@article{fdi:010085336,
  title = {{N}ova {C}olinas, {M}aranhao {S}tate : a newly confirmed, complex impact structure in {B}razil},
  author = {{R}eimold, {W}. {U}. and {F}erriere, {L}. and {C}rosta, {A}. {P}. and {V}asconcelos, {M}. {A}. {R}. and {G}ottwald, {M}. and da {S}ilva {B}orges, {M}. and de {A}lmeida, {T}. {I}. {R}. and {P}ereira, {F}. {L}. and {G}oes, {A}. {M}. and {H}auser, {N}. and {J}essell, {M}. and {B}aratoux, {D}avid},
  editor = {},
  language = {{ENG}},
  abstract = {{T}he {N}ova {C}olinas structure is an approximately 7 km wide, nearly circular feature centered at 07 degrees 09 ' 33 ' {S}/46 degrees 06 ' 30 ' {W} in {N}ova {C}olinas municipality in southwestern {M}aranhao {S}tate, {B}razil. {T}he area has been investigated for 40 yr and it has been suggested repeatedly that the structure could be of impact origin-without proof having been furnished. {M}agnetic anomaly maps depict the structure clearly with a strong, positive magnetic anomaly over the apparent rim zone. {T}he central area is characterized by significant positive {K} and {T}h radiometric anomalies. {F}ieldwork showed that the structure has annular features along the outside and some prominent, structurally dissected hills in the interior. {T}hirty-three arenite samples were collected for petrographic analysis, mostly from within the structure. {M}icrodeformation, in the form of cataclasis; concussion fractures related to compaction, and presence of planar fractures, feather features, and planar deformation features in quartz are reported. {T}hree samples with a multitude of quartz grains with these microdeformations were analyzed by universal stage to determine the crystallographic orientations of planar fractures and planar deformation features. {T}he results provide robust evidence that these microdeformation features represent shock metamorphism, with low (approximately 5-10 {GP}a) to moderate (10-16 and 10-20 {GP}a) shock levels. {T}hus, the {N}ova {C}olinas structure is now confirmed as a bona fide meteorite impact structure. {T}he structure is moderately eroded, as shown by the absence of stronger shock deformation. {T}he still limited available structural geological field evidence, paired with remote sensing and geophysical data, indicates that the innermost part of the structure may have a sizable remnant of a central uplift. {T}he {N}ova {C}olinas impact age is only poorly constrained from stratigraphic inference to an upper limit of about 200-250 {M}a.},
  keywords = {{BRESIL} ; {MARANHAO} {ETAT}},
  booktitle = {},
  journal = {{M}eteoritics and {P}lanetary {S}cience},
  volume = {[{E}arly access]},
  numero = {},
  pages = {[23 ]},
  ISSN = {1086-9379},
  year = {2022},
  DOI = {10.1111/maps.13833},
  URL = {https://www.documentation.ird.fr/hor/fdi:010085336},
}