Friday, May 8, 2020

5/8/20 Report - Must Read: All About Near Shore Shipwrecks. Pre-Columbian Florida. Erosion.


Written by the TreasureGuide for the exclusive use of treasurebeachesreport.blogspot.com.

South of Turtle Trail Access Around Noon 5/7
A front came through yesterday and the wind was coming from the north. As I expected, there was a little erosion to some of the beaches.

Ambersands Beach Around 1PM On 5/7

The wind continued into the evening, so there could have been some more erosion.

Ambersands Beach Around 1PM on 5/7
There was one detectorist at Ambersands.  You can barely see him in the photo above.

Treasure Shores Beach Around 1PM on 5/7.

The tides will be high Friday, but the surf will be only two or three feet.

Unfortunately the surf predictions for the weekend are now looking like only three or four feet, at the most.  A few days ago it was looking a little more promising.

I'm adding this photo from Jerry P. showing the damaged access to Seagrape.  The Seagrape access is still closed.

Seagrape Trail Access.

Jerry stopped at Turtle Trail yesterday also and said finds were very few.  He saw no other detectorists.

Thanks Jerry.

Looks like the wind has changed Friday morning.  I wouldn't expect much more erosion.  Probably some filling soon.

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It appears Florida tourism has been going on for thousands of years.

… Archaeologists estimate small-scale ceremonies began at Crystal River around A.D. 50, growing substantially after a residential community settled the site around A.D. 200. Excavations have uncovered minerals and artifacts from the Midwest, including copper breastplates from the Great Lakes. Similarly, conch shells from the Gulf Coast have been found at Midwestern archaeological sites.
"There was this long-distance reciprocal exchange network going on across much of the Eastern U.S. that Crystal River was very much a part of," Duke said.
Religious ceremonies at Crystal River included ritual burials and marriage alliances, Duke said, solidifying social ties between different groups of people. But the community was not immune to the environmental and social crises that swept the region, and the site was abandoned around A.D. 650. A smaller ceremonial site was soon established less than a mile downstream on Roberts Island, likely by a remnant of the Crystal River population....
Here is that link.


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Anyone seriously interested in tracking shipwrecks or artifacts will want to read The Archaeology of Shore Stranded Shipwrecks of Southern Brazil, a dissertation by Rodrigo De Oliviera Torres, Texas A and M University, 2015.  While the study was conducted in Brazil the same principles apply locally, although the seasons are different and the most significant winds for us are from the north, while their's comes from the south.  Otherwise there is little difference.

I'll give you just a few examples from the dissertation to give you the idea of the types of things you will find in the dissertation.

First is the distribution of shipwrecks in the area (Fig. 19 below).  You will notice a clustering around the bar near the inlet.  Also most wrecks are near shore.  There are relatively few in deeper water.

Four sections of the hull of one wreck was buried on the beach.  Below is one of those after excavation.

Excavated Hull Section.
Below is a diagram showing the relative positions of the four beached sections of the hull.


While sections 1 and 2, which were larger and farther back on the beach, remained in the same relative position, sections 3 and 4 were moved over a three year period.

In the following photos you can see that the two sections are closer together in 2009 than they were in 2006.


It is not surprising, but it illustrates how even large sections like this can be moved on a beach.

Of course, weather and beach dynamics are discussed.  Below is an example.

Remember, the directions are reversed.  Their south winds are more like our north winds.



Notice the alternating erosional and depositional areas.

Here is one more diagram from the dissertation.

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And here is another paragraph from the dissertation.

McNinch et al. (2006), studying artifact deposition in a similar shallow, energetic
setting in North Carolina (Queen Anne’s Revenge site), observed that wrecks in these
conditions will normally settle into the sand via episodic scour processes driven by
storms and inlet migration, favoring preservation of heavier artifacts and hull parts. The
authors concluded that depending on the underlying geology and hydrodynamics, a
shipwreck could in fact settle through several meters of substrate in highly dynamic
settings. Although no systematic survey has ever been carried out in the area
surrounding the sand shoals at the Rio Grande bar, shipwreck debris varying from small
coal chunks to glass bottles and large timbers are frequently washed out onto the beach
after storms, suggesting shipwreck remains are still being reworked (Figure 60).


I don't really like the word "settle" as it is used here, but it does explain that it occurs along with the scour processes.  It is not a passive process, as "settle" would seem to imply.

Well, I can't go over the entire dissertation, but think I've given you enough to let you decide if you want to browse it for yourself.

Here is the link,.

https://www.academia.edu/12852042/The_Archaeology_of_Shore_Stranded_Shipwrecks_of_Southern_Brazil_Torres_2015_?email_work_card=view-paper

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