The Holocene, Journal Year: 2024, Volume and Issue: unknown
Published: Nov. 30, 2024
Schmidt-hammer exposure-age dating (SHD) was applied to selected rock glaciers in the south central Ben Ohau Range, Southern Alps, New Zealand, expand available regional data set following a previous pilot study. Additional SHD-sampling conducted on high-altitudinal moraines at two locations with published cosmogenic 10 Be surface-exposure ages and utilised establish new SHD-age calibration equation. estimates for total of eight based >16,000 sampled boulders were analysed chronological, morphodynamic, palaeoclimatic context. initiation glacier formation indicated by age their respective frontal ridges spread between 12.1 ± 1.6 7.2 0.8 ka cluster four individual features 9.3 8.6 ka. Activity some commenced immediately after local deglaciation all are considerably older than previously anticipated. Successive transverse dated reveal clear general trend increasing distance from rooting zone. This reflects conveyor-like transport predominantly stable position surface. The themselves interpreted as morphological evidence phases strong morphodynamic activity connected cold periods increased debris supply climate-driven frost weathering. All investigated show climax such during Early Holocene. After c. 7.0 became less frequent subsequently rare Late-Holocene. These newly obtained chronological constraints discussed context related conditions potential complement hitherto limited records Holocene glacial activity.
Language: Английский