Semiquantitative occurence of various minerals in sediment core CRP-2A

• Main Authors: Neumann, M, Ehrmann, Werner
• Format: Dataset
• Language: English
• Published: PANGAEA 1999
• Subjects: 14.2 km at 096° true from Cape Roberts; Amphibole/standard ratio; Cape Roberts Project; Core wireline system; CRP; CRP-2; CRP-2A; CWS; DEPTH; sediment/rock; Feldspar/standard ratio; Feldspar 3.18 Å (Plagioclase)/standard ratio; Feldspar 3.24 Å (Kalifeldspar)/standard ratio; Grain size; sieving/settling tube; Kalifeldspar/Plagioclase ratio; off Cape Roberts; Ross Sea; Antarctica; Opal-CT/standard ratio; Pyroxene/standard ratio; Quartz/Feldspar ratio; Quartz/standard ratio; Sampling/drilling from ice; Sand; X-ray diffraction (XRD); Zeolite/standard ratio; McMurdo Sound; Transantarctic Mountains; Cape Roberts; Antarc*
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.55616; https://doi.org/10.1594/PANGAEA.55616

The mineralogy of the lower Oligocene to Quaternary sediments of core CRP-2/2A drilled on the continental shelf of McMurdo Sound in Ross Sea, Antarctica, was examined by the X-ray diffraction method. Quartz, plagioclase feldspar and K-feldspar are the most important non-clay minerals. Pyroxene and amphibole occur in minor amounts throughout the core. The composition of the sediments points to an origin in the Transantarctic Mountains for the majority of the detrital components. There, the plutonic and metamorphic rocks of the basement, the sediments of the Beacon Supergroup and the volcanic rocks of the Ferrar Group could serve as possible source lithologies. The distribution of the detrital minerals reflects a long-term history of successive erosion and valley incision. During the deposition of the lower part of the core, the detrital minerals were probably mainly derived from the sediments of the Beacon Supergroup, as indicated by the high quartz but relatively low feldspar abundances. In the upper c. 350 m of the core, the influence of a source in the basement became stronger and results in lower quartz contents but increasing abundance of feldspar. Some diagenetic alteration of the sediments is indicated by the occurrence of zeolites below c. 320 mbsf and of opal-CT above c. 320 mbsf.