Carbonate drowning successions of the Bird’s Head, Indonesia

Abstract

environment. Already foundering carbonate platforms due to environmental deterioration were left vulnerable to submergence and eventually succumbed to drowning. Low rates of carbonate production were outpaced by the rate of relative sea-level rise caused by high-amplitude oscillations in global glacio-eustatic sea-level change and/or regional tectonic subsidence. The duration of the drowning event across the entire Bird's Head region is interpreted to have lasted a duration of approximately 9.5 My, between 18.0 and 8.58 Ma. This has implications when interpreting timings of sedimentary basin fill across western New Guinea and in other basins where carbonate platform drowning is recorded.

Timing and Pacing of Indonesian Throughflow Restriction and Its Connection to Late Pliocene Climate Shifts

“…We therefore interpret Interval 2 at Site U1463 to reflect increasing "northern ITF source waters" from the north Pacific as indicated by decreasing SST at Site 763 after 3.54 Ma. This interpretation is in line with the proposed closure and/or restriction of the equatorial Pacific ITF pathway due to the uplift of Halmahera and closure of the Halmahera strait (Godfrey, 1996;Gold et al, 2017;Hall, 2002;Hall et al, 1988;Kuhnt et al, 2004;Molnar & Cronin, 2015;Wijeratne et al, 2018; Figures 2, 3, and 5b). This led to a possibly narrower LC, similar to its modern configuration, with more turbulent flow and stronger LC eddy formation (Waite et al, 2007).…”

“…Deep blue lines indicate active subduction zones during the Pliocene (Hall, , ). Uplift of Timor is implied by 3.5 Ma (Tate et al, ); closure of the Halmahera straight and uplift of Halmahera during this timeframe is implied by modeling data and field studies (Audley‐Charles, ; Cane & Molnar, ; Godfrey, ; Gold et al, ; Hall, ; Hall et al, ; Kuhnt et al, ; Molnar & Cronin, ). Vegetation cover was reduced in this map to reflect lower riverine influx indicating reduced precipitation.…”

Tectonic Mode Switches Recorded at the Northern Edge of the Australian Plate During the Pliocene and Pleistocene

“…It is also recorded in offshore seismic data which shows the Miocene Klasafet Formation (and age equivalent units) have been folded (e.g., Bailly et al, , and arguably Pairault et al, , as well as Sapin et al, ; Figure ), the local sea‐level curve differs to global sea‐level curves. The local sea‐level curve shows a change from deeper water conditions (50–100 m) to shallower water conditions (0–10 m) between the Early to Late Pliocene (Gold, Burgess, et al, ; Gold, White, et al, ; Figure d), the removal of early Pliocene to Mesozoic sequences due to erosion—as recorded in various hydrocarbon exploration wells (cf. Figure 18 in Gold, White, et al, ) as well as in regional offshore seismic imagery (e.g., Bailly et al, ; Pairault et al, ). Our structural and geochronological data combined with these other data sources confirms the suggestion that the Lengguru Fold Belt must have developed due to a young (5–3 Ma) episode of crustal shortening (e.g., Decker et al, ; Dow et al, ; Moffat et al, ; Pieters et al, ; Visser & Hermes, ), rather than an earlier episode at ca.…”

“…At least two major accretion events are recognized along the length of New Guinea between ~45 Ma and the present day; (1) the obduction of the Papuan Ophiolites, accretion of volcanic arc fragments of Pacific affinity, and the development of a widespread unconformity across western New Guinea and the southern Molucca's during the Oligo‐Miocene (Ali & Hall, ; Gold, Burgess, et al, ; Gold, White, et al, ; Hall, ; Hall, Ali, & Anderson, ; Hall, Ali, Anderson, & Baker, ; Holm et al, , ), and (2) accretion of the additional arc material during the Pliocene‐Pleistocene (e.g., Davies, ; Dow et al, ; Holm et al, ; Monnier et al, ; Pigram & Symonds, ; Pubellier et al, ). These accretionary events are considered to have been driven by the northward advance of the Australian Plate since the Eocene and 40° clockwise rotation of the Philippine Sea Plate along the northern margin of the Australian Plate between the Early Neogene and present day (Ali & Hall, ; Hall, , ; Hall, Ali, & Anderson, ; Hall, Ali, Anderson, & Baker, ; Hill & Hall, ).…”

Evolution and Geological Significance of Larger Benthic Foraminifera

“…Tracing the stratigraphic distribution of the larger benthic foraminifera allows the understanding of the impact of climate, tectonic activity and volcanism on long-term (i.e. millions years) evolution of these shallow-water carbonate platforms (Courgeon et al, 2016(Courgeon et al, , 2017Gold et al, 2017aGold et al, , 2017b. Larger foraminifera and planktonic foraminifera overlap in occurrence in many localities allowing direct comparison of larger foraminifera "letter stages" biozones with oceanic planktonic scales (BouDagher-Fadel, 2002;BouDagher-Fadel, 2013, 2015Sharaf et al, 2013).…”