Friday, September 16, 2016

WINDS OF EDEN - What's the Gunk on That Rock?

Figure One. The artifact inspiring the SHADOWS ON THE TRAIL TRILOGY.
Side B of 4.1 inch long discoidal biface made from Alibates Chert.
For those of you who are not aware, the seed for the SHADOWS ON THE TRAIL TRILOGY sprouted on an early summer morning in 2010 on a northern Colorado ranch when
I found a prehistoric stone tool made from a red and gray striped rock only found in a prehistoric rock quarry in Texas (Figures One and Two). I believe that the mysterious Folsom People made this prehistoric stone tool sometime between 10,900 and 10,200 years ago.
Figure Two. The artifact inspiring the SHADOWS ON THE TRAIL TRILOGY.
Side A not demonstrating much pedogenic carbonate.
When I found this prehistoric tool, I stared at it for some time, wondering about the ancient people who made it. How did this stone tool end up all the way to a prehistoric campsite in northern Colorado, five hundred miles to the north of the prehistoric rock quarry? Who actually made it? What was he or she like? What happened on its journey from Texas to northern Colorado? Since it was impossible for me to ask the person who made it, I wrote my own version of the journey in the SHADOWS ON THE TRAIL TRILOGY.    
Below, I copied a highlighted paragraph from my third book of the prehistoric thriller series entitled the SHADOWS ON THE TRAIL TRILOGY. In this particular paragraph, the prehistoric stone tool I write about in paragraph one and two is lost only to be found by me 10,700 years later. I will catch you on the other side of the highlighted paragraph.

Far to the north, near the village of the Folsom People, lightning filled the sky as black clouds rolled in from the west. Chayton’s grandson Cansha and his friends had been hunting and were now running down the steep slope of the bluffs, trying to reach the safety of the village before the storm arrived. The red and gray inyan wakan – sacred rock bounced up and down in the satchel where Cansha kept his grandfather’s gift. As he sprinted to the village, Cansha never noticed that the red and gray sacred rock had fallen out of his satchel and landed on the trail. Later, a vicious thunderstorm struck the village, flooding the grasslands and creeks while burying the red and gray sacred rock. The red and gray sacred rock lay buried on that prairie for well over ten thousand winters until another human came along and discovered it eroding from a dry streambed.

So, what happened to the stone tool between the time it was lost around 10,700 years ago and the time I recovered it in 2010? Obviously, it was buried, otherwise, someone else would have found it before me or a cow or horse hoof would have found it and shattered it into tens of pieces. But, what is that white stuff growing on the top of it in Figure one? That is what is called pedogenic (secondary) carbonate and I will explain it to you.   

Figure Four. Side A of 6.5 inch long ultrathin knife form, made
from obsidian. Side A shows little pedogenic carbonate.   
Pedogenic carbonation occurs when rainwater and atmospheric carbon dioxide combine to form diluted carbonic acid in the soil. This weak acidic water dissolves minerals in the soil, yielding water-soluble calcium carbonate, bicarbonate, and other salts capable of precipitating on other minerals if ground water conditions are suitable.

Figure Five. Side B of 6.5 inch long ultrathin knife form
showing extensive pedogenic carbonate.   
Low rainfall is the single most important factor for the development of pedogenic carbonate. Low rainfall allows the formation of pedogenic carbonates near the surface of the ground. However, high rainfall washes the water-soluble salts into the ground’s water table, removing them from the sediment where we find most artifacts.

Pedogenic carbonate accumulates on or between sediment grains, occluding and cementing the sediment as a result. Pedogenic carbonate forms a geopetal structure that first accumulates on the lowest part of the buried artifact and as time goes on, coats more elevated areas. A geopetal indicator is a characteristic relationship observed in a rock, or sequence of rocks, that makes it possible to determine whether they are the right side up (i.e. in the attitude in which they were originally deposited, also known as "stratigraphic up") or have been overturned by subsequent movement. Regardless of the position the artifact is found, carbonate presence establishes the original up and down surfaces.     

Where It All Began - CLICK TO ORDER