Kalewa Section, Sample 21 (Eocene of Myanmar)

Where: Sagaing, Myanmar (23.2° N, 94.3° E: paleocoordinates 14.7° N, 94.2° E)

• coordinate stated in text

• small collection-level geographic resolution

When: Yaw Formation, Late/Upper Eocene (37.2 - 33.9 Ma)

• "U–Pb dating of a tuff layer (Licht et al. 2019), magnetostratigraphy, U–Pb apatite dating and apatite fission track dating (Westerweel et al., 2020) provide an age of c. 38–37 Ma, which is also supported by the palynological evidence discussed below and in Huang et al. 2020, Huang et al. 2018." (Huang et al. 2023)

• bed-level stratigraphic resolution

Environment/lithology: fluvial; lithified sandstone and mudstone

Size class: microfossils

Collection methods: chemical

• "Two palynological processing methods were performed to ensure maximum recovery. One set of samples was processed for quantitative analysis. The processing was as follows: 1.3 g of sample was boiled in 10% sodium pyrophosphate, and then treated with 10% HCl, and sieved with 5 μm and 212 μm meshes. The sample was then heated in acetolysis mixture to 100 °C. Bromoform-treatment was applied to separate any remaining inorganic fraction to produce residue. A second set of selected samples was processed mainly for microphotography. The processing method was as follows: 30 g of washed and dried sample was treated with 10% HCl and 40% HF. Then a heavy liquid separation was used to separate the organic and remaining inorganic fractions. All resulting residues were mounted on a slide in glycerin and sealed with paraffin for light microscope (LM) observation. Residues were further used for analysis with LM and scanning electron microscopy (SEM) at the Department of Palaeontology (DoP), University of Vienna, Austria. Details on the two methods were presented in Huang et al. (2020)." (Huang et al. 2023)

Primary reference: H. Huang, R. J. Morley, A. Licht, G. Dupont-Nivet, D. Pérez-Pinedo, J. Westerweel, Z. Win, D. Wa Aung, E. Budi Lelono, G. N. Aleksandrova, R. K. Saxena and C. Hoorn. 2023. A proto-monsoonal climate in the late Eocene of Southeast Asia: evidence from a sedimentary record in central Myanmar. Geoscience Frontiers 14(1):101457 [B. Allen/B. Allen]more details

Purpose of describing collection: paleoecologic analysis

PaleoDB collection 227669: authorized by Bethany Allen, entered by Bethany Allen on 26.10.2022

Creative Commons license: CC BY (attribution)

Taxonomic list

unclassified
  -
 Anthocerotophyta -
Anthocerisporis sp. Krutzsch 1963 hornwort
Polypodiopsida
  - Polypodiaceae
 Polypodiales - Polypodiidae
Pterisisporites sp. Sung and Zheng
Pteridopsida
  -
Deltoidospora sp. Miner 1935
Angiospermae
 Fagales - Fagaceae
 Malpighiales - Euphorbiaceae
Euphorbiaceae indet. Jussieu 1789 spurge
 Malpighiales - Calophyllaceae
Calophyllumpollenites sp. Sah and Kar 1974
 Rosales - Urticaceae
Urtica sp. Linnaeus 1753 nettle
 Fabales - Fabaceae
Margocolporites sp., "Leguminosae indet." = Fabaceae
Margocolporites sp. Ramanajuan 1966 legume
"Leguminosae indet." = Fabaceae Lindley 1836 legume
 Sapindales - Sapindaceae
Sapindaceae indet. de Jussieu 1789 soapberry
Cupanieidites sp. Cookson and Pike 1954 soapberry
 Malvales - Malvaceae
Discoidites sp. Muller mallow
 Mesangiosperms - Arecaceae
 Mesangiosperms - Araceae
Proxapertites operculatus Van der Hammen 1956
Pandaniidites sp. Elsik 1968
Dicotyledoneae
 Myrtales -
Myrtaceidites sp. Cookson and Pike 1960
Ranunculacidites
  -
Ranunculacidites operculatus Jaramillo and Dilcher 2001
Lycopodiopsida
 Selaginellales - Selaginellaceae
? Selaginella sp. Beauvois 1804 spikemoss
Acrostichum
  -
Acrostichum sp. Linnaeus 1753