Deformation history and timing of granite emplacement in the Butchers Hill – Helenvale region, northern Hodgkinson Province, Queensland
Granite plutons of the Whypalla Supersuite in the Butchers Hill — Helenvale region of north Queensland were intruded into the upper crust of the Hodgkinson Formation during contractional deformation associated with the Permian-Triassic Hunter-Bowen Orogeny. A four-stage structural history has been resolved for the area, with fabric overprinting relationships, porphyroblast-matrix microstructural geometries and isotopic ages being consistent with granite emplacement during D4 shortening at ca 274 Ma. Microstructural relationships suggest the possibility of a minor syn-D3 phase of granite emplacement. The deformation-emplacement history of the Butchers Hill — Helenvale area is consistent with that recognised regionally for the Hodgkinson Province, indicating province-wide synchronous syntectonic granite intrusion during a major phase of contractional deformation. Intense syn-emplacement deformation partitioning was ongoing in the country rocks during progressive D4 and was associated with upward translation of country rock from the microscale to the macroscale along D4 cleavages and shears. Kinematic indicators show that this progressive uplift, at the scale of the area examined, was east-side-up.