Strongly SiO₂-undersaturated alkalic rocks (Mg# > 50, SiO₂ ≤ 45 wt%, Na₂O + K₂O ≥ 3 wt%) occur in three early-stage (Sarnu-Dandali, Mundwara, Bhuj) and one late-stage (Murud-Janjira) rift-associated volcanic complexes in the Cretaceous-Paleogene Deccan Traps flood basalt province of India. Thermobarometry based on clinopyroxene-liquid equilibrium suggests that they mostly crystallized beneath the Moho at ~ 15 kbar/1270 °C to ~ 11–12 kbar/1115–1156 °C pressures and temperatures. Primary magma compositions in equilibrium with lherzolite were estimated through reverse fractionation calculations by incrementally adding equilibrium phases to the rocks in olivine:clinopyroxene:spinel:phlogopite = 12:68:20:15 proportions at low temperatures followed by olivine:clinopyroxene:spinel = 12:68:20 proportions at higher temperatures. A comparison of the primary magmas with experimentally generated melts shows that their compositions are consistent with an origin from garnet lherzolite sources with < 1 wt% H₂O and CO₂. Hornblendite, pyroxenite (except for some Bhuj rocks) and carbonated eclogite are unlikely sources for the Deccan alkalic rocks. The Sarnu-Dandali and Bhuj alkalic rocks and the Murud-Janjira lamprophyres probably originated by < 5% melting of ~ 1.3 times Ti-enriched lherzolitic sources compared to primitive mantle. The primary magmas of the Murud-Janjira basanites calculated through reverse assimilation-fractional crystallization by assimilating lower crustal and mantle xenoliths found in younger lamprophyre dikes of the same area indicate that contamination by the Indian lithosphere was unlikely during their ascent. The basanites evolved by mixing with phonotephritic melts, and they probably originated from a Ti-poor (0.7 times) lherzolite source. The temperature of the melts at the base of the lithosphere was ~ 1325 °C beneath Sarnu-Dandali and ~ 1285 °C beneath Bhuj and Murud-Janjira.

强烈的SiO ₂ -undersaturated碱性岩石（MG＃> 50的SiO ₂  ≤45％（重量），钠₂ O + K ₂O≥3 wt％）发生在印度白垩纪-古近纪Deccan圈闭洪水泛滥的三个早期阶段（Sarnu-Dandali，Mundwara，Bhuj）和一个晚期阶段（Murud-Janjira）与裂谷有关的火山复合体中。基于斜茂铁-液平衡的热压法表明，它们在Moho下大部分在约15 kbar / 1270°C至约11-12 kbar / 1115-1156°C的压力和温度下结晶。通过反向分馏计算，通过在低温下逐渐增加橄榄石：斜长石：尖晶石：金云母= 12：68：20：15的比例的岩石中的平衡相，然后通过橄榄石：斜长石：尖晶石= 1​​2，通过反分馏计算来估算与锂铁矿平衡的主要岩浆成分。在较高温度下以68:20的比例混合。₂ O和CO ₂。斜方晶石，辉石体（某些Bhuj岩石除外）和碳酸榴辉岩不太可能是Deccan碱性岩石的来源。与原始地幔相比，Sarnu-Dandali和Bhuj碱性岩石以及Murud-Janjira煌斑岩可能是<5％的富含Ti的片石质来源的1.3倍以下的熔化。Murud-Janjira basanites的主要岩浆是通过反向同化-分馏结晶而获得的，该同化作用是通过吸收在同一地区较年轻的煌斑岩堤中发现的下部地壳和地幔异种岩而得出的，这表明印度岩石圈在上升过程中不太可能受到污染。玄武岩是通过与磷相熔体混合而演化而来的，它们可能起源于贫钛（0.7倍）的锂铁矿源。