Mantellic degassing of helium in an extensional active tectonic setting at the front of a magmatic arc (central Mexico)
Por:
Billarent-Cedillo, Andrea, Hernandez-Perez, Eliseo, Levresse, Gilles, Inguaggiato, Claudio, FERRARI, LUCA, Inguaggiato, Salvatore, Lopez-Alvis, Jorge, Silva-Fragoso, Argelia
Publicada:
1 feb 2023
Ahead of Print:
1 dic 2022
Resumen:
The physicochemical and isotopic characteristics of groundwater and
dissolved gas of central Mexico provide valuable information about the
geologic and tectonic context of the area. Low-high- enthalpy
manifestations (up to 98 degrees C in springs and more than 100 degrees
C in geothermal wells) are distributed within the San Juan del Rio,
Queretaro, and Celaya hydrologic basins, located at the boundary between
the current Mexican magmatic arc and an extensional continental area
with intraplate volcanism called Mesa Central Province. Groundwaters in
the study area represent a mixture between the cold water end- member
with a Ca2+-Mg2+-HCO3- composition and a hydrothermal end- member
enriched in Na+, K+, SO42-, and Cl-. Cold and hot groundwaters delta 2H
and delta 18O plot along the same evaporation lines and do not exhibit a
magmatic input. Dissolved and free gas do not show a typical volcanic
composition signature. He and Ne isotope composition provide evidence of
an important contribution of non- atmospheric noble gases. Although
helium composition mainly has a crustal origin (21-83%), the mantellic
contribution (1-39%) is higher than expected for an area lacking recent
volcanism. A volatile- rich magma aging at depth was discarded as the
source of this mantellic helium signature but points out a recent
mantellic contribution. Thus, we propose that mantellic helium comes
from the sublithospheric mantle into the shallow crust through the
highly permeable tectonic boundaries between the geologic provinces,
namely the N-S Taxco-San Miguel de Allende and ChapalaTula fault
systems. Mantellic helium flow rates through these fault systems were
estimated to have values ranging from 0.1 m/yr to 2.9 m/yr. This He flux
range implies that aside from subduction, mantle volatile degassing
enhanced by crustal fault systems is the main degassing process in the
region studied.
Filiaciones:
Billarent-Cedillo, Andrea:
Posgrad Ciencias Tierra, UNAM Campus Juriquilla, Blvd Juriquilla 3001, Queretaro 76230, Mexico
Hernandez-Perez, Eliseo:
Posgrad Ciencias Tierra, UNAM Campus Juriquilla, Blvd Juriquilla 3001, Queretaro 76230, Mexico
Levresse, Gilles:
Ctr Geociencias, UNAM Campus Juriquilla, Blvd Juriquilla 3001, Queretaro 76230, Mexico
Univ Utrecht, Dept Earth Sci, NL-3584 Utrecht, Netherlands
Inguaggiato, Claudio:
Ctr Invest Cient & Educ Super Ensenada CICESE, Dept Geol, Carretera Ensenada-Tijuana 3918, Ensenada, Baja California, Mexico
FERRARI, LUCA:
Ctr Geociencias, UNAM Campus Juriquilla, Blvd Juriquilla 3001, Queretaro 76230, Mexico
Inguaggiato, Salvatore:
Ist Nazl Geofis & Vulcanol, Sez Palermo, via Ugo Malfa, 143, I-90145 Palermo, Italy
Lopez-Alvis, Jorge:
Ctr Geociencias, UNAM Campus Juriquilla, Blvd Juriquilla 3001, Queretaro 76230, Mexico
Silva-Fragoso, Argelia:
Ctr Geociencias, UNAM Campus Juriquilla, Blvd Juriquilla 3001, Queretaro 76230, Mexico
gold, Green Submitted, Gold
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