The volcanic record in the ANDRILL McMurdo Ice Shelf AND-1B drill core
نویسندگان
چکیده
The 1285 m thick MIS core offers an invaluable opportunity to obtain a detailed record of volcanism in McMurdo Sound. Volcanic stratigraphy and preliminary petrologic data on volcanic rocks in the AND-1B core are reported here. Remarkable volcanic deposits include: a) a phonolitic pumice layer found at ≈85 mbsf which is not correlated to any known vent onshore; b) a black well sorted volcanic sands succession (132.83 to 146.79 mbsf) interpreted as being derived mainly from subaerial Hawaiian/Strombolian eruptions; c) a thick volcanic succession in the middle part of the core with an interbedded submarine lava flow. The flow may be derived from a nearby (≈4 km) vent on the seafloor according to average length of the lavas with similar composition; d) deeply altered tuffs and minor sandstone below 1220 mbsf. Diagenesis and intense alteration at depths >600 mbsf, hamper the interpretation of magma evolution and provenance.
منابع مشابه
Synthesis of the Initial Scientifi c Results of the MIS Project (AND-1B Core), Victoria Land Basin, Antarctica
The ANDRILL Program successfully recovered a 1285 m-long succession of cyclic glacimarine sediment with interbedded volcanic deposits in its fi rst season of drilling from the McMurdo Ice Shelf (MIS). The MIS AND-1B drill core represents the longest and most complete (98% recovery) geological record from the Antarctic continental margin to date, and will provide a key reference record of climat...
متن کاملClast provenance and variability in MIS (AND-1B) core and their implications for the paleoclimatic evolution recorded in the Windless Bight - southern McMurdo Sound area (Antarctica)
Talarico, F. and ANDRILL-MIS Science Team, "Clast provenance and variability in MIS (AND-1B) core and their implications for the paleoclimatic evolution recorded in the Windless Bight-southern McMurdo Sound area (Antarctica)" (2007). ANDRILL Research and Publications. Paper 2. Summary Granule-to cobble-grade clasts in the uppermost 575 m of the MIS drill-core (AND-1B) highlight significant down...
متن کاملProvenance of Pleistocene sediments in the ANDRILLAND-1B drillcore: Clay and heavy mineral data
The cryosphere in the McMurdo Sound region has undergone significant modifications during the last 1 Ma. Consequently, the sedimentary sequences underlying the modern McMurdo Ice-Shelf provide geological data to reconstruct variations in transport and depositional mechanisms of terrigenous material due to variations in ice sheet extension, grounding line position and main icestream flow directi...
متن کاملGeochemical variations detected with continuous XRF measurements on ANDRILL AND-1B core - preliminary results
Antarctica and especially its ice sheets play a major role in both the global ocean current system and climate. The ANDRILL (Antarctic Geological Drilling) MIS deep drilling project (McMurdo Sound, NE Ross Ice Shelf, drilled core AND-1B during austral summer 2006/2007) is located in a flexural moat basin filled with glaciomarine, terrigenous, volcanic, and biogenic sediments (Horgan et al., 200...
متن کاملPalaeomagnetism of the AND-1B Core, ANDRILL McMurdo Ice Shelf Project, Antarctica
Preliminary palaeomagnetic data are presented for the AND-1B drill core. A total of 1309 samples were collected from the drill core immediately following recovery and splitting. Natural remanent magnetisation (NRM) and bulk magnetic susceptibility data were determined for all samples using a Molspin spinner magnetometer and Bartington Instruments susceptibility bridge, respectively, immediately...
متن کامل