Expert: Ralph Salier - 5/25/2011

Question
QUESTION: I'm a novelist, writing about an archaeological find of 17th century human bones and artifacts in a very dry, air tight cave (I've worked hard to get the geology right to make this reasonably feasible.) After the archaeologists have thoroughly studied the cave and contents as found, they remove everything to a university laboratory.  What kind of lamps would they use to study the cave?  Would they be wearing gloves?  How and in what would they transport the bones and artifacts?  Separately?  Well marked?  Cushioned or wrapped?
Thank you,
Ellie

ANSWER: Hi Ellie,

I believe that your premiss may be slightly flawed.  An air tight cave is almost a contradiction in terms.  A man made tomb is much more likely to be air tight so a natural cave would need to have been modified OR you may have had a cave with a cave in that sealed a portion of the cave in a relatively air tight manner.

If a human was interred in such a situation an the "seal" was occurred prior to de comp, then you could have a mummification of the remains.  So, depending on the condition of the remains, gloves may be used to preserve these delicate remains and they would have been sealed in a container with as much air removed as possible to keep the remains from quickly decaying further with exposure to air.  

I'd like to help you out,  further but need more details.  Could you provide more information?  I'd like for you to have the best possible details.

---------- FOLLOW-UP ----------

QUESTION: Thank you Mr. Salier.

Yes, my cave is sealed in low water-absorbing, dolomitic limestone. A family (two adults, an adolescent, and a one-year-old baby) had hidden inside and died of carbon monoxide poisoning when their persecutors set fire to the surrounding hillside. The hillside collapsed, plugging the small opening with a large stone, which tightened into a seal as the gases inside cooled. (I need to confirm my physics here.)

330 years later, the human tissue is mostly gone and the bones have collapsed on the floor of the cave. (I'm assuming the cave couldn't be 100% air-tight.) Other organic materials remain in remnants: cloth, leather, wood, and paper (a book).  Does all this sound right?  Would there be more skin left than I thought?  Hair?  Teeth? Would many of the baby's bones be left?

If quick decay in the sudden air exposure is a concern, how much time would the archaeologists take studying the find "in the field"?  Part of the mystery of the family's identity and plight is solved by studying the positions of the bones and their relationship to the surrounding materials.

Can you describe the sealed containers they would be carried out in? Size, shape, material, method of extracting air, how much of one skeleton in each container.... How would the archaeologists transport the inorganic matter: glass, ceramics, and metal?

Thank you very much for giving your time and knowledge.

Ellie

ANSWER: Hi Ellie,

Dolomitic limestone is alkiline based and as a result has the ability to neutralize acids. In a mesic or very dry environment can and often does lead to the mummification of human remains. This means that the skin, bones, teeth, clothing, leather items, papers and every thing would be beautifully preserved. And yes, over time, the air would exchange but very slowly.  In sealed Egyptian tombs, these were so well sealed that modern archaeologists have been able to "grab" samples of anicent air as they unseal these tombs with amazing results.

The concern, as noted in my previous response is the sudden exposure to air and moisture. Both will cause the rapid deteriorazation of the remains. Once exposed, the remains could begin to deteriorate immediately. In such situations, many photos are taken as quickly as possible to set the "scene" in situ (in place) and then the remains are quickly placed into containers from which air can be evaculated (creating a partial vacuum). Also CO2 and Nitrogen is used to replace the air in the container so retain the very dry nature of the air and remove oxygen.
The totes used would  be the nearly indestructable Rubbermaid totes with an additional silicone sealant around the inner sealing surface. 2 holes are punched into the top tire valves are then inserted into the these holes to allow for a vacuum pump to be attached and nitrogen/CO2 lines and then these are capped like a car's tire valves would be. Each body would get its own container and all of the surrounding soils and materials related to that body would be placed ito the container as well for further study.

The relationship of the remains may help in understanding the nature of the family but the genetic study would indicate the actual relationships between the individuals. It would be assumed that if these were all found together in the cave that there was some kind of relationship between them.  That is why the genetic study would be called for.

Books, containers (filled and unfilled) ceramics, etc... would also get their own totes and would be treated in the same way. All actions would be photographed or filmed and each object numbered insitu and that number placed with the object and into the tote. In this way, the secne can be re=created in the lab with high precision. They may even use a laser to do a 3D image of the space for the purposes of re-creation.

The archaeologists would in all likelihood wear protective tyvek suits and gloves and based on your previous explanation of the deaths being caused by CO (Carbon Monoxide) they may be wearing resperators to do the work. All items would be handled with gloved hands as if it were a crime scene.  

This would be unlike a typical cave excavation in  that 1) most cave excavations are in open air situations and deteriorazation of remains is not at issue. 2) it is typically chilly and wet in most caves and  this leads to differential preservation 3) most materials are intered or buried and are excavated, using the tools of the archaeologist, 4) the dust or materials in the air generally require resperators to be worn in dry conditions, animal feces can harbor some real nasty bugs 5) Places like Mesa Verde which are high and dry are also open and looters have generally cleaned out the good stuff so the archaeologists are looking for the stuff that the looters are not interested in but still provide key information about the people and use of the site.

330 years ago from when? Today or some time in the future?  If it is some time in the future then you may want to consider what modern technological things could come along in archaeology that would help them with this process.  If it is today and the remains are from that far back, we are looking at +/- 1681. What would these people have had, why, how did they get there etc...

What is the back story?  This is what the archaeologists will be looking for and trying to figure out.









---------- FOLLOW-UP ----------

QUESTION: Excellent. So helpful. Thank you!  

Three more important clarifying questions:  

Due to a cataclysmic geological event, the cave tomb is cracked open underground and exposed to the damp, winter air/gases of a tightly closed-up cellar (sealed perhaps 200 years ago.) The cellar collapses and the cave is discovered about four days later. Would the skin, hair, etc. have disintegrated by then? The bones still connected with tissue or in a heap on the floor?  

How fast would the archaeologists rush in to photograph and remove the remains?  Would they feverishly work through the night, racing against the minutes?  Or would they wait until morning and work over a period of hours, maybe days?

Would they bring down bright lights/lamps to work under?  

Would they study the cave further after the remains have been removed?

P.S.  Good guess for the date.  The hiding/burning incident took place in 1678 in Perthshire, Scotland (not so dry as Egypt!) during the "Highland Hosts" persecution of the Presbyterians.

Answer
Hi Ellie,

Well this change in senerio does change the complexion of the situation. First of all if the cellar was part of a building, chances are it was not well sealed given the nature of decay and atmospheric exposure which along with the geological cataclysim caused the structure to collapse and the cave to be exposed.  In this 4 day period the moisture probably would allow mould to begin growing on the skin and other surfaces, the skin would begin to turn to dust and fall away. Where there is clothing it would protect the skin to a degree and prevent rapid decay but the cloth too would be impacted by the higher moisture content and also deteriorate (after more then 4 days). The added oxygen would also accelerate decay. The bones would still be connected and the mummified remains would still be mummified but decay would be setting in and the mould would accelerate over time. The Archaeologists would probably work day and night to recover the remains to reduce the impact of the damage from the environment. They would also seal the remain as before but would also add an antifungal agent in aerosol form to curtail the ongoing decay by the mould. There are several agents that can be used for this but care must be taken to also preserve the remain.  Most antifungals are not kind to such remains.  For more detail, look up data on the frozen guy found in the Alps and the conservation of those remains.

Special lights would be used to which do not promote decay but delay it.  It is a type of "green" light which also has light bands of UV that helps to kill bacteria.

They would study the cave once the remains and other materials were removed just to have a clear understanding of what may have occured and how these individuals became trapped in the cave.

I hope this additional information is helpful.