Institutes

Current Project

Title: CAVE - Karstic caves of Central Portugal as palaeoenvironmental archives: speleogenesis and present-day dynamics.

FCT Ref.: PTDC/CTE-GIX/117608/2010

Funded by: Fundação para a Ciências e Teconologia (FCT)

Co-funded by: European Operational Competitiveness Programme - COMPETE

Funding Period: 01/05/2012 to 01/05/2015

Main Area: Earth Sciences - Internal and External Geodinamics

Secondary area: Geography

Institutions' involved: Coimbra University - CEGOT (Portugal), Dryas Arqueology Lda (Portugal), Lisbon University - IGOT (Portugal), Evora University (Portugal), Bari University (Italy).

Member list: Prof. Ph.D. Lúcio José Sobral da Cunha, Ph.D. Carlos Alexandre da Silva Ribeiro, Ph.D. Giuseppe Stella, A.M. Isabel Maria Rodrigues Paiva, Dr. Luca Antonio Dimuccio, C.M. Lúcia Cristina Lourinho Rosado, Dr. Maria João de Sousa Neves, Ph.D. Maria Luisa Estevão Rodrigues, Dr. Miguel Jorge Gomes Tavares de Almeida, Dr. Paulo Messias Oliveira Guerreiro, Ph.D. Thierry Jean Aubry, Ph.D. Vincenzo Iurilli, Research fellow.

Abstract

The establishment and development of karst systems, particularly endokarst, depend on multiple parameters, including lithology, tectonics, climate (rainfall and temperature), CO₂ partial pressure, soil type, vegetation, hydrology (sea level, regional hydrologic baseline, and origin of water), and human activity.

Karst systems record changes in these parameters and preserve this valuable information over time. Because of their natural conditions and their isolation from the exterior environment, caves, with or without present-day hydrological activity, represent a “living” archive of extreme importance to understanding the evolution of karst systems and the environmental changes to which cave environments have been exposed.

By focusing on its genesis and evolution, we can achieve both a better comprehension of the present-day dynamics of endokarstic systems and new insights into their future evolution related to extrinsic threats from either global climate change or local economic activities.

In Portugal, the work of local speleological teams mostly consists of the inventory and topographic analysis of caves. The resulting observations are rarely scientifically published. Scientific studies on karstic areas remain very rare and have been neglected for some time. One exception is CRISPIM’s work (CR05; CR99), in particular on the caves of the Estremadura and Arrábida Carbonate Massifs.

Because of their genetic and evolutionary specificity, national value, and environmental fragility, most of the Portuguese karst systems are within protected areas. Nevertheless, particular land use and management problems persist, threatening the integrity of karst resources for future generations. This project aims to achieve a better understanding of endokarst systems and to improve the capability of predicting the consequences of human activities, which are of great importance for territorial management. For this reason, the scientific data resulting from this project (an inventory of speleological heritage and a karst hydrological resources vulnerability evaluation) will be directly applicable to the management and conservation of karstic environments at a regional scale.

The CAVE project proposes an integrated approach based on an analysis of the various palaeoclimatic archives from caves and karst deposits. Of these, the most important are the stable isotope analyses and absolute dating in speleothems (mostly calcite formations in caves) and property analyses of fluviatile, lacustrine and other cave sediments. Most of the above deposits contain information relevant to the palaeoclimate evolution at a regional scale and sometimes show evidence or archaeological materials correlated with human occupation. The combination of data from various features (speleothems, clastic cave sediments, cave animals remains and archaeological evidence) within the same karstic environment allow for the ability to overcome the limitations of some absolute dating methods, to combine different climate records into a composite record, to carry on time-series analyses taking into account regional or global climate records and to identify the regional constraints of climate oscillations.

The proposed research will focus on the main karstic massifs of Central Portugal (Outil/Cantanhede Massif, Sicó Massif and Estremadura Massif) and has the following aims:

1. The creation of an evolutionary model of caves (speleogenesis) based on structural, morphological, sedimentological and geoarchaeological analyses; this model will further be integrated with known geological and geomorphological regional evolutionary models;
2. Understanding of contemporary cave activity and groundwater dynamics as well as their vulnerability to human activities;
3. Transfer of the project results and conclusions to public and private institutions with territorial planning and conservation responsibilities in karstic areas.

The project will be developed by a team with vast field-experience in karst geomorphology and the necessary laboratory and field techniques in geology, geochemistry, cartography, climatology, hydrology, archaeology and physics. In addition, the team has a deep knowledge of the natural and human conditions of these carbonate massifs (CU90; CU96; CU03; RO98; DICU99; DICU07; AUDIN11), and most of the members have the necessary qualifications and knowledge to work in subterranean environments. Finally, we emphasise the previous collaborative work of most members of this team (AUALDICU07; ROCURARATEDI07; AUDI10; AUDIN11), which demonstrates their abilities to develop coordinated scientific research activities.