TO: Tom Davies

FM: Carlos A. Alvarez Zarikian


JA Daily Science Report for Expedition 306, 30 March 2005.


LOCATION: Site U1313 (IRD3A)



Coring in Hole U1313B concluded at 1925 hr with the retrieval of Core 32H at a final depth of 302.4 mbsf and a recovery of 102%. The final cored interval at Hole U1313B spans from the Holocene to the Late Miocene (~6 Ma) according to foraminifer and nannostratigraphy. As in Hole U1313A, Cores 1H to 3H are mainly composed of moderate to highly bioturbated nannofossil ooze, foraminifer nannofossil ooze and silty clay foraminifer nannofossil ooze. Core 1H exhibited up to 20% diatom content. The top of Core 1H was characterized by brownish (10YR 8/3, 10YR 7/3, 2.5Y 7/4) sediments while the rest of the core down to Core 3H were dominantly medium light gray (N6), with light olive gray (5Y 6/2), light gray (5Y 7/1), olive yellow (5Y 6/6), and greenish (5Y 6/3) mm-cm thick laminae.


At Hole U1313A, Cores U1313A-19H to 33H mainly consist of white (N9) nannofossil ooze. Two conspicuous foraminifer sand layers were observed in Core 12H Section 1 (0.42-0.71 m) and Core 20H Section 1 (1.24-1.33m), respectively. The Matuyama/Gauss and the Gauss/Gilbert boundaries were identified at Hole U1313A at a depth of 111 m (2.581 Ma) and 155.2 m (3.58 Ma), respectively.