lithic analysis

Jesse Walker – My Day of Archaeology, 2016

by Jesse Walker
Archaeological Society of New Jersey
Newsletter Editor and Executive Board Member

On Wednesday July 27, 2016, I devoted time to the Archaeological Society of New Jersey. Newsletters were printed for mailing to new society members. Emails from Executive Board Members were reviewed to ensure events, deadlines, and other organization tasks were addressed. One of major tasks the society is publishing a professional bulletin with articles about archaeology in the Garden State. I am editing an article about Native American flake stone tools that were excavated from a stratified site on the Delaware River floodplain near Frenchtown New Jersey. The results of microscopic analysis of flake tools are presented in the article. Editing involves checking grammar, formatting the manuscript, and reviewing the research design, archaeological data and conclusions. Publishing excavation results is a key responsibility in archaeology. It is eye opening to see how much effort goes into writing, editing, and prepared articles for publication in journals and bulletins. The membership dues to the Archaeological Society of New Jersey help fund the printing costs of the bulletin. Please consider joining the Archaeological Society of New Jersey to receive a copy of future bulletins.

Come Up to the Lab and See What’s on the Slab


MicrotalkHello all, I’m Spence and I’m an archaeological lithics specialist. You might know me on the Twitter as @microburin and for my sometimes irreverent blog where stones tell stories about our Mesolithic forebears. And yes, I have a lithics lab located in north-west London which I’m leasing until I have finished the detailed analysis and cataloguing of several lithic assemblages – largely comprised of flint – from the North York Moors in north-east England. The beauty of having a dedicated space is that you can lay out all the lithics from each ‘site’ or assemblage. This helps not just with becoming intimate with each assemblage, raw materials, artefacts, and debitage (we NEVER say ‘waste’ in the the world of lithics!) but also with attempts to refit pieces, almost the reverse of the reduction process, so that we can understand the flint knapper’s strategy, perhaps even their competence.

Chain gangs

The other key aspect of lithic analysis is that the debitage can tell us even more than the artefacts – for this period that means items such as microliths, scrapers, piercing tools, burins, denticulates, blades and the like. Together, the patterns of presence and absence of debitage and utilised items in any given place, and the raw materials that were sourced in often distant locations, form what we call a chaîne opératoire – literally an operational sequence – that helps us begin to understand what our Mesolithic friends were up to. I’ll come back to this a little later.

The excavation of features in the Mesolithic, especially in my study area, is rare. Firstly, there simply haven’t been any large scale excavations conducted to modern standards. Secondly, feature survival itself is relatively rare – organic survival is seldom encountered (and so it’s largely lithics that survive) and the very nature of Mesolithic activities and mobility through the landscape over millennia leave little evidence most of the time. The Mesolithic, for me, is all more interesting for being distant, often ephemeral in terms of what survives, mysterious and hovering around being just within and yet just beyond reach. It’s frustrating and rewarding at the same time.

Image_MesokidImage credit: hans s | Foter | CC-BY-ND

The Captain has turned on the seat belt sign – a little turbulence ahead

Whether the Mesolithic really existed at all outside artefact typologies and our own convenient constructs, sandwiched as it is between the climatic warming of the last glaciation (Late Devensian) and the onset of the Neolithic ‘package’, it was far from a time of continuity or stability. From the time of the return of pioneer communities, climatic volatility like the so-called 8ka event which saw a period of cooling, rapid sea-level rise with positive and negative undulations, eventually saw the separation of Britain from the continent. Vast ancestral tracts that were rich in resources disappeared. We also have evidence for at least one major tsunami event – the Storegga slide – that certainly had a catastrophic  impact on coastal communities and completed the inundation of Doggerland. There’s an increasing body of evidence too for repeated fire-events in the Mesolithic forests and around lake edges that are posited as indications, at least in part, of human management of the landscape and its resources.

“Far from being an endless period of hazelnut crushing, berry picking, game stalking and salmon fishing, the Mesolithic was a time of turbulence – climatic, environmental, social and technological – where many of the themes surely resonate with our own challenging world experiences today.”

Lithic life

Image_AdderMost days, like The Day of Archaeology today, are spent in the lab surrounded by my babies. I’m focused primarily on the analysis of an assemblage I excavated some years ago on the North York Moors uplands – now largely humanly-transformed heather-clad grouse moors on acidic peat. After falling into a griff (water channel), being bitten by an adder (thick boots), I came across a small, sandy eroded area with – you guessed it – flints on the surface. The rescue excavation, with kind permissions from the landowners and National Park archaeologists, lasted about ten days (and it only rained once) in a remote area. Every flint was plotted over 20 sq metres to reveal discreet knapping events, firespots, a stone-lined hearth containing burnt microliths and indications of a possible structure. Flat-stone features seem to be associated with knapping, microlith manufacture and tool concentrations including scrapers.


Terminal nail-biting

The results so far from the lithic analysis and processing of charcoal samples from the firespots and hearth are particularly exciting. Remember, there have been few excavations of any size in the last seventy or more years in this area, fewer still with results that allow spatial analysis. These are also the first feature-associated radiocarbon dates for the Late Mesolithic for north-east Yorkshire with a final suite in-process at SUERC right now. This is a nail-biting time! What we appear to be looking at is a multi-period site, a palimpsest, a persistent place that our Mesolithic friends returned to repeatedly over at least 2,000 years and where we might be looking at the very time of transition between the “terminal” Mesolithic and Neolithic. What this also proves is that knapping events within just a few metres of each other can span at least a couple of thousand years. This means that many of the large-area surface assemblages gathered by collectors over the past seventy years (but seldom if ever spatially recorded) probably represent many individual events over a considerable time period, each plausibly for different purposes or motives.


Joined at the hips

Once complete, I’ll be moving onto several other surface assemblages from the vicinity – with the sense of caution given the findings at the excavated site, although spatial plotting has been undertaken where possible. Here is where laying out all the lithics from neighbouring assemblages has proved a boon and a surprise. A rejoining utilised (micro-wear) flint blade had each half in two different assemblages, recorded ten years apart, and almost 200m from each other. ‘Paired sites’ are rare but do occur, for example in the Central Pennines. Might one be looking at coeval activities in the vicinity of what was once a small lake (which has been pollen-cored), long-since dried up? Read more about the project and view the poster on the Lithoscapes website »

Tools of the trade

spencer_banner.inddIn the header image, perhaps a little contrived, I’ve tried to illustrate the lithicist’s toolkit. You’ll already have noticed that the lab is less bestrewn with slabs than belittered with handy polystyrene insulation blocks procured from my local DIY store. They’re great for flagging lithics with cocktail sticks. The camera desk clamp, or tripod collapse avoidance device, is a recent addition after months of searching. On a good day I can process perhaps 30 to 50 lithics at a detailed level of attribute and metrical recording. That leaves more detailed analysis of particular artefact groups for a further round, in addition to photography and, ultimately, selective drawing.

And yes, that is a Lotto ticket on the scales! You know how archaeology is these days.

Is that a rod microlith or are you just happy to see me?

One of the significant hurdles for lithicists is recording assemblages systematically according to a replicable set of standards – ones without ambiguity for future researchers and with absolute clarity in describing morphology, typology, right down to the raw material type. This subject could see me ramble on for far longer than your patience will endure, suffice to say here that I am using and testing a typological protocol developed by my friend and colleague at Lithoscapes, Paul Preston. His doctoral research, soon to be published, extensively reviewed our legacy of lithics classifications and taxonomies to form a new standard. I’m delighted – and undeniably relieved – that he’s shared this with me and allowed me to apply it to the assemblages presently in my guardianship. Learn more about Lithoscapes Archaeological Research Foundation »

It’s knocking on a bit now on the Day of Archaeology, perhaps time for a cheeky chardonnay. Thanks so much for reading and taking an interest in the Mesolithic and stones with stories in resonating places. My thanks to the team of organisers, muddy or otherwise, behind this special international event. The many hundreds of posts each year provide the most fascinating insights into the inner workings of archaeologists and specialists – a through-the-keyhole peek at the world around us. May I also take this opportunity to congratulate Lorna Richardson, one of DoA’s lynchpins, on her recent rites-of-passage achievement. Well done Dr Richardson!

Best wishes,

Mesolithic Spence


Microburin has left the building!

Microwear analysis-determining the function of chipped stone tools

One of my technical specialties is high-powered microwear analysis, a method by which the function of chipped stone tools can be determined. Pioneered by Semenov (1964) and refined by Keeley (1980), the high-powered magnification approach has repeatedly demonstrated that variability in polish formation on utilized surfaces is related to tool use on different materials (e.g. soft tissue, hide, bone, wood, etc.). Striations, or the grooves and scratches of varying orientation and dimensions which often result from abrasive forces imparted during tool use are important indicators of intentional and unintentional motion, such as friction between a stone tool and its haft and/or the contact material being worked.  Taken together, micropolish and striations provide information on contact material, tool motion, and hafting.  In this manner, the identification of distinct surface and edge alteration of tools can be related to prehistoric patterns of activity and raw material use and utilized in the reconstruction of the organization of cultural behaviors.

Today I continue to work on material from three sites. Two sites were recently excavated by a Cultural Resource Management firm as contract excavations. These sites, which date from the Late Archaic and Woodland periods, were investigated to fufill compliance laws prior to disturbance. As part of the data recovery plans, the principle investigators have included a budget for analysis, a part of which is microwear analysis to determine the function of chipped stone tools recovered on site. A range of formal and informal tools were recovered, and so far, results indicate a wide variety of tasks  including butchery, hide,  and bone and wood working occurred on site.

The third site I am working on is the famous Lindenmeier Folsom site in Colorado. These materials were excavated and/or collected in 1934-40 during work at the site by Frank Roberts. Microwear analysis of a sample of endscrapers recovered from the site reveal that many of them were employed in the later stages of hide working. Edge wear in the form of eroded resharpening scars and heavily rounded edges along with a well formed dull-pitted polish characteristic of dry hide was present (see photomicrograph).  During late stage hide working, the edges of the tools are allowed to dull, so that accidental tearing of the hide during stretching and softening is lessened. Some endscrapers were discarded with sharp, fresh edges indicating use during earlier stages of hide working where cleaning and thinning is the object. These discard patterns illuminate the activities that took place on site, and when coupled with an assemblage of worn out, broken and discarded projectile points suggest active hunting and transport of fresh hides for processing at the site was common.  Here is a prime example of the value of why collections should be curated, as when they continue to be available for analysis, we can continue to learn from them.

Heavily worn and rounded distal edge of unifacial endscraper used on dry hide.

Another kind of human: researching Neanderthal archaeology

As I described in my first post, my research is on the last Neanderthals, a field I find fascinating through the ‘alternate universe’ of hunter-gatherer adaptations and lifeways they represent as a different kind of human. I’m a lithics geek, which means I study, in loving detail, the stone tools that Neanderthals made and which were fundamental to their everyday lives. My PhD involved looking at the evidence from Britain of the re-occupation by Neanderthals of this landscape around 55,000 years ago, after they had been absent for about a hundred thousand years. This meant in practice spending a year visiting a LOT of museums, to record information from over 1000 stone tools. This might sound like a big number, but in fact it’s a very small sample when you’re talking about sites which probably span over 10,000 years in time. Big French cave sites of the same period can have ten times that amount of lithics from a single occupation layer.

After this recording phase was another year (or two…) of data crunching to find out what the stones were telling me. The results showed that Neanderthals moving into Britain during a very unstable climatic period (termed Marine Isotope Stage 3; we’re now at Stage 1, and the last proper ice age was Stage 2) were living very mobile lives, with a highly organized technological strategy that promoted flexibility in their tool production and maintenance.  So where am I now two years later, on 29th July in 2011?

At the moment I have several different projects, and multi-tasking is definitely something as a researcher you need to get to grips with. I’ve just got back from three-weeks of fieldwork in Jersey, as part of a really exciting project called the Quaternary Archaeology and Environments of Jersey, which will be featured in the first episode of the new Digging for Britain tv series. Although Jersey is a small island, it has a fantastically rich archaeological record.  We’re interested in the hunter-gatherers who lived there from the Neanderthals right up to the people who lived in the forested landscapes after the last ice age. My part in the project is to study the lithics (stone tools) from the upper layers of one of the most important Neanderthal sites in the world, a collapsed cave/ravine called La Cotte de St Brelade.

La Cotte de St Brelade, Jersey. The original excavations were underneath and behind the rock arch, originally thought to be a cave until the roof of sediment collapsed in the early 20th century.