Complex patterns of schist tor exposure and surface uplift, Otago (New Zealand)

Landscapes are subjected to surface denudation during their complex and non-linear evolution. In order quantify the in situ lowering and, thus, or soil erosion rates, new, multi-millennia archives needed must be rigorously tested. Large residual rocks, tors, basis for Tor Exhumation Approach. Here we present novel results on meta-sedimentary (schist) rock tors using this approach, which previously has only been applied granitic terrains. The exhumation patterns of eight schist three landscape locations (valley, ridge, distal) Otago, New Zealand, were studied cosmogenic dating. 10Be ages have high variability along individual vertical tor profiles. Average age is 122 ± 12 ka ranges from 836 89 19 2 ka. majority investigated surfaced MIS 5 was one wettest warmest climate periods. resulting trend differs. valley commenced no earlier than ~200 with rates ~0.22 [m kyr?1] ~0.02 kyr?1]. contrast, exposure started at ridge position around 230 ~0.03 An inversion found considered result mushroom-like by undercutting repeated breakoffs. distal site exhumed continuously ~120 a rate ~0.2 ~0.05 We identified mix emergence such as continuous-, mushroom-, tafoni- structural-like. comparison modern indicates that increased up factor ten last few decades. To determine actual uplift, linked derived uplift data. data decrease Middle Pleistocene (0.04–0.09 kyr?1]), remained relatively low Late (~0.01 kyr?1]) increase again Holocene (c. 0.21–0.64 kyr?1]). summary, pattern local enabled reconstruction evolution Pleistocene-Holocene surfaces East Otago.