Geological Cross-Section Techniques

This video tutorial explains how to draw a geological cross-section using a topographic base. It covers setting up the scale on graph paper, plotting the topographic profile, and transferring geological data onto the profile. The tutorial also analyzes the relationships between different geological units and discusses the implications of these relationships in the subsurface. Key concepts include understanding contour lines, scale setup, and geological mapping techniques.

What is the first step in drawing a cross-section using a topographic base?

• Plotting the topographic profile

• Drawing the section line

• Setting up the scale

• Marking geological boundaries

Why is it important to set the scale on graph paper before plotting?

• To ensure the cross-section is drawn at the same scale as the map

• To make the drawing look neat

• To avoid errors in geological boundaries

• To save time during plotting

What is the contour spacing used in the video for plotting the topographic profile?

• 25 meters

• 100 meters

• 50 meters

• 200 meters

What tool is used to measure the section length on the map?

• Map strip

• Protractor

• Ruler

• Compass

What is the purpose of adding color to the geological units on the profile?

• To make the profile visually appealing

• To differentiate between different geological units

• To highlight the topographic features

• To indicate the depth of each unit

Which geological unit is represented by the color gray in the video?

• Metamorphic rocks

• Sandstone group

• Quartzite

• Annelid formation

What is an outlier in geological terms as described in the video?

• An isolated patch of rock separated from the main outcrop

• A rock layer that is more eroded than others

• A rock layer that is deeper than others

• A rock layer that is thicker than others

What does the term 'discordance' refer to in the context of the video?

• A boundary between two different rock types

• A difference in the angle of bedding between two rock layers

• A fault line in the geological map

• A color difference in the geological units

What is the significance of identifying an unconformity in a geological cross-section?

• It highlights the topographic features

• It marks the boundary between two different geological units

• It indicates a change in rock type

• It shows a period of erosion or non-deposition

What additional problem is identified in the final section of the video?

• The incorrect scale of the cross-section

• Metamorphic rocks lying on top of sedimentary rocks

• The misalignment of the section line

• The presence of a fault line