Fecha: 4 agosto 2026
Autores Ckelar: Francisca Aguirre, Gabriel Ureta, Amiel Nieto y Rodrigo González
Otros autores: Gary S. Michelfelder y Mauricio Torreblanca
Revista científica: Geology
Abstract
The distinction between nearby groups of volcanic monogenetic centers (MCs) is often unclear, yet it is crucial for understanding the formation and evolution of monogenetic volcanic
fields (MVFs). This uncertainty is illustrated by the Negros de Aras and El Negrillar volcanic
groups—located south of the Salar de Atacama (northern Chile)—that have been variously
identified as a single MVF or two separate ones. This issue becomes especially significant when
MC groups show contrasting features—such as distribution patterns, eruptive timelines, or
morphological and geochemical traits—that make it difficult to define clear volcanic field
allocations. We analyzed the spatial distribution patterns of 88 MCs over an area of 187 km2
,
along with morphometric parameters, structural controls, and whole-rock geochemistry (165
samples) associated with Negros de Aras and El Negrillar groups, to determine whether they
form a single MVF or two different fields. Multiple factor analysis results reveal differences
between the two groups. Based on these findings, we define two distinct MVFs: the Negros
de Aras MVF and the El Negrillar MVF. Our results emphasize the importance of using a
multi-parameter approach when mapping MVF allocations, especially in tectonically active
regions. This case study and our integrated approach help advance efforts to better define
MVF allocations at both local and regional levels, opening the challenge of the concept of
monogenetic, or distributed, volcanic fields for future research.