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Chinese Science Bulletin, Volume 65, Issue 10: 948-954(2020) https://doi.org/10.1360/TB-2019-0704

Yilan crater, a newly identified impact structure in northeast China

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  • ReceivedNov 3, 2019
  • AcceptedDec 5, 2019
  • PublishedDec 24, 2019

Abstract

This study reports the discovery of Yilan crater, a newly identified impact structure in northeast China. The crater has a rim-to-rim diameter of 1.85 km, and is located in Yilan County of Heilongjiang Province. The latitude and longitude coordinates of the crater are 46°23′03″N and 129°18′40″E, respectively. The crater lies in a low mountainous and hilly area of the southwest border of the Xiaoxinganling mountain range. Most of the crater is covered with dense forests. Geotectonically, the area belongs to the eastern Central Asian Orogenic Belt where strong tectonic and magmatic activities have occurred since the late Proterozoic. The crater was entirely formed within the bedrock of Cretaceous granite and appears as a bowl-shaped structure. Approximately one-third of the southern part of the crater rim has been significantly eroded and mostly removed; otherwise, most of the crater rim is well preserved. In a panoramic view, the crater appears as an unclosed ring mountain surrounding a circular depression, and it has steep walls and a relatively flat floor. The crater rim raises approximately 70–120 m above the surrounding terrain. The maximum elevation of the crater rim over the present crater floor is approximately 150 m. Most of the crater rim is composed of granite impact breccia varying from granules to boulders in size. The crater’s interior has been filled by a large amount of granite impact breccia at the bottom and lacustrine deposits at the top. The target rock of granite contains abundant quartz. This study investigated the planar deformation features (PDFs) in the quartz, which is one of the commonest shock metamorphic features in numerous terrestrial impact structures. For the investigation, granite impact breccia was collected from the crater floor. Most of the samples were made into polished thin sections for identifying the PDFs in quartz. Some fine-grained fragments of quartz were also collected from the samples for observation and analysis. The crystallographic orientations of the quartz PDFs were observed on a 4-axis universal stage under an optical microscope. No PDFs in quartz were observed in the quartz of large granite breccia fragments, but many PDFs appeared in the quartz of the fine-grained samples. One to four sets of PDFs in quartz were observed. The forms of the PDFs with Miller indices, such as (0001), {101¯1} and {101¯3}, were indexed. The observed multiple sets of PDFs in quartz provide unambiguous evidence of shock-metamorphism and confirm an impact origin of the structure. The topographic and structural features of the crater, as well as the occurrences of crater-filled materials (impact breccia and lacustrine deposits), characterize a bolide impact site. Based on 14C dating of the lacustrine deposits from the crater floor, the Crater Lake disappeared approximately 10 ka ago; this disappearance can be related to the loss of crater rim in the southern part of the crater. The large-scale absence of the crater rim cannot be explained by tectonic activity, normal weathering, or erosional process, and must correspond to directional erosion caused by a specific exogenic geological process after the formation of the impact crater. The geologic agent, mechanism, and history of the strong erosion of the crater rim require further investigation. The Yilan crater is the second confirmed impact structure in a large country (China) with an area of 9.6 million square kilometers.


Funded by

中国科学院B类战略性先导科技专项(XDB18010405)

国家自然科学基金(41672032,41921003)

中国科学院广州地球化学研究所所长基金(2019)


Acknowledgment

黑龙江省依兰县人民政府协助该项研究. 依兰县文体广电和旅游局徐立星、王本昆、孙大成和李美洪,以及依兰县迎兰乡郭洪涛和李凤民协助了部分野外地质调查工作. 中国科学院广州地球化学研究所曹裕波对研究提出了建设性意见. 中国科学院广州地球化学研究所丁平完成14C年代测定.


References

[1] The University of New Brunswick, Canada. Earth Impact Database. http://www.passc.net/EarthImpactDatabase/New%20website_05-2018/Index.html, 2018. Google Scholar

[2] Chen M. Impact-derived features of the Xiuyan meteorite crater. Chin Sci Bull, 2008, 53: 392-395 CrossRef Google Scholar

[3] Xu X, Kenkmann T, Xiao Z, et al. Reconnaissance survey of the Duolun ring structure in Inner Mongolia: Not an impact structure. Meteorit Planet Sci, 2017, 52: 1822-1842 CrossRef Google Scholar

[4] Chen M, Xiao W S, Xie X D, et al. Xiuyan crater, China: Impact origin confirmed. Chin Sci Bull, 2010, 55: 1777-1781 CrossRef Google Scholar

[5] McCall G J H. Impact crater breaks China duck. Geoscientist, 2012, 22: 8−9. Google Scholar

[6] Chao E C T. Shock effects in certain rock-forming minerals. Science, 1967, 156: 192-202 CrossRef PubMed Google Scholar

[7] Stöffler D, Langenhorst F. Shock metamorphism of quartz in nature and experiment: I. Basic observation and theory. Meteoritics, 1994, 29: 155-181 CrossRef Google Scholar

[8] Grieve R A F, Langenhorst F, Stöffler D. Shock metamorphism of quartz in nature and experiment: II. Significance in geoscience. Meteorit Planet Sci, 1996, 31: 6−35. Google Scholar

[9] French B M. Traces of Catastrophe: A Handbook of Shock-metamorphic Effects in Terrestrial Meteorites Impact Structure. LPI Contribution 954. Houston, Texas: Lunar and Planetary Institute, 1998. Google Scholar

[10] Koeberl C. Mineralogical and geochemical aspects of impact craters. Mineral Mag, 2002, 66: 745-768 CrossRef Google Scholar

[11] Ferrière L, Morrow J R, Amgaa T, et al. Systematic study of universal-stage measurements of planar deformation features in shocked quartz: Implications for statistical significance and representation of results. Meteorit Planet Sci, 2009, 44: 925–940. Google Scholar

[12] Xu X, Trumbore S E, Zheng S, et al. Modifying a sealed tube zinc reduction method for preparation of AMS graphite targets: Reducing background and attaining high precision. Nucl Instrum Methods Phys Res Sect B-Beam Interact Mater Atoms, 2007, 259: 320-329 CrossRef Google Scholar

[13] Windley B F, Alexeiev D, Xiao W, et al. Tectonic models for accretion of the Central Asian Orogenic Belt. J Geol Soc, 2007, 164: 31-47 CrossRef Google Scholar

[14] Heilongjiang Geological Bureau. Yilan Geological Map (L-52-XVI, 1:200000) (in Chinese). Regional Geological Investigation Reports, 1972 [黑龙江省地质局. 依兰幅地质图(L-52-XVI, 1:200000). 区域地质调查报告, 1972]. Google Scholar

[15] Trepmann C A, Spray J G. Shock-induced crystal-plastic deformation and post-shock annealing of quartz: Microstructural evidence from crystalline target rocks of the Charlevoix impact structure, Canada. Eur J Mineral, 2006, 18: 161-173 CrossRef Google Scholar

[16] Fredriksson K, Dube A, Milton D J, et al. Lonar Lake, India: An impact crater in basalt. Science, 1973, 180: 862-864 CrossRef PubMed Google Scholar

[17] Chen M, Koeberl C, Xiao W, et al. Planar deformation features in quartz from impact-produced polymict breccia of the Xiuyan crater, China. Meteorit Planet Sci, 2011, 46: 729-736 CrossRef Google Scholar

[18] Wurster C M, Bird M I, Bull I D, et al. Forest contraction in north equatorial Southeast Asia during the Last Glacial Period. Proc Natl Acad Sci USA, 2010, 107: 15508-15511 CrossRef PubMed Google Scholar

[19] Jin C Z, Xu Q Q, Zheng J J. On the dispersal events of Mammuthus during the Late Late Pleistocene (in Chinese). Vert PalAs, 1998, 36: 47−53 [金昌柱, 徐钦琦, 郑家坚. 中国晚更新世猛犸象(Mammuthus)扩散事件的探讨. 古脊椎动物学报, 1998, 36: 47−53]. Google Scholar

[20] Hao Z G, Fei H C, Hao Q Q, et al. China has built a Mammoth museum. Acta Geol Sin, 2016, 90: 1039-1040 CrossRef Google Scholar

  • Figure 1

    Schematic geological map of Yilan crater after Yilan Geological Map (1:200000)[14]. 1, Permian alkali-feldspar granite; 2, cretaceous alkali-feldspar granite; 3, granite breccia; 4, quaternary soil; 5, quaternary alluvial deposits; 6, position of Yilan crater

  • Figure 2

    Images of Yilan crater. (a) A panoramic photograph of the crater. Most regions of the crater are covered with dense forests; (b) a satellite image of the crater (taken on 7 December 2013) from Google Earth; (c) a hypsographic map. The red dashed circle on the map indicates the position of Yilan crater

  • Figure 3

    Crater-filled breecia. (a) An artificial groove 60 cm in depth on the surface of crater floor discloses a number of fragments of granite which were covered by a thin layer of soil, where is 100 m to the crater wall; (b) fresh fragments of granite

  • Figure 4

    PDFs-bearing granite and quartz clasts. (a) A granite clast containing quartz grains with one set of PDFs parallel to (0001) (running NE-SW) under plane-polarized light; (b) a quartz clast containing two sets of PDFs (running NE-SW and NNW-SSE) under plane-polarized light; (c) a quartz clast containing three sets of PDFs (running NW-SE, N-S and NEE-SWW) under plane-polarized light; Qz, quartz; Fsp, feldspar

  • Figure 5

    PDFs in quartz observed under cross-polarized optical microscope. (a) One set of PDFs parallel to {101-3}; (b) two sets of PDFs parallel to {101-3}

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