Paleaogeography and Climatic Change recorded on Viviparidae Carbon and Oxygen Isotope in Mae Moh Coal Mine, Northern Thailand

Abstract

Viviparidae fossil collected from the R-, Q-, and K-coal zones of the Mae Moh coal mine, northern Thailand were analyzed for 13 Carbon and 18 Oxygen isotopes at Akita University, Japan. The result reveals that Viviparidae of the lower part of the coal mine contribute much heavier carbon isotopes than the upper part. The results revealed that Viviparidae shell O ‰ value between -6.64 to -7.04 ‰ PDB. The isotopic results of Viviparidae fossil shells from Mae Moh basin show the gradually change from the R-coal zone to the Q-, and the K-coal zone and significantly different from the Recent Viviparidae in the area. The heavy carbon isotopes in the R-coal zone could imply a much cooler climate than during the Q-and K-coal zone depositing period and the area were more close to the sea. The climatic condition during the Q-and K-coal zone depositing period was warmer and at a geographically higher elevation or latitude than during depositing the R-coal zone. The changing records in Mae Moh coal field are confirmed by temperate fossils in the other Oligocene to Lower Miocene basins in Northern Thailand. The change to a more tropical climate could have occurred during the Middle Miocene period, as indicated by paleomagnetic age dating in the K-and Q-coal zone. The northward movement of the Australian-Indian plate and collision with the Eurasian plate are suspected to be the main cause of the change.

Biotic interchange between the Indian subcontinent and mainland Asia through time

“…Thus, reduced dispersal from India to Asia could be explained by decelerated phylogenetic diversification during the establishment of more seasonal conditions in the source biota. The same applies for the interval from 24 to 21 Ma, when MDE to the Indian subcontinent from Asia was stagnant, as there is good evidence that the climate in northern mainland SE Asia was warm temperate during the Oligocene and Early Miocene 21 29 30 , changing again to more perhumid climates only during the Middle Miocene 30 .…”

Relative CO2Column Height for CO2Geological Storage: A Non-Negligible Contribution from Reservoir Rock Characteristics

“…This structural trap consists of fine-particle claystone (NK) acting as a seal that covers the prospective storage formation of limestone (TR 4 ) located underneath. Further lithology details in the Mae Moh basin can be found in the work by Ratanasthien et al…”

“…44 More scores were even added to top-rank this source−sink pair due to the short distance between them (∼15 km) and hence considerably low CO 2 transportation cost from the source (power plant) to the coal mine sink area. A specific location (cross section line N30.5) with promising formation (i.e., structural trap and sedimentary basins) was selected in the current study by reviewing updated information, 45,46 where the rock samples were cored for examinations (Figure 2b). This structural trap consists of fine-particle claystone (NK) acting as a seal that covers the prospective storage formation of limestone (TR 4 ) located underneath.…”

First Record of Fungal Diversity in the Tropical and Warm-Temperate Middle Miocene Climate Optimum Forests of Eurasia

“…Thus, rocks deposited in these environments range from fluvial sandstones with associated finer-grained overbank deposits to lacustrine mudstones and oil shales, and to mire-associated claystones and lignitic coal seams (Morley and Racey, 2011;Friederich et al, 2016). Considering that many of the basins in Thailand are both sources of coal and hydrocarbons and paleontologically important, significant data exists on intra-basin stratigraphy, biostratigraphy, magnetostratigraphy, and plant-and animalbased paleoecology (Benammi et al, 2002(Benammi et al, , 2010Ratanasthien, 2002;Songtham et al, 2005;Ratanasthien et al, 2008;Thasod et al, 2008;Coster et al, 2010;Sepulchre et al, 2010;Friederich et al, 2016;Grohé et al, 2020;among others). This makes it possible to organize individual coal seams that occur within the basins by age.…”

“…Plant-based reconstructions from coal basins in northern Thailand have indicated a transition from warm-temperate climates in the early Burgidalian (Chiang Mai lignites) to tropical climates by the late Burgidalian-early Langhian (Hod lignites) that largely persisted through the early middle and upper middle Miocene (Ratanasthien et al, 2008;Morley and Racey, 2011). It has been suggested that these changes coincide with increasing paleotopographic relief and intensification of the SE Asian monsoon (Morley, 2012;Steinthorsdottir et al, 2021).…”