Flakes

If you spend any amount of time hiking in the Southwest you will eventually happen upon a scatter of lovely, multicolored stone flakes lying in the sand. In some areas, black obsidian predominates, and in others yellow and red jasper. But most often you’ll find a beautiful mix of jasper, chalcedony, quartzite, and petrified wood spanning all of the colors of the rainbow and most of the delicate shades in between. What you have found is the remains of ancient tool manufacture.

Native Americans roamed the Southwest for at least fourteen thousand years, and likely much longer. They were skilled at utilizing almost every natural resource at hand, whether animal, vegetable or mineral. They were particularly talented at creating flaked stone implements – spear points, knives, scrapers, and eventually arrowheads. In this part of the country, the most available and appropriate materials were usually also the most attractive. The archaeological record tells us that Native Americans visited the sources of the best materials for thousands of years and often traded what they collected there. But as they hunted and gathered their way across these arid landscapes, they also kept an eye out for good quality stone wherever it might be found. The result is that in most places you’d be hard pressed to find a square mile that isn’t graced by these elegant remnants of ancient workmanship.

The number of lithic scatters (the name used by archaeologists) in the Southwest must certainly be in the millions; I’ve personally found hundreds. Similar scatters exist throughout the country, but only in the Southwest, with its sparse vegetation, are so many in plain view. If you know what to look for, you’ll find them everywhere, reminders that what seems deserted today has been the home of countless inhabitants since long before the age of the pyramids.

Suitable materials for knapping (fabrication of stone tools) most often occur in the Southwest in the form of heavy cobbles the size of your fist or larger. On the outside, they look like avocadoes. But beneath this dull, weathered rind lies a shiny volcanic rock formed when silicate-rich magma cooled quickly, producing lithic material with an extremely fine-grained crystalline structure. It it is this feature that makes the cobbles so well suited for tool manufacture. Striking a cobble at just the right angle with another rock produces smaller pieces of stone with very sharp edges. So sharp, in fact, that obsidian flakes have been used as scalpels in surgery.

The reason for the ubiquity of these scatters is practical. Native Americans had no beasts of burden until the re-introduction of the horse by the Spanish. Depending on its interior structure, any cobble might yield many, a few, or perhaps no usable tools at all, providing ample incentive to turn large lumps of stone into smaller, lighter sizes and shapes able to be turned with assurance into a variety of tools.

If camp was nearby, a cobble might be reduced to a “core” by knocking off the weathered exterior to confirm quality and reduce bulk. Or the tool maker might go farther, striking off large, thin sections and then further reducing them to create oval shapes archaeologists call preforms. These much lighter elements were easily transported, either for trade, or for later transformation into tools.

When you discover broken chunks of smooth, colorful stone, you’ve discovered a quarry site where cores were mined. If instead it’s a feast of fine flakes you’ve round, it’s a campsite you’ve stumbled upon. Look carefully and you’ll often find a hammer stone as well: a dense round or oval stone with one end scarred and flattened by turning cobbles into more usable pieces of stone.

Still, you might ask, do you really mean millions of lithic scatters? Absolutely. Consider that at first hundreds, then thousands, and ultimately tens of thousands of individuals roamed the Southwest over for more than a hundred and forty centuries. Until a few millennia ago, all were hunter-gatherers (and many remained so), roaming across large areas of varying elevation to exploit sparse, seasonal resources. Each time a band camped, new tools were likely made, old ones sharpened, and broken ones turned into smaller tools. If you do the math – fourteen thousand years times tens of thousands of individuals times perhaps thirty campsites a year – it becomes clear the number of scatters to be found is enormous. And this leaves out one-night hunting party campsites and the quarry sites themselves.

I expect another factor explains why lithic scatter sites are so numerous. I call it the “knitting effect.”

Often enough, you may find a scatter of flakes that covers only a few square feet rather than a large area. My guess is that someone stopping for a rest might have opened up his leather pouch of preforms and knocked out a finished tool or two to while away the time, much as a knitter pulls out her needles and yarn when chatting with a friend. Several times I’ve sat on the only conveniently sized rock around, confident my hiking shoes were resting in the same exact spots as the sandaled feet of the ancient knapper responsible for the brilliant display of flakes surrounding my feet.

If you find pieces of stone (archaeologists call such lithic waste debitage) across a larger area, the likely interpretation is you’ve discovered a camp.

Quarry sites can be small or very large indeed, sometimes many acres in size. Often this occurs where erosion uncovered thousands, or even tens of thousands of cobbles, spread widely across a plain, perhaps the remnants of a long-evaporated lakebed. In such a place you’ll find almost endless amounts of shattered, multicolored stone, most pieces from a half to a couple to four inches in length. But few or no small flakes. You would search in vain for completed artifacts, because the task at hand in locations like these was to create cores and preforms. If some pieces of broken stone appear bright and fresh and others dull and blotchy, you’ve stumbled on a quarry site utilized over many thousands of years.

If you look carefully at the squared off end of a large flake, you will often see a bulge on the long side just below the break. It’s called a “bulb of percussion,” and marks the place where the energy imparted by a hand-held hammer stone dissipated. Look more closely and you might observe fine, concentric circular lines emanating from the top of the bulge, together resembling the striations on a seashell. Archaeologists call this a conchoidal fracture (deriving from the Greek word for a mussel shell). It’s the tell-tale sign of a knapping flake, as the same pattern almost never occurs naturally.

Where you find smaller bits of debitage you are looking at reduction flakes, removed from a larger piece to create a preform, or to turn a perform into a tool.

Flakes the size of your thumbnail are often produced by a different process, using a heavy billet cut from the base of an elk or mule deer antler rather than a stone. This softer material provides a greater degree of control as the delicacy of the process increases. Like the larger pieces of debitage, these are called percussion flakes, as they are struck off by forceful blows.

The tiniest bits of stone – the size of your little fingernail or smaller – you may find were likely derived through a different technique. They were again produced using a softer tool, like an antler tine, to press rather than strike small flakes off the cutting edge of the tool. If you look at a finely created artifact edge-on, you will see a barely zigzagging line created as a just such a minute flake was removed from first one side, and then the other. The broad faces of the finest and oldest artifacts display a pattern of tiny flake scars that evidences very fine and meticulous work indeed.

Figuring out where to hunt for quarry and habitation sites can provide an interesting focus when choosing a hiking route in the Southwest. And there’s more to find than flakes. I’ve discovered the ruins of many small pueblos and pit houses, and the closer you get to the Four Corners intersection of Utah, Colorado, New Mexico and Arizona, the more frequent, diverse and colorful the pieces of ancient, broken pottery become. You may also find broken basaltic manos and metates (used to grind corn and seeds into flour), beads, shell bracelets, and more.

But before you become too interested in that pursuit, know that almost all of the Southwest is “catch and release” territory: it’s perfectly acceptable to look for habitation sites, but keeping anything you find there is illegal almost everywhere. If you violate the rules, you run the risk of being caught (and not released).

The moral of the story is that, unless you’re willing to take nothing more than pictures of what you find, you might want to take up bird watching instead.

Which, by the way, is also great out here.

August 27, 2005

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