SUMMARY
Piero Netti - FSP 2010
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 (1995, 1999*), 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 archieve 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 an sometimes show evidence or archaeological materials correlated with human occupation.
Piero Netti - FSP 2010
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.
*CRISPIM, J.A. (1999) - Seismotectonic versus man-induced morphological changes in a cave on the Arrábida chain (Portugal). Geodinamica Acta (Paris), 12, 3-4: 135-142.
CRISPIM J. A. (1995) - Dinâmica cársica e implicações ambientais nas depressões de Alvados e Minde. PhD Thesis, Lisbon, 394p.