Multiproxy Chronologies of the Hurd Rock Glacier (Livingston Island, South Shetland Islands, Maritime Antarctica): Between the Late‐Stage Stabilization and Flow Deceleration

ABSTRACT The Hurd Rock Glacier, located on Livingston Island (South Shetland Islands archipelago, Maritime Antarctica), is a tongue‐shaped feature composed of angular boulders, displaying transverse ridges and furrows, and featuring lobate structures, which are more prominently developed in its frontal sector. At the top, an inactive glacier moraine overlies the rock glacier body. To understand the recent evolution of this system, a geochronological survey has been carried out through a combination of three dating techniques: (i) Cosmic‐ray exposure (CRE) dating based on the 36 Cl cosmonuclide applied to six boulders from the rock glacier frontal lobes; (ii) lichenometric dating, using Rhizocarpon geographicum species, of the upper glacier moraine; and (iii) 12 weathering measurements performed with a Schmidt hammer on the rock glacier lobes as well as on the glacier moraine. The results support an evolutionary model involving the following phases: (i) stabilization of the rock glacier front and/or a reduction in its kinematics around 3–4 ka; (ii) a progressive stabilization or slowing down of the rock glacier suggested by decreasing Schmidt‐hammer exposure‐age dating (SHD) values with increasing distance (and elevation) from the rock glacier front; and (iii) a very recent abandonment age of approximately 66 years for the upper moraine. These findings are consistent with the glacial and periglacial dynamics documented in this region of maritime Antarctica over the last few millennia.