scholarly journals Hydrothermal alteration at the basalt‐hosted Vista Alegre impact structure, Brazil

2021 ◽  
Author(s):  
Jitse Alsemgeest ◽  
Fraukje M. Brouwer ◽  
Luis F. Auqué ◽  
Natalia Hauser ◽  
Wolf Uwe Reimold ◽  
...  
Keyword(s):  
Hydrothermal Alteration ◽  
Impact Structure

Hydrothermal alteration in basalts from Vargeão impact structure, south Brazil, and implications for recognition of impact-induced hydrothermalism on Mars

Icarus ◽  
2015 ◽  
Vol 252 ◽  
pp. 347-365 ◽  
Author(s):  
Elder Yokoyama ◽  
Anne Nédélec ◽  
David Baratoux ◽  
Ricardo I.F. Trindade ◽  
Sébastien Fabre ◽  
...  
Keyword(s):  
Hydrothermal Alteration ◽  
Impact Structure ◽  
South Brazil

Impact-induced hydrothermal dissolution in pyroxene: Petrographic and geochemical characterization of basalt-dominated polymict impact breccias from the Vargeão Dome, Brazil

2021 ◽  
Author(s):  
Jennifer Epstein ◽  
Lidia Pittarello ◽  
Álvaro P. Crósta ◽  
Christian Koeberl
Keyword(s):  
Hydrothermal Alteration ◽  
Hydrothermal Fluids ◽  
Terrestrial Planets ◽  
Impact Structure ◽  
Impact Event ◽  
Southern Brazil ◽  
Geochemical Characterization ◽  
Heterogeneous Nature ◽  
The Impact

ABSTRACT Constraints on impact-related hydrothermal alteration are important to enable the reconstruction of the possible processes affecting the surface of other terrestrial planets, such as Mars. Terrestrial impact structures excavated in basaltic targets provide the opportunity for analog studies. In Brazil, seven impact structures have been confirmed so far. Three of them, Vargeão Dome, Vista Alegre, and Cerro do Jarau, were formed in the same basaltic province belonging to the Paraná Basin, and they have several common characteristics. Oxidized basaltic breccias locally containing sandstone clasts occur in all these structures. In this work, selected samples of such breccias from the Vargeão Dome impact structure in southern Brazil were petrographically and geochemically investigated to further constrain the effects of the postimpact hydrothermal alteration. The breccia matrix shows typical oxidation effects induced by postimpact hydrothermal fluids, which highlight its heterogeneous nature, related to the impact event, and mixing components from different pre-impact stratigraphic formations. The detection of partially dissolved exsolution lamellae in pyroxene and of related alteration products constrains the effects of hydrothermal alteration in the basalts of the Vargeão Dome, which could serve as a terrestrial analog for planetary studies.

Hydrothermal alteration at the Lonar Lake impact structure, India: Implications for impact cratering on Mars

2003 ◽  
Vol 38 (3) ◽  
pp. 365-381 ◽  
Author(s):  
Justin J. HAGERTY ◽  
Horton E. NEWSOM
Keyword(s):  
Hydrothermal Alteration ◽  
Impact Structure ◽  
Impact Cratering ◽  
Lonar Lake

Shock metamorphism and hydrothermal alteration of mafic impact ejecta from the Lockne impact structure, Sweden

GFF ◽  
2016 ◽  
Vol 139 (2) ◽  
pp. 119-128
Author(s):  
Axel S. L. Sjöqvist ◽  
Paula Lindgren ◽  
Erik F. F. Sturkell ◽  
K. Johan Hogmalm ◽  
Curt Broman ◽  
...  
Keyword(s):  
Hydrothermal Alteration ◽  
Shock Metamorphism ◽  
Impact Structure ◽  
Impact Ejecta

Putative fossil life in a hydrothermal system of the Dellen impact structure, Sweden

2010 ◽  
Vol 9 (3) ◽  
pp. 137-146 ◽  
Author(s):  
Paula Lindgren ◽  
Magnus Ivarsson ◽  
Anna Neubeck ◽  
Curt Broman ◽  
Herbert Henkel ◽  
...  
Keyword(s):  
Hydrothermal Alteration ◽  
Hydrothermal System ◽  
Hydrothermal Systems ◽  
Microbial Colonization ◽  
Early Earth ◽  
Impact Structure ◽  
Microbial Life ◽  
Fine Grained ◽  
Evolution Of Life ◽  
Alteration Minerals

AbstractImpact-generated hydrothermal systems are commonly proposed as good candidates for hosting primitive life on early Earth and Mars. However, evidence of fossil microbial colonization in impact-generated hydrothermal systems is rarely reported in the literature. Here we present the occurrence of putative fossil microorganisms in a hydrothermal system of the 89 Ma Dellen impact structure, Sweden. We found the putative fossilized microorganisms hosted in a fine-grained matrix of hydrothermal alteration minerals set in interlinked fractures of an impact breccia. The putative fossils appear as semi-straight to twirled filaments, with a thickness of 1–2 μm, and a length between 10 and 100 μm. They have an internal structure with segmentation, and branching of filaments occurs frequently. Their composition varies between an outer and an inner layer of a filament, where the inner layer is more iron rich. Our results indicate that hydrothermal systems in impact craters could potentially be capable of supporting microbial life. This could have played an important role for the evolution of life on early Earth and Mars.

scholarly journals Hydrothermal alteration in the core of the Yaxcopoil-1 borehole, Chicxulub impact structure, Mexico

2004 ◽  
Vol 39 (7) ◽  
pp. 1199-1221 ◽  
Author(s):  
Lukas ZüRCHER ◽  
David A. KRING
Keyword(s):  
Hydrothermal Alteration ◽  
Impact Structure ◽  
The Core ◽  
Chicxulub Impact

Hydrothermal alteration in the Bosumtwi impact structure: Evidence from 2M1-muscovite, alteration veins, and fracture fillings

2007 ◽  
Vol 42 (4-5) ◽  
pp. 655-666 ◽  
Author(s):  
Michael T. PETERSEN ◽  
Horton E. NEWSOM ◽  
Melissa J. NELSON ◽  
Duane M. MOORE
Keyword(s):  
Hydrothermal Alteration ◽  
Impact Structure
Sign in / Sign up

Export Citation Format

Share Document