La Matilde Formation

{{Infobox rockunit

| name = La Matilde Formation

| image =

| caption =

| type = Geological formation

| period = Kimmeridgian

| age = Bathonian-Kimmeridgian
~{{fossil range|167|151}}

| prilithology = Claystone, sandstone, siltstone

| otherlithology = Coal beds, conglomerate, tuff

| namedfor =

| namedby =

| location = Patagonia

| region = Santa Cruz Province

| country = Argentina

| coordinates = {{coord|47.6|S|68.1|W|display=inline,title}}

| paleocoordinates = {{coord|44.2|S|27.3|W|display=inline}}

| unitof =

| subunits =

| underlies = San Julián Formation

| overlies = Chon Aike Formation

| thickness =

| extent = Austral Basin

| area =

| map = {{Location map+ | Argentina

| relief = 1

| width = 250

| float = center

| places =

{{Location map~ | Argentina

| lat_deg = -47.6

| lon_deg = -68.1

| mark = Cyan pog.svg

| marksize = 12

}}

| map_caption =

}}

La Matilde Formation is a Jurassic geological formation in the Austral Basin of Santa Cruz Province, Patagonia, Argentina. It is dated to the Middle to Late Jurassic. From the Bathonian age (164.7 to 167.7 million years ago) to the Kimmeridgian age (150.8 to 155.7 million years ago) at the latest.Channing et al., 2007Clarke et al., 2011

The area was once part of the subtropical and temperate regions of the southern supercontinent Gondwana in the Mesozoic era, a more or less continuous landmass consisting of what is now modern South America, Africa, Antarctica, Australia, New Zealand, and New Guinea.Sequiera & Farrell, 2001Iglesias et al., 2011

Description

La Matilde consists primarily of sedimentary rocks. It includes claystone, coal beds, conglomerates, siltstones, sandstones, and volcanic tuff. La Matilde overlies but sometimes intersperses with the Middle Jurassic Chon Aike Formation.{{cite journal|author1=Ana Parras |author2=Miguel Griffin |year=2009|title=Darwin's great patagonian tertiary formation at the mouth of the río Santa Cruz: a reappraisal|journal=Revista de la Asociación Geológica Argentina|volume=64|issue=1|issn=1851-8249|url=http://www.scielo.org.ar/scielo.php?pid=S0004-48222009000100009&script=sci_arttext }} The two formations are the subunits of the Bahía Laura Group.{{cite journal|author=Claudio A. Sylwan|year=2001|title=Geology of the Golfo San Jorge Basin, Argentina|journal=Journal of Iberian Geology|volume=27|pages=123–157|issn=0378-102X|url=http://www.ucm.es/BUCM/revistas/geo/16986180/articulos/JIGE0101110123A.PDF }}

Fossil content

La Matilde is known for the abundant fossils recovered from it. Notable fossil localities in the formation include the Cerro Cuadrado Petrified Forest, the Cerro Madre e Hija Petrified Forest, and the remains and trace fossils (including trackways) of dinosaurs in the Laguna Manantiales Farm.{{cite book|author=Fernando E. Novas|title =The age of dinosaurs in South America|publisher =Indiana University Press|year =2009|page=99|isbn =978-0-253-35289-7|url=https://books.google.com/books?id=dXYi6j7QQ-YC&dq=Petrified+forest+la+matilde&pg=PA99}}{{cite book|author=IUCN Commission on National Parks and Protected Areas|title =IUCN directory of neotropical protected areas|publisher =IUCN |year = 1982|pages=[https://archive.org/details/iucndirectoryofn82iucn/page/26 26]–27|isbn =978-0-907567-62-2|url =https://archive.org/details/iucndirectoryofn82iucn}}

Fossil taxa recovered from the La Matilde Formation include:{{cite book|author1=Thomas N. Taylor |author2=Edith L. Taylor |author3=Michael Krings |title =Paleobotany: the biology and evolution of fossil plants|publisher =Academic Press|year =2009|page=844–845|isbn =978-0-12-373972-8|url =https://books.google.com/books?id=_29tNNeQKeMC&dq=Petrified+forest+la+matilde&pg=PA844}}{{cite journal|author1=Ruth A. Stockey |author2=T.N. Taylor |year=1978|title=On the structure and evolutionary relationships of the Cerro Cuadrado fossil conifer seedlings|journal=Botanical Journal of the Linnean Society|volume=76|issue=2 |pages=161–176|url=http://paleobotany.bio.ku.edu/taylorPDFs%5C%5B1978%5D%20Stockey%20and%20Taylor-Cerro%20Cuadrado%20fossil%20conifer%20seedlings.pdf|doi=10.1111/j.1095-8339.1978.tb01504.x}}

;Flora

Agathoxylon matildense
Araucaria mirabilis
Araucarites sanctaecrucis
Brachyphyllum
Equisetum thermale{{cite journal |last1=Channing |first1=A. |last2=Zamuner |first2=A. |last3=Edwards |first3=D. |last4=Guido |first4=D. |year=2011 |title=Equisetum thermale sp. nov. (Equisetales) from the Jurassic San Agustin hot spring deposit, Patagonia: Anatomy, paleoecology, and inferred paleoecophysiology. |journal= American Journal of Botany |volume=98 |issue=4 |pages=680–697 |doi= 10.3732/ajb.1000211 |pmid=21613167|doi-access=free |hdl=11336/95234 |hdl-access=free }}
Pararaucaria patagonica

;Ichnofossils

Ameghinichnus patagonicusLeonardi, 1994, p.27
Casamiquelichnus navesorum
Delatorrichnus goyenechei
Grallator
Notobatrachus degiustoi
Sarmientichnus scagliaiLeonardi, 1994, p.26
Wildeichnus navesiLeonardi, 1994, p.25

References

= Bibliography =

{{citation |last1=Channing |first1=Alan |last2=Zamuner |first2=Alba B. |last3=Zúñiga |first3=Adolfo |year=2007 |title=A new Middle–Late Jurassic flora and hot spring chert deposit from the Deseado Massif, Santa Cruz province, Argentina |url=https://www.researchgate.net/publication/259438468 |journal=Geological Magazine |volume=144 |issue=2 |pages=401–411 |doi=10.1017/S0016756807003263 |bibcode=2007GeoM..144..401C |accessdate=2019-03-26}}
{{citation |last1=Clarke |first1=John T. |last2=Warnock |first2=Rachel C.M. |last3=Donoghue |first3=Philip C.J. |year=2011 |title=Establishing a time-scale for plant evolution |url=https://www.researchgate.net/publication/51467182 |journal=New Phytologist |volume=192 |issue=2011 |pages=266–301 |doi=10.1111/j.1469-8137.2011.03794.x |pmid=21729086 |accessdate=2019-03-26}}
{{citation |last1=Iglesias |first1=Ari |last2=Artabe |first2=Analia E. |last3=Morel |first3=Eduardo M. |year=2011 |title=The evolution of Patagonian climate and vegetation from the Mesozoic to the present |doi=10.1111/j.1095-8312.2011.01657.x |journal=Biological Journal of the Linnean Society |volume=103 |issue=2 |pages=409–422 }}
{{citation |last=Leonardi |first=Giuseppe |year=1994 |title=Annotated Atlas of South America Tetrapod Footprints (Devonian to Holocene) with an appendix on Mexico and Central America |url=https://www.researchgate.net/publication/309643073 |publisher=Ministerio de Minas e Energia - Companhia de Pesquisa de Recursos Minerais, Geological Service of Brazil |pages=1–248 |accessdate=2019-03-25}}
{{citation |last1=Sequiera |first1=Andrea S. |last2=Farrell |first2=Brian D. |year=2001 |title=Evolutionary origins of Gondwanan interactions: How old are Araucaria beetle herbivores? |url=https://www.researchgate.net/publication/228545908 |journal=Biological Journal of the Linnean Society |volume=74 |issue=4 |pages=459–474 |doi=10.1111/j.1095-8312.2001.tb01405.x |accessdate=2019-03-26}}
{{citation |last1=Weishampel |first1=David B. |author2-link=Peter Dodson |last2=Dodson |first2=Peter |author3-link=Halszka Osmólska |last3=Osmólska |first3=Halszka |year=2004 |title=The Dinosauria, 2nd edition |url=https://books.google.com/books?id=vtZFDb_iw40C |publisher=Berkeley: University of California Press |pages=1–880 |accessdate=2019-02-21 |isbn=0-520-24209-2 |author1-link=David B. Weishampel }}

La Matilde Formation

Description

Fossil content

See also

References

= Bibliography =

Further reading