Nogoya meteorite, Nogoya, Algarrobitos District, Nogoyá Department, Entre Ríos Province, Argentinai

Regional Level Types
Nogoya meteorite	Meteorite Fall Location
Nogoya	City
Algarrobitos District	District
Nogoyá Department	Department
Entre Ríos Province	Province
Argentina	Country

Classification: Carbonaceous Chondrite [CM2, S1]

The Nogoya meteorite fell on 30 June 1879 in Argentina. A single stone with a mass of 4 kg was recovered. The matrix is dominated by various phyllosilicates which have been altered by pre-terrestrial interactions with water. Nogoya itself has been classified as a CM2 (Mighei-like) Carbonaceous Chondrite. All carbonaceous chondrites have nearly solar Mg/Si ratios and roughly similar oxygen isotope ratios. In addition to some tighter chemical constraints, Nogoya and the other members of the CM chemical group are distinguished by small chondrules and inclusions, abundant fine-grained matrix (~70 vol%), and abundant hydrated minerals. The CM2 type is further characterized by their Ni-bearing sulfides. Nogoya has also been exposed to some moderate shock (Shock stage ‘S1’) either on its original homeworld or during its wanderings thru space after ejection from the homeworld.

Nogoya is the 2nd oldest and the 5th most massive of the 15 observed CM meteorite falls. In late 2013 the Meteorite Society’s homepage also listed over 400 recovered CM finds — all of them less massive than Nogoya. All CM falls have been classified as type CM2, but a few CM1 and CM-an types are recorded among the finds.

Occasional hints of presolar gases [usually within Nogoya’s inclusions] are important in current research. However, a good deal of current work with all CM Carbonaceous Chondrites is concerned with determining which chemical parameters and mineralogical features can be definitively assigned to preterrestrial processes instead of subsequent weathering. Much of this work — as with all phyllosilicates, terrestrial and otherwise — focuses on mineralogical intergrowths which are not easily described by conventional mineralogical terminology. In any case, in spite of Nogoya’s relatively well-preserved condition, it has not received as much attention as some of the larger CM2 falls.

Other Regions, Features and Areas containing this locality

References