Update per new & easier guidelines....*** Another Earthcache here... no container but interesting spot to ponder & answer questions below...
After reading about Tafoni and checking rocks, please message me these answers... And add picture of yourself or group to your log..no spoilers please..
1. Why does one rock have more Tafoni than the other?
2. Is there any Tafoni on the opposite sides of these rocks? Why or why not?
These 2 rocks (see waypoint, for 2nd one, or can look to you right).. will show you some awesome Tafoni(see picture at bttom of description)... I remember my first EC about this was in West Virginia, called Tafoni at Falls Mills, GC3A5A7.. beautiful area..
Tafoni - etymology of the word is unclear…may come from Greek word “taphos” for tomb or from Sicilian word “tafoni” for holes, or “tafonare” meaning to perforate… The earliest know published use of the term “tafoni” (plural of “tafone”, was in 1882..
Tafoni have, also, been called fretting, stone lace, stone lattice, honeycomb weathering, and alveolar weathering.. but I like the word, “Tafoni”...
Tafoni are natural weathering phenomenons, that are pan-to-bowl shaped to small cave-like features found in granular rock such as sandstone, granite, and sandy-limestone… often occurring in groups that riddle a hillside, cliff, or other rock formations…such as these…bored primarily by rock weathering processes and secondarily by erosional processes.
Can be found in all types of climates…
Honeycomb weathering, a form of calcium/salt weathering, is the most common explanation. It occurs when calcium/salt collects on the surface of permeable rocks, usually by ocean waves, mist, or wind. As the saltwater evaporates, it leaves the salt behind. The salt works its way into the rock pores, where it crystallizes and pushes the pores open further, which can become cavities…
The surface layer of rock is harder than the interior, allowing a hardened crust to encompass the softer rock inside, usually a sandstone.. Ran water soaks deep into sandstone mixing with existing calcium/salt… during dry seasons water evaporates from the stone, carrying dissolved calcium/salt to the surface of the stone…as salt is distributed unevenly, there are hard/high and soft /low salt areas… In time when the outer surface areas become cracked and broken, erosion affects the softer areas more quickly…. Wind promotes evaporative salt growth between grains on a stone surface, resulting in the development of small, randomly distributed cavities…Cavity interiors are cooler as are sheltered from the sun…when most air enters a cool cavity, it condenses onto the shadier part of the interior… with differential weathering processes these weather in an upward and backward direction…
These enlarged rock cavities become susceptible to additional weathering including wetting-drying, freezing-thawing cycles, wind corrosion… After a significant amount of time, the weathering becomes noticeable in the form of tafoni.
This can take hundred, thousand, or millions of years…
A little info about wind & rain to help with answers…Wind movement in the middle latitudes (35-65 degrees latitude) of the United States comes from the West, known as “prevailing westerlies”. (Wiki - Prevailing winds).... Rain in the United States, usually, comes west to east because that is the direction the jet stream blows…(Scholastic.com Weather Watch)
References:
www.nps.gov - tafoni,... urses.lumenlearning.com Weathering and Erosion,... Wiki - tafoni,... Rodriguez-Navarro, C., Doehne, E., Sebastian, E., 1999, Origins of Honeycomb Weathering: The role of salts and wind