A previously undescribed meteorite crater in Chile

Abstract

A previously undescribed meteorite crater having dimensions of 455 m average diameter and 31 m average depth has been discovered in northern Chile at 23ø55.6'S, 68ø16.7'W. Meteorites have not been recovered, but iron shale and impactite material verify its meteoritic origin. The crater is eraplaced in granite, overlain by a thin ignimbrite sheet. From the apparent disruption of the local Pleistocene drainage pattern, the age of formation of the crater must be Pleistocene or Recent. It may have been formed by the same meteoroid that created the Campo del Cielo craters in Argentina. The name Monturaqui crater is proposed.The diameter of the crater is 470 m E-W X 440 m N-S. The wall height is very variable, ranging from 16 to 48 m above the low point. The variable wall height was probably caused by topographic irregularities in the pre-impact surface. The low point, seen in the aerial photograph as a white spot of fine clay and silt, is off-center toward the northeast; thus the crater is somewhat asymmetric.

The Atacama Desert: A preferential arid region for the recovery of meteorites—Find location features and strewnfield distribution patterns

“…Later results were given by Fletcher (1889) and Philippi (1856Philippi ( , 1860. Most samples recovered at this time were donated to the Universidad de La Serena, La Serena (Chile) and, at present, make up one (Sa´nchez and Cassidy, 1966) and there was a renewed interest in meteoritics. Since 1980, the rediscovery of Imilac and Vaca Muerta strewnfields and the finding of the Pampa recovery site have reinvigorated the studies of meteorites from the Atacama Desert (Killgore, 1997;Pedersen et al, 1992;Zolensky et al, 1990;Rull and Martı´nez-Frı´as, 2003;Rull et al, 2004;Scorzelli et al, 2000;Wasson, 1992;Zolensky et al, 1995b).…”

An integrated geophysical and geological study of the Monturaqui impact crater, Chile

“…Monturaqui was first referred to as an impact crater by Sánchez and Cassidy (1966). Its dimensions, measured first by Buchwald (1975), are 350 × 370 × 34 m. Petrographic studies on impactite samples from the crater have been published by Bunch and Cassidy (1972).…”

“…5a) is characterized by a basement of Paleozoic granites (Tucucaro Pluton outcropping in the area, 441 ± 8 Ma [Ramirez and Gardeweg 1982]), overlain by Pliocene ignimbrite units (Tucucaro ignimbrite, 3.2 ± 0.3 Ma [Ramirez and Gardeweg 1982]). Previous studies in the area have presented only a general geomorphological (Manriquez 2001) and geological description (Sánchez and Cassidy 1966;Bunch and Cassidy 1972;Roeschmann and Rada 2000).…”

Early fracturing and impact residue emplacement: Can modelling help to predict their location in major craters?

“…The nature of an extraterrestrial body that has created a terrestrial impact crater through a hypervelocity impact can sometimes be determined by the collection of disrupted and shocked impactor as loose fragments or within small bodies of impact melt from the ground surface in and around the crater, e.g., iron meteorites from the vicinity of the Barringer crater, USA (Rinehart 1957); Henbury, Australia (Spencer and Hey 1933); Sikhote Alin, Siberia (Krinov 1966); meteoritic debris and impact glasses from Lonar, India (Frederiksson et al 1979); Wabar, Saudi Arabia (Spencer and Hey 1933); and Monturaqui, Chile (Sanchez and Cassidy 1966). Meteoritic debris may be found in sedimentary sequences deposited around oceanic impact events, e.g., from the Eltanin impact (SE Pacific), sampled from the deep sea (Kyte and Brownlee 1985;Kyte 2002).…”