Prominent deformation features and interpretation of sediment core CRP-2/2A (Table 1), supplement to: Passchier, Sandra (2000): Soft-sediment deformation features in core from CRP-2/2A, Victoria Land Basin, Antarctica. Terra Antartica, 7(3), 401-412

• Main Author: Passchier, Sandra
• Format: Dataset
• Language: English
• Published: PANGAEA - Data Publisher for Earth & Environmental Science 2000
• Subjects: Depth, top/min; Depth, bottom/max; Deformation structure, type; Facies name/code; Geology, comment; Core wireline system; CRP-2; Sampling/drilling from ice; Cape Roberts Project CRP; Antarctic; Cape Roberts; Victoria Land; Antarc*; Antarctica; antartic*
• Online Access: https://dx.doi.org/10.1594/pangaea.144477; https://doi.pangaea.de/10.1594/PANGAEA.144477

Sediment deformation features in CRP-2/2A were described during normal logging procedures and from core-scan images. In this paper the origin of soft-sediment folding, contorted bedding, microfaulting, clastic dykes, shear zones and intraformational breccias is discussed. The features have a stratigraphic distribution related to major unconformities and sequence boundaries. Hypotheses for the origins of sediment deformation include hydrofracturing, subglacial shearing, slumping, and gas hydrate formation. Shear zones, microfaults, clastic dykes and contorted bedding within rapidly deposited sediments, suggest that slumping in an ice-distal environment occurred in the early Oligocene. A till wedge beneath a diamictite at 364 mbsf the mid-Oligocene section represents the oldest evidence of grounded ice in CRP-2/2A. Shear zones with a subglacial origin in the early late Oligocene and early Miocene sections of the core are evidence of further grounding events. The interpretation of sediment deformation in CRP-2/2A is compared to other Antarctic stratigraphic records and global eustatic change between the late Eocenel/early Oligocene and the middle Miocene.