A limonitic layer at the base of the Otoceras‐Ophiceras zone in the Lalung section in Spiti valley shows a significant positive europium anomaly with maximum Eu/Eu* = 1.9. This layer defines the contact between the earliest Griesbachian and the Permian Productus shale sequence. The layer shows a small cerium anomaly having the maximum value of (Ce/La)N = 1.4. The iridium concentration in this layer, at 73 pg/g, is only marginally above the levels found in the adjacent shales although higher than that found in the overlying limestones. Another horizon having 114 pg/g of Ir occurs 70 cm below this limonitic layer in the shale sequence. These observations have important implications, both for the terrestrial (mainly volcanic) and extra‐terrestrial impact hypotheses for the Permo‐Triassic transition which are discussed.

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Planktic and benthic foraminifera including uvigerinids are documented from the Upper Bhuban Formation, exposed at Thingdawl village, Kolasib district, Mizoram. The foraminiferal assemblage is poorly preserved and consists of index fossils useful for precise biochronology and interpretation of the depositional environment. A total of ten benthic and six planktic foraminiferal species are described. Six species belong to the genus Uvigerina, four to Ammonia, one species each of Globorotalia, Globigerinoides, Clavatorella, Praeorbulina and two species of the genus Orbulina. Based on lithological and foraminiferal assemblage, middle neritic to upper part of outer neritic paleobathymetry is inferred for the deposition of this part of the Upper Bhuban Formation. The foraminiferal assemblage suggests late Early Miocene to early Middle Miocene, (~16 Ma) equivalent to planktic foraminiferal zones N8-N9 for the Upper Bhuban Formation.