Tectonic, magmatic and hydrothermal evolution of ocean floor spreading at Macquarie Island

Macquarie Island offers a rare land-based cross-section through the deep ocean floor, which covers 60% of our Earth. It formed 11 million years ago as slow spreading crust, which has had minimal study compared to more common fastspreading crust. Does the difference in spreading speed produce different crustal geometry, composition, hydrothermal fluids, and cycling of sulfur between ocean and crust? To gain insights to these and related questions, we propose to study uplifted and eroded sections through a series of fault zones, spaced along the length of Macquarie Island, which were the last magmatic, structural and hydrothermal events to occur before shifting stresses drove the seafloor up to form the Macquarie Ridge mountain chain.

This dataset is a summary of samples obtained by Mr Steve Lewis for the purposes of investigating hydrothermal alteration in oceanic crust on Macquarie Island. Samples derive from the major lake, Lusitania Bay, and Caroline Cove areas. Each sample consists of rock chips up to a maximum of 1 kg.

Samples were all obtained by hand with a geological hammer.

The fields in this dataset are:

Sample
Easting Northing
Date
Location
Transect
Details