40Ar-39Ar investigation of volcanic clasts in glaciogenic sediments at ODP Sites 1097 and 1103 ...

• Main Authors: Di Vincenzo, Gianfranco, Caburlotto, Andrea
• Format: Article in Journal/Newspaper
• Language: English
• Published: PANGAEA 2001
• Subjects: Drilling/drill rig; Leg178; Joides Resolution; Ocean Drilling Program ODP; Antarc*; Antarctic; Antarctic Peninsula
• Online Access: https://dx.doi.org/10.1594/pangaea.737366; https://doi.pangaea.de/10.1594/PANGAEA.737366

Three selected diamictite samples recovered within sequence group S3 at Sites 1097 (Sample 178-1097A-27R-1, 35-58 cm) and 1103 (Samples 178-1103A-31R-2, 0-4 cm, and 36R-3, 4-8 cm) of Ocean Drilling Program Leg 178 have been investigated by scanning electron microscope, electron microprobe, and 40Ar-39Ar laser-heating techniques. They contain variable proportions of fragments of volcanic rock groundmass (mostly in the range of 100-150 µm) with textures ranging from microcrystalline to ipocrystalline. Their rounded shapes indicate mechanical reworking. Fresh groundmass glasses, recognized only in grains from samples of Site 1103, show mainly a subalkaline affinity on the basis of total alkali-silica variations. However, they are characterized by relatively high TiO2 and P2O5 contents (1.4-2.8 and 0.1-0.9 wt%, respectively). Because of the small size of homogeneous grains (100-150 µm), they were not suitable for single-grain total fusion 40Ar-39Ar analyses. The incremental laser-heating technique was applied to ... : Supplement to: Di Vincenzo, Gianfranco; Caburlotto, Andrea; Camerlenghi, Angelo (2001): 40Ar-39Ar investigation of volcanic clasts in glaciogenic sediments at Sites 1097 and 1103 (ODP Leg 178, Antarctic Peninsula). In: Barker, PF; Camerlenghi, A; Acton, GD; Ramsay, ATS (eds.) Proceedings of the Ocean Drilling Program, Scientific Results, College Station, TX (Ocean Drilling Program), 178, 1-26 ...