SP Carter Caves - Natural Bridge EarthCache

EARTHCACHE REQUIREMENTS
Each cacher must send his/her own answers BEFORE logging a find. Enjoy the journey (learning adventure) as well as the destination (smiley earned). Remember to take only pictures and leave only footprints. To get credit for this Earthcache, complete the following tasks:

1. MESSAGE …. The picture shows a prominent example of herringbone crossbedding. a. Where is it located? ... b. Either via measurement or feel, what is the difference in thickness of the crossbeds? ... c. Based on the thickness of the layers, what is the relative speed of the paleocurrent in each direction?

2. MESSAGE …. Hypothesize why the layers are not uniform.

3. LOG …. Post a picture of you or your signature item at or near the coordinates. This picture is your log signature.

OPTIONAL - Please respect the time and effort involved in creating this earthcache by adding A and B to your log.

A. JOURNEY OF THE MIND ... Science explains what we observe. Relate (in your own words) something you found interesting in the reading. This adds to your learning adventure and your log.

B. JOURNEY OF THE HEART ... Art shares our personal experience of what we see. Share something special you found on site, and why it is special to you. This is a memorable addition to your log and will make other hearts smile.

Journeys of Heart and Mind ... 
Stories to Touch the Heart and Puzzles to Challenge the Mind / Rainbow Tree Story

THANK YOU Chris Perry (Park Manager) and Robert Myers (State Park Naturalist) for permission to share this learning adventure. ... Your permit for the earthcache “Natural Bridge” is 19104CCSRP.


NATURAL BRIDGE
The opening is 180 ft long, 60 ft wide, and nearly 40 ft high. The thickness of the overhead span averages 15 ft and is thick enough to support the road running over it. This is the only natural bridge in Kentucky that supports a paved highway. The approach to the bridge is along the valley of Cave Branch. This entire section is within the Warix Run Member of the Slade Formation. "The area in front of the bridge is a small karst window, or an area of collapse in which a stream flows out of a cave on one side across an open area and back into a cave on the other side."

HERRINGBONE CROSSBEDDING
Named because it resembles the backbone of a herring fish. This type of crossbedding shows dips in two directions at an angle to each other. Preserved in the rock record is this indicator of former tidal activity and illustrates the two common directions of tidal currents (ebb and flood). The time period between each cross-stratified layer is many years.

Photo showing bidirectional (herringbone) crossbedding ... Resource #1.

RESOURCES
1. https://kycarter.com/the_original_peoples/geology_tour.pdf
2. https://www.uky.edu/KGS/geoky/fieldtrip/2005%20AIPG%20Guidebooks/NaturalBridge.pdf
3. https://www.earthlearningidea.com/PDF/195_Cross_bedding_2.pdf
4. https://www.revolvy.com/page/Herringbone-cross%252Dstratification
5. https://ocw.mit.edu/courses/earth-atmospheric-and-planetary-sciences/12-090-introduction-to-fluid-motions-sediment-transport-and-current-generated-sedimentary-structures-fall-2006/course-textbook/ch16.pdf