Journal Pre-proof

First finding of impact cratering in the Korean Peninsula

Jaesoo Lim, Sei-Sun Hong, Min Han, Sangheon Yi, Sung Won Kim

PII: S1342-937X(20)30310-5 DOI: https://doi.org/10.1016/j.gr.2020.12.004 Reference: GR 2459

To appear in: Gondwana Research

Received date: 14 November 2020 Revised date: 27 November 2020 Accepted date: 2 December 2020

Please cite this article as: J. Lim, S.-S. Hong, M. Han, et al., First finding of impact cratering in the Korean Peninsula, Gondwana Research (2020), https://doi.org/10.1016/ j.gr.2020.12.004

This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

© 2020 Published by Elsevier. Journal Pre-proof

First finding of impact cratering in the Korean Peninsula

Jaesoo Lima, Sei-Sun Honga, Min Hana, Sangheon Yia, Sung Won

Kima,* [email protected] aGeology Division, Korea Institute of Geoscience and Mineral Resources,

Daejeon, 305-350, Republic of Korea

*Corresponding author.

Abstract

The 7 km-diameter Jeokjung–Chogye Basin in Hapcheon, southeastern Korean Peninsula, is well-known for its bowl-shaped geomorphology. Here we report the first direct evidence of impact cratering from this basin based our investigations on a 142 m-deep core. The lithological units could be divided into soil-channel sediments (0~6.2 m), lacustrine sediments with fine silt-clayey lamination (6.2~72 m), and impact (72~142 m). We report for the first time, unique impact- driven metamorphic features, including shatter cones at 130 m and planar deformation features (PDFs) in quartz grains from the impact breccia. Based on the radiocarbon dates of charcoals in the lacustrine sediments, we estimate that the impact likely happenedJournal during the last glacialPre-proof period, although further confirmation using other dating techniques is awaited. This relatively young crater provides a rare opportunity to reconstruct high-resolution paleoclimate changes recorded in laminated lacustrine sediments, and to investigate in a location that experienced significant surficial weathering and erosion under a tropical–temperate climate.

Keywords: ; ; Planar deformation features, PDFs; Impact breccia, Jeokjung–Chogye Basin, Korean Peninsula

Journal Pre-proof

1. Introduction

Impact cratering, once considered a minor astronomical process, is now known to be an important terrestrial event with major impacts on the geological and biological history of the Earth (French, 1998; Schmieder and Kring, 2020). For example, about 65 mya, the 180-km-diameter , in Yucatan, Mexico was produced by impact that changed the course of evolution on Earth. This event at the Cretaceous–Tertiary boundary led to the mass extinction of dinosaurs and resulted in mammals becoming major players in terrestrial life (Hildebrand et al., 1991; Kring, 1995 and 2007a; Schulte et al., 2010).

The discovery of impact craters has been facilitated by the identification of petrological and geochemical features corresponding to the distinctive shock- metamorphic effects, where rocks and minerals are affected by the intense impact- driven shock waves (Dietz, 1959; Roddy and Davis, 1977; Stöffler, 1984; Gibson and Spray, 1998; Wieland et al., 2006; Fackelman et al., 2008; Li et al., 2018). Unlike the static load pressure produced by the weight of overlying rock, which is generally less than a few gigapascals (GPa), the transient pressure on rocks due to the typical impact velocity of tens of km/s may exceed 500 GPa at the impact point, and may be as high as 10–50 GPa throughout large volumes of surrounding rock. Furthermore, high shock pressure (> 50 GPa) may produce high temperatures (> 2,000℃), causing largeJournal-scale melting after Pre-proof the shock wave has passed (Stöffler, 1984; French, 1998; Stöffler et al., 2018). These physical effects, and extremely high pressures and temperatures, lead to mineral deformation and melting of the rocks, and serve as markers of impact craters.

Shock-metamorphic effects can be divided into four types based on increasing shock pressure: mechanical deformation, phase transformation, decomposition, and melting (French, 1998; Stöffler et al., 2018). Microscopic shock-produced deformation features include: (1) kink bands in micas, (2) planar deformation

Journal Pre-proof

features (PDFs) in quartz, feldspar, and other minerals, (3) isotropic (diaplectic or thetomorphic) mineral glasses mainly derived from quartz and feldspar, without any actual melting, and (4) selective melting of individual minerals (French, 1998; Gurov and Koeberl, 2004; Fackelman et al., 2008; Ferrière, et al., 2010; Stöffler et al., 2018). On a megascopic (hand specimens to outcrop) scale, shatter cones are the only distinct shock-deformation fractures. Shatter cones are partial-to-complete cones characterized by distinct curved and striated fractures (Dietz, 1959; Roddy and Davis, 1977; Gibson and Spray, 1998; Baratoux and Melosh, 2003; Wieland et al., 2006; Fackelman et al., 2008; Baratoux and Reimold, 2016). Shatter cones have been found in rocks below crater floors, usually in the central uplift area and rims of complex impact craters, and in breccia dikes and crater-fill impact melt rock (Osinski and Ferrière, 2016).

According to Schmieder and Kring (2020), 200 craters have been confirmed worldwide, although the Xiuyan Crater in China is the only one reported in the East Asia continent (Chen et al., 2010). The very small number of craters in the East Asia continent may be due to their complex geological features, including significant tectonic deformation, igneous intrusions, and volcanic eruptions (e.g., Kim et al., 2016 and 2017; Yang et al., 2018; Kim et al., 2020), and to the tropical–temperate climate causing marked surface weathering and erosion.

Here, we report for the first time, the microscopic (PDFs) and megascopic (shatter cones) evidence for impactJournal cratering in thePre-proof Korean Peninsula, based on investigations on samples from a 142 m-long core drilled in the Jeokjung–Chogye Basin, southeastern Korean Peninsula.

2. Study area and methods

The study basin and coring site (35°32'57.02"N, 128°16'7.59"E) in the towns of Jeokjung and Chogye, Hapcheon-gun, in the southeastern Korean Peninsula are

Journal Pre-proof

located near the middle reach of the Nakdong River, and is famous for its bowl- shaped landscape (Fig. 1). This remarkable ring-like depression measures 6~8 km from rim to rim. As shown by satellite images, the difference in relief of the west and east rims from the floor is ~600 and ~200 m, respectively.

As shown in Fig. 1, the study area is dominantly composed of the Dongmyeong (DMF), Chilgog (CGF), and Silla conglomerate (SCF) formations, which are Cretaceous and Mesozoic formations of non-marine origin (Chang, 1968; Kim and Lee, 1969). The DMF surrounding most of the basin consists of grey to greenish grey sandstone and shale, dark grey to shale, sandy shale, line nodules, a thin limestone bed, grey mudstone and conglomerate. The -thick (up to 800m) CGF contains purple shale and sandstone, greenish grey to dark grey, greenish sandstone, grey to dark grey shale, sandy shale, mudstone, lime nodules, thin limestone beds, and conglomerate. The 100~350 m-thick SCF is distributed in the southeast area of the map shown in Fig. 1, and is composed mainly of purple and greyish brown conglomerate, conglomeratic sandstone, sandy conglomerate with intercalations of greyish brown or purple mudstone, greyish brown sandstone, sandy shale, purple and grey shale, and grey siltstone. The SCF is characterized by purple-colored beds and subrounded to rounded pebbles. Unlike the SCF and CGF, the DMF shows remarkable intercalations of dark grey to black shale, and no purple shale (Chang, 1968; Kim and Lee, 1969). The formation of the JeokjungJournal–Chogye Basin Pre-proof in the southeastern Korean Peninsula has been discussed in terms of differential erosion (Son, 2000), a meteorite impact (based on a gravity survey; Choi et al., 2001 and 2004), and bedrock weathering along fault lines due to ground motion (Hwang and Yoon, 2016). However, the origin of this basin remains equivocal and required confirmation through a careful lithological study using a drill core in the inner basin. A recent study based on the seismic response to a microtremor in the basin suggested that there is ~100 m of sediment in the basin (Lee et al., 2017). Based on the estimated thickness, we selected a drilling point and then drilled a borehole, named core CR05 (35°32'57.02"N, 128°16'7.59"E), to 142 m depth inside the crater to collect underground lithologic information. The sedimentary core was recovered using a rotary corer, which returns 1 m-long, 50 mm-diameter core samples

Journal Pre-proof

in a plastic liner through continuous coring. Figure 2 shows selected photographs of the drilled core.

To determine the deposition age of the sediments in the core, charcoal in the lacustrine sediments was used for radiocarbon dating, and the analysis was performed at the accelerator mass spectrometry facility of the Korea Institute of Geoscience and Mineral Resources (KIGAM). The details of analytical techniques are given in Supplementary Appendix File. The dating results are shown in Table 1 and Fig. 3.

3. Results and discussion

3.1. Implications of the lithologic information for impact cratering

To understand basin formation, it is important to characterize the geological structure and obtain stratigraphic information from the basin using drilled cores. After the forms a crater, the crater is immediately filled, probably up to half of its original depth, by a mixture of redeposited (fallback) ejecta and debris slumped in from the walls (French, 1998; Keerthy et al., 2019). This crater-filling unit is called a breccia lens; crater-fill breccia consists of rock fragments, or lenses, of shock-melted rock (impact melt). The crater-fill breccia may then be covered by subsequent sedimentary deposits.

As shown in Figs. 2 andJournal 3, the lithologic Pre-prooffeatures of the recovered core can be divided into four units. In ascending order, Unit 1 (142–72 m) is characterized by brecciated basement rocks consisting of fragments of grey and greenish grey sandstone and shale, dark grey to black shale, sandy shale, grey mudstone, and conglomerate. There are no purple fragments in this polymictic breccia, suggesting that it was formed from the bedrock of the DMF. Unit 2 (72–60 m) is characterized by lake deposits with very fine laminations, showing clear alternation of light- greyish clay and sandy-grained layers partly with rock clasts. Unit 3 (60–6.2 m)

Journal Pre-proof

characterized by a remarkable laminated sequence consisting of alternating layers of grey fine sand and dark-grey fine silt with micro- to macro-plant fragments (mainly charcoals). Interestingly, Units 2 and 3 have features indicating considerable depth of water and suggesting a clear lacustrine origin, which could account for the fine laminations. This suggests that the basin was closed hydrologically during the period of deposition of Units 2 and 3. The transition from Unit 3 to 4 is sharp, and seems to have resulted from rapid coverage by gravels via stream flooding. This suggests a rapid drop in the lake water level occurred. Unit 4 (6.2–0 m) shows mainly subaerial deposits consisting of a mixture of grey to brown clayey silt and gravel sediments, including organic layers.

Although we lack information on fractured bedrock, the sedimentary records of core CR05 are very similar to those observed in other impact craters with similar diameters. The 1.13 km-diameter Pretoria Saltpan Crater in South Africa shows 90 m of lacustrine crater sediments, with a few debris flows underlain by 53 m-thick unconsolidated fragmental breccia consisting of granitic sand intercalated with fractured granite boulders (Reimold et al., 1992), whereas the 1.2 km-diameter Crater in the USA has 200-m-thick breccia (Kring, 2007). In China, the 1.8- km-diameter Xiuyan Crater is characterized by a 188-m-thick breccia lens overlying 107 m-thick lacustrine sediments (Chen et al., 2010). The 1.83 km-diameter Lonar Crater in India has ~100 m of lake sediments and underlying breccia more than ~300 m thick (FredrikssonJournal et al., 1977). ComparedPre-proof with these breccia units, the at least 70 m-thick crater-fill breccia discussed in the current study can be considered as evidence of impact cratering on the Jeokjung–Chogye Basin. The upper lacustrine units suggest that the crater structure remained stable, with a high water level, during deposition of the 66 m-thick lake sediments.

3.2. Microscopic evidence for impact cratering

Journal Pre-proof

Although we found an impact lens in the drilled core that is very similar to those reported in previous studies, it is necessary to confirm impact cratering based on shock metamorphic effects. Shock waves during impact cratering lead to microscopic deformation of quartz and mica (French, 1998; Stöffler et al., 2018).

It has been suggested that PDF is clearly distinct from the deformation features produced in quartz by nonimpact processes, such as cleavage or tectonic (metamorphic) deformation lamellae (French, 1998; Gurov and Koeberl, 2004; Fackelman et al., 2008; Ferrière, et al., 2010; Chen et al., 2010; French and Koeberl, 2010; Stöffler et al., 2018). As shown in Fig. 4, quartz grains at depths of 86 and 142 m show clear PDF. The observed PDF seems to have been altered, showing distinct and discontinuous small fluid inclusions. These inclusions in the PDF have been attributed to recrystallization of the original amorphous material in the PDF, called decorated PDF (Stöffler and Langenhorst, 1994; French, 1998). Notably, the quartz grains found at 86 m show at least two prominent sets of decorated PDFs, as indicated by the arrows (Fig. 4). These deformation effects correspond to 15~35 GPa (French, 1998; Stöffler et al., 2018). In addition to PDF in quartz, kink bands may suggest a shock impact. Kinking is a deformation mode commonly seen in minerals with a sheet structure, such as muscovite and biotite. Kink bands were found frequently in our study because mica is common in the base rock in the basin. For example, Fig. 5 shows kink band deformation in muscovite grains in the breccia. Journal Pre-proof

3.3. Megascopic evidence for impact cratering

Shatter cones are a distinct shock-metamorphic feature that can be found in hand specimens and outcrops. Shatter cones can form in all kinds of rock, including sandstone, shale and carbonates. More delicate, well-formed cones form in fine- grained rocks (French, 1998; Fackelman et al., 2008; Ferrière, et al., 2010; French and Koeberl, 2010; Stöffler et al., 2018). Recently, Osinski and Ferriere (2016) suggested

Journal Pre-proof

that shatter cones can be found in several stratigraphic settings within and around impact structures, such as in the central uplifts and rims of complex impact craters, and in breccia dikes and crater-fill impact melt rock.

As shown in Fig. 6, shatter cones were observed in the 6-cm-long shale clast which we found at 130 m depth of the drilled core, and are characterized by striated fractures that typically form partial to complete cones. The surface striations are directional, and form a distinct pattern in which the acute angle of the intersection points toward the apex of the cone. Interestingly, the shatter cones point upward, and their axes lie at a high angle relative to the bedding of the shale clast. These findings are consistent with the features reported in several studies (Dietz, 1959; Roddy and Davis, 1977; Gibson and Spray, 1998; Wieland et al., 2006; Fackelman et al., 2008; Osinski and Ferrière, 2016).

Previous studies reported that shatter cones form under relatively low shock pressures of 2~10 GPa in a large volume of rock below the crater floor (French, 1998; Stöffler et al., 2018). In this study, shatter cones were found at 130 m depth, included the crater-filling breccia. This suggests that the shock pressure around this depth was at least 2~10 GPa during the impact cratering.

3.4. Estimation of impact event age based on radiocarbon dates

In this study, a possibleJournal impact age for thePre-proof cratering in the study area was estimated by radiocarbon dating of charcoal in the lacustrine sedimentary cores. Previous studies estimated impact events using organic matter in lacustrine sediments in the Xiuyan Crater in China (Liu et al., 2013), and charcoals emplaced within proximal ejecta blankets in Estonia (Losiak et al., 2016 and 2020).

It is clear that after impact cratering, the crater surface was covered by -fall breccia, forming the base of the post-impact sediment. As shown in Fig. 3, fine laminated lacustrine sediments (Unit 2) overlying the impact breccia (Unit 1) were

Journal Pre-proof

deposited by rainfall or debris slumped in from the steep crater rim. 14C dating revealed that the dates of the charcoals were not consistent with depth (Table 1, Fig. 3). The lacustrine sediments at 51.3~31.9 m depth seem to have been deposited between 44,000~53,400 yr. BP, giving a sedimentation rate of 2.11 mm/y. If we apply this sedimentation rate before and after this period, the lake environment in the basin seems to have formed roughly between 30,000 and 63,000 yr. BP. Based on these ages, the impact event responsible for the underlying impact breccia might have occurred before 63,000 yr. BP, during the last glacial period or late Pleistocene. This age should be considered as the maximum age for the impact crater because: (1) the sedimentation rate would have been steeper around the base of the post-impact sediment; and (2) it is possible that previously deposited charcoals were reworked during the impact event. The impact age needs to be verified using other methods, for example U-Pb and Ar–Ar dating (e.g., Schultz et al., 2004; Young et al., 2013; Biren et al., 2019; Jourdan et al., 2019). However, it is likely that the impact cratering forming the present Jeokjung–Chogye Basin occurred during the last glacial period, at the end of the late Pleistocene, indicating that it is relatively young crater.

4. Conclusion

The presence of unique impact-driven metamorphic features is required to confirm an impact origin. In thisJournal study, we report Pre-proof for the first time, shatter cones and PDF in quartz grains from a drilled core, providing the first robust evidence for impact cratering from the Korean Peninsula. Our study suggests that the Jeokjung–Chogye Basin in the southeastern Korean Peninsula was formed by an impact event, and not by differential erosion or bedrock weathering along fault lines due to ground motion. The sedimentary records recovered in this study are interpreted in terms of impact-filling breccia and subsequent lacustrine sediments. Based on the

Journal Pre-proof

radiocarbon dates of charcoals in the lacustrine sediments, the impact forming this basin is estimated to have occurred at the end of the late Pleistocene.

The Jeokjung–Chogye Basin, with its signs of impact metamorphic effects, provides a rare opportunity to investigate shock metamorphism in a location where the tropical–temperate climate has caused significant surface weathering and erosion. The laminated lacustrine sediments preserved in the basin serve as a rare archive of high-resolution paleoclimate changes in the East Asian continent.

Acknowledgements

We thank GR Associate Editor Prof. Andrea Festa and two anonymous referees for their comments. This research was supported by the Basic Research Project (GP2020-003), entitled ―Geological survey in the Korean Peninsula and publication of the geological maps‖ of the Korea Institute of Geoscience and Mineral Resources (KIGAM). We are grateful to Mr I.K. Cha for his valuable contribution to the core drilling. We also thank Prof. M. Santosh for help, valuable comments, and support.

Credit author statement

Data curation, investigation, writing original draft

Funding acquisition, visualization, supervision, writing original draft, review and editingJournal Pre-proof Jaesoo Lim: data curation, investigation, writing original draft

Sei-Sun Hong: data curation, investigation

Min Han: S: data curation, investigation angheon Yi: data curation, investigation

Sung Won Kim: funding acquisition, review and editing

Journal Pre-proof

Declaration of interests

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

References

Baratoux, D., Melosh, H. J., 2003. The formation of shatter cones by shock wave interference during impacting. Earth and Planetary Science Letters, 216, 43-54.

Baratoux, D., Reimold, W. U., 2016. The current state of knowledge about shatter cones: Introduction to the special issue. Meteoritics & Planetary Science 51, 1389- 1434.

Biren, M. B., Wartho, J. A., Van Soest, M. C., Hodges, K. V., Cathey, H., Glass, B. P.,

Koeberl, J.W., Horton, Jr., Hale, W., 2019. (U‐Th)/He zircon dating of Chesapeake Bay distal impact ejecta from ODP site 1073. Meteoritics & Planetary Science 54, 1840- 1852.

Chang, K. H., 1968, Explanatory text of the geological map of Habcheon sheet (1:50,000), Geological Survey of Korea, 21p (in Korean with English summary). Chang, J. H., 2002, GraniteJournal Erosion Landforms Pre-proof of Korea, Chen, M., Xiao, W., Xie, X., Tan, D., Cao, Y., 2010. Xiuyan crater, China: Impact origin confirmed. Chinese Science Bulletin 55, 1777-1781.

Choi, K.-S., Lee, S.-W., Lee, Y.-A., 2001, Circular landform and basin of the Chogye·Jeokjung area in Hapcheon-gun, 2001 Fall Conference of the Geological Society of Korea (in Korean).

Choi, K.-S., Lee, S.-W., Lee, Y.-S., 2004. A study on the sub-stratum structure in and around the Chogye-myon and Jukjung-myon of Hapchun-gun by gravity analysis,

Journal Pre-proof

The Journal, College of Education, Pusan National University, 43, 201-227 (in Korean with English abstract).

Dietz, R. S., 1959. Shatter cones in structures (meteorite impact?). The Journal of Geology 67, 496-505.

Fackelman, S. P., Morrow, J. R., Koeberl, C., McElvain, T. H., 2008. Shatter cone and microscopic shock-alteration evidence for a post-Paleoproterozoic terrestrial near Santa Fe, New Mexico, USA. Earth and Planetary Science Letters 270 290-299.

French, B. M., 1998. : A handbook of shock-metamorphic effects in terrestrial meteorite impact structures. Lunar and Planetary Institute.

Fredriksson, K., Dube, A., Milton, D. J., Balasundaram, M. S., 1973. Lonar Lake, India: An impact crater in basalt. Science 180, 862-864.

French, B. M., Koeberl, C., 2010. The convincing identification of terrestrial meteorite impact structures: What works, what doesn't, and why. Earth-Science Reviews 98, 123-170.

Ferrière, L., Raiskila, S., Osinski, G. R., Pesonen, L. J., Lehtinen, M., 2010. The Keurusselkä impact structure, Finland—Impact origin confirmed by characterization of planar deformation features in quartz grains. Meteoritics & Planetary Science 45, 434-446. Journal Pre-proof

Garde, A. A., Søndergaard, A. S., Guvad, C., Dahl-Møller, J., Nehrke, G., Sanei, H., Weikusat, C., Funder, S., Kjær, K.H., Larsen, N. K., 2020. Pleistocene organic matter modified by the Hiawatha impact, northwest Greenland. Geology 48, 867-871.

Gibson, H. M., Spray, J. G., 1998. Shock‐induced melting and vaporization of shatter cone surfaces: Evidence from the Sudbury impact structure. Meteoritics & Planetary Science 33, 329-336.

Journal Pre-proof

Gurov, E. P., Koeberl, C., 2004. Shocked rocks and impact glasses from the El'gygytgyn impact structure, Russia. Meteoritics & Planetary Science 39, 1495-1508.

Hildebrand, A. R., Penfield, G. T., Kring, D. A., Pilkington, M., Camargo Z, A., Jacobsen, S. B., Boynton, W. V., 1991. Chicxulub crater: a possible Cretaceous/Tertiary boundary impact crater on the Yucatan Peninsula, Mexico. Geology, 19(9), 867-871.

Hong W, Park JH, Kim KJ,Woo HJ, Kim JK, Choi HK, Kim GD. 2010a. Establishment of chemical preparation methods and development of an automated reduction system for AMS sample preparation at KIGAM. Radiocarbon 52(3), 1277–1287.

Hong W, Park JH, Sung KS, Woo HJ, Kim JK, Choi HW, Kim GD. 2010b. A new1MV AMS facility at KIGAM. Radiocarbon 52(2), 243–251.

Hwang, S., Yoon, S. O., 2016. Geomorphic development of the Jeogchung· Chogye Basin and inner alluvial fan, Hapcheon, South Korea. Journal of the Korean association of regional geographers 22, 225-239 (in Korean with English abstract).

Jourdan, F., Nomade, S., Wingate, M. T., Eroglu, E., Deino, A., 2019. Ultraprecise age and formation temperature of the Australasian constrained by 40Ar/39Ar analyses. Meteoritics & Planetary Science 54, 2573-2591.

Keerthy, S., Vishnu, C. L., Li, S. S., Reshma, N., Praveen, M. N., Oommen, T., Singh, S.P., Sajinkumar, K. S.,Journal 2019. Reconstructing Pre-proof the dimension of Dhala Impact Crater, Central India, through integrated geographic information system and geological records. Planetary and Space Science 177, 104691.

Kim, K.W., Lee, Y.J., 1969. Explanatory text of the geological map of Changryeong sheet (1:50,000), Geological Survey of Korea, 18p (in Korean with English summary).

Kim, S. W., Kwon, S., Park, S. I., Lee, C., Cho, D. L., Lee, H. J., Ko, K., Kim, S. J. 2016. SHRIMP U–Pb dating and geochemistry of the Cretaceous plutonic rocks in the

Journal Pre-proof

Korean Peninsula: A new tectonic model of the Cretaceous Korean Peninsula. Lithos 262, 88-106.

Kim, S. W., Park, S. I., Jang, Y., Kwon, S., Kim, S. J., Santosh, M., 2017. Tracking evolution of the South Korean Peninsula from detrital zircon records: Implications for the tectonic history of East Asia. Gondwana Research 50, 195-215.

Kim, S. W., Kee, W. S., Santosh, M., Cho, D. L., Hong, P. S., Ko, K., Lee, B.C., Byun, U.H., Jang, Y., 2020. Tracing the Precambrian tectonic history of East Asia from Neoproterozoic sedimentation and magmatism in the Korean Peninsula. Earth- Science Reviews, 103311.

Kretschmer W, Anton G, Bergmann M, Finckh E, Kowalzik B, Klein M, Leigart M, Merz S, Morgenroth G, Piringer I, Küster H, Low RD, Nakamura T. 1997. 14C dating of sediment samples. Nuclear Instruments and Methods in Physics Research B 123, 455-459.

Kring, D. A., 1995. The dimensions of the Chicxulub impact crater and impact melt sheet. Journal of Geophysical Research: Planets, 100(E8), 16979-16986.

Kring, D. A., 2007a. The Chicxulub impact event and its environmental consequences at the Cretaceous–Tertiary boundary. Palaeogeography, Palaeoclimatology, Palaeoecology 255, 4-21.

Kring, D. A., 2007b. GuiJournaldebook to the geology Pre-proof of barringer meteorite crater, arizona (aka Meteor Crater) (p. 150). Houston: Lunar and Planetary Institute.

Lee, H., Kim, R., Kang, T. S., 2017. Seismic Response from Microtremor of Chogye Basin, Korea. Geophysics and Geophysical Exploration 20, 88-95.

Li, S.S., Keerthy, S., Santosh, M., Singh, S.P., Deering, C.D., Satyanarayanan, M., Praveen, M.N., Aneeshkumar, V., Indu, G.K., Anilkumar, Y. and Sajinkumar, K.S., 2018. Anatomy of and shocked zircon grains from Dhala reveals

Journal Pre-proof

Paleoproterozoic meteorite impact in the Archean basement rocks of Central India. Gondwana Research, 54, pp.81-101.

Liu, K. X., Chen, M., Ding, X. F., Fu, D. P., Ding, P., Shen, C. D., Xiao, W. S., 2013. AMS radiocarbon dating of lacustrine sediment from an impact crater in northeastern China. Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms 294, 593-596.

Losiak, A., Wild, E. M., Geppert, W. D., Huber, M. S., Jõeleht, A., Kriiska, A., Kulkov, A., Paavel, K., Pirkovic, I., Paldo, J., Steier, P., Välja, R., Wilk, J., Wisniowski, T., Zanetti, M., 2016. Dating a small impact crater: An age of Kaali crater (Estonia) based on charcoal emplaced within proximal ejecta. Meteoritics & Planetary Science 51, 681- 695.

Losiak, A., Jõeleht, A., Plado, J., Szyszka, M., Kirsimäe, K., Wild, E. M., Steier, P., Belcher, A.M., Jazwa, A.M., Helde, R., 2020. Determining the age and possibility for an extraterrestrial impact formation mechanism of the Ilumetsa structures (Estonia). Meteoritics & Planetary Science, 55(2), 274-293.

Osinski, G. R., Ferrière, L., 2016. Shatter cones:(Mis) understood?. Science Advances 2, e1600616.

Pessenda LCR, Gouveia SEM, Aravena R. 2001. Radiocarbon dating of total soil organic matter and humin fraction and its comparison with 14C ages of fossil charcoal. RadiocarbonJournal 22(3), 853-857. Pre-proof

Reimer, P., Austin, W. E., Bard, E., Bayliss, A., Blackwell, P. G., Bronk Ramsey, C., ... & Grootes, P. M. (2020). The IntCal20 Northern Hemisphere radiocarbon age calibration curve (0-55 kcal BP). Radiocarbon.

Reimold, W. U., Koeberl, C., Partridge, T. C., Kerr, S. J., 1992. Pretoria Saltpan crater: Impact origin confirmed. Geology 20, 1079-1082.

Journal Pre-proof

Roddy, D. J., Davis, L. K., 1977. Shatter cones formed in large-scale experimental explosion craters. In Impact and explosion cratering: Planetary and terrestrial implications (pp. 715-750).

Schmieder, M., Kring, D. A., 2020. Earth's Impact Events Through Geologic Time: A List of Recommended Ages for Terrestrial Impact Structures and Deposits. Astrobiology 20, 91-141.

Schulte, P., Alegret, L., Arenillas, I., Arz, J. A., Barton, P. J., Bown, P. R., Bralower, T.J., Christeson, G.L., Claeyes, P., Cockell, C.S., Collins, G.S., Deutsch, A., Goldin, T.J., Goto, K., Grajales-Nishimura, J.M., Grieve, R.A.F., Gulick, S.P.S., Johnson, K.R., Kiessling, W., Koeberl, C., Kring, D.A., MacLeod, K.G., Matsui, T., Melosh, J., Montanari, A., Morgan, J.V., Neal, C.R., Nichols, D.J., Norris, R.D., Pierazzo, E., Ravizza, G., Rebolledo-Vieyra, M., Reimold, W.U., Robin, E., Salge, T., Speijer, R.P., Sweet, A.R., Fucugauchi, J.U., Vajda, V., Whalen, M.T., Willumsen, P.S., 2010. The Chicxulub asteroid impact and mass extinction at the Cretaceous-Paleogene boundary. Science 327, 1214-1218.

Schultz, P. H., Zárate, M., Hames, B., Koeberl, C., Bunch, T., Storzer, D., Renne, P., Wittke, J., 2004. The Quaternary impact record from the Pampas, Argentina. Earth and Planetary Science Letters 219, 221-238.

Son, M. W., 2000. Landscape of Erosional Basin in Korea-In case of land-use changes of hills. Journal of the Korean association of regional geographers 6, 83-96.

Stewart, A., Mitchell, K.Journal, 1987. Shatter cones Pre-proof at the Lawn Hill circular structure, northwestern Queensland: Presumed astrobleme. Australian Journal of Earth Sciences 34, 477-485.

Stöffler, D., 1984. Glasses formed by hypervelocity impact. Journal of Non-Crystalline Solids 67, 465-502.

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

Journal Pre-proof

Stöffler, D., Hamann, C., Metzler, K., 2018. Shock metamorphism of planetary silicate rocks and sediments: Proposal for an updated classification system. Meteoritics & Planetary Science 53, 5-49.

Wessel, P., Luis, J. F., Uieda, L., Scharroo, R., Wobbe, F., Smith, W. H. F., Tian, D., 2019. The Generic Mapping Tools version 6. Geochemistry, Geophysics, Geosystems 20, 5556–5564.

Wieland, F., Reimold, W. U., Gibson, R. L., 2006. New observations on shatter cones in the Vredefort impact structure, South Africa, and evaluation of current hypotheses for shatter cone formation. Meteoritics & Planetary Science 41, 1737- 1759.

Xu S, Zheng G. 2003. Variations in radiocarbon ages of various organic fractions in core sediments from Erhai Lake, SW China. Geochemical Journal 37(1), 135-144.

Yang, F., Santosh, M., Kim, S. W., 2018. Mesozoic magmatism in the eastern North China Craton: Insights on tectonic cycles associated with progressive craton destruction. Gondwana Research 60, 153-178.

Young, K. E., van Soest, M. C., Hodges, K. V., Watson, E. B., , B. A., & Lee, P. 2013. Impact thermochronology and the age of Haughton impact structure, Canada. Geophysical Research Letters 40, 3836-3840.

Journal Pre-proof

Fig. 1. Study area and the surrounding region (Jeokjung–Chogye Basin, southeastern Korean Peninsula). The Dongmyeong (DMF), Chilgog (CGF), and Silla conglomerate (SCF) formations are Cretaceous and Mesozoic formations of non- marine origin (Chang, 1968; Kim and Lee, 1969)). (A) is drawn using the Generic Mapping Tools (Wessel et al, 2019); (B) and (C) are revised from the Multiplatform Geoscience Information system (https://mgeo.kigam.re.kr/); (D) is revised from Google maps.

Journal Pre-proof

Fig. 2. Selected photographs of core CR05 (142 m long) from the Jeokjung–Chogye Basin, southeastern Korean Peninsula.

Fig. 3. Simplified lithological features and results of radiocarbon dating of core CR05 from the Jeokjung–Chogye Basin in Hapcheon, southeastern Korean Peninsula. SR: sedimentation rate (mm/y).

Fig. 4. Decorated planar deformation features (PDFs) in quartz from core CR05 from the Jeokjung–Chogye Basin, southeastern Korean Peninsula. A, 86 m and F, 142 m; all cross-polarized light. Scale bars represent 50 µm.

Fig. 5. Kink band deformation in muscovite from core CR05 from the Jeokjung– Chogye Basin, southeastern Korean Peninsula. Cross-polarized light at depth of 137.94 m. Scale bars represent 100 µm.

Journal Pre-proof Fig. 6. Shatter cones from 130 m in core CR05 from the Jeokjung–Chogye Basin, southeastern Korean Peninsula, offering a critical evidence for impact cratering.

Table 1. Results of radiocarbon dating of core CR05 from the Jeokjung–Chogye Basin, southeastern Korean Peninsula.

Depth (m) 14C yr. BP Error δ13C (‰) Dating material Lab code

Journal Pre-proof

6.37 55,214 1260 –28.75 Charcoal KGM-IWd200398

7.47 53,502 1009 –25.4 Charcoal KGM-IWd200399

8.25 48,880 669 –28.12 Charcoal KGM-IWd200400

10.37 50,248 944 –31.32 Charcoal KGM-IWd200401

12.82 45,934 528 –28.1 Charcoal KGM-IWd200402

14.1 53,713 1060 –32.36 Charcoal KGM-IWd200403

17.33 45,496 635 –33.83 Charcoal KGM-IWd200404

18.0 46,521 544 –29.52 Charcoal KGM-IWd200405

20.31 51,639 826 –25.05 Charcoal KGM-IWd200406

21.65 49,902 745 –28.71 Charcoal KGM-IWd200407

31.87 43,992 522 –29.56 Charcoal KGM-IWd200408

37.54 47,384 758 –37.22 Charcoal KGM-IWd200409

41.65 56,384 1383 –31.88 Charcoal KGM-IWd200410

50.73 53,389 1020 –33.53 Charcoal KGM-IWd200411 50.75 57,049 Journal1421 –29.92 Pre-proofCharcoal KGM-IWd200412

Graphical abstract:

Highlights

First report of robust evidence for impact cratering from Korean Peninsula

Shatter cones and PDF in quartz grains from a drilled core

Sedimentary records for impact-filling breccia and subsequent lacustrine sediments

Journal Pre-proof

Radiocarbon dates of charcoals constrain impact event at end of the late Pleistocene.

A rare archive of high-resolution paleoclimate changes in the East Asian continent.

Journal Pre-proof

Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6