Cape Roberts Project

In October of 1997 drilling started on fast sea ice at 77°0.48 S and 163°45.3 E approximately 16 km off Cape Roberts located south of Granite Harbor and about 30 km from the floating ice of the Mackay Glacier in Eig. 19.3. The drill site is underlain by 150 m of water near the margin of the Victoria Land Basin. Drilling had progressed to a depth of 148 m below the sea floor when operations were hurriedly suspended on 

October 24, 1997, because the sea ice began to break up after a severe windstorm (Cape Robert Science Team 1998). 

The core recovered at CRP-1 consists of43.55 mbsf (meters below sea floor) of glacial sediment of Quaternary age overlying early Miocene glacigenic sediment. The oldest sediment recovered at the bottom of the CRP-1 core is a mudstone dated at 22-24 Ma (early Miocene). 

The drill site is located on the western edge of the Victoria Land Basin which extends to a depth of about 15 km below sea level and is filled with sedimentary and volcanic rocks on a basement of granitic gneisses. The sedimentary rocks are in large part of glacial origin. The Victoria Land Basin formed by crustal extension and subsidence related to the Cenozoic West Antarctic Rift (Section 15.5.5). 

The isotopic composition of strontium of mollusc shells in the early Miocene section of the CRP-1 core (46-62 mbsf) indicated dates of 16.6 0.4 and 18.7 0.3 Ma in agreement with the diatom biostratigraphy of Harwood et al. (1998). The Ar/ Ar date of a volcanic clast (18.4 1.1 Ma) measured by McIntosh (1998) confirms the early Miocene (Burdigalian) age of the sediment. 

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The most detailed historical record of McMurdo Sound is contained in the driU cores that have been recovered from McMurdo Sound, which includes not only CIROS-1, CIROS-2, and MSSTS-1, but also DVDP 15 (Dry Valley Drilling Project McGinnis 1981) and CRP-1, CRP-2/2A, and CRP-3 (Cape Roberts Project Terra Antartica, 1998-2001). 

Fig. 19.3 The Cape Roberts Project drilled three holes through the sea ice about 16 km off the coast of southern Victoria Land at Cape Roberts. The cores are identified as CRP-1, CRP-2, 2A, and CRP-3 and were located close to CRP-1. The Cenozoic sediment at these sites dips away from the coast into the Victoria Land Basin. The cores consist of Oligocene to Miocene sediment composed of glacial diamictite interbedded with mudstone and sandstone. The sediment records the gradual cooling of the climate and increasing deposition of glacial sediments. CRP-3 bottomed in Devonian sandstone of the Beacon Supergroup (Adapted from Cape Roberts Science Team (1998) published in Terra Antartica vol. 5(1) 1-30, 1998)...

Barrett PJ (1998a) Studies from the Cape Roberts Project, Ross Sea, Antarctica. Scientific Report of CRP-1, overview. Terra Antartica 5(3) 255-258... 

Cape Roberts Science Team (1998) Background to CRP-1, Cape Roberts Project, Antarctica. Terra Antartica 5(1) 1-30 Carlquist S (1987) Pliocene Nothofagus wood from the Transantarctic Mountains. ALISO ll(4) 571-583 Cartwright K, Treves SB, Torii T (1974) Geology of DVDP 4, Lake Vanda, Wright Valley, Antarctica. Dry Valley Drilling Project (DVDP) Bull 3 49-74... 

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