Raman and infrared spectroscopy investigation of the root fossil (rhizoliths) from the Carboniferous period, Piauí Formation, Parnaíba Sedimentary Basin, Northeast Brazil

Silva, J.H. da; Saraiva, G.D.; Campelo, S.C. Memória; Cisneros, Juan Carlos; Viana, Bartolomeu C.; Bezerra, Francisco Irineudo; Abagaro, B.T.O.; Freire, Paulo de Tarso Cavalcante

doi:10.1016/j.vibspec.2018.11.007

Cited by 3 publications

(2 citation statements)

References 41 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Soil‐biotic subfossils are often associated with pedogenic carbonate and calcareous crusts, and provide insights into past environmental, ecological and hydrological conditions (e.g. Kraus and Hasiotis, 2006; Genise et al ., 2011; Da Silva et al ., 2019; Srivastava et al ., 2021; Sun et al ., 2021, and references therein).…”

Section: Introductionmentioning

confidence: 99%

Where did the water come from? Wetlands and shallow lakes in semi‐arid dunefields from South America during the Pleistocene–Holocene transition

Tripaldi,

Ozán,

Heider

et al. 2024

J Quaternary Science

View full text Add to dashboard Cite

Stabilized and active dunes and sand sheet deposits abound in a small lake‐dotted semi‐arid region of the Western Pampean Dunefield, Argentina. Here, a multi‐scale and multi‐proxy study of three sites, across a hydrologic gradient from lakes to a dryland with groundwater levels at more than 25 m depth, analyzes calcareous and ferruginous rhizoliths, calcareous crusts, hypocoatings, pedogenic carbonate and amorphous Mn‐oxide precipitates within blowout dunes. These palustrine‐related features indicate significantly wetter conditions that allowed the development of shallow lakes and expanding wetlands during the Pleistocene–Holocene transition, limited by associated optically stimulated luminescence ages between ca. 14.7 and 11.6 ka. These wetter conditions, also identified in other nearby proxy records, may be associated with a strengthened South American Monsoon System, potentially during the Younger Dryas Chronozone, though other geological, ecological and climatic forcings cannot be ruled out with available data. Such a scenario lacks a modern analogue, since current hydrologic excess, evidenced in the formation of lakes and new rivers, is not observed in the localities which record paleolakes. This study underlines the variable conditions for pronounced hydrologic excess in semi‐arid eolian environments in western Argentina with complex ecological, anthropogenic and climatic linkages.

show abstract

Section: Introductionmentioning

confidence: 99%

Where did the water come from? Wetlands and shallow lakes in semi‐arid dunefields from South America during the Pleistocene–Holocene transition

Tripaldi,

Ozán,

Heider

et al. 2024

J Quaternary Science

View full text Add to dashboard Cite

show abstract

“…Firstly, it is a powerful tool to identify fossil damage, especially sulfate efflorescence [11]. Secondly, it is useful for detecting the chemical composition of fossils, such as identifying minerals in wood fossils [12], root fossils (rhizoliths) [13], insect cuticle fossils [14], microscopic fossils [15], and ctenophore embryos [16]. Moreover, Raman spectroscopy is powerful for detecting organic matter, such as organics in the silica matrix [17] and kerogen in fossils [14,18].…”

Section: Introductionmentioning

confidence: 99%

Apatite in Hamipterus tianshanensis eggshell: advances in understanding the structure of pterosaur eggs by Raman spectroscopy

et al. 2022

View full text Add to dashboard Cite

Pterosaur eggs can offer information about pterosaur reproductive strategies and are extremely precious because only a small number of specimens have been discovered. Previous studies have mainly focused on morphological descriptions of pterosaur eggs and their embryos while the chemical composition of pterosaur eggs has received little attention. The conventional view believed that the eggshell was composed of calcite. However, previous SEM–EDS results for Hamipterus tianshanensis showed that the eggshell contains phosphorus. Therefore, the object of this research is to determine the mineral composition of the eggshell of H. tianshanensis. Two eggs were analyzed by scanning electron microscopy coupled with energy dispersive X-ray spectrometry (SEM–EDS) and Raman spectroscopy. The SEM–EDS results show that both surface and cross section are porous and characterized by small irregularly shaped particulates. Moreover, the distribution of Ca and P has a strict coincidence in the cross-section of eggshells. Furthermore, neither the intense peaks of calcite nor organic peaks can be observed by Raman spectroscopy in eggshells. Meanwhile, the Raman spectroscopy mapping analysis result shows a sharp and intense peak at approximately 966 cm−1 among the white eggshell, which can be hard evidence that H. tianshanensis eggs are mainly composed of calcium phosphate. Combined with the present of F in the eggshell, it can be inferred that fluorapatite Ca5(PO4)3F is the main mineral. The fluorapatite eggshell can be interpreted in two ways. One explanation is that H. tianshanensis laid apatite-shelled eggs, similar to living Salvator merianae, and the bioapatite transformed to fluorapatite over geological time. Another possible explanation is that the fluorapatite comes from the result of phosphatization of soft egg membrane tissues through taphonomic processes, indicating that H. tianshanensis might have laid soft eggs. Regardless, the results show that fluorapatite, rather than calcite is the main preserved mineral composition of H. tianshanensis eggshell, correcting the previous view. This study contributes to the present understanding of the mineral composition of pterosaur eggshells and may offer some insight into the pterosaur reproduction pattern.

show abstract

Diagenetic development of rhizoliths in the Ironshore Formation (Pleistocene) of the Cayman Islands

Jones,

Booker

2024

Sedimentary Geology

View full text Add to dashboard Cite

Raman and infrared spectroscopy investigation of the root fossil (rhizoliths) from the Carboniferous period, Piauí Formation, Parnaíba Sedimentary Basin, Northeast Brazil

Cited by 3 publications

References 41 publications

Where did the water come from? Wetlands and shallow lakes in semi‐arid dunefields from South America during the Pleistocene–Holocene transition

Where did the water come from? Wetlands and shallow lakes in semi‐arid dunefields from South America during the Pleistocene–Holocene transition

Apatite in Hamipterus tianshanensis eggshell: advances in understanding the structure of pterosaur eggs by Raman spectroscopy

Diagenetic development of rhizoliths in the Ironshore Formation (Pleistocene) of the Cayman Islands

Contact Info

Product

Resources

About