Palynology and palynofacies analysis of a Silurian (Llandovery–Wenlock) marine succession from the Precordillera of western Argentina: Palaeobiogeographical and palaeoenvironmental significance

Muro, Victoria J. García; Rubinstein, Claudia V.; Martínez, Mauro

doi:10.1016/j.marmicro.2016.06.002

Cited by 10 publications

(3 citation statements)

References 66 publications

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“…Based on the brachiopod fauna, Benedetto () confirmed an early Llandovery age (Rhuddanian) for the lower to middle part of the La Chilca Formation at the Cerro del Fuerte and Cerro La Chilca sections. Llandovery and Wenlock ages were confirmed by García Muro, Rubinstein, and Martinez () based on palynology and palynofacies analysis on the deposits from the Ancha Creek.…”

Section: Geologic Settingmentioning

confidence: 61%

Stratigraphy and facies analysis of the La Chilca Formation, Central Precordillera: Insights on the postglacial Ordovician–Silurian boundary and Early Silurian deposits from Argentina

2018

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The La Chilca Formation is exposed at the Poblete Norte and Ancha sections, Talacasto, Central Precordillera. Detailed facies analysis on field outcrops suggests a tide-dominated tidal plain model on the Silurian siliciclastic ramp, integrated by supratidal to subtidal plain deposits. The lower part of the La Chilca Formation (upper supratidal plain) is herein attributed to reworked glaciomarine deposits that occurred during interglacial Hirnantian age, under conditions of sea rise and the action of tidal amplification. The intertidal-supratidal depositional environments are represented by tidal channels, scour and fill, tidal dunes, and hummocky cross-stratified sandstones. The estimated tidal conditions for the tidal plain were mesotidal to macrotidal, under action of combined flows, attributed to the interaction of tidal currents and orbital low-velocity waves. The identification of microbially induced sedimentary structures (MISS) in these deposits, such as petee polygonal structures, pitted texture, imploded sand volcanoes, Astropolithon sp., Manchuriophycus sp., domal build-ups, biofilms, elephant skin, and trace fossils such as Chondrites sp., Zoophycos sp., Undichnia sp., Planolites sp., Monomorphichnus sp., and gastropod traces, may have played a protection and stabilization role on the clastic sediment surfaces against erosion of the La Chilca Formation deposits. The prolific growth of microbial mat on the intertidal to supratidal zone occurs explicitly at the turning points of transgression-regression cycles in shallow-water environments under stable base-level conditions. The middle-upper section of the La Chilca Formation shows non-cyclic rhythmites that are replaced by the cyclic rhythmites, suggesting an open tidal plain subject to an orbital/climatic rather than a tectonic control of cyclicity (Milankovitch cycles). The aggradation in this section indicates a shallowing towards the top of the formation. The La Chilca Formation records two third-order transgressive events and a shallowing event. The transgressive events are found in the base and top of the formation and are marked by the presence of Fe-oolites, while the shallowing event is determined by the presence of MISS.

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Section: Geologic Settingmentioning

confidence: 61%

Stratigraphy and facies analysis of the La Chilca Formation, Central Precordillera: Insights on the postglacial Ordovician–Silurian boundary and Early Silurian deposits from Argentina

2018

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“…Paleogeographically, the marine phytoplankton of the La Chilca and Los Espejos formations show a cosmopolitan distribution, sharing species with Avalonia, Baltica, Laurentia, Armorica, and other Gondwanian regions [50,44]; while the terrestrial palynomorphs from the Los Espejos Formation show affinities with Gondwanian regions like Brazil and North Africa [51,44].…”

Section: Silurian Flora In Argentinamentioning

confidence: 99%

The southwesternmost record of late Silurian (Pridolian) early land plants of Gondwana.

Drovandi,

Conde,

Lopez

et al. 2024

Preprint

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The Silurian constitutes a key period in the evolutionary history of land plants. However, records of Pridolian plants in western Gondwana are scarce, limited to outcrops located in southern Bolivia. In this contribution, an association of fossil plants housed in the Rinconada Formation, San Juan Province,Argentina, is presented. This association corresponds to fossil remains of primitive flora with reproductive structures and sterile axes linked to basal tracheophytes. The fossil assemblage is composed of Salopella marcensis, Hostinella sp, Aberlemnia caledonica, Cooksonia paranensis, C. pertoni, C. cambrensis, Steganoteca striata, Isidrophyton sp, Caia langii, two morphotypes of doubtful taxonomy, and graptolites colonies. The association between flora remains and graptolites, represents a parautochthonous fossil assemblage in an inner marine platform, dominated by gravity flows. This fossil record has paleophytogeographic importance since it allows extending the northwest Gondwana-southern Laurrusia unit to more southern areas of Gondwana. This expansion would have been favoured by the post-glacial climatic improvement of the late Silurian, together with a great radiation capacity and environmental flexibility of the flora. Furthermore, this contribution extends the biocron of three South American taxa (A. caledonica, C. paranensis and Isidrophyton sp) first known from the Lochkovian, to the Pridoli. Keywords: Early land plants, Pridoli, Gondwana, Paleophytogeography, Rinconada Formation.

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“…Regarding the early Silurian (Llandovery) of South America, as in the whole world, cryptospores are more widespread. They have been recorded in Argentina, from the Lipeón Formation, Aeronian–Telychian of the Sierras Subandinas (Rubinstein, 2005) and the Cordillera Oriental (Rubinstein & Toro, 2006; Rubinstein et al , 2016), and the La Chilca Formation, Aeronian–Telychian of the Precordillera Basin (Rubinstein & Brussa, 1999; García Muro et al , 2016).…”

mentioning

confidence: 99%

First Record of Cryptospores from the Late Ordovician–Early Silurian of Colombia: New Contribution to the Understanding of Plant Terrestrialization

Rubinstein¹,

Vargas²,

Parra³

et al. 2023

Ameghiniana

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The present study involves the palynological analysis of Late Ordovician-early Silurian samples coming from two wells drilled in the Llanos Basin of Colombia. Thirteen core samples of well A yielded a moderately preserved cryptospore assemblage comprising 17 taxa. Although composed mainly of simple forms without stratigraphic value, the marine organic-walled phytoplankton allows us to constrain the age of the palynological assemblage from the Late Ordovician (Katian-Hirnatian) to the early Silurian. A ditch-cutting sample of well B yielded marine organic-walled phytoplankton and one trilete spore species. The marine phytoplankton suggests an age no older than early Silurian for the assemblage of well B. The paleoenvironment of well A, interpreted as a braided fluvial channel system with sporadic and slight tidal influence, is supported by palynological data. The distribution of palynomorphs also suggests an increasing marine influence from the bottom to the top of the studied section. The cryptospore assemblage constitutes the first record of cryptospores of Colombia and northern South America and, therefore, the oldest evidence of land plants in this region. The presence of the trilete spore Ambitisporites avitus in strata of probably early Silurian age would represent the first record of Silurian sediments in the Llanos Basin and the oldest record of trilete spores in Colombia.

show abstract

Palynology and palynofacies analysis of a Silurian (Llandovery–Wenlock) marine succession from the Precordillera of western Argentina: Palaeobiogeographical and palaeoenvironmental significance

Cited by 10 publications

References 66 publications

Stratigraphy and facies analysis of the La Chilca Formation, Central Precordillera: Insights on the postglacial Ordovician–Silurian boundary and Early Silurian deposits from Argentina

Stratigraphy and facies analysis of the La Chilca Formation, Central Precordillera: Insights on the postglacial Ordovician–Silurian boundary and Early Silurian deposits from Argentina

The southwesternmost record of late Silurian (Pridolian) early land plants of Gondwana.

First Record of Cryptospores from the Late Ordovician–Early Silurian of Colombia: New Contribution to the Understanding of Plant Terrestrialization

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