{{short description|Geologic formation in Korea}} {{Infobox rockunit | name = Jindong Formation | image =GoseongJin32.jpg | caption = | type = Geological formation | age = Cenomanian-Turonian<br />~{{fossilrange|100|93}} | period = Cenomanian | prilithology = Mudstone, siltstone | otherlithology = Sandstone, shale | namedfor = | namedby = | region = Gyeongsangnam-do | country = South Korea | coordinates = {{coord|35.4|N|128.4|E|display=inline,title}} | paleocoordinates = {{coord|44.7|N|122.9|E|display=inline}} | unitof = Hayang Group | subunits = | underlies =Yucheon Group (volcanics) | overlies =Haman Formation | thickness = | extent =Gyeongsang Basin | area = | map = {{Location map+ | South Korea | relief = 1 | width = 250 | float = center | places = {{Location map~ | South Korea | lat_deg = 35.4 | lon_deg = 128.4 | mark = Green pog.svg | marksize = 10 }} }} | map_caption = }} The '''Jindong Formation''' ({{Korean|hangul=진동층|rr=Jindong-cheung|hanja=鎭東層}}) is a geological formation located in South Korea. It is dated to the Cenomanian-Turonian stages of the Late Cretaceous, between 99.9 ± 0.7 Ma and 93.1 ± 0.3 Ma.<ref>{{Cite journal|last1=Lee|first1=Tae-Ho|last2=Park|first2=Kye-Hun|last3=Yi|first3=Keewook|date=October 2018|title=Nature and evolution of the Cretaceous basins in the eastern margin of Eurasia: A case study of the Gyeongsang Basin, SE Korea|url=https://linkinghub.elsevier.com/retrieve/pii/S1367912018302669|journal=Journal of Asian Earth Sciences|language=en|volume=166|pages=19–31|doi=10.1016/j.jseaes.2018.07.004|bibcode=2018JAESc.166...19L |s2cid=135061525 |url-access=subscription}}</ref><ref>{{cite journal|last1=Chae|first1=Yong-Un|last2=Choi|first2=Taejin|last3=Joo|first3=Young Ji|last4=Kim|first4=Kyung Soo|last5=Ha|first5=Sujin|last6=Lim|first6=Hyoun Soo|year=2026|title=Effective application of multidimensional scaling for detrital zircon geochronology in the southern Miryang Subbasin, Gyeongsang Basin, Korea|journal=Journal of Asian Earth Sciences|volume=299|article-number=106954|doi=10.1016/j.jseaes.2026.106954|doi-access=free}}</ref>
== Geological background == The Jindong Formation consists of thick, fine-grained, altered volcaniclastic sediments. Most of these sediments are ash-rich mudstone, siltstone, and very fine sandstone. There are also coarser sandstone, conglomerate, carbonates, and tuff. <!--The alterations are... which complicate the process of determining the age of dinosaur and bird tracks.--><ref>{{cite journal |journal=Cretaceous Research|date=February 2006|title=Life in an active volcanic arc: Petrology and sedimentology of dinosaur track beds in the Jindong Formation (Cretaceous), Gyeongsang Basin, South Korea|volume=27|issue=1|pages=102–122|first1=Karen J.|last1=Houck|first2=Martin G.|last2=Lockley|doi=10.1016/j.cretres.2005.10.004<!--|access-date=2012-11-22 -->|bibcode=2006CrRes..27..102H |url=http://doc.rero.ch/record/15481/files/PAL_E2869.pdf }}</ref>
== Paleontology == The Jindong Formation has yielded numerous of dinosaurs and bird tracks.<ref name="HHPCK03">{{cite journal |last1=Huh |first1=Min |last2=Hwang |first2=Koo Geun |last3=Paik |first3=In Sung |last4=Chung |first4=Chull Hwan |last5=Kim |first5=Bo Seong |title=Dinosaur tracks from the Cretaceous of South Korea: Distribution, occurrences and paleobiological significance |journal=Island Arc |date=June 2003 |volume=12 |issue=2 |pages=132–144 |doi=10.1046/j.1440-1738.2003.00386.x|bibcode=2003IsArc..12..132H }}</ref><ref name="LHYML06">{{cite journal |last1=Lockley |first1=Martin G. |last2=Houck |first2=Karen |last3=Yang |first3=Seong-Young |last4=Matsukawa |first4=Masaki |last5=Lim |first5=Seong-Kyu |title=Dinosaur-dominated footprint assemblages from the Cretaceous Jindong Formation, Hallyo Haesang National Park area, Goseong County, South Korea: Evidence and implications |journal=Cretaceous Research |date=February 2006 |volume=27 |issue=1 |pages=70–101 |doi=10.1016/j.cretres.2005.10.010 |bibcode=2006CrRes..27...70L |url=http://doc.rero.ch/record/15480/files/PAL_E2868.pdf}}</ref> Ichnofossils including unnamed tracks of sauropods<ref>{{cite journal |last1=Hwang |first1=Koo-Geun |last2=Huh |first2=Min |last3=Paik |first3=In Sung |title=Sauropod trackways from the Cretaceous Jindong Formation at Docheon-ri, Changnyeon-gun, Geongsagnam-do, Korea |journal=Journal of the Geological Society of Korea |date=June 2004 |volume=40 |issue=2 |page=145-159 |url=https://www.researchgate.net/publication/221675531}}</ref> and pterosaurs,<ref name="HCLKKK18">{{cite journal |last1=Ha |first1=Sujin |last2=Chae |first2=Yong-Un |last3=Lim |first3=Jong Deock |last4=Kim |first4=Cheong-Bin |last5=Lim |first5=Hyoun Soo |last6=Kim |first6=Kyung Soo |title=Cretaceous Pterosaur Tracks in Daegok-ri, Ulju-gun, Ulsan: Spatio-temporal Distribution of Pterosaur in the Korean Peninsula|journal=Journal of the Korean Earth Science Society |date=30 October 2018 |volume=39 |issue=5 |pages=458–472 |doi=10.5467/JKESS.2018.39.5.458}}</ref> the isolated sauropod skin impression not associated with trackways,<ref name="KKLS10">{{cite journal |last1=Kim |first1=Jeong Yul |last2=Kim |first2=Kyung Soo |last3=Lockley |first3=Martin G. |last4=Seo |first4=Seung Jo |title=Dinosaur skin impressions from the Cretaceous of Korea: New insights into modes of preservation |journal=Palaeogeography, Palaeoclimatology, Palaeoecology |date=July 2010 |volume=293 |issue=1–2 |pages=167–174 |doi=10.1016/j.palaeo.2010.05.012|bibcode=2010PPP...293..167K }}</ref> and the poorly preserved juvenile sauropod trackway with no ichnotaxon assignment<ref>{{Cite journal|last1=Yoon |first1=H. S. |last2=Lee |first2=Y.-N. |last3=Park |first3=E. |last4=Lee |first4=S. |year=2024 |title=A small sauropod trackway from the Upper Cretaceous Jindong Formation (Cenomanian), Goseong County, South Korea |journal=Cretaceous Research |volume=166 |at=106022 |doi=10.1016/j.cretres.2024.106022 }}</ref> have been reported.
{| class="wikitable" |+ ! colspan="7" |Ichnofossils of the Jindong Formation<ref>{{cite journal |last1=Xing |first1=Lida |last2=Díaz-Martínez |first2=Ignacio |last3=Lallensack |first3=Jens N. |last4=Kim |first4=Kyung Soo |last5=Buckley |first5=Lisa G. |last6=Romilio |first6=Anthony |last7=Piñuela |first7=Laura |last8=Wang |first8=Donghao |last9=Chen |first9=Qiyan |last10=Yang |first10=Qing |last11=Chou |first11=Chunyong |last12=Yin |first12=Hang |last13=Jin |first13=Yufei |title=Cretaceous vertebrate tracks |journal=Vertebrate Ichnology |date=2025 |pages=479–747 |doi=10.1016/B978-0-443-13837-9.00002-0|isbn=978-0-443-13837-9 }}</ref> |- |'''Ichnogenus''' |'''Ichnospecies''' |'''Region''' |'''Member''' |'''Material''' |'''Notes''' |'''Image''' |- |''Brontopodus''<ref name="LHYML06" /> |''B.'' isp. | | | |Sauropod tracks | |- |''Caririchnium''<ref name="LHYML06" /> |''C.'' isp. | | | |Ornithopod tracks | |- |''Goseongornipes''<ref name="LHYML06" /> |''G. markjonesi'' | | | |Bird tracks | |- |''Gyeongsangornipes''<ref name="KKOL13">{{cite journal |last1=Kim |first1=Jeong Yul |last2=Kim |first2=Min Kyeong |last3=Oh |first3=Mun Seop |last4=Lee |first4=Chang Zin |title=A New Semi-Palmate Bird Track, Gyeongsangornipes lockleyi ichnogen. et ichnosp. nov., and Koreanaornis from the Early Cretaceous Jindong Formation of Goseong County, Southern Coast of Korea |journal=Ichnos |date=3 April 2013 |volume=20 |issue=2 |pages=72–80 |doi=10.1080/10420940.2013.787071|bibcode=2013Ichno..20...72K }}</ref> |''G. lockleyi'' | | | |Bird tracks | |- |''Hadrosauropodus'' |''H. kyoungsookimi''<ref>{{cite journal|last1=Yoon|first1=Han Sang|last2=Lee|first2=Yuong-Nam|last3=Jung|first3=Seung-Ho|last4=Kong|first4=Dal-Yong|last5=Kim|first5=Su-Hwan|last6=Son|first6=Minyoung|year=2021|title=A juvenile ornithopod-dominated tracksite from the Lower Cretaceous Haman Formation, South Korea|journal=Cretaceous Research|volume=125|article-number=104877|doi=10.1016/j.cretres.2021.104877|doi-access=free}}</ref> | | | |The first trackway of a quadrupedal ornithopod discovered in Korea, originally attributed to the ichnogenus ''Caririchnium''.<ref>{{cite journal |journal=Ichnos|volume=19|issue=1–2|date=March 19, 2012|title=The Trackway of a Quadrupedal Ornithopod from the Jindong Formation (Cretaceous) of Korea|pages=101–104|first1=Jong-Deock|last1=Lim|first2=Martin G.|last2=Lockley|first3=Dal-Yong|last3=Kong|doi=10.1080/10420940.2012.664059|bibcode=2012Ichno..19..101L |s2cid=129058417}}</ref> | |- |''Jindongornipes''<ref name="LHYML06" /> |''J. kimi'' | | | |Bird tracks | |- |''Koreanaornis''<ref name="LHYML06" /> |''K. hamanensis'' | | | |Bird tracks | |- |''Ornithopodichnus''<ref>{{cite journal |last1=Kim |first1=Jeong Yul |last2=Lockley |first2=Martin G. |last3=Kim |first3=Haang Mook |last4=Lim |first4=Jong-Deock |last5=Kim |first5=Kyung Soo |title=New dinosaur tracks from Korea, Ornithopodichnus masanensis ichnogen. et ichnosp. nov. (Jindong Formation, Lower Cretaceous): implications for polarities in ornithopod foot morphology |journal=Cretaceous Research |date=December 2009 |volume=30 |issue=6 |pages=1387–1397 |doi=10.1016/j.cretres.2009.08.003|bibcode=2009CrRes..30.1387K }}</ref> |''O. masanensis'' | | | |Currently regarded as dubious ichnotaxon made by ornithopod trackmakers. | |- |cf. ''Ruopodosaurus''<ref>{{cite journal |last1=Yoon |first1=Han Sang |last2=Kim |first2=Hyun Wook |last3=Park |first3=Jin-Young |last4=Jung |first4=Seung-Ho |last5=Kong |first5=Dal-Yong |last6=Lee |first6=Yuong-Nam |title=First reports of a probable ankylosaurian (Thyreophora) trackway from the Jindong Formation (Cenomanian) of Goseong County, South Korea |journal=Cretaceous Research |year=2025 |at=106240 |doi=10.1016/j.cretres.2025.106240 }}</ref> |cf. ''R.'' isp. | | | |Ankylosaur trackway, possibly made by (sub)adult Ankylosaurid trackmaker | |- |''Undichna''<ref>{{cite journal |last1=Kim |first1=Kyung Soo |last2=Lockley |first2=Martin G. |last3=Romilio |first3=Anthony |last4=Bae |first4=Seul Mi |last5=Lim |first5=Jong Deock |title=Fish swim traces from the Jindong Formation (Cretaceous) Korea: Implications for lake basin ichnofacies and paleoecology |journal=Cretaceous Research |date=1 March 2022 |volume=131 |article-number=105070 |doi=10.1016/j.cretres.2021.105070|bibcode=2022CrRes.13105070K }}</ref> | *''U. simplicatis'' *''U. bina'' *''U. britannica'' | | | |Fish swim traces | |}
== See also == * List of fossil sites
== References == {{reflist}}
Category:Geologic formations of South Korea Category:Upper Cretaceous Series of Asia Category:Cretaceous South Korea Category:Cenomanian Stage Category:Mudstone formations Category:Siltstone formations Category:Tuff formations Category:Fluvial deposits Category:Lacustrine deposits Category:Ichnofossiliferous formations Category:Paleontology in South Korea