GSA Connects 2021 in Portland, Oregon

Paper No. 149-1
Presentation Time: 8:05 AM


JORDAN, Brennan, Sustainability & Environment, University of South Dakota, Vermillion, SD 57069

The best opportunities for geoheritage promotion are sites of outstanding natural beauty or clearly compelling geologic character, but opportunities to connect people with geoheritage also exist at sites of cultural heritage where geology is responsible for critical aspects of the site. A class of cultural heritage sites that exemplifies this opportunity is strategic points. General examples include high points, topographic barriers, passes, straits, and isthmuses. Several examples are highlighted.

Edinburgh Castle, Scotland, Castle Rock: volcanic plug formed by magmatism associated with Carboniferous extension, sculpted by Pleistocene glaciers to form a crag-and-tail. Occupied because of its strategic value back to the Iron Age, it is the site of many sieges, and is Scotland’s most visited tourist attraction.

Hadrian’s Wall, England, Whin sill: Carboniferous/Permian sill complex crosses much of Great Britain south of Scotland. Along much of its length, Hadrian’s Wall takes advantage of the natural barrier provided by north-facing cliffs of the sill. Roman emperor Hadrian ordered the building of the wall which marked the northern extent of Roman Britannia.

Corinth and Acrocorinth, Greece: the 6-km-wide isthmus below Ancient Corinth separates the Gulf of Corinth and the Saronic Gulf and connects mainland Greece to the Peloponnese. Corinth was a prominent city in antiquity due to this position. The low isthmus (graben) and the high citadel of Acrocorinth (horst) owe their existence to Neogene to Recent extension. That extension continues is manifested by the fact that the Roman harbors are now submerged.

Gettysburg Battlefield, Pennsylvania, Gettysburg sill: the Jurassic Gettysburg sill (York Haven diabase) and related dikes intruded Triassic sedimentary rocks of the Gettysburg Basin during the early stages of the opening of the Atlantic Basin. Resistant intrusive rocks underlie hills and ridges of the battlefield (e.g. Cemetery Ridge) which played a critical role in the outcome of the battle.

The geoscience community would be well served by seeking opportunities to include geoheritage interpretation at such sites. Cultural heritage site managers may be resistant in some cases, concerned with distracting from the cultural interpretation program, but positive engagement may lead to opportunities.