Tuesday, July 12, 2011

Gezer Dig 2011 Report – Part Two

By Jim Parker, Ph.D.

The last few days of digging in the Gezer Water System were exceedingly difficult this year.  In the previous post you saw, in a photograph, the size and the number of stones that went down the tunnel in the retaining wall collapse in 1908.  It was these stones that we were excavating and pulling out of the tunnel the last days of this year’s dig.  We had dug some rock all the way down the tunnel, but when we encountered these, we knew we were close to the bottom.  This excitement did not relieve the burden of removing the rocks. Also, the deeper we got, the wetter the soil got.  We knew we were getting closer and closer to the water table as we descended.  The part of the debris that was not rock became sticky mud.  It would suck you into it and you could barely get your feet out.  This added to the rigors of the digging too. We kept consoling ourselves with the fact that we were only cleaning the dirt out of the tunnel; what would it have been like to have been the people that used flint tools to cut the rock originally?  We were most grateful when the cave opening finally presented itself to us on June 7. 

Macalister had discussed the condition of the roof of the cave in the 16th Report.  He mentioned how fearful he was that there would be a collapse and that someone would be killed.  He, it seems, was relieved when the upper works collapsed without injuring anyone, but that collapse prevented him from having to return to the cave.  I must say that reading his words some 100 years later did concern me.  He described the roof of the cave as “rotten.”  Although not a technical term, one immediately recognizes this as a term for a roof that will need a lot of support.  What would we find?  Would we be able to enter into the cave?  There was great relief when we finally got to the cave opening.  We had only advanced a few feet when a large section of the cave roof did collapse.  Everyone was out of the way, so there was no damage, but this gave us an opportunity to study the nature of the roof.  When this area of rock formed (Noah’s flood?), along with the harder, structurally stronger Eocene chalk that makes up the tunnel and cave roof, a layer of softer chalk about 18 inches or 2 feet thick formed to the underside of the roof.  Perhaps the cave was initially an air bubble. It is this rock that has collapsed in places and we did find some blocking our way into the cave.  This is good news.  First, this rock can be easily knocked loose with a long bar and caused to fall without endangering anyone.  Secondly, this is reasonably soft chalk; if we have to quarry any of it to remove it from the cave, it will not be so difficult.  We have advanced 17 feet into the cave through a 3 feet wide trench and so far the silt goes all the way to the roof.  This will be much to our advantage as we continue work in the cave as we can use the silt to support the roof, creating rooms and pillars in the beginning if need be.

Photo from Macalister's Dig in 1908
This is a view looking up the tunnel.  Dirt was initially left on the left side with steps cut into it so that the team passing the baskets up and out would have a place to work.  This was eventually removed after the cave was reached. Note the wear on the rock steps just to the left and above the man.  Macalister supposed that this wear was caused by about 400-500 years of use.  Based on the latest pottery he found in the tunnel dating to around 1450 BC, he surmised that the tunnel had originally been cut around 2000 BC.


Photo from Macalister's Dig in 1908


Again, note the wear on the steps.  These had been totally encapsulated for 3,350 years when Macalister uncovered them.   As we began, there was anywhere from 4 feet to 20 feet of material above the steps. 

Since the roof of the tunnel is substantially half of a circle, when we began to dig, we took about two-thirds of the tunnel, about 8-9 feet wide and began our desent.  In the following scaled drawing that I made after the 2011 dig ended, you can see that from where the tunnel turns down, there is about 3 feet of dirt over the steps down to the first arch (the vertical blue lines).  At the level of the bottom of the arch, the tunnel was level full.  Our probe is the open space at the roof of the tunnel that leads down to the cave. 

In 2010, we removed approximately 1,040 cubic feet (39 cubic yards – 29 cubic meters) of debris (approximately 50 percent rock and 50 percent dirt) which equated to 336 bags.  Some are interested in the weight of the material.  Using 130 pounds per cubic foot for this type of material, in 2010 we removed about 68 tons of debris averaging about 400 pounds per bag.  

In 2011 we removed approximately 3,560 cubic feet (132 cubic yards- 101 cubic meters) which equated to 1,372 bags or 231 tons, about 337 pounds per bag. 

Eventually the Israel Parks Authority will likely remove all of the debris from the tunnel and hopefully open the water tunnel as a tourist site like they have done at Meggido and Hazor.  There is approximately 13,306 cubic feet (493 cubic yards – 377 cubic meters) or 4,685 bags of debris left to remove.  [An average bag of material based on the 2010 and 2011 digs is approximately 2.85 cubic feet (.08 cubic meters) per “big bag.”]

Drawing by Jim Parker

Before leaving Israel, Dan Warner, Dennis Cole, and myself met with Tsvika Tsuk and  the Israel Nature and Parks Authority team to plan for the 2012 dig season.  The dates from May 27 through June 15, 2012 were chosen. The dig plan will include removing the hump of debris just underneath the mantle (also called the second arch), face up the cave entrance and widen the 3 foot wide entrance to the full tunnel width at the entrance and then proceed into the cave, and also to probe the “water source”, which on the above drawing is the flat area from the cave entrance back to the the bottom step. 

Perhaps you will join us as we continue this wonderful adventure back in time to the era of Abraham and the patriarchs of Israel.  What might we find?  Come see!

Jim Parker, Ph.D., is Associate Professor of Biblical Interpretation and Associate Vice President of Facilities at New Orleans Baptist Theological Seminary.


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The Gezer Water System project is co-sponsored by the Israel Nature and Parks Authority and New Orleans Baptist Theological Seminary under the direction of Tsvika Tsuk, chief archaeologist at INPA, and Dan Warner, co-director of the Center for Archaeological Research at NOBTS.



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