Notice: "Cache seekers assume all risks and responsibilities involved in seeking this earthcache."
Warning: This is an agricultural area where many long-haul trucks full of wheat, corn, onions, potatoes, carrots, sugar beets and other commodities are busy going down the road. Most of us locals are accustomed to these trucks. If you don’t feel safe or comfortable stopping alongside the road or in a pullout to observe the geology, “Don’t Stop”. Don’t let earthcaching control you, but rather you control earthcaching. “Just because it is there, doesn’t mean you have to stop!”
“For your safety, even though the shoulder may be wide enough to stop and make observations, please park in the designated parking pullout and walk to the final. The road does get busy at times. If you feel uncomfortable with the suggested parking location, find a wider spot down the road and walk back.”
Lenore Lake: Enigma
Between Lenore Lake and Alkali Lake on Washington County Road 17 north of the town of Soap Lake is a formation consisting of basalt pipes (horizontal columns) created during the Grande Ronde Basalt Floods some 15.6-16.5 million years ago from fissure in southeast Washington. How they were created is somewhat of a mystery. These types of structures may be explained by hot gas, steam, and even glacier ice. Through observation, which one of these explanations is the most correct or is there something else going on here?
Observation
1. There is a vertical entablature (top of the solidified lava flow) on the right side of the formation. This may suggest the cooling occurred on both sides of the pipes.
2. The basalt joints have a slight upward curvature. This may suggest part of the cooling is also directed upwards.
3. The diameter and the length of the basalt pipes show that the basalt cooled slowly. This may suggest the solidification (liquid to solid) took years, maybe even decades.
Scientific Understanding
Geologist have extensively studied how basalt columns are created during the process of the fluid lava hardening into solid vertical hexagon/polygon structure. The process in nature and the lab has shown “The cooling surface is always perpendicular to the basaltic joints.” In other words, under normal circumstance of a lava flowing across level ground, the lava will cool and create vertical columns.
Possible option in no particular order
- The lava flow came up against a glacier and the side of the flow became cooler than the surface of the flow.
- The flow expended gas or steam from cracks cooling the sides of the flow more than the surface of the flow.
- The lava flowed into a cavity or large pot hole. The lava current was not swift enough to push the lava filled cavity out of the hole. The lava continued to flow over the filled cavity as the lava began to cooled from the sides.
- The lava flowed into and filled a box canyon. The sides of the canyon cooled the flow more than the air above the flow.
- “The truth lies in the irregularities of the relief.”
Lenore Lake: Enigma Close-up
To log this Earthcache, please send me the answers to the following questions.
1. Which possible explanations for the horizontal piping/column would you agree with and why, or what explanation would you give to explain the enigma?
2. Describe the discoloration of Lake Lenore shoreline?
Optional: You may upload a photo to the page of any local wildlife, unique vegetation or geology in the area.
Sources:
Moore, James G., “Mini-columns and ghost columns in Columbia River lava”,
Journal of Volcanology and Geothermal Research, Volume 374, 2019, Pages 242-251,