Conference Agenda

The Shillong Plateau (SP) of northeast India preserves an enigmatic lower-crustal archive whose tectonic evolution remains poorly constrained due to unresolved relationships among deformation, metamorphism, melt evolution and geochronology across crustal scales. A key geological problem is whether the SP records a single tectonothermal cycle or multiple episodes of crustal reworking associated with supercontinent amalgamation and break-up. The paleogeographic position of the SP during Proterozoic-Cambrian orogenesis remains equally unresolved, as does the relationship between the (ultra)high-temperature (UHT/HT) metamorphism of the basement Assam-Meghalaya Gneissic Complex (AMGC) and the supercontinent cycle. To address these problems, this study integrates zircon and monazite U–Pb geochronology, trace element geochemistry, Ti-in-zircon thermometry, and phase equilibria modelling of metapelite and metabasic rocks exposed across the Eastern and Western sectors of the SP. Zircon and monazite geochronology reveal that the major metamorphic episode occurred during Cambrian orogenesis at ca. 500 Ma, linked to Gondwana amalgamation. Peak metamorphic assemblages from the Western Sector indicate ultra-high temperature conditions of ~930–980°C at 7–8 kbar, whereas the Eastern Sector preserves comparatively lower P–T conditions (~750–780°C at 5.5–6 kbar) with abundant leucosome development, reflecting contrasting melt evolution across the plateau.

We propose that magmatic underplating triggered deep crustal heating and UHT metamorphism, while upward melt migration thermally buffered the mid-crust. Subsequent deformation and exhumation along major high-strain zones exposed an E-W crustal section characterised by a high metamorphic field gradient (~29°C/km). The Shillong Plateau likely occupied a leading-edge position within the Indo–Australo–Antarctic orogenic system during Gondwana amalgamation.

This study provides a comprehensive sedimentology and detailed field sequence stratigraphic study of Enugu, Mamu and Ajali Formations.Thirty-two (32) outcrop sections were mapped: six (6) in Enugu Formation, eight (8) in Mamu Formation and six (6) in Ajali Formation respectively. Sedimentologic, sequence stratigraphic and biostratigraphic analyses were applied towards the Geology of the area. Eleven (11) lithofacies were identified: cross-stratified sandstone, bioturbated cross-stratified sandstone, parallel laminated sandstone, wavy laminated sandstone, sand-dominated heterolithics, mud-dominated heterolithics, mudstone/shales, conglomerate/ pebbly sandstone, Shelly limestone, oolithic ironstone,coals/lignite.The field sequence stratigraphic interpretation reveals: two (2) sequence boundaries (SB), one (1) lowstand systems tract (LST), one transgressive systems tract (TST), one (1) maximum flooding surface (MFS) and two (2) highstand systems tract (HST) in the three formations altogether. Biostratigraphic microfossils recorded are as follows: Cingulatisporites ornatus, Longapertities sp., Laevigatosporites sp., Buttania andreevi, Trichodium sp., Milfordia sp., Monocolpites marginatus, Longapertities marginatus, Proxapertities Cursus, Botryococcus braunii, Haplophragmoides excavata and Trochammina sp. The synthesis of the foregoing results suggest a Late Campanian-Maastrichtian age in a central estuarine to coastal to shallow marine shelf environments. The results generated above if applied in the future will fasciliitate the interpretation of the sedimentology and field sequence stratigraphy of Anambra Basin.

Keywords: Depositional environments, sequences, stacking patterns, cyclicity, Anambra Basin.

The global transition toward low-carbon energy systems has intensified demand for critical raw materials, particularly lithium, a key component of lithium-ion batteries used in electric vehicles (EVs), renewable energy storage systems, and advanced electronics. As countries pursue decarbonization strategies, securing reliable lithium supply chains has become a major geopolitical and economic priority. Africa possesses significant reserves of critical minerals, and Nigeria is increasingly emerging as a promising lithium province within the global energy transition framework. This study provides a strategic assessment of lithium resources in Nigeria and evaluates their potential contribution to Africa’s green energy future. The research synthesizes geological data on lithium-bearing pegmatites within the metasedimentary and granitic complexes in Nigeria, Zimbabwe, Mali, Congo DR and Namibia. These deposits host lithium-bearing minerals such as spodumene, lepidolite, and petalite associated with rare-metal pegmatites formed during different orogenic events. The study further examines the implications of rising global lithium demand driven by the rapid expansion of EV manufacturing and renewable energy storage technologies. However, global lithium demand is projected to increase up to thirteen-fold by 2040, thus, intensifying competition for new sources of supply. Nigeria’s emerging lithium sector therefore represents a strategic opportunity for Africa to participate more actively in the global battery supply chain. Ultimately, Nigeria possesses considerable geological potential, achieving resource security requires improved exploration, sustainable mining practices, and the development of domestic mineral processing and battery manufacturing industries. Integrating these strategies could position Nigeria as a key contributor to Africa’s critical mineral supply for the global energy transition.