On 27st June, 1994, at approximately 12 noon local time, a rock, weighing 1.477 kg and measuring 78 x 8.5 x 8 cm, struck a car, which was travelling south on the Madrid-Andalucia roed (Getafe city, south Madrid). This area is open country made up of marls, gypsum beds and claystones, without bridges or other high places from which the rock could have been thrown. The incident was spectacular. The rock impacted the car at about 30" from the horizontal and hit the steering wheel and the driver's right hand with such force that the steel wheel was deformed. This work constitutes the first contribution on the study of the Getafe rock (GR), displaying a detailed analyses of the trajectory of fall, effects of impact and morphotextural evidence of flight. The GR is a semi-oriented specimen (apex angle -75")) with an external scoriaceous texture which resembles either an industrial slag or the highly vesicular "scoriaceous-type" micrometeorites (AMI0 and M4) which were recovered in Antarctica. It does not appear to have fusion crust, although textural and colour differences exist between its external and internal parte. At least two different systems of friction striae as well as two types (milky and dark) of droplet-globules (700 m-500 m) were found scattered on its frontal, smooth surface. Sorne of these show presence of impact microcraters. Although the circurnstances surrounding the fall are very well documented and despite clear evidence of flight were found, the CR does not exactly match any of the previously classified meteorites nor any known rocks (terrestrial or extraterrestria).

4 páginas, 2 figuras.-- Trabajo presentado a la 26ª Sesión Científica, Ávila 1999.

Peer reviewed