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IODP Expedition 369

Australia Cretaceous Climate and Tectonics


Daily Science Report for 19 November 2017

Location:
• Hole U1516D (34°20.9277′S, 112°47.9573′E)
• In transit to Site U1513

Science Update: After drilling without coring from 123 to 458 m, we recovered Cores 2R to 5R to 477.6 m, which spanned the Cenomanian/Turonian boundary interval. Core recovery was excellent (95%). We brought the drill string up to the rig floor by 2255 h. Shortly after, we started our transit back to Site U1513 where we plan to extend the total depth of the site and recover additional basalt, as well as attempt wireline logging again.

Cores U1516C-37R to 41R were described; they consist of black to dark greenish gray claystone with nannofossils. Inoceramid fragments and prisms are present in discrete intervals in Cores 34R, 40R, and 41R. Quartz, glauconite, pyrite, and plant debris are commonly seen in smear slides. Based on calcareous nannofossils and planktonic foraminifera, all of this material is Albian in age.


Daily Science Report for 18 November 2017

Location:
• Hole U1516C (34°20.9272′S, 112°47.9711′E; 2677 m water depth)
• Hole U1516D (34°20.9′S, 112°47.9′E)

Science Update: We recovered Cores 30R to 41R to 541.6 m, the target depth of Hole U1516C. We then pulled the drill string out of the hole, clearing the seafloor at 1950 h. We offset the ship 20 m west and started Hole U1516D at 2115 h. We drilled without coring to 123 m. The plan for this hole is to recover a second copy of the Cenomanian/Turonian boundary interval (~470 m) and Oceanic Anoxic Event (OAE) 2.

Cores 24R to 36R were described. Core 24R is a sponge spicule-rich nannofossil chalk with clay. Core 25R to Section 26R-4 is a nannofossil-rich claystone. From Section 26R-4 to 31R-3 is calcareous or nannofossil chalk with chert. There is a transition from the greenish gray chalk to green claystone in Section 31R-3 which directly overlies a black shale (OAE 2) in Section 31R-CC and 32R-1. Below this and to the base of Core 33R, the lithology is a clayey nannofossil chalk that alternates in color between gray, green, and black. Cores 34R to 36R are mottled black claystone. Based on calcareous nannofossils and planktonic foraminifera, the base of Core 24R is Eocene in age. There is then a large hiatus; the base of Core 26R is Turonian in age. Cores 27R through the base of 31R is Turonian, and Cores 32R to 34R are Cenomanian. Cores 35R and 36R are Albian in age.


Daily Science Report for 17 November 2017

Location: Hole U1516C (34°20.9272′S, 112°47.9711′E; 2677 m water depth)

Science Update: We recovered Cores 9R to 29R to 460 m.

Cores 7R to 23R were described. Cores 7R and 8R consist of calcareous ooze, which transitions to calcareous chalk from 9R to 16R. Cores 17R to 23R are nannofossil chalk. Clay becomes a major component in Core 23R. Sponge spicules are abundant throughout. Based on calcareous nannofossils and planktonic foraminifera, the base of Core 7R is middle Miocene in age, Cores 10R to 16R are Oligocene in age, and Cores 17R to 22R are Eocene. The base of Core 23R was composed of chert.


Daily Science Report for 16 November 2017

Location: Hole U1516C (34°20.9272′S, 112°47.9711′E; 2677 m water depth)

Science Update: After offsetting the ship 20 m south, we began preparations for RCB coring. We started Hole U1516C at 1240 h and drilled without coring to 196 m. We then recovered Cores 2R to 8R to 263.2 m. Cores 2R and 6R had very little recovery (0.04 and 0.07 m, respectively), but we averaged 43% recovery on the other cores.

Cores U1516A-25F to 29F (200.1–223.72 m CSF-A, the base of Hole U1516A), and U1516C-2R to 6R (196.0–234.47 m CSF-A) were described and consist of nannofossil ooze. Sponge spicules are abundant throughout. Based on calcareous nannofossils and planktonic foraminifera, all of the described material is late Miocene in age.


Daily Science Report for 15 November 2017

Location:
• Hole U1516A (34°20.9169′S, 112°47.9553′E; 2677 m water depth)
• Hole U1516C (34°20.9′S, 112°47.9′E)

Science Update: We recovered Cores 13H to 29F to 223.6 m. We had difficulty recovering Core 29F, so we decided to stop coring in this hole. In total for Hole U1561A, we recovered 233.26 m from 223.6 m cored (104%). Then we pulled the drill string clear of the seafloor and started Hole U1516B at 1905 h. We recovered two cores from this hole (to 16.2 m), and all of the material was sectioned on the catwalk for postexpedition analyses. Then we began pulling the drill string back up to the rig floor to change the coring system to the RCB for Hole U1516C, and the ship was offset 20 m south.

Cores 5H to 24F were described. Cores 5H to 16H consist of calcareous ooze, and Cores 17H to 24F consist of nannofossil ooze. Sponge spicules are abundant throughout. The ~5 cm thick intervals of darker gray/black silty siliciclastics still occur about once per core. There is a discrete pyrite interval (2 cm thick) in Section 11H-5. These intervals all have a sharp bottom contact and a gradational top contact. Based on calcareous nannofossils and planktonic foraminifera, Cores 5H to 14H are Pliocene in age, and the material below the base of Core 15H is Miocene.


Daily Science Report for 14 November 2017

Location: Hole U1516A (34°20.9169′S, 112°47.9553′E; 2677 m water depth)

Science Update: We arrived on site at 0148 h and began preparations for piston coring. Hole U1516A was started at 1220 h. We recovered Cores 1H to 12H to 109.2 m (104% recovery). We successfully obtained in situ formation temperature measurements while taking Cores 3H, 5H, and 7H.

Cores 1H to 4H were described and consist of calcareous ooze with sponge spicules. There are ~5 cm thick intervals (at least one per core) of darker gray material that contain higher siliciclastic components and pyrite. These intervals generally have a sharp bottom contact. Based on calcareous nannofossils and planktonic foraminifera, Cores 1H to 3H are Pleistocene in age, and the base of Core 4H is late Pliocene.


Daily Science Report for 13 November 2017

Location:
• Hole U1515A (33°16.1890′S, 114°19.3666′E; 850 m water depth)
• In transit to Site U1516 (proposed Site MBAS-10C)

Science Update: We recovered Core 55R to 517.1 m, which was the final core of Hole U1515A. In total, we recovered 93.62 m of the 517.1 m cored (18%). Then we brought the drill string back up to the rig floor by 1350 h and were underway to Site U1516 at 1400 h.

Cores 49R through 55R consist of black to gray sandstone and silty sandstone interbedded with claystone. The bedding is slightly inclined. Plant debris and quartz are abundant. Strict age control from microfossils is not possible, but rare spores have been observed that indicate the material is Jurassic in age.


Daily Science Report for 12 November 2017

Location: Hole U1515A (33°16.1890′S, 114°19.3666′E; 850 m water depth)

Science Update: We recovered Cores 41R through 54R to 507.5 m. A total of 25.04 m of material was recovered from 134.4 m cored (22%). Cores 51R and 52R had no recovery.

Cores 36R through 48R were described. These cores are black sandstone interbedded with siltstone and claystone. The cores are mottled or massive and there are normally graded sequences in each of the cores. Occasionally, there are laminated intervals. On the whole, the bedding is slightly inclined. Sections 45R-1 and 47R-1 contain anthracite, and pyrite nodules are common throughout. Additionally, plant debris, quartz, and feldspar are abundant.


Daily Science Report for 11 November 2017

Location: Hole U1515A (33°16.1890′S, 114°19.3666′E; 850 m water depth)

Science Update: We retrieved Cores 19R through 40R to 373.1 m. We recovered 24.12 m of material from 211.2 cored (13%). Cores 19R to 21R, 25R, 27R, and 28R had no recovery.

Cores 12R through 35R were described. Core 12R is calcareous chalk with silicified limestone and chert. Cores 13R and 14R are chert. Core 16R is sandy limestone. Cores 24R to 31R are glauconitic sand, and Cores 32R to 35R are glauconitic sandstone. Based on calcareous nannofossils and planktonic foraminifera, Cores 11R to 14R are Miocene to Eocene in age. Core 15R could be late Campanian, based on the nannofossil assemblage. Below Core 15R, there are no microfossils.

The science party completed the Site U1514 reports.


Daily Science Report for 10 November 2017

Location: Hole U1515A (33°16.1890′S, 114°19.3666′E; 850 m water depth)

Science Update: After arriving on site at 0005 h, we started coring in Hole U1515A at 0650 h. We retrieved Cores 1R to 18R to 161.9 m. Core recovery was variable, but relatively low (~30%) and Cores 3R, 16R, and 18R had no recovery.

Cores 1R to 8R consist of calcareous ooze. Cores 9R to 11R are calcareous chalk. Sponge spicules are abundant throughout. Intervals of silicified limestone are present in Sections 10R-1, 10R-CC, and 11R-1. Based on planktonic foraminifera, Cores 1R and 2R are Pleistocene, the base of Core 4R is late to mid-Pliocene, Cores 5R to 7R are Pliocene, and Cores 8R to 10R are Miocene. The base of Core 11R is Eocene, according to both calcareous nannofossils and planktonic foraminifera.

The science party also continued working on their Site U1514 reports.


Daily Science Report for 9 November 2017

Location:
Hole U1514C (33°7.2443′S, 113°5.4799′E; 3839 m water depth)
In transit to Site U1515 (proposed Site MBAS-9A)

Science Update: The modified triple combination tool string was deployed at 0015 h. It logged the entire length of the open borehole to 516.8 m. The tool string was back on the rig floor at 0630 h and dissembled by 0815 h. We then pulled the drill string out of the hole, clearing the seafloor at 0855 h. The acoustic positioning beacon was recovered at 1415 h. The drill string was back on the rig floor at 1735 h, ending Site U1514. At 1745 h, we were underway to Site U1515, and arrived on site just at midnight.

Cores 32R to 35R were described. Cores 32R and 35R are dark greenish gray claystone. Cores 33R and 34R are dark greenish gray nannofossil-rich claystone. Bioturbation is sparse to moderate throughout. Drilling disturbance (fracturing) varies from slight to severe. Based on calcareous nannofossils and planktonic foraminifera, the material from Cores 32R to 35R is Albian in age.

The science party began finalizing their Site U1514 reports.


Daily Science Report for 8 November 2017

Location: Hole U1514C (33°7.2443′S, 113°5.4799′E; 3839 m water depth)

Science Update: Cores 27R to 35R were cut to 516.8 m, the total depth of the hole. Of the 321.2 m cored in Hole U1514C, 247.47 m was recovered (77%). After coring finished, we circulated the hole with high-viscosity mud and released the bit at the bottom of the hole at 1635 h. We then displaced the hole with heavy mud and raised the drill string up to logging depth (82.2 m) by 2115 h. The modified triple combination tool string was assembled by midnight.

Cores 22R to 31R were described. Nannofossil-rich claystone is the dominant lithology to Section 22R-6, after which there is a change in both color and lithology to dark greenish gray claystone. Cores 23R to 25R consist of claystone with varying amounts of nannofossils, and exhibit colors varying from gray to greenish gray, reddish yellow, and light brown. Cores 25R to 29R also consist of greenish gray, pink, light brown, and reddish yellow/orange claystone; however, these cores exhibit soft sediment deformation, including ball and pillow structures as well as hinges from folding. Overall, the bedding is convoluted but there are thinly laminated intervals present. Chert is present in Sections 27R-4 and 27R-6, and 28R-1 and 28R-2. Cores 30R and 31R consist of dark brown claystone. Bioturbation is sparse to moderate throughout. Drilling disturbance (fracturing) varies from slight to severe. Based on calcareous nannofossil and planktonic foraminifera, the base of Core 23R is late Maastrichtian in age, and more detailed biostratigraphy constrained the K/Pg boundary to Section 23R-2. The base of Core 23R is late Campanian, and the base of 27R is early Coniacian. The base of Core 28R is late Turonian and Core 29R is Cenomanian. Cores 30R and 31R were barren of all calcareous microfossils.


Daily Science Report for 7 November 2017

Location: Hole U1514C (33°7.2443′S, 113°5.4799′E; 3839 m water depth)

Science Update: Cores 14R to 26R were cut to 430.4 m, recovering 85.93 m of material (69%).

Cores 10R to 21R were described. Core 10R is a pale yellow clayey nannofossil chalk with biosiliceous components. Cores 11R through 21R are greenish gray nannofossil-rich claystone. There are intervals of darker greenish gray that occur about once a section. Bioturbation is sparse to moderate throughout. From calcareous nannofossil and planktonic foraminifer data, the base of Core 10R is early Eocene (Ypresian) in age and the base of Core 11R is late Paleocene. Cores 15R to 19R are dated to the middle Paleocene (Selandian). The base of Core 21R is barren of foraminifera, but is middle to early Paleocene based on calcareous nannofossils.


Daily Science Report for 6 November 2017

Location: Hole U1514C (33°7.2443′S, 113°5.4799′E; 3839 m water depth)

Science Update: We drilled without coring to 195.6 m then pulled the center bit. Cores 2R to 13R were cut to 302.6 m, recovering 93.58 m of material (85%).

Cores 2R to 9R from Hole U1514C were described and consist of clayey nannofossil chalk with biosiliceous components. Bioturbation is sparse to moderate. There is a color change in Core 6R from light greenish gray to pale yellow, which continues in subsequent cores. However, there are 10–20 cm thick intervals of greenish gray sediment throughout Cores 6R to 9R. There is a thin (<10 cm) interval of calcareous claystone in Section 7R-2. There are also multiple 20 cm thick laminated intervals in Cores 8R and 9R. Based on calcareous nannofossils and planktonic foraminifera, the base of Cores 2R to 4R is middle Eocene (Lutetian) and the material from the base of Core 5R is early Eocene (Ypresian) in age.


Daily Science Report for 5 November 2017

Location:
Hole U1514B (33°7.2335′S, 113°5.4798′E; 3839 m water depth)
Hole U1514C (33°7.3′S, 113°5.5′E; 3839 m water depth)

Science Update: We pulled the drill string back up to the rig floor by 0925 h and changed the bottom-hole assembly in preparation for RCB coring. We offset the vessel 20 m south. We then lowered the drill string and started Hole U1514C at 1940 h. We then drilled without coring to 166.7 m. The plan for this hole is to drill without coring to ~200 m and then core with the RCB to ~450 m.

Cores 28X to 31X were described and consist of sponge spicule-rich nannofossil chalk with clay. There is a color change in Core 29X from light greenish gray to pale yellow, which continues in subsequent cores. All of the cores show slight to moderate bioturbation. The cores also show biscuiting drilling disturbance. Based on calcareous nannofossils and rare planktonic foraminifera, the base of Core 31X is early Eocene (Ypresian).


Daily Science Report for 4 November 2017

Location:
Hole U1514A (33°7.2327′S, 113°5.4672′E; 3838 m water depth)
Hole U1514B (33°7.2335′S, 113°5.4798′E; 3839 m water depth)

Science Update: We recovered Cores 22F to 24F to 197.3 m. Piston coring refusal was reached with Core 24F, so we switched to the XCB system and recovered Cores 25X to 31X to 255.6 m at 1900 h. At this point, we were unable to penetrate any deeper with the XCB system, so we decided to finish coring in Hole U1514A. Core recovery was excellent throughout the hole with 255.2 m of material recovered from 255.6 m cored (99%). Then we pulled the drill string out of the hole, clearing the seafloor at 2015 h. We offset the vessel 20 m east and started Hole U1514B at 2200 h. We recovered Cores 1H and 2H to 15.1 m. These cores were sectioned into 30 cm whole-rounds on the catwalk for postexpedition optically stimulated luminescence analyses. We then pulled the drill string clear of the seafloor at 2355 h. Our plan for further coring at this site will be to RCB core from ~200 m to ~470 m.

Cores 11H to 27XH were described. Cores 11H to 21F consist of sponge spicule-rich clay with nannofossils. Cores 22F to 27X consist of clayey nannofossil chalk. All of the cores are greenish gray and show mottling with burrows from moderate bioturbation. Cores recovered with the XCB system (25X to 27X) show severe biscuiting. Based on calcareous nannofossils and planktonic foraminifera, the base of Core 15H is middle Eocene in age, with the base of Core 23F dated to the Lutetian. The base of Core 27X is early Eocene (Ypresian).


Daily Science Report for 3 November 2017

Location: Hole U1514A (33°7.2327′S, 113°5.4672′E; 3838 m water depth)

Science Update: We recovered Cores 2H to 19H to 169.6 m. Core 19H recorded a partial stroke, so we switched to the HLAPC to recover Cores 20F and 21F to 182.9 m. Core recovery is excellent with an average of 104%.

Cores 1H to 10H were described. Cores 1H to Section 10H-4 consist of nannofossil ooze that are rich in sponge spicules and radiolarian. Sections 10H-5, 10H-6, and 10H-7 are nannofossil-rich clay with sponge spicules. Cores 1H to 8H are pale brown in color, but this transitions to a greenish gray for Cores 9H and 10H. In general, the material is massively bedded, but there are some intervals of bioturbation. Rarely, burrows are infilled with iron and/or manganese oxides. Based on calcareous nannofossils and planktonic foraminifera, the base of Core 1H is dated to the mid to late Pleistocene, the base of Core 2H is late Pliocene, the base of Core 3H is late Miocene, and Core 4H is mid-Miocene. The base of Core 6H is early Oligocene. The base of Core 7H is Oligocene to Eocene, and from the base of Core 8H, the material is late Eocene in age.

The science party also completed their Site U1513 reports.


Daily Science Report for 2 November 2017

Location:
Hole U1513D (33°47.6196′S, 112°29.1339′E; 2789 m water depth)
Hole U1514A (33°7.2327′S, 113°5.4672′E; 3838 m water depth

Science Update: The drill string was pulled up onto the rig floor, which ended Hole U1513D. We began transiting to Site U1514 (proposed Site MBAS-8D) at 0145 h. We lowered the thrusters and ended the transit at 0800 h. The acoustic positioning beacon was deployed at 0830 h. We then began preparations for coring with the APC/XCB system. We started Hole U1514A at 2220 h, and recovered Core 1H (8.1 m).

The science party has been finalizing the Site U1513 Report. We also reviewed the stratigraphic correlation over the Cenomanian/Turonian boundary interval, as well as the logging data from Site U1513.


Daily Science Report for 1 November 2017

Location: Hole U1513D (33°47.6196′S, 112°29.1339′E; 2789 m water depth)

Science Update: With the drill string at logging depth (157.4 m) by 0015 h, we assembled the modified triple combination tool string. We were able to log down to 346 m before encountering an obstruction. We brought the tool string to the rig floor at 0740 h and exchanged the magnetic susceptibility sonde for the hole-finder. We deployed the tool string again at 0955 h. It encountered another obstruction at 337 m, which we were unable to get past. We decided to abandon logging at Site U1513. The tool string was back on the rig floor at 1405 h, and we disassembled it. Then we pulled the drill string out of the hole, clearing the sea floor at 1637 h. Starting at 1745 h, several attempts were made to release the acoustic positioning beacon, but we were not able to recover it.

Cores 68R to 75R were described. Cores 68R to 70R are porphyritic to glomeroporphyritic basalt. Native copper is present in Sections 70R-1 and 70R-2, and rounded basalt xenoliths are present. Cores 71R to 74R are dominated by aphyric microcrystalline basalt. Spherical to elongate infilled vesicles are present in Core 71R. Cores 73R and 74R commonly contain xenoliths of porphyritic basalt, with pyroxenes altered to green chlorite. Core 75R contains an intercalated volcaniclastic breccia, present between two basalt flow sequences. The contact with the upper basalt flow is chilled and brecciated, and the contact with the lower basalt flow is erosional. The lower basalt flow consists of moderately altered brown vesicular basalt (Section 75R-4), agglomerate with agglutinated basalt fragments (Sections 75R-5 and 75R-6), and vesicular basalt (Section 75R-7).