Congratulations to Burnt Turtles and GEOTRIBEFIVE for their co-FTF of my first ever EarthCache! Your writeups and posted pics are much appreciated.
The Treasure Cave geocache is an EarthCache (EC), so there is no physical geocache. Instead, this is a unique type of virtual cache that teaches and showcases earth science and geology. The geocache also requires some logging tasks in order to be recorded as found.
For more information on ECs, and even submitting one of your own ECs, see the Geological Society of America's website.
Per communication with Natural Resource Property Supervisor Oliver Reistroffer, this cave is closed yearly from October 1st through May 15th.
Logging requirements:
To cut to the chase, this EC has 4 logging requirements (which are reposted below):
1. Standing at the entrance to Treasure Cave, and looking directly in front of you towards the cave entrance, what geological feature do you see lying in front of it? Do you believe this originated from within the cave itself, or did it come from another area?
2. What type of erosional cave is Treasure Cave? Did more than one erosional force act here? Explain your reasoning.
3. Which life cycle stage is Treasure Cave currently at? Early development? Active growth? Explain your reasoning.
4. With GZ at your back, take a picture of yourself or your GPS or personal item(s) and add it to your log. Please try to not post the answers to the questions in your pictures, as much as reasonably possible.
Erosion and caves
Except for tectonic shift, the most common catalyst of cave formation is geologic erosion. There are different types of erosion, and therefore there are different types of caves formed from the action of these forces. The four cave types that result from erosion are the following:
- Solution Caves: These are the most common type of caves and are formed through the chemical weathering and dissolution of soluble rocks, primarily limestone, dolomite, gypsum, and salt. Acidic water, often containing carbonic acid formed from rainwater mixing with carbon dioxide in the atmosphere or soil, seeps through cracks and dissolves the rock over time, creating underground voids and passages. Example: Mammoth Cave in Kentucky.
- Sea Caves: These caves are formed by the mechanical erosion of coastal cliffs by the relentless action of waves and tides. The continuous pounding of waves erodes weaker sections of the rock, gradually creating cavities that can expand into larger caves Example: The sea caves along the coast of the Apostle Islands in upper Wisconsin.
- Erosional Caves: These caves are created by the physical erosion of rock by natural forces such as water flow, wind, or glacial movement. Rivers or streams can carve out caves in softer rock like sandstone or conglomerate, and glaciers can erode bedrock to form glacial caves. Example: Wind Cave in South Dakota.
- Lava Tube: Although not formed by erosion in the traditional sense, lava tubes are a type of cave formed by volcanic activity. When a lava flow cools and solidifies on the surface while the molten lava beneath continues to flow, this action can create a hollow tube. After the eruption ceases, the remaining lava drains away, leaving a hollow cave. Example: Thurston Lava Tube in Hawaii.
Each type of cave represents unique geological processes and environmental conditions, contributing to the diversity of cave formations found around the world.
Treasure Cave is composed of limestone/dolomite and dates from the Ordovician era. It is the product of one or more of the erosional forces noted above. One of your logging requirements will be to observe the cave's erosional state and select the force(s) that shaped it.
Cave life cycle
Caves undergo a life cycle that consists of formation, expansion, and eventual demise.
Caves that are formed by geologic forces such as erosion typically go through a series of stages in their life cycle. Here’s an overview:
1. Initiation Stage
- Formation of fissures and bedding planes: The process begins with the development of fissures and bedding planes in soluble rock, often limestone. This can be caused by tectonic forces that create fractures.
- Water infiltration: Rainwater, which absorbs carbon dioxide from the atmosphere and soil to form a weak carbonic acid, infiltrates these fissures.
2. Early Development Stage
- Chemical weathering: The acidic water begins to dissolve the rock along the fissures and bedding planes. This process is known as chemical weathering or dissolution.
- Enlargement of pathways: Over time, these pathways widen as more rock is dissolved, forming initial small cavities.
3. Active Growth Stage
- Formation of passages and chambers: Continued dissolution leads to the development of larger passages and chambers. Groundwater flow becomes more significant in shaping the cave.
- Speleogenesis: The cave develops a more complex network of tunnels and rooms. Speleothems (cave formations like stalactites and stalagmites) may start to form as mineral-laden water drips and deposits calcite. This phenomenon is also termed 'decoration.'
4. Mature Stage
- Stabilization of features: The cave reaches a more stable form where major passages and chambers are well-developed.
- Speleothem growth: Speleothems continue to grow, and the cave may exhibit a wide variety of formations.
5. Decline Stage
- Reduced water flow: Changes in the landscape, such as the lowering of the water table or changes in surface drainage patterns, reduce the amount of water flowing through the cave.
- Collapse and erosion: Roof collapses may occur as the structural integrity of the cave weakens over time. Sediment and debris can fill passages.
6. Fossilization Stage
- Inactive cave: The cave becomes inactive as water flow ceases. It is now referred to as a fossil or relict cave.
- Sedimentation: Over time, sediments can fill the cave, and speleothems may stop growing. The cave can become entirely filled and buried by surface processes.
Summary
The life cycle of a cave created by erosion involves initiation through the dissolution of rock, development of passages and chambers, maturation with the stabilization of features, decline as water flow reduces, and eventual fossilization where the cave becomes inactive and may be filled with sediments or landslide rubble. This entire process can take millions of years, showcasing the dynamic and ever-changing nature of geological formations.
As an FYI, another one of your EC logging requirements will be to observe and comment on the life cycle stage of Treasure Cave.
Treasure Cave logging requirements
Wyalusing State Park features a number of naturally formed caves, including caves with waterfalls, accompanying historical lore, and amazing cliff views of the confluence of the Mississippi and Wisconsin Rivers below. Treasure Cave, which you will need to access and view directly, is reached via a short hike on the Bluff Trail to a stone keyhole entryway, followed by ladder descent and then ascent. Because ladder climbing is required to access the cave entrance, I have set the terrain rating higher. Sheer cliff dropoffs exist here (up to 600 foot drops!), so please keep children and pets in check. Also, because Treasure Cave is maintained by the Wisconsin DNR, a vehicle entrance sticker is required to drive into the park.
You may start or park at either of the two noted parking lots within the park, then walk to Point Lookout. The closest parking lot is located at the cross section of Long Valley Road and State Park Lane. Once you reach Point Lookout, look to your left. There, you will see a wooden fence barrier and the start of the Bluff Trail. To help you out, here is a PDF map of Wyalusing State Park. The Bluff Trail does slope down initially. About 50 stone steps, irregularly placed in spots, take you to the first natural wonder:
The Keyhole
The keyhole is the most direct entryway to Treasure Cave.
At the referenced keyhole entry, you will descend a few steps down, and then you will need to use a ladder to get to the base of the cave. From this small landing, you will ascend up another ladder, towards the entryway of the cave itself. Use care here, as the ascent is fairly steep.
Now that you are at the actual cave, you are ready to complete the logging requirements of this EC. Please do not submit the answers to the first three questions in your log- please email or message them to me directly. However, please do feel free to post pictures of your journey here, to encourage others to complete this EC. Thank you!
1. Standing at the entrance to Treasure Cave, and looking directly in front of you, towards the cave entrance, what geological feature do you see here? Do you believe this originated from within the cave itself, or did it come from another area?
2. What type of erosional cave is Treasure Cave? Did more than one erosional force act here? Explain your reasoning.
3. Which life cycle stage is Treasure Cave currently at? Early development? Active growth? Explain your reasoning.
4. With GZ at your back, take a picture of yourself or your GPS or personal item(s) and add it to your log. Please try to not post the answers to the questions in your pictures, as much as reasonably possible.
Good luck and happy spelunking! Incidentally, the study of caves is called speleology.
Why is it called Treasure Cave?
There are at least two stories about treasure being left behind at Treasure Cave. View the complete Treasure Cave storyline, as provided by the Friends of Wyalusing State Park, and learn the backstory of the silver coin treasure allegedly hidden here during the time of the Black Hawk War. The second treasure story, provided here, tells of possible French coins and other valuables tucked away in this cave during the time of the War of 1812.
Do you see a stone face?
Before you traverse the keyhole, stand at the top of the steps and check out the stone outcrop ahead of you. What do you see there? Perhaps a face?
There is local lore that this is the Guardian of the Treasure Cave. The explanatory lore goes something like this:
"As long as the visage remains visible, the treasure remains secure...As soon as the guardian vanishes, the treasure will be exposed."
Also:
"Until the guardian fades away completely and the needle's eye seals shut, only then will the novel pathway be unveiled, leading to the elusive treasure."
Permission
The Geocache Notification Form has been submitted to, and permission granted for this placement, by Oliver Reistroffer, the Natural Resource Property Supervisor for Wyalusing and Nelson Dewey State Parks. Geocaches placed on Wisconsin Department of Natural Resource managed lands require permission by means of a notification form. Please print out a paper copy of the notification form, fill in all required information, then submit it to the land manager. The DNR Notification form and land manager information can be obtained at https://www.wi-geocaching.com/info/wdnr_geocache_placement_notification_2500-118.pdf or by going to the hosting web page here.