SAWMILL SINK, ABACO: INDUSTRIAL ARCHAEOLOGY IN A POST-APOCALYPTIC LANDSCAPE
1. BLUE HOLES
The Blue Holes of Abaco are geological wonders about which much has been written – much of it in the NATIONAL GEOGRAPHIC MAGAZINE. Sawmill Sink is one of the best-known inland ones; and there are other holes in the shallow seas on both sides of the island. They are deep chasms in the limestone rock, many leading to extensive and complex cave systems under the island. Divers exploring Sawmill Sink have found many prehistoric fossils, including those of an extinct giant tortoise, and land crocodiles. Most conveniently, this fascinating blue hole is close to Delphi, hidden deep in the pine forest and accessible only by historic logging tracks.
AERIAL VIEW OF SAWMILL SINK DEEP IN THE PINE FOREST
This article is not about Blues Holes in general, nor Sawmill Sink specifically. I have such a post planned, but for the moment I’ll put some relevant links at the end of this one. Feel free to scroll straight there if the cumbersome heading has already put you off… but in an effort to hold your interest, here’s an image of the Sink to give you an idea of what it looks like. There are wooden steps down and a platform to enable you to swim in it (there are no crocodiles these days. So they say…).
2. A LOGGING HISTORY
South Abaco – defined loosely as the area south of Marsh Harbour – is dominated by pine forest. There are a few settlements and individual residences, all by the coast. The forested swathes are criss-crossed by an extensive system of logging tracks, many now all but impassable. They are reminders of Abaco’s historic importance as a source of wood deriving from the ubiquitous tall, slim pines. One use to which they were put was as mine pit props in the collieries of Wales.
Last June when we went to Sawmill Sink, we saw a rusty rail sticking up from the undergrowth. We were with Ricky Johnson, the man who could invariably answer any question about Abaco; he explained that there had at one time been a light railway through the forest to carry the felled timber to the highway, where it was transported to the coast for loading onto ships.
Last month we returned to Sawmill Sink. The south part of the island was enduring the annual outbreak of forest fires, most (if not all) believed to be set by hunters wanting to clear to undergrowth to make hog-hunting easier. While the occasional natural fire is actually good for the forest (cf burning moorland), the set fires do great damage over a vast area. On some days there were 6 or more separate seats of fire appearing in one day – highly unlikely to be the work of nature. Thick palls of smoke drifted across the island, and out to sea. Even far out on the Marls, the fires were visible, with the smell of burning carried on the wind. This year, the fires came uncomfortably close to some of the settlements. Night-long community action was needed in some places to protect property. At Delphi, the fires came within 300 feet or so before finally fizzling out in the coppice… Two years ago, they came nearly as close. For a post-fire wander round the Delphi drive circuit click FOREST FIRES (it was one of the first, tentative posts on this blog – and boy, does it show… it needs a rethink)
DELPHI GUEST DRIVE: A WARM WELCOME
The photos that follow show the track to Sawmill Sink immediately after a fire had swept through the area. Trees were still smouldering and in places the ground was still hot to the touch. Along the way the evidence of the former usage had been laid bare. Some images show the paved path that leads from the logging track to the Sink. I have no idea if these are the first images of so many visible remains of the logging trade, revealed by the burnt-off undergrowth. I haven’t tracked down any others at all so far. I write as a non-resident of the island, so if anyone can add any information, please do so via the COMMENT box.
Finally, we found this rock close to the Sink. Are those plant fossils? Bearing in mind that sea probably covered this area entirely (the highest point on Abaco is a mere 134 feet ASL), might these be anemones or sponge fossils of some sort? Comments from fossilologists welcome.
STOP PRESS thanks to FOSSIL LADY (aka Kathi) for the following: “Those don’t look like plant fossils to me, they remind me of stromatolites, a sponge like creature that first dominated the earth billions of years ago. Some varieties still survive today. It would be worth it to have a geologist have a look see. ps the sinkhole is awesome!”
SOME BLUE HOLE LINKS TO EXPLORE
BAHAMAS CAVES RESEARCH FOUNDATION
FRIENDS OF THE ENVIRONMENT, ABACO
ADVANCED DIVER MAGAZINE ARTICLE
As a reward for having waded through the smoke and ash above, here’s a short video of what you can see if you dive in a blue hole. It’s worth saying (1) that you need to check you are allowed dive – some holes are subject to ongoing research and (2) blue hole diving and caving is an inherently unsafe activity unless you have the right equipment and know exactly (by which I don’t mean “hey, I can wing it”) what you are doing…
Photo credits: all RH except header (adventureactivist, youTube); pit props (Scottish Mining Museum); aerial view (Gmaps)
Hello I’m from florida studied clemson(horticuture) lot of friends in forestry it is good thing …lighting strikes and poor land mgmt cause prop damage controlled burns is the norm char bark …and pine straw/cones will not catch trees
Thanks for your comment, Sam. Point taken – natural or controlled fires are good for regeneration. But we have times (spring, mainly) when fires are deliberately set over several days in several locations and may even join up; often very close to the main highway which has forest on both sides and is easily jumped; and with a change of wind the fires burn close to settlements. Way too close, sometimes, requiring entire communities to spend the night protecting their buildings. Also, many trees do in fact burn down, as well as utility poles etc. The island is not a place where controlled burning is really possible, anyway. And there are no fresh water sources – e.g. rivers or streams. So in general, yes, I entirely agree with you; but in Abaco’s circumstances randomly set fires can be as damaging as they are useful. That said, the understory / coppice is quick to regenerate. RH
thanks for this article full of information. I have read about it in National Georgraphic but your point of view helped ma to understand more. And as Jack says before: great pictures.
Have a great weekend
Thanks, Klausbernd. It was surprising to see so much evidence revealed by the fire. In two months, it will all be hidden again by new growth! The main interest there is obviously in the Blue Holes, which others have covered thoroughly already. This was a new twist on the area… RH
Hello RH, Those don’t look like plant fossils to me, they remind me of stromatolites, a sponge like creature that first dominated the earth billions of years ago. Some varieties still survive today. It would be worth it to have a geologist have a look see. ps the sinkhole is awesom! :O) Kathi
That’s fascinating, Kathi, and certainly fits in with the sea-level drop over the aeons. There are quite a few sinkholes of this sort in the forests. The ones off-shore are extraordinary – circular, dark blue in surrounding turquoise water, and full of large creatures. Chuck a line in and some heavy thing may take it straight downwards until it breaks… RH
Excellent coverage sir! I thank you. J. Bowers, RPh
Why thanks, Jack. Enjoyable to put together – especially the photography part. RH