Meteorites from the Lut Desert (Iran)

Abstract

We present for the first time a detailed report on the discovery of a new meteorite collection region in the Lut Desert, eastern–southeastern Iran, describing its geological, morphological, and climatic setting. Our search campaigns, alongside with the activity of meteorite hunters, yielded >200 meteorite finds. Here, we report on their classification, spatial distribution, and terrestrial weathering. All the collected meteorites are ordinary chondrites (OCs). The most abundant by far are the highly weathered paired H5 distributed in the northwest of Kalut area (central Lut, Kerman dense collection area). The second are well‐preserved paired L5 also found in Kalut region. A detailed study of the geochemistry and mineralogy of selected meteorites reveals significant effects of terrestrial weathering. Fe,Ni metal (hereafter simply metal) and troilite are transformed into Fe oxyhydroxides. A rather unusual type of troilite weathering to pyrite/marcasite is observed in most of the Lut Desert meteorites. Magnetic measurements and X‐ray diffractometry confirm the occurrence of terrestrial weathering products, with the dominance of maghemite, goethite, and hematite. Mobile elements, such as Li, Sr, Mo, Ba, Tl, Th, and U, are enriched with respect to fresh falls. Meanwhile, a decrease in the V, Cr, Co, Rb (and possibly Fe) due to terrestrial weathering is detectable. The total carbon and CaCO3 is higher than in samples from other hot deserts. The weathering effects observed in the Lut Desert OCs can be used as distinctive indicators to distinguish them from meteorites from other regions of the Earth. Measurements of terrestrial age (14C) show a range of 10–30 ka, which is in the range of ages reported for meteorites from other hot deserts except the Atacama Desert (Chile). Considering the high potential of the Lut Desert in meteorite preservation, systematic works should lead to the discovery of more samples giving access to interesting material for future studies.

On the footsteps of Théodore Monod: biogeographical and ecological implications of an insect assemblage from the hottest spot on earth (in central Lut Desert, SE Iran)

“…Iran displays a wide variety of bioclimates rang-up to about 80°C! Such extremely high temperatures have recently been confirmed by instrumental measurements which reveal 61 °C temperature in July 2014 (Pourkhorsandi et al, 2019). Most of the Lut Desert has been described as "abiotic" or at least "aphytic" due to the near absence of any visible sort of life (Dresch, 1968;Monod, 1973;Mobayen, 1976).…”

“…A data logger was installed in this site to record temperature and relative humidity over a year. The results are reported in Pourkhorsandi et al (2019).…”

“…in the supposedly "hottest spot on Earth" (Mildrexler et al, 2006(Mildrexler et al, , 2011. A Thermometer installed in near standard conditions of meteorological stations in 2014, recorded 61 °C in July 2014 suggesting that the soil temperatures exceeding 70 °C are quite possible (Pourkhorsandi et al, 2019).…”

The effects of terrestrial weathering on samarium‑neodymium isotopic composition of ordinary chondrites

“…During terrestrial weathering they alter to Fe oxyhydroxides (e.g., Pourkhorsandi et al, 2019). To study the possible effects of the meteorite find region on the trace elements and Sm-Nd isotopic composition, meteorites from the Asuka dense collection area (DCA) in Antarctica (Zekollari et al, 2019), the Atacama (Chile) (Drouard et al, 2019;Hutzler et al, 2016;Gattacceca et al, 2011) and Lut (Iran) (Pourkhorsandi et al, 2019) hot deserts were selected. In order to observe possible effects of (Fe,Ni) metal abundance and mineral chemistry on REE budgets during weathering, we chose members from both H and L groups, as well as LL for Antarctic samples.…”

The Kumtag Meteorite Strewn Field

“…To date, a large number of meteorites are found in many hot deserts worldwide. The regions include the Atacama (Muñoz et al 2007;Gattacceca et al 2011;Hutzler et al 2016), Sahara (Bischoff and Geiger 1995;Schluter et al 2002;Ouazaa et al 2009), Southwestern United States (Zolensky et al 1990; Rubin et al 2000;Kring et al 2001;Hutson et al 2013), the Lut Desert in Iran (Pourkhorsandi et al 2013(Pourkhorsandi et al , 2019, and the Xinjiang Province in China (Li et al 2014(Li et al , 2017Zeng et al 2018). Although large number meteorites from hot deserts have been studied over the years, there are only very few studies of meteorites from China.…”