Geology

Rob Ixer’s Day of Archaeology

A pretty average day, I am a geologist, or to be specific a mineralogist who did a little archaeology in the 1960s.

Now I look at rocks, pots and ores for archaeologists to try to determine their geographical origins using a couple of rather large and now ancient microscopes. I am retired and like to think of myself as a 21st century Victorian ‘Divine’ so self funded mainly but free to look where and at what I want or am asked to.
After looking at some Neolithic pottery from the West Country to decide if more work should be done on them, slicing them and grinding them to make thin sections. Some is commercial work and some is from interested amateurs and done for the joy of knowing.

However, today I have two main tasks:

To look at rocks from the Sacred Valley (‘septic valley’) in Peru as part of a long standing, over 30 years, study of Inka use of stone in their pottery and buildings. The Inka produced very large very beautiful pottery now called ATF ware now but it was called Inka Fine Ware or Cuzco Inka -it seems that the use of certain rocks from certain places was very special to the Inka.

To start to read and review two very splendidly illustrated Conference volumes on ancient gold and silver (as a mineralogist I specialised in gold, silver and PGE minerals), Recently a number of books on exotic ‘well-furnished’ grave goods have appeared from Wessex and from Europe.

I shall take a day off from my ‘day job’ working on Stonehenge although I shall trawl the Stonehenge blogs to see what is new, always something.

So a very typical day, slow progress (I hope) in old style data-gathering archaeology. I hope not to hear the words post-processualist all day.

Dr Rob Ixer, FSA

A Day of Archaeological Survey in the Jungles of Northern British Columbia

Name: Paulina Dobrota.

Position: field archaeologist/ PhD student

I started working in interior B.C. in summer 2012. Although I’ve seen a couple of tough outdoors in my life, I am always baffled by the terrain here. After the beetle kill plague that hit these parts 10 years ago, the forests of northern British Columbia are jungles. Some days, I don’t even touch the ground at all. I walk on logs, balancing precariously. If they’re good, a pair of boots may last a whole season. Pants start tearing immediately in the thorny underbrush and the dreaded Devil’s club. And wait until you see the mosquitoes and flies!

I like to think of ourselves here as archaeological managers. We work for the logging industry. Like scores of other interested parties, we enter cut blocks prior to logging and do our part of the work. In our case, we rate the archaeological potential of each proposed development and proceed to mitigate or exclude areas of archaeological significance. We deal with archaeological sites and traditional use areas, and a lot of culturally modified trees (CMTs). Our work goes by a predictive model that isolates areas of interest which have to be surveyed on foot. As an amateur geologist and a geoarchaeologist in training, I am immensely thrilled by the breadth of our focus. We look out for cultural materials but also do terrain, hydrology, soil and sediment classifications and indicator plant species. Although we get to see artifacts quite rarely here, the scope of our survey makes this one of the most fun and stimulating areas I’ve ever worked in.

Every year, before returning to the field, I spend a month jogging 1 hour every day. I spruce up my gear and replace broken equipment. I re-read The Amateur Geologist’s Field Guide, and Indicator Plants of British Columbia and I’m ready to go.
On July 11 this year, we were notified that we were going to access a cut block by helicopter. We had already traveled to the area the previous day and were spending the night at a motel in a nearby town. We breakfasted in a road-side diner with other workers, piled into our trucks and drove out. First we negotiated our way through the forest road traffic, to the assembly point. Here, we had to wait in the grass by the side of the road with other forestry crews, joking with each other and spying at each other’s gear. Forestry crew often know lots about archaeology. Every time they meet us, they tell us about areas they think might have artifacts.

1 - logging road traffic

Logging road traffic

2 -  heli ride to the block

Heli ride to the block

The helicopter was making its way and we could hear the sound of the propellers through the air. We got a brief safety training and then we lined up for pick up. My team was last. We were going to get dropped off into a swamp, make our way across and get picked up from the other side of our block.

I pulled down my hard hat, my survey vest, laden with flagging ribbon, my field gear and my water pack. Each object – GPS, a compass, a camera – was tied up with reflecting yellow ribbon and secured with carabiners to my vest, which gave a faint smell of insect repellent, sun screen and sweat. I crouched down and ran up to the door. The air was completely still, so the ride was very smooth. We arrived to our area and circled it a couple times then proceeded to descend onto the swamp. We dropped out and my feet were immediately ankle deep in water. We crouched down again and ran to the forest line with our gear at knee level.

Once in the block, we make a game plan, spread out in transects with a width based on visibility and start walking. I always like to state my goals for the day. “Today, I want to find a cache with at least 10 pre-Clovis points in a tree-throw”. Actually, this has been my goal for the past 3 years. I’m still working on it.

2 - surveying in the block

Surveying in the block

First I check out the forest cover, and figure out what the likeliness of finding culturally modified trees is. Then I start noting plant species, observing vegetation patterns, marking out slope degree and aspect on my map while waving away mosquitoes. We call out for each other sometimes, “Marco!”, and wait to hear “Polo!”.

The survey is advancing smoothly through a rolling terrain. Two hours in, we hit a body of water and start following its course. We hike up a slope, just 20 m above the water’s edge. At the top, I already see a nice, flat ground covered in ground cedar and reindeer lichen. “What do you think of this place?” It’s just about 10 by 10 m or so. I kick up a bit of sod and do a soil check. “All good! I’m taking this one!”. We flag it with ribbons looped around trees, GPS it and take notes on laminated sheets (our “field paper”). Based on our client’s decision, we will either excavate or exclude this area from the development.

3 - surveying in the block

Surveying in the block

Surveying by a wetland

Surveying by a wetland

Landscape

Landscape

a CMT

a CMT

Cut mark on a CMT

Cut mark on a CMT

We continue with our survey and reach our pick up place hours in advance of the helicopter. “It’s only 2 pm, we got a 2 hrs and a half wait”. We vote on it. “Lets walk it!” We got our truck location, it’s only 5 km away and the map shows that there’s a DR (deactivated road) in 1 km. Now comes the portion we call ‘dead walk’. We finally hit the road and start making our way. The day is hot, I’m tapping my last water resources and some granola bars from the bottom of my survey vest pocket. It’s been years now since I have eaten a granola bar that was not sun baked.

Like archaeologists all around the world, all we talk about is places we worked in, places we could work in, places we would like to work in and FOOD. Foods we’ve eaten, and foods we will eat when we’re not in the field.

We finally reach our truck. We see the helicopter parked nearby, with the driver reading in the back seat and wave at him. We throw our gear in the back, get on, I write some finishing notes about our block and we drive away. “Tomorrow, my goal is to find a a cache with at least 10 pre-Clovis points…”

Arrow point found in 2012

Arrow point found in 2012


A Day of Archeology in Blytheville, Arkansas, USA

A typical day in my archeology job is anything but typical. It can be anything from a full day of excavating, to a day working in the lab or doing public presentations. I wrote about all of the various things I may do during a day in last year’s Day of Archaeology post. This year, I’m starting a large scale research project, so my day of archaeology is a lot more library driven.

I start out my day by getting on the University of Arkansas-Fayetteville library website.  Because I am stationed in Blytheville, which is about a 6 hour drive from Fayetteville, I have access to the library as an employee of the University, but I have to search for the books I want on their website and then have them mailed to me.  It makes the process for books a bit longer, but is better than having to drive to Fayetteville whenever I need something.  The library website also has access to an excellent variety of journals and journal articles that can be viewed online or downloaded.  I like to use journal articles for research as they are generally a bit more current and specific to a topic than books, so this works out well even from the other side of the state.

Blytheville, Ar is located in the New Madrid Seismic Zone, which is a spot in the middle of a continental plate that produces earthquakes.  From what I’ve been reading, no one is really sure why earthquakes happen here, but they certainly do.  I haven’t felt one myself yet, but last year there was an earthquake large enough to be felt and shake things in houses about 75  miles SW of Blytheville.  Historically the earthquakes here can be very large.  In 1811-1812 there was a series of 2 large (~M7) earthquakes centered on the city of New Madrid, MO and then thousands of aftershocks for the following years.  Large earthquakes like this also happened in the 1450’s and 900’s.  In the delta region of the Mississippi River (where we are only a few feet above the water table) there are hundreds of feet of sand covering the bedrock below.  Because of this, when a large earthquake strikes, the shaking of the wet sand causes it to become a liquid that moves up to the surface of the ground and come out almost like a volcano, covering the area around the crack with wet sand.  This phenomenon is called a sandblow.  You can see these sandblows all around this area in farm fields.  Often the crops don’t grow as well in these areas because the sand doesn’t have as many nutrients in it and it doesn’t hold water as well as the surrounding silt.

When the wet sand comes up out of the earth and covers the surface is when it gets interesting in terms of the archaeology.  Sometimes what is on the surface is an archaeological site.  If the sand covers the site and is fairly thick, it prevents the site from being destroyed by plowing.  Due to the huge amount of farming that is done in the Delta (where the soil is excellent for growing a variety of crops), many archaeological sites are at least partially destroyed by plowing and planting crops.  Many sites are almost on the surface as they are only a few hundred years old, so any plowing hurts them and deep plowing or leveling can destroy them completely.  If a sandblow is covering the site, it mitigates these effects.  It can also cause the site to be unknown completely if it is totally buried.

DSC00477

As a research project, my station plans to look at these buried sites in a variety of ways.  First, we want to do some survey to try to find completely buried sites.  There are known sites here and there along the Bayou, but we think that there may well be more that are deeply buried.  To find them we want to put in deep shovel tests in areas that look like a good location for an archaeological site (generally higher areas near the Bayou or another water source).  If we find these sites, we want to bring in a specialist to do geophysical survey so that we can try to see if there are any possible cultural features that could be excavated to tell us more about the people who lived on the site.

We also want to look at the ways in which different groups responded to the large earthquakes.  Did the people move away from the site?  Did they stay and rebuild?  Did they leave but then come back again later?  We hope that by looking at a variety of sites we’ll be able to see some of these things archaeologically.

During this initial background literature search, I have come across reports of a number of archaeological sites in this area that have been excavated in which the people who lived at the sites seem to have reacted in different ways.  I’m very excited to find out if we will see the same kinds of things in our project.

After the literature review, I am going to write up a research plan/agenda for the project.  I want to be able to present it to the landowners and farmers that we’ll be working with as well at to the Native American groups whose ancestors lived in this area.  The background is an important part because it explains why we want to do the project and why it should work the way that we think it will.  Using geology and seismic data I can talk about how the earthquakes would cause the sandblows and how they work and using other archaeological reports I can talk about what other researchers have done, what worked, what didn’t and how we plan to do our project.

So despite seeming a bit boring for awhile while I sit at my desk in my office day in and day out, this is the first step to starting what could be a very interesting and long-lasting line of research that could produce some really interesting results.  Hopefully next year for A Day of Archaeology I can update you on what step of the project we are on by then.

 

Tracing Neandertal Territories in the Mountains of Southeast France

Day of Archaeology 2013 for me means being away on 2 months of fieldwork in the southern Massif Central, France.  I’ve been contributing to DOA since 2011, and if you look back, it’s clear a lot has changed  since then (see my four 2011 posts, and 2012). After my PhD I was searching for a postdoc for several years, ran out of time and money to keep looking, and ended up seredipitously with a contract to write a book about humans and birds in prehistory.

I thought that would be it, and that the 2013 Day of Archaeology would take place without a contribution from me. But it seems that archaeology wasn’t quite done with me…

My workspace at the field station, Laussonne, Haut Loire

My workspace at the field station, Laussonne, Haut Loire

As I wrote in a postscript comment to my post last year, only a few days after writing about the difficult process of changing paths from a research career to one focused on writing and wider communication, an email dropped into my inbox from the European Commission offering the very last postdoc funding I applied for- a Marie Curie Intra European Fellowship to work in at the PACEA lab, Universite of Bordeaux. After a lot of soul-searching on the wisdom of doing another 180 degree turn in my life trajectory, and talking with my husband about him coming out with me, I decided to go for it. And so here I am, in the mountains of the Massif Central!

Laussonne map

Laussonne map

The field station for Archeo-Logis at Laussonne, Haut Loire

The field station for Archeo-Logis at Laussonne, Haut Loire

My postdoc is focused on two elements: training in a new skill (the Marie Curie Fellowships are especially concerned with career development), and applying this method to an archaeological context. I’ve written on my own blog in more detail about my project, which is called TRACETERRE. This stands for “Tracing Neandertal Territories: Landscape Organisation and Stone Resource Management“. It’s part of a larger collaborative project directed by my boss, Jean-Paul Raynal, and Marie-Helene Moncel.

Essentially I’ll be learning a detailed geological technique called petro-archaeology, that allows us to determine where in the landscape Neandertals were obtaining the raw materials to make their stone tools. Specifically, we are especially interested in the flint sources: most of the geology in the area is igneous, which means it comes from volcanic action (the Massif Central is a world famous centre for volcanology, where you can see virtually every type of volcano and lava).

Sancy Massif

Sancy Massif, north of where I am based, showing volcanic formations

It’s possible to make stone tools from these kinds of rocks, but they are often very hard, and can also be coarse. Flint is a sedimentary rock, meaning it forms from the slow accumulation of mineral deposits. Flint is famous for the high quality tools that can be made from it, because of the predictable way it fractures. It’s often associated with Cretaceous chalk deposits, such as the big cliffs in the southern UK, where you can see black bands of flint nodules. So flint forms in marine contexts, but it can also form in other situations such as in lakes.
Although there are few primary sources of flint in the Massif Central (i.e. outcrops of rock containing flint), there are many different secondary sources. These can be eroded outcrops, material washed into river gravels and other kinds of sources. My training will be in identifying these secondary types of sources, based on the way the outer surface of flint cobbles changes during the process of first formation, erosion and later exposure at archaeological sites.

Some of the geological reading I've been getting up to speed on. Volcanoes galore!

Some of the geological reading I’ve been getting up to speed on. Volcanoes galore!

Because there are more than 70 different secondary sources in the region which have been painstakingly identified over more than thirty years (by Paul Fernandes, who will train me), this is too much to try to attempt to learn in two years. So I will be using a source-centred approach, where I look at one flint source, and see how this particular rock has been used by Neandertals. In particular, we are interested in where this rock ends up: which caves or open-air archaeological sites is it found in? And secondly, in what form does it occur: as finished tools, raw blocks, or flakes of stone that have been struck off blocks (cores) but not yet made into tools.

Finding these things out can tell us a huge amount about techno-economics: the way in which Neandertals were choosing to organise their exploitation of resources on landscape scales. For example, working out which types of technology they used to make tools and which stages of tool production occur where can reveal the level of investment of energy: were they making tools quickly, and dropping them soon afterwards? Or were they carefully choosing which kinds of tools to make, and which ones to take with them in toolkits, maintaining them by re-sharpening? Both these strategies can be used as adaptations to different situations, particularly the level of mobility.

A handaxe, one type of tool Neandertals seem to have carried with them as part of mobile toolkits, which could be re-sharpened and used in many tasks. This one is from near Bournemouth, UK

A handaxe, one type of tool Neandertals seem to have carried with them as part of mobile toolkits, which could be re-sharpened and used in many tasks. This one is from near Bournemouth, UK

The question of Neandertal mobility is also a key reason for studying in such detail the different sources of stone used. We want to know where the stone from a flint source was going: which sites is it found in? How far was flint being transported, especially in comparison to other stone types? We can even begin to work out the paths taken through the landscape by Neandertals: did they have to cross rivers, high mountainous areas? Which passes would have been likely to be used? We also plan to excavate at the flint source itself, to see what activities were taking place, and also which tools came from other places in the landscape.

We can then begin, by combining all the geological and techno-economic data, to build up a detailed understanding of the inter-connections between different parts of the landscape that Neandertals were living in. And this is just the stone tools: other parts of the archaeological record, such as animal bones preserved in caves, are studied by other project members. We can use these to determine things like what season people were living at sites, and where they were probably hunting the animals in the landscape.

Gravel bar system, Switzerland- one example of a secondary source of stone. Image used with permission via Creative Commons: " I, Paebi [GFDL (http://www.gnu.org/copyleft/fdl.html), CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0/) or CC-BY-SA-2.5-2.0-1.0 (http://creativecommons.org/licenses/by-sa/2.5-2.0-1.0)], via Wikimedia Commons"

Gravel bar system, Switzerland- one example of a secondary source of stone. Image used with permission via Creative Commons: ” I, Paebi CC-BY-SA-2.5-2.0-1.0 (http://creativecommons.org/licenses/by-sa/2.5-2.0-1.0)], via Wikimedia Commons”

All this creates a web of the palaeo-landscapes that Neandertals were inhabiting. But the impact of sourcing flint tools goes even further, because if we can map the extent of inhabited landscapes, we can start to think about territories. This is crucial because territories are not just regions full of resources- they probably were also involved in defining social interactions between different Neandertal groups. This is something we are still learning how to measure, but it has huge significance because different kinds of territories and social interactions suggests particular cognitive capacities. This is of course one of the key areas of research in human evolution: how did Neandertals differ from us, and how were they similar? Did they have similar webs of social connections, or were they living local, isolated lives in small groups that did not regularly meet? If this was the case, how did they find mates, and prevent huge in-breeding? All these fundamental questions can be advanced by new data and investigations such as the research I am doing.

Right now, I’ve only been here just over a week, and am only one month into a two year postdoc. So there’s a long way left to go. But it’s very exciting, and I hope to start the petro-archaeology training and looking at the flint collections very soon. Meanwhile, there’s always time on fieldwork to have a day off, check out the local wildlife, cuisine and culture, and enjoy some of the lovely sunsets in this region. Very different landscapes to when Neandertals were living here!

 Sunset at Laussonne

Sunset at Laussonne

I am funded through a European Commission Framework 7 Marie Curie Intra-European Fellowship for Career Development, and I work at the PACEA laboratory, UMR-5199, Universite Bordeaux 1.

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Moving a dune, eroding archaeology on Scotland’s north east coast.

The sand dunes at Brora, Sutherland, on Scotland’s north east coast, are over four metres high. Buried within them are the remains of the late 16th / early 17th century saltpans. Over the centuries, the wind had blown sand over the site, completely covering it until it became forgotten about.

Sand dune at Brora

Sand dune at Brora

In recent years, coastal erosion had exposed part of the front wall of one of the buildings, and on the Day of Archaeology, we finished machining and started cleaning up the site.

We knew that masonry remained buried in the dunes as we had uncovered half of a building in 201. Although we had seen the front wall of the buried portion, we did not know how much would survive.

In order to uncover the site, we had to remove hundreds of tons of sand and had spent the previous two days landscaping the dune. Removing the sand would allow us to work safely , but we had to make sure that the wind would not blow away the reshaped dune, so were replacing the turf on the remodelled dune as quickly as possible.

Machine stripping of dune

Machine stripping of dune

We were finished with the machine by 9:00am (the machine driver had another job to go to so started early, one of the benefits of long summer days up in the north!). The machine had taken out the bulk of the sand while we dug close to the walls to ensure that the machine bucket didn’t damage the masonry.

Cleaning site by hand

Cleaning site by hand

When the machine had gone, the walls plotted with the EDM, and loose of unsafe masonry was drawn, photographed and then removed.

Using an EDM for survey

Using an EDM for survey

There was also much collapsed masonry within the building, and once the machine had left, this had to be removed by hand.

Heavy work, moving stones

Heavy work, moving stones

We also spent time videoing Calum, a young volunteer who helped us out last year also, and had been inspired to use the Brora dig for a school project.

By the end of the day, we had cleared enough sand to reveal a small room, roughly 4 m x 4.5m, with a doorway facing the sea and a fireplace in one wall. While machining we had seen the lintel of the fireplace and it seemed to have initials carved into it. As we removed more sand from around it, we could see that there were further initials on one of the jambs; the other had nicks etched into its edge, perhaps where people had sharpened their knives.

Fireplace

Fireplace

The project had been initiated due to Jacqueline Aitken’s passion for, and concerns about, the archaeology of Brora. Jacquie remembers playing on eroding masonry (now long gone) when she was a child and was worried that Brora’s industrial heritage was being washed away by the sea. A member of the Clyne Heritage Society, she contacted SCAPE (Scottish Coastal Archaeology and the Problem of Erosion) and a joint project, (also involving the University of St Andrews where Jo and I are based), was established. Thanks to funding from Historic Scotland, a small bit of Brora’s past is being recorded before it is lost forever.

Clyne Heritage group members

Clyne Heritage group members