The deeply derived CO2 from tectonically active areas is contributing in a significant proportion,
still unquantified
in detail, to CO2 Earth degassing. Several studies highlighted how in these
tectonically active areas most of the CO2 is dissolved in the groundwaters circulating in the large
regional aquifers hosted by the permeable formations of the active orogens. Quantifying the
amount of deep CO2 dissolved into groundwater can represent a powerful tool for regional
investigations, because springs are representative of their catchment area that can extend from
tens to hundreds of square kilometers.
In the framework of a Deep Carbon Observatory supported project, we investigated for the first
time, the geogenic carbon emission from the Balkan Peninsula (southeastern Europe). This area
is known for its high carbon Earth degassing (both CO2 and CH4), but lacks the necessary data
for quantification and for determining the origin of carbon (especially for what regards the
isotopic composition of dissolved carbon). We investigated thermal manifestations (thermal
springs and drillings), CO2 emission (including dry and wet moffetas), thermal wells containing
CH4 and karst springs from tectonically active areas.
During the field investigation, we visited Romania (Mangalia and Tyulenevo coastal area
(Romania and Bulgaria), Apuseni Mountains, Ciuc Basin and Herculane Graben), Slovenia, Central
Serbia, Macedonia and Croatia visiting and collecting more than 350 sites. Water samples were
collected for water chemistry, water stable isotopes, carbon13
from TDIC, dissolved H2S,
dissolved gas composition, carbon13
from CO2 and CH4 from dissolved gases, and for dissolved
noble gases (He, Ne, Ar). For those sites were also free gas was present, the team collected free
gas samples for compositional, isotopic and noble gas analyses.
The availability of this data is the first attempt in quantifying the carbon flux with real data from
this tectonically active area