Sunday, September 2, 2012

Siccar Point, One of the Most Important Field Sites in Historical Geology is Threatened...with Agricultural Sewage

Siccar Point is in the far distance on the left
The abyss of time is about to become a cesspool...

An issue has crossed my desk that ought to be upsetting to anyone who has followed geology as a career or has any passing interest in the history of geology. Siccar Point in southern Scotland is under serious threat of "development". Not development as in hotels and parking lots, but as in "being turned into a pile of sewage". An agricultural company is proposing to cut a pipeline through the point, to be used to transport rotting vegetables and agricultural wastes, untreated, into the sea a very short distance offshore. Information about this desecration and efforts being made to stop it can be found here: The response time is very short, so I hope that as many geologists as possible will be heard from.
Geotripper lends scale to an outcrop of the crossbedded Old Red Sandstone
I had a single chance to visit Siccar Point back in 2001. We made all the special arrangements with the touring company to get to the locality on the back roads, but a rather awful incident in Scotland interfered in a big way: hoof and mouth disease. The malady was detected and wholesale destruction of the cattle herds in the country followed. The few unaffected herds were placed in quarantine, and no one was allowed to cross pastures (which was necessary to get to the point). One cannot imagine how disappointed we were. I started studying the maps and realized that a second access point might exist, one that wouldn't threaten any herd animals. We drove to a campground at Pease Bay and started walking along the shoreline (actually, I was running, an act that is legend in our department; it was pretty rugged and I should have broken something). We were able to get within sight of the point (it's the point of rocks in the farthest distance of the top picture; click on the picture for a better view).
Although we couldn't stand on the Siccar Point unconformity, a lesser exposure was visible along the shoreline cliffs.
Why is the point important in the history of geology? There is an angular unconformity between the Old Red Sandstone and the underlying graywacke sandstones that provided the most vivid evidence of James Hutton's revolutionary idea of uniformitarianism, the principle that was the impetus for the modern development of geology as a science. John Playfair's description of his visit to Siccar Point is one of the more stirring descriptions of deep time as you will ever read:

"The ridge of the Lammermuir Hills in the south of Scotland, consists of
primary micaceous schistus, and extends from St. Abb's head westward, till it
joins the metalliferous mountains above the source of the Clyde. The
sea-coast affords a transverse section of this alpine tract at its eastern
extremity, and exhibits the change from the primary to the secondary strata,
both on the south and on the north. Dr. Hutton wished particularly to examine
the latter of these, and on this occasion Sir James Hall and I had the
pleasure to accompany him. We sailed in a boat from Dunglass, on a day when
the fineness of the weather permitted us to keep close to the foot of the
rocks which line the shore in that quarter, directing our course southwards,
in search of the termination of the secondary strata. We made a high rocky
point or headland, the Siccar, near which, from our observations on the
shore, we knew that the object we were in search of was likely to be
discovered. On landing at this point, we found that we actually trod on the
primeval rock, which forms alternately the base and the summit of the present
land. It is here a micaceous schistus, in beds nearly vertical, highly
indurated, and stretching from south-east to north-west. The surface of this
rock runs with a moderate ascent from the level of low-water, at which we
landed, nearly to that of high-water, where the schistus has a thin covering
of red horizontal sandstone laid over it; and this sandstone, at the distance
of a few yards farther back, rises into a very high perpendicular cliff.
Here, therefore, the immediate contact of the two rocks is not only visible,
but is curiously dissected and laid open by the action of waves. The rugged
tops of the schistus are seen penetrating into the horizontal beds of
sandstone, and the lowest of these last form a breccia containing fragments
of schistus, some round and others angular, united by an arenaceous cement.
Dr. Hutton was highly pleased with appearances that set in so clear a light
the different formations of the parts which compose the exterior crust of the
earth, and where all the circumstances were combined that could render the
observation satisfactory and precise. On us who saw these phenomena for the
first time, the impression made will not easily be forgotten. The palpable
evidence presented to us, of one of the most extraordinary and important
facts in the natural history of the earth, gave a reality and substance to
those theoretical speculations, which, however probable, had never till now
been directly authenticated by the testimony of the senses. We often said to
ourselves, What clearer evidence could we have had of the different formation
of these rocks, and of the long interval which separated their formation, had
we actually seen them emerging from the bosom the deep? We felt ourselves
necessarily carried back to the time when the schistus on which we stood was
yet at the bottom of the sea, and when the sandstone before us was only
beginning to be deposited in the shape of sand or mud, from the waters of a
superincumbent ocean. An epocha still more remote presented itself, when even
the most ancient of these rocks instead of standing upright in vertical beds,
lay in horizontal planes at the bottom of the sea, and was not yet disturbed
by that immeasurable force which has burst asunder the solid pavement of the
globe. Revolutions still more remote appeared in the distance of this
extraordinary perspective. The mind seemed to grow giddy by looking so far
into the abyss of time; and while we listened with earnestness and admiration
to the philosopher who was now unfolding to us the order and series of these
wonderful events, we became sensible how much farther reason may sometimes go
than imagination can venture to follow. As for the rest, we were truly
fortunate in the course we had pursued in this excursion; a great number of
other curious and important facts presented themselves, and we returned,
having collected, in one day, more ample materials for future speculation,
than have sometimes resulted from years of diligent and laborious research."

A nice exposure of the Old Red Sandstone near Pease Bay.
Standing at (or near, in my case) Siccar Point should be near the top of any geologist's life list. To mar it with a pipeline and might as well build sewage treatment plant in the middle of Stonehenge. This shouldn't be happening. All geologists should be heard from as soon as possible to stop this wanton destruction of one of the most important outcrops in the world. It should be under protection as a World Heritage Site, but instead is subject to abuse and misuse. Please make yourself heard, and soon.

1 comment:

Nina Fitzgerald said...

Siccar Point is very high on my geology bucket list (well, everything on my bucket list is geological!).
Thanks for the link - I'll send a message today.