Did the Himalayan eclogitization occur before or after the India-Asia collision?

Eclogites exposed in the Kaghan Valley of Pakistan are divided petrologically into two groups as high- pressure (HP) and ultrahigh-pressure (UHP) eclogites. Group I (HP) eclogites are composed of garnet + clinopyroxene + quartz + amphibole ± phengite ± epidote/allanite + rutile ± ilmenite with abundant zircon grains of large size (> 250 µm), considered as derived from a gabbroic protolith. Group II (UHP) eclogites are composed of garnet + clinopyroxene + coesite + epidote + phengite + amphibole + rutile/ilmenite with rare zircon grains of small size (< 50 µm), considered as the products of tholeiitic basalts. Whole-rock multi-isotope systems indicate considerable trace element mobility or fluid infiltration during subduction of the Indian plate under the Asian plate. Due to this mobility or fluid infiltration, the Sm-Nd, and Lu-Hf isotope systems do not define a geologically meaningful age. The very low Sm/Nd (< 0.6) and Lu/Hf (< 0.4) ratios of garnet and the variable two- or three-point Sm-Nd and Lu-Hf isochrons/mixing lines indicate mineral disequilibrium. Two generation of zircons are found in these eclogites. First generation zircons are of magmatic origin. They are large and concentrically zoned. Second generation zircons are of metamorphic origin. They are small and or occur as overgrowths along the magmatic portions. The U-Pb concordant age of 267 ± 2 Ma, from the core portion of zircon (magmatic) from Group I eclogites, is assumed to be the eclogite protolith age, whereas, the 71 ± 6 Ma from the rim portion of zircon (metamorphic overgrowth) provides evidence that the eclogite protolith subducted before the India-Asia collision, and the UHP event took place afterwards when these rocks reached to depth more than 90 km.