Kalewa Section, Sample 29 (Eocene of Myanmar)

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

• Paleocoordinates: 11.5° N, 97.6° E (Wright 2013)

• 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 227696: authorized by Bethany Allen, entered by Bethany Allen on 27.10.2022

Creative Commons license: CC0 (CC0)

Taxonomic list

Polypodiopsida
  - Polypodiaceae
Verrucatosporites sp. Pflug and Thomson 1953
Verrucatosporites usmensis Germeraad et al. 1968
Laevigatosporites sp. Ibrahim 1933
 Polypodiales - Polypodiidae
Pterisisporites sp. Sung and Zheng
  - Blechnaceae
Leptolepidites sp. Couper 1953
Pteridopsida
  -
Deltoidospora sp. Miner 1935
Ranunculacidites
  -
Ranunculacidites operculatus Jaramillo and Dilcher 2001
Psilatricolpites
  -
Psilatricolpites sp. Van der Hammen and Wijmstra 1964
Angiospermae
 Magnoliales - Magnoliaceae
Magnoliaceae indet. de Jussieu 1789 magnolia
  -
 Sapindales - Sapindaceae
Sapindaceae indet. de Jussieu 1789 soapberry
Cupanieidites sp. Cookson and Pike 1954 soapberry
 Fabales - Fabaceae
Margocolporites sp. Ramanajuan 1966 legume
 Mesangiosperms - Arecaceae
 Mesangiosperms - Araceae
Pandaniidites sp. Elsik 1968
 Gentianales - Apocynaceae
Cricotriporites sp. Leidelmeyer 1966 dogbane
 Santalales - Loranthaceae
Gothanipollis sp. Krutzsch 1959 mistletoe
 Santalales -
 Proteales -
Dicotyledoneae
 Ericales - Sapotaceae
Palaquium sp. Blanco 1837
Sapotaceoidaepollenites sp. Potonié et al. 1950
 Myrtales - Onagraceae
Corsinipollenites sp. Nakoman 1965 willowherb
Acrostichum
  -
Acrostichum sp. Linnaeus 1753