I went out for a fifth time on May 18th to continue digging at Park Caverns. We started at 9:30 am and did not stop for the day till 7:00 pm. This was by far the longest I had worked before inside a cave and super dead afterward.
How the rock was broken up with rock chipper
Last time Justin and I were down there, there was a giant rock blocking the entrance into the air pocket. We first dug out the ground in the tunnel so that we could sit down and use the rock chipper. Justin was able to cut the rock in half. We broke down the lower half into little chunks and hauled them out, but we couldn't do much to the upper half. So, we just pushed it to the side and made an artificial wall because of how heavy it was.
Unfortunately, after doing so, we noticed another rock that was lodged into the floor like a tooth. Justin broke it down with the chipper and then I went into the area to see where we would go next. We did this process about three times until Justin pulled aside a rock and found a pit leading down. At this point, our work area was about 5 ft deep and shaped like a funnel into this pit. Both of us couldn't see the bottom and dirt kept feeding into it. I poured some water down it and I could hear it slowly trickle down into the crevices for a couple of seconds.
I started looking at the walls of the work area and found a lot of flowstone that was covered in dust and also more bits of formations. From what we could see, it appears that we hit this third room, but we could not confirm it.
At this point, it was already around 6 pm, so we decided to start cleaning up and plan when we would come back.
Sun setting on Park Caverns
Geology of Park Caverns
About a week before, Denise and I met with the geologist at Natural Bridge who had previously come out to the property when she first found the cave. He gave a lot of pointers about what to do next, but most importantly, he said that the cave is probably a vertical cave because of the limestone.
Geological Map of Comal County. Taken from Comal RHCP (with the exception of yellow dots)
Nearby is the Bat Cave Fault which changed the levels of both in a specific area. Referring to the map, Park and Natural Bridge Caverns are about 2 miles apart but are based on two different types of limestone: Edwards and Glen Rose respectively. Edwards Limestone tends to produce vertical caves while Glen Rose will be more horizontal. So, her cave may have more pits rather than horizontal passages. This would support the work we did and also what we found. If we dig down far enough and hit Glen Rose, we could potentially find more lateral passages.
I’ll post one more time this weekend about what happened this past Thursday when I went out there, so stay tuned!