” field. Choose “geographic” type of rotation.4. Turn on labels for the field, with the “Symbol_Text” as the label field. Use the “Placement

Properties” to select the “Placement” tab. Select the “Rotation” button to use a geographic angle from the “Text_Rotation” field.

With the above settings the orientation symbols and text will be correctly placed and rotated. Have your instructor check for proper placement before proceeding.

Step 11 – Add Digital Elevation Model (DEM) DataA digital elevation model is an X,Y,Z grid that contains x,y UTM locations and the elevation (z) at that location point. The DEM data we are using is based on the 30m spacing that the USGS uses for 24k topographic quadrangles. The DEM data can add the “shaded relief” effect to your project by providing a realistic 3D topographic effect. This is especially effective when the topographic base and geology is draped over the DEM.

To add the DEM as a “Hillshade” to the project follow the below steps:

1. Download the ASCII DEM file from: http://www.usouthal.edu/geography/allison/gy461/ts_dem.asc

2. Use the toolbox function “Conversion > to raster > ASCII to raster” to add the DEM to the project. Note that the raw DEM does not look like a shaded relief map. Save the converted DEM to your working directory as “ts_dem”.

3. Follow the directions in the ArcGIS 10.1 help topic: “Displaying a DEM as a shaded relief”4. In the above directions the hillshade is stored in a temporary location. You can check that with a

right-click on the feature name and then “Properties > Source”. To save it to you geodatabase file right-click on the feature class name and select “Data > Export” and follow prompts to export to the geodatabase (.mdb) file. The spatial reference information is not transferred so use ArcCatalog to set the coordinate system to UTM27-16 (demonstrated in class).

Step 12 – Format Layout for Plotting at 1:24,000This final step will prepare the project file for plotting on the large-format HP 5500 Designjet plotter in room 137 LSCB (ask your instructor for the door and workstation codes). To fit a full 1:24,000 scale map with legend information on a plotter you will need a media size of approximately 46 x 34 inches in landscape mode. These media sizes are often referred to as “Architectural E” or “ANSI E” in the U.S. Follow the below steps to set up the layout view for a final hard copy plot:

1. Use “File > Page and Print Setup” to select a media size of “E size sheet” in landscape orientation with Microsoft XPS document writer (see Figure 1).

2. Select “View > Layout View”. Set the map frame to a 1:24,000 scale and re-size as needed the frame window so that all of the map area is displayed.

3. Insert the title: “Geology of the Talladega Springs, Alabama, 1:24,000 Quadrangle”4. Insert the legend from the “insert” menu. Turn off the “stations”, “Reference points”,

“O33086A4.tif”, “ts-geo.tif” features before inserting the legend. Accept all defaults except add a 1-pixel wide frame around the legend. Check the TOC to make sure everything is spelled out as you want it in the legend. When you edit the TOC symbology the changes will automatically appear in the legend.

When you take your project to 333 LSCB all that you will need to do is use “File > Print” and switch to the HP Designjet 5500 driver. Make sure you have your instructor do this before sending the plot to the plotter.

Figure 1: Print and Page setup prior to Layout view.

Figure 2: Layout view before plotting.