This dataset contains provenance detrital data from the glacimarine sequence of Deep Sea Drilling Project Leg 28, Site 271 e 272. The two boreholes are located in the middle of the Ross Sea, in a key site close at 180° longitude that is considered the present confluence between ice flows fed by West Antarctica and East Antarctica. These two sites, together, provide insights to Middle Miocene to Present ice sheet dynamics.
We analyzed eight detrital samples of glaciomarine sediments, four from 272 drill core and 4 from 271. We used an integrated single-grain provenance approach (Olivetti et al., 2023). This multi-proxy provenance study employs conventional U-Pb detrital zircon dating integrated with apatite U-Pb and fission-track dating and trace element analysis of detrital apatite.
The dataset suggests a recurrent E - W oscillations of the ice flow divide between ice fed by West and East Antarctica ice sheets, respectively.
This data-set contains provenance detrital data from the glacimarine sequence of Deep Sea Drilling Project Site 270. The 270 site was cored on a flank of the Central High in the central Ross Sea and recovered a thick Oligocene to lower Miocene glacimarine sequence, overlain by ~20 m of Pliocene to Recent strata. This site provides important temporal constraints on regional stratigraphy and insights into late Oligocene to early Miocene ice sheet dynamics. We analyzed eight detrital samples of glaciomarine sediments distributed along the core and two from the basement rocks recovered during coring, by using an integrated single-grain provenance approach. This multi-proxy provenance study employs conventional U-Pb detrital zircon dating integrated with apatite U-Pb and fission-track dating and trace element analysis of detrital apatite and clast petrology. The data-set suggests a general evolution from local erosion due to small ice caps to far-travelled glacial detritus responding to the continuous sea floor subsidence. The detrital age spectra of a late Oligocene diamicitite is consistent with far travelled grains from southern West Antarctica (WA), suggesting an expansion of the WA ice sheet that should be the oldest and first evidence of ice sheet growth on the WA.