MRT lends expertise to Woody Hill Point field trip
On October 13, 2025, Carl Jackman, from Mineral Resources Tasmania, assisted with a field-based trip coordinated by the Wynyard University of the Third Age (U3A), which looked at the diversity of rocks that outcrop along the beach and headland at Woody Hill Point, between Somerset and Wynyard.
The U3A is an is an international movement whose aims are the ongoing education of mainly retired and semi-retired members of the community. The Wynyard U3A has a diverse education and activities program that includes guest speakers from a variety of different fields. This U3A branch is particularly interested in the Earth Sciences, taking advantage of the unique geology of the northwest coast of Tasmania, and has previously had guest speakers from MRT deliver presentations on a variety of topics as part of their community engagement program. The field trip coincided with Seniors Week in Tasmania (October 13th to October 19th), and was attended by the local Member for Braddon, Roger Jaensch.
The rocks at Woody Hill Point include a sequence of fine-grained glass-shard rich volcaniclastics, which were redeposited on a volcanic slope in a marine setting. These now form glassy sandstone layers but when the sediment was still wet, lava flows mingled with the sediment, forming hyaloclastite and peperite - a kind of volcanic breccia. These are visible along the base of the lavas. The lava flows show polygonal and curvi-planar joints. Concentric jointing is visible around circular depressions in the lava flows.
These relatively young volcanic rocks occur above the folded, slatey pelitic rocks of the Neoproterozoic Oonah Formation. There is an angular unconformity between the two units, and a channel of conglomerate appears to overlap with the volcanic rocks beneath.
The field trip was fortunate to have favourable weather and tides, and some of the participants commented that they were surprised to learn of the complex geological processes that occurred along a stretch of coastline they drive past every day.