3 research outputs found
Physico-chemical parameters of traditional salt producing springs of Ancient Assam, Northeast India
No full text119-127Three salt springs of ancient Assam (currently in a part of Assam and Arunachal Pradesh, Northeast India) situated in the Mohong area (Phullung and Khela) and Samkhor have been studied to bring out their physico-chemical characteristics by using ionic concentration ratios along with SEM and EDS techniques. The high TDS values of the studied salt springs (wells) under investigation infers mildly brackish water type. The Disang Group of rocks are the dominant lithotypes connected with the spring. The positive correlation between Na+ and Cl- indicates the samples have an origin including halite (NaCl) dissolution, which may imply that the study area's saline and salty springs come from the incongruent dissolution of halite. The larger concentrations of almost all ionic values of Cl-, SO42-, Ca2+, Mg2+, and K+ were found inPhullung and Khela, while lower values were found in Semkhor, which suggests that from Semkhor to Phullung and Khela (i.e., towards northeast), the concentration of salinity increases. The occurrences of the development of crystal phases in the SEM and EDS results also substantiate the salinity increasing trend towards the northeast. The studied samples have lower Na+/Cl-, K+/Cl- and SO42-/Cl- indicating a deeper aquifer source and minimal anthropogenic impact. The average value ofsodium absorption ration (SAR) of 30.62 indicates that the studied water quality is not permissible for agricultural use. The negative BEX values ranging from -20.58 to -203.74 suggest that the aquifer of the studied well are being salinized
Chronological and Archaeometric Evaluation of Bricks from Archaeological Sites of Upper Assam, Northeast India: Estimation of the Firing Temperature and Civilization History
No full textThis study aimed to uncover the chronology and production technologies of ancient bricks unearthed from various locations in Upper Assam, Northeast India. To achieve this goal, complementary spectroscopic techniques such as Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), Scanning Electron Microscope (SEM) coupled with Energy Dispersive Spectrometer (EDS), as well as Thermoluminescence (TL) and Optically Stimulated Luminescence (OSL/IRSL) dating, were applied. FTIR and XRD analyses revealed the presence of quartz, feldspar (microcline, orthoclase, albite), kaolinite, chlorite, cerussite, palygorskite, magnetite, hematite, and organic carbon. The mineralogical composition indicates two distinct groups with firing temperatures below 650 °C and above ~800 °C. These two groups could be the first indication of the presence of two civilizations or at least two different production technologies involving different firing temperatures and kiln atmospheric conditions. Further, the SEM-EDS study suggests that both calcareous and non-calcareous clays were used in brick making, which have low and high refractory properties, respectively. The internal morphology of the samples shows the existence of micropores and microfractures, indicating the influence of higher-temperature firing. Absolute dating techniques associate the two brick groups with different age ranges: a firing temperature above ~800 °C indicates a superior technology corresponding to a production period between the 7th and 10th centuries CE. In contrast, a temperature below 650 °C indicates a technologically less advanced group of people, with the age group dated between the 11th and 14th centuries CE
Physico-chemical parameters of traditional salt producing springs of Ancient Assam, Northeast India
Full text linkThree salt springs of ancient Assam (currently in a part of Assam and Arunachal Pradesh, Northeast India) situated in the Mohong area (Phullung and Khela) and Samkhor have been studied to bring out their physico-chemical characteristics by using ionic concentration ratios along with SEM and EDS techniques. The high TDS values of the studied salt springs (wells) under investigation infers mildly brackish water type. The Disang Group of rocks are the dominant lithotypes connected with the spring. The positive correlation between Na+ and Cl- indicates the samples have an origin including halite (NaCl) dissolution, which may imply that the study area's saline and salty springs come from the incongruent dissolution of halite. The larger concentrations of almost all ionic values of Cl-, SO42-, Ca2+, Mg2+, and K+ were found in Phullung and Khela, while lower values were found in Semkhor, which suggests that from Semkhor to Phullung and Khela (i.e., towards northeast), the concentration of salinity increases. The occurrences of the development of crystal phases in the SEM and EDS results also substantiate the salinity increasing trend towards the northeast. The studied samples have lower Na+/Cl-, K+/Cl- and SO42-/Cl- indicating a deeper aquifer source and minimal anthropogenic impact. The average value of sodium absorption ration (SAR) of 30.62 indicates that the studied water quality is not permissible for agricultural use. The negative BEX values ranging from -20.58 to -203.74 suggest that the aquifer of the studied well are being salinized
