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Jurassic Global Stratotype Section and Points (GSSPs)-a potential serial World Heritage Site?

Page K., Melendez G., Henriques M.

Volumina Jurassica

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2008

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Vol. 6, no. 1

155-162

EN

The Operation Guidelines for the UNESCO World Heritage Convention state that proposed areas should: “..be outstanding examples representing major stages of Earth’s history, including the record of life”, “..contain all or most of the key interrelated and interdependent elements in their natural relationships”, “..have a management plan…” and “..have adequate long-term legislative, regulatory, institutional or traditional protection..”. By definition, Global Stratotype Sections and Points (GSSPs) should satisfy all these criteria, although in isolation, the proposal of any single GSSP is unlikely to succeed, however, as an individual site may lack a broader context. Nevertheless, combining a suite of GSSPs sites for a System within a ‘serial’ World Heritage site proposal would satisfy such a concern and could be an ultimate goal for the International Subcommission on Jurassic Stratigraphy.

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Waterloo Bay, Larne, Northern Ireland: a potential GSSP for the base of the Jurassic System

Simms M., Jeram A.

Volumina Jurassica

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2006

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Vol. 4, no. 1

297-298

EN

Northern Ireland is the type area for two basal Jurassic ammonites, Psiloceras sampsoni (Portlock 1843) and Caloceras intermedium (Portlock 1843). However, with its small and patchy exposures of Triassic and Jurassic strata the region has subsequently been largely overlooked compared with sites in SW England. A foreshore section at Waterloo Bay, Larne, on the east coast of Northern Ireland, exposes an almost uninterrupted succession from the upper part of the Mercia Mudstone Group (Triassic, Norian) through to the Bucklandi Zone of the Lias Group (Jurassic, Sinemurian). Recent study has established that the boundary section here is superior in many respects to that at St. Audrie's Bay, SW Britain, a long-standing candidate GSSP for the base of the Jurassic System. What has the Larne section to offer? 1. Exceptionally thick succession across the Triassic/Jurassic boundary. The boundary succession is significantly thicker, and deposition demonstrably more continuous, at Larne than anywhere else in NW Europe. 2. Potential biohorizon stratotypes for the Planorbis Zone. Clearly definable biohorizons can be recognised for Psiloceras erugatum, Neophyllites imitans, N. antecedens, Psiloceras planorbis/sampsoni and P. plicatulum. This site would make an ideal stratotype for the first three of these, for which currently no surface stratotypes are proposed (Bloos & Page 1998). Ammonites are very common in this section, and preservation by pyrite, or in nodules, is often excellent. 3. Diverse non-ammonite macro- and microfauna, already partly documented. A rich fauna of bivalves, gastropods, echinoids, crinoids, trace-fossils and occasional vertebrates are present at this site. Preliminary stratigraphic distribution of the fossil macrofauna, and of palynomorphs, through correlative strata in the nearby Larne borehole has already been published (Ivimey-Cook 1975; Warrington & Harland 1975). 4. Potential for correlation. Sedimentary cycles, of two orders, are clearly developed here. Combined sequence and cyclostratigraphic analysis indicates that the cycles reflect eustatic fluctuations, and therefore have significant potential for global correlation. A major seismite unit and associated desiccation-cracked bed in the Penarth Group provides an important datum correlated across the UK (Simms 2003).

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Jurassic Global Stratotype Section and Points (GSSPs) – a potential serial World Heritage Site?

Page K., Melendez G., Henriques M.

Volumina Jurassica

|

2006

|

Vol. 4, no. 1

253-253

EN

The Operation Guidelines for the World Heritage Convention include the following criteria for the selection of natural heritage sites, which states that they should: "…be outstanding examples representing major stages of Earth's history, including the record of life, significant ongoing geological processes in the development of land forms, or significant geomorphic or physiographic features" [Criteria a (i)]; "The sites listed in a (i) should contain all or most of the key interrelated and interdependent elements in their natural relationships…" [Criteria b (i)]; "The site described in paragraph (a) should have a management plan…" [Criteria b (v)]; "A site described in paragraph (a) should have adequate long-term legislative, regulatory, institutional or traditional protection..." [Criteria b (vi)]. Global Stratotype Sections and Points (GSSPs) represent, by definition, the most stratigraphically complete and globally important stage-boundary sections known. They therefore fully satisfy the World Heritage criterion a (i). Crucially, their identification and ratification is regulated globally by the International Union of Geological Sciences (IUGS) which also advises UNESCO on the selection of World Heritage Sites for geological features - such a ratification can be taken as confirmation of global significance in more than just a technical or scientific sense. In addition, as part of the GSSP selection process aspects of the site's conservation status and safeguard for future study are also taken into consideration, Criterion b (vi) and be satisfied, if not b (v) as well. The proposal of any single GSSP in isolation as a World Heritage site is unlikely succeed, however, as individually such sites may lack a broader context. Combining a suite of GSSPs sites in a "serial" World Heritage site proposal - a well established approach in other contexts - is however, conceptually much more likely to succeed. In particular a proposal incorporating all the applicable GSSPs for a single system could certainly satisfy Criterion b (i), especially as all key interrelated and interdependent elements would then be included, i.e. all component stages of that system. Such a proposal could be an ultimately goal for the ISJS, as a celebration of decades of intensive work by many colleagues from many countries. Such a project would require a high degree of international agreement and already five countries are implicated in the process: Portugal, Spain, England, Scotland and France. Nevertheless, the close working relationships between specialists in different nations established through the Working Groups of the Subcommission can offer a marvellous opportunity for such collaboration.