ADVENTURES WITH ROCKS (TM): To Sea or Not to Sea

Cacti Blooming At Mud Mound

We were here. The Beatty Mud Mound. We had been talking about it all week- to customers, to people in town, to each other, and even to friends from Quartzsite who saw our Facebook post about going out to the Mud Mound in a day or two. They had been there before and wanted us to let them know what we found when we went. And so the excitement had been building for several days, while we worked diligently at the shop, waiting for a slow day so that we could close early and go play out in the desert. And so today was the day. At the fork in the gravel road, we chose the right fork, marked by the sign that said Mud Mound, and now we were here.

I headed up the hill after Al. He got about halfway up to an outcropping and stopped. He looked back at me and said, "You know, I just realized I'm not even sure what we're looking for..." "Fossilized algae and stuff", I said. "Well, what does that look like?" "I don't know...algae that looks like rocks? Rocks that look like algae? I guess we'll know when we see it." I said, trying to seem like I was sure of myself- after all I do own a rock shop- but then again, I had never seen fossilized algae before, either. Rocks and traveling are kind of similar- the more you see the more you realize that you haven't seen... and the list always gets bigger, never smaller. I call it the 10 for 1 exchange. Check off one, find out about 5 more, research them, learn about more, and then add 10 to the list. And so, the more fossils, rocks, animals, places, etc. I see in my life, the more I realize I haven't seen and want to see.

We got to the main outcropping- and it looked like a big ancient pile of mud- a Mud Mound. It was gray, with cracks and lines through it, like a clay-mud on the shoreline of a swamp or shallow pond. It looked like a place where we would find fossilized algae and other types of aquatic species. I stood and stared at it for a while. Al said, "What?...what do you see?" And that was it, I was trying to "See"- sometimes it takes some imagination to see what you are looking for. You have to imagine what a place would have been like at that time, and then the pieces of the puzzle will start to fall together and you can "see" what's there. To find gold, you have to read the river, and see what it would have looked like in a flood. Here, we had to see what the desert would have looked like many millions of years ago as a swampy shoreline of a shallow inland sea - a flat plain of quartz-rich sandstone covered with shallow water and layers of silt, clay, and mud. So in my mind, I was looking at this gray hunk of clay-looking rock sticking up out of the desert and trying to "See" the ancient Sea that used to be there. I said to Al, "You know what a muddy shoreline looks like, with mats of algae and mud kind of covering everything? That's what we are looking for."

Geologically speaking, the Beatty Mudmounds are large mounds of calcite mud. Initially they were formed at the beginning of the Paleozoic Era, in shallow water (about 100 feet deep) as deposits created huge underwater sand dunes, well, technically "Mud Dunes". The surfaces of the mounds were covered by thick mats of algae which trapped sediments moved by currents. Layers of algae and trapped sediments bound together, and layer by layer the Mounds grew into monstrous algae mats which supported enormous quantities of animal life in this ancient underwater environment. Eventually the seas deepened, reefs formed and larger forms of aquatic life began to take hold, including the ichtyosaurs that are famous in Nevada.

The surface environment eventually went from sea to swamp to jungle and then to woodlands. Volcanoes became prevalent. For hundreds of millions of years our Mud Mounds and their fossils lie buried. Then, about 2 million years ago, the Sierra Nevada Mountains were uplifted and the treasures of our Mud Mounds found their way to the surface of the arid desert lands that would eventually become Nevada. Over time, wind and water eroded away the softer limestone and exposed the ancient Mud Mounds. And so here we were, surrounded by rocks hundreds of millions of years old, waiting to see what they would reveal to us.

Fossilized Algae at Mud Mound

We looked for about 20 minutes, and then finally we saw one: a piece of gray fossilized mud like the Mud Mound, but covered with a several inch thick layer of brown fibrous-looking, ALGAE-LIKE rock- and we could see it in our heads- this ancient clay/mud dune covered with algae and teeming with life. It was like a window in time- and then next thing we knew, we were seeing fossilized algae all around us, in sparsely covered sections of the Mud Mound outcroppings.

Look how cool this is! I exclaimed. This is amazing! We found several nice sections of the fossilized algae a little further up and were looking for some specimens that we could collect. A local woman I had talked to a couple of weeks ago had said that the Mud Mound fossils were getting increasingly hard to find because people had been chipping them off for several years. What was left of the Mud Mound fossils was sparse. Several groups were even petitioning to close the site to the public to protect what was left of the fossils. Even though we had our rock hammers with us, we decided not to remove any of the fossils we found unless they were on the ground already. We found a few nice pieces and put them gently on the floor of the Samurai to take back with us. These rocks, while not particularly fragile, were extremely old. And I don't mean that in the obvious sense. These were old even for fossils.

This area of Nevada abounds in fossilized marine life. After all, many of the mineral mines in this area are Dolomite, Diatomite, Limestone, and Marble- all of which are some form of fossilized sea creatures. Many of the other fossils found in Nevada like ammonites, trilobites, crinoids and other sea creatures, including the state fossil, the ichyosaurus are about 250 million years old. But the Mud Mounds that formed in the very early ancient seas across southern Nevada, were from a time much older than that. These particular fossils were Ordovician- about 480 million years old! We had just picked up rocks containing some of the oldest organisms found on earth!

We were ecstatic! And...there was still one more place to look. We had been told that not far from the Mud Mound was another, less well known site with fossils from the same time period. A less well known site meant more fossils- not as picked over and decimated. We looked out across the desert from our vantage point up on Mud Mound. The wind had picked up, and the temperature started to drop somewhat. The sun was getting lower in the sky. It was time to move on. A few more hours of daylight afforded us enough time to explore another site and see what treasures it held for us.

We bade Mud Mound goodbye, jumped in the Samurai, and headed back down to the gravel road. In a short time, after several twists, turns and traverses up some steep sections, we came to the next chapter in our geologic adventure and our quest for fossils from early "Nevada". The information we had was vague. Once again, we didn't exactly know what we were looking for, or what we would find, but then, that is part of the Adventure.