Search for Impact Craters in Iran: Citizen Science as a Useful Method

To recognition probable impact craters in Iran, we use Google Earth data in the first step. Some probable structures identified and studies suggest non-impact origin for them. Studies on other craters in Iran are in progress.Comment: Large Meteorite Impacts and Planetary Evolution V (2013

Crystal size and shape distribution systematics of plagioclase and the determination of crystal residence times in the micromonzogabbros of Qisir Dagh, SE of Sabalan volcano (NW Iran)

The Qisir Dagh igneous complex occurs as a combination of volcanic and intrusive rocks to the south-east of the Sabalan volcano, north-western Iran. Micromonzogabbroic rocks in the region consist of plagioclase, alkaline feldspar and clinopyroxene as the major mineral phases and orthopyroxene, olivine, apatite and opaque minerals as the accessory minerals. Microgranular and microporphyritic textures are well developed in these rocks. Considering the importance of plagioclase in reconstructing magma cooling processes, the size and shape distribution and chemical composition of this mineral were investigated. Based on microscopic studies, it is shown that the 2-dimensional size average of plagioclase in the micromonzogabbros is 538 micrometers and its 3-dimensional shape varies between tabular to prolate. Crystal size distribution diagrams point to the presence of at least two populations of plagioclase, indicating the occurrence of magma mixing and/or fractional crystallization during magma cooling. The chemical composition of plagioclase shows a wide variation in abundances of Anorthite-Albite-Orthoclase (An = 0.31—64.58, Ab = 29.26—72.13, Or = 0.9—66.97), suggesting a complex process during the crystal growth. This is also supported by the formation of antiperthite lamellae, which formed as the result of alkali feldspar exsolution in plagioclase. The calculated residence time of magma in Qisir Dagh, based on 3D crystal size distribution data, and using growth rate G = 10—10 mm/s, varies between 457 and 685 years, which indicates a shallow depth (near surface) magma crystallization and subvolcanic nature of the studied samples

Asuka 12325: A new depleted shergottite

The Tenth Symposium on Polar Science/Special session: [OA] Antarctic meteorites, Thur. 5 Dec. / 3F Multipurpose conference room, National Institute of Polar Researc

A detailed record of the BELARE 2019－2020 meteorite recovery expedition on the Nansen Ice Field, East Antarctica

2019－2020 年の夏期に，東南極セール・ロンダーネ山地南部においてベルギー南極観測隊（BELARE）により隕石探査を実施した．ナンセン氷原には，2020 年1 月15 日から2 月6 日まで23 日間滞在し，採取した隕石の総数は66 個，合計重量は約8 kg であった．ナンセン氷原での隕石集積機構を解明するために，隕石の他に氷，火山灰層や岩石の破片も採取した．採取した隕石は，凍結したまま国立極地研究所に輸送された．これら採取した隕石が国際隕石学会の隕石命名委員会に認可された後，分類データはMeteorite Newsletter で公開される．This report summarizes the Belgian Antarctic Expedition (BELARE) 2019－2020 meteorite search and recovery expedition near the Sør Rondane Mountains of East Antarctica during the 2019－2020 field season. This expedition took place from 15 January to 6 February 2020 within the area defined as ＂C＂ of the Nansen Ice Fields (S72°38\u27−72°48\u27S, 24°35\u27−25°06\u27E). The expedition team consisted of four scientists and two field guides, who systematically searched the ice field area and collected 66 meteorites. The total weight of the meteorites was determined to be ～8 kg. In addition to meteorites, blue ice samples, volcanic ash layers, and wind-blown terrestrial rock fragments were collected from the area to study in detail the nature of the mechanisms concentrating meteorites on the Nansen Ice Fields. The recovered meteorites were transported in a frozen state to the National Institute of Polar Research, Japan for dry-thawing and subsequent classification

Meteorites of Iran

info:eu-repo/semantics/publishe

Quadrantid meteor shower observing report

info:eu-repo/semantics/publishe

Red rubies of sky, a telescopic guide to observing Carbon stars

info:eu-repo/semantics/publishe

Meteorites of Iran and hot deserts: classification and weathering

info:eu-repo/semantics/nonPublishe

What Draconids did? Results of Draconid meteor shower

info:eu-repo/semantics/publishe