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Marine Isotope Stage 5 deposits have been reported on many tropical Pacific islands. This paper presents a database compiled through the review of MIS 5e (last interglacial – LIG) coral reef records from islands belonging to French Polynesia (Anaa, Niau, Makatea, Moruroa, Takapoto, Bora Bora), the Hawaiian Islands (Oahu, Lanai, Midway Atoll), Tuvalu, Kiribati (Christmas Island, Tarawa), the Cook Islands (Mangaia, Atiu, Mitiaro, Mauke, Pukapuka, Rakahanga, Rarotonga), Tonga, Samoa, the Federal States of Micronesia, the Mariana Islands, the Marshall Islands (Enewetak, Bikini), New Caledonia, Papua New Guinea, the Solomon Islands, Vanuatu, Fiji and Niue. Studies reporting other sea-level indicators dated to other Pleistocene interglacials and Holocene sea-level indicators were not inserted in the database but are included in this data description paper for completeness. Overall, about 300 studies concerning Pleistocene and Holocene sea-level indicators have been reviewed, and finally 163 age data points and 94 relative sea-level (RSL) data points from 38 studies on the MIS 5e have been inserted in the database. An additional 155 age data points have been reviewed; i.e. the tropical Pacific islands database contains 318 age data points. The main sea-level indicators include emerged coral reef terraces, but also reef units recovered in drill cores from a few islands, thus reflecting the diversity of tectonic settings and sampling approaches. Future research should be directed towards better constrained RSL reconstructions, including more precise chronological data, more accurate elevation measurements and a better refinement of the palaeo-water-depth significance of coralgal assemblages. The database for tropical Pacific islands is available open access at this link: https://doi.org/10.5281/zenodo.3991672 (Hallmann and Camoin, 2020).

Sundaland, the inundated shelf separating Java, Sumatra and Borneo from the Malay Peninsula, is of exceptional interest to biogeographers for its species richness and its position at the junction between the Australasian and Indomalay biogeographic provinces. Owing to its low elevation and relief, its physiography is contingent on relative sea-level change, which drove Quaternary species burst in response to flooding episodes. New findings show that the region was predominantly terrestrial during the Late Pleistocene requiring a reassessment of the drivers of its recent biodiversity history. Here we show that physiographic changes have modified the regional connectivity network and remodelled the pathways of species dispersal. From combined landscape evolution and connectivity models, we found four phases of drainage reorganisation and river captures. These changes have fragmented the environment into multiple habitats connected by migratory corridors that cover 8% of the exposed shelf and stretch across the biogeographic provinces. Our results support the theory that rapidly evolving physiography could foster Quaternary biodiversification across Southeast Asia. Physiographic changes such as river catchment drainage reorganisations played an important role in Quaternary species diversification in Sundaland, Southeast Asia, according to simulations using combined landscape evolution and connectivity models.

Mature orogenic plateaux grow in response to the lateral redistribution of plateau material, driven by gravitational potential energy, from the thick plateau crust toward the thinner foreland crust. Folding and thrusting in the shallow crust as well as flow of weak deep crust toward the foreland result in plateau growth. The balance between plateau growth processes, including gravitational collapse of the orogenic crust, and the resistance to plateau propagation controls the position of plateau margins. Toward the end of orogenic plateau development, plateau margins are the loci of steep topographic gradients, where erosional processes can be aggressive. The margins also represent the transition between thick crust and thin/weak lithosphere beneath the plateau, and thinner crust and strong/thick lithosphere below the foreland.The juxtaposition of thick and thin lithosphere favors strain localization along plateau margins, where thick lithosphere may partially subduct, or where strike-slip systems, such as the Altyn Tagh region of northern Tibet, develop. In either case, it is likely that the deep, flowing, partially molten crust will sample and entrain high-P (HP) metamorphic rocks such as granulite and eclogite. In the case of lithospheric strike-slip systems, crustal thickening in transpressional domains may lead to HP metamorphism, and crustal thinning in transtensional domains may lead to rapid exhumation of the deep crust, particularly where pull-apart structures in the shallow-crust allow the upward flow and emplacement of migmatite domes. For example, the Montagne Noire dome (French Massif Central) formed at the southern margin of the Variscan orogen in the late Carboniferous (315-295 Ma). This dome is filled with Variscan migmatite containing eclogite fragments that were sampled near Moho depths and entrained in the flowing partially molten crust; eclogitization and early crystallization of melt were coeval. In this example, the redistribution of mass and heat across the plateau margin, including the exhumation of near-Moho rocks, stabilized the crust and marked the end of orogeny.

International audience

International audience; Absolute reference frames are a means of describing the motion of plates on the surface of the Earth over time, relative to a fixed point or “frame.” Multiple models of absolute plate motion have been proposed for the Cretaceous–Tertiary period, however, estimating the robustness and limitations of each model remains a significant limitation for refining both regional and global models of plate motion as well as fully integrated and time dependent geodynamic models. Here, we use a novel approach to compare five models of absolute plate motion in terms of their consequences for forward modelled deep mantle structure since at least 140 Ma. We show that the use of hotspots, either fixed or moving, or palaeomagnetics, with or without corrections for true-polar wander, leads to significant differences in palaeo-plate velocities of over 10 cm/yr as well as differences in the location of palaeo-plate boundaries of up to 30° in longitude and latitude. Furthermore, we suggest that first order differences in forward predicted mantle structure between the models are due mostly to differences in palaeo-plate velocities, whereas variation in the location of plate boundaries may contribute to smaller wavelength offsets. We present a global comparison of the absolute reference frames in terms of mantle structure, which we have tomographically filtered to reflect the resolution of the seismic tomography model S20RTS. At very long wavelengths hotspot models best reproduce the mantle structure. However, when geometry and the match of smaller-scale subducted slab volumes are compared, a hybrid model based on moving hotspots after 100 Ma and palaeomagnetic data before (with no corrections for true-polar wander), best reproduces the overall mantle structure of slab burial grounds, even though no single model fits best at all mantle depths. We find also that the published subduction reference frame tested here results in a modelled mantle structure that agrees well with S20RTS for depths > 2500 km, equivalent to subduction before the Cretaceous, but not for shallower depths. This indicates that a careful assimilation of hotspot, palaeomagnetic and seismic tomography data into future absolute plate motion models is required to derive a more robust subduction reference frame.