Analysis of nutrient content in rocks from New South Wales A study of nutrient content in sedimentary and igneous rock samples within the wider Blue Mountains and Sydney Basin, New South Wales, Australia

Abstract

Nitrogen, phosphorus and potassium are three of the main nutrients for the primary functioning of all biological life. These elemental nutrients are abundant in terrestrial systems and the lithosphere, where microbes and plants can access the nutrients in the rocks at the surface. This study focused on the nutrient content in sedimentary and igneous rock material from New South Wales, Australia, to locate the most nutrient rich areas based on their sedimentary environment. The methods that were used to analyze the total nutrient content of nitrogen (N), phosphorus (P) and potassium (K) were XRF and IRMS. The rock samples were collected from several areas spread out from Sydney Basin to the Blue Mountains. These areas encompass Narrabeen, Leumeah Road, Bradbury, Australian Botanical Garden, Mulgoa National Park, Bilpin, Kurrajong Heights, Mount Wilson, Mount Banks, as well as Lithgow and Sunny Corner. The results showed a high nutrient content in a specific shale called the Ashfield shale, which is the base formation of the Wianamatta shale. This shale was collected in the area of Leumeah Road and Bradbury in the southern part of New South Wales. The N/K correlation of the Ashfield shales gave a result of ~0,99, while the N/C correlation gave the result of 0,7. The analysis shows that the most nutrient rich rocks are based in the Triassic areas of New South Wales, where there used to be a shallow marine to brackish environment close to the Lachlan Fold Belt.