IODP Expedition 341

Southern Alaska Margin Tectonics, Climate & Sedimentation

Daily Science Report for 28 July 2013

LOCATION: In transit to Valdez, Alaska

SCIENCE UPDATE: The transit from Site U1421 to Valdez, Alaska began at 1245 h. The ship is scheduled to dock in Valdez at 1100 h on 29 July. The science lab teams have been finalizing reports and the technical staff cleaned the lab areas.

Daily Science Report for 27 July 2013

LOCATION: Hole U1421C (59°30.4298′N, 143°2.7387′W, 721.8 m water depth)

SCIENCE UPDATE: The Vertical Seismic Imager (VSI) logging tool string was run into Hole U1421A at 0925 h. The VSI reached 697.3 m and seismic data was collect data at several stations at different depths in the hole. The ship was offset and Hole U1421B was spudded at 1925 h. Core U1421B-1H was recovered and, because the core was not properly offset vertically for stratigraphic correlation, the hole was terminated and the ship was offset for Hole U1421C. Hole U1421C was spudded at 2005 h. Coring at Hole U1421C was difficult and only Cores U1421C-1H to ‑6H (0–38.2 mbsf) were recovered.

The lithology of the cores from Holes U1421B and U1421C consists of mud with dispersed to abundant clasts and diatom-rich mud. The science labs are preparing for the end of the Expedition and writing the site reports for Site U1421.

Daily Science Report for 26 July 2013

LOCATION: Hole U1421A (59°30.4399′N, 143°2.7395′W, 718.5 m water depth)

SCIENCE UPDATE: Cores U1421A-80X to ‑85X (644.5–702.7 mbsf) were cut. The hole was conditioned for downhole logging and the drill pipe was pulled back to ~95 mbsf. The Sonic Induction tool string was run to the base of the hole (702.7 mbsf) and the Vertical Seismic Imager tool string is currently being run in the hole. Logging operations will continue through the afternoon and Hole U1421B will be spudded this evening. The scientists are working on the site reports for Site U1421 and cleaning up the labs in preparation for the end of the Expedition.

Daily Science Report for 25 July 2013

LOCATION: Hole U1421A (59°30.4399′N, 143°2.7395′W, 718.5 m water depth) SCIENCE UPDATE: Cores U1421A-65X to ‑79X (506.8–644.5 mbsf) were recovered. The lithology of the cores includes green laminated diatom ooze and gray diamict. The paleomagnetics indicate that the sediment is of normal polarity. The sediments are within diatom Zone NPD12 (0–0.3 Ma) and radiolarian biostratigraphy indicates the age is between 0.03–0.5 Ma. The geochemistry lab is currently analyzing samples for C/H/N and carbonate.

Daily Science Report for 24 July 2013

LOCATION: Hole U1421A (59°30.4399′N, 143°2.7395′W, 718.5 m water depth) SCIENCE UPDATE: Cores U1421A-49X to ‑64X (372.5–506.8 mbsf) were drilled. The lithologies recovered include gray to greenish-gray diamict, color-banded diatom ooze with ash, and heavily bioturbated, grenish-gray mud with shell fragments. There is evidence of sediment reworking within a diamict interval in Core U1421A-61X. Several rock clasts were retrieved with diverse compositions. The paleomagnetics indicate that the sediment is of normal polarity. Siliceous microfossils are mostly barren, but are well preserved with present. Radiolarian biostratigraphy indicates that the sediment is between 0.03–0.5 Ma and diatoms suggest that the sediment is likely in Zone NPD 11 (0.3–1.1 Ma). Benthic foraminifera are abundant and there is evidence of both a transported assemblage and an in situ assemblage occurring in the samples. The interstitial waters have a salinity of 22.

Daily Science Report for 23 July 2013

LOCATION: Hole U1421A (59°30.4399′N, 143°2.7395′W, 718.5 m water depth)

SCIENCE UPDATE: Cores U1421A-30X to ‑48X (190.2–372.5 mbsf) were retrieved with less than 10% recovery. These cores contain dark gray diamict, green diatom-rich mud, and rock clasts of a several different types. The paleomagnetics indicate that the sediment is of normal polarity. Siliceous microfossils are rare, but diatom and radiolarian biostratigraphy indicates the sediments are between 0.03–0.3 Ma in age. Methane concentrations are variable, with values increasing from 1,000 to 34,000 ppm between Cores U1421A-35X and ‑39X.

Daily Science Report for 22 July 2013

LOCATION: Hole U1421A (59°30.4399′N, 143°2.7395′W, 718.5 m water depth)

SCIENCE UPDATE: Cores U1421A-1H to ‑8H (0–65.5 mbsf) were cored using the APC system. The half-length APC system was deployed from Core U1421A-9H to ‑19H (65.5–96.4 mbsf). After reaching APC refusal, the XCB system was used for Cores U1421A-20X to ‑29X (96.4–190.2 mbsf).

Cores U1421A-1H to ‑23X (0–132.0 mbsf) have been split and described. The lithology of cores includes greenish-gray diatom-rich mud with black mottling, biosiliceous mud with laminations, dark gray clast-rich diamict, and silty clast-poor diamict. Lone stones, shell fragments, and rock clasts were also observed. Associated with the clast-poor diamict is relatively high shear strengths of ~78 kPa as compared to the background values. This interval is interpreted to be a potential debris flow deposit. The paleomagnetics indicate that the sediment is of normal polarity. Diatom and radiolarian biostratigraphy indicates that Core U1421A-22X is within diatom zone NPD 12 (0–0.3 Ma) and the radiolarian Botryostrobus aquilonaris zone (0–0.5 Ma). Methane concentrations are low (<200 ppm) and the pore water salinity is 20–23. The logging data from Hole U1420A is being processed.

Daily Science Report for 21 July 2013

LOCATION: Site U1421 (59°30.44′N, 143°2.74′W)

SCIENCE UPDATE: A modified downhole logging tool string was deployed in Hole U1420A and run to 290 mbsf, at which point the tool encountered a bridge that was impassible. Two passes of the logging tool string were made. The tool string became stuck in the BHA when re-entering the pipe, so the Kinley Cutter was deployed. Once the drill pipe and logging tool string was recovered, the ship was prepared for transit. After a 12 nmi transit, the ship reached Site U1421 (proposed site GOA-17B).

The science lab teams spent the past day working on site reports for Site U1420.

Daily Science Report for 20 July 2013

LOCATION: Hole U14120A (59°41.3399′N, 143°12.0599′W, 248.2 m water depth)

SCIENCE UPDATE: Cores U1420A-104R to ‑106R (991.7–1020.8 mbsf) were recovered and coring in Hole U1420A was completed. The total core recovery percentage for Hole U1420A was 14%. The hole was conditioned for logging by using mud sweeps and the bit was released in the hole. Currently, the downhole logging tool string is being rigged up.

The lithology of Cores U1420-104R to ‑106R is a dark gray, clast-rich diamict and rock clasts. The sediment geomagnetic polarity is normal. The geochemistry lab is running samples on the IC. The lab groups are analyzing data and writing site reports for Site U1420.

Daily Science Report for 19 July 2013

LOCATION: Hole U14120A (59°41.3399′N, 143°12.0599′W, 248.2 m water depth)

SCIENCE UPDATE: Cores U1420A-91R to ‑103R (865.6–991.7 mbsf) were recovered. The lithologies of the cores are a very dark gray, sandy, clast-rich diamict and a dark gray, clayey, clast-poor diatmict. There are intervals where the diamict is intrastratified with mud. The sediment geomagnetic polarity is normal. The interstitial water samples have a salinity of 16–23 and methane concentrations fluctuate from 2,000–25,000 ppm.

It is anticipated that the target depth of 1020 mbsf is will be reached this afternoon and downhole logging operations will commence after the hole is conditioned.

Daily Science Report for 18 July 2013

LOCATION: Hole U14120A (59°41.3399′N, 143°12.0599′W, 248.2 m water depth)

SCIENCE UPDATE: Cores U1420A-79R to ‑90R (749.2–865.6 mbsf) were recovered. The lithologies of these cores include dark-gray, sandy, clast-rich diamict with shell fragments and greenish-gray mud that is heavily bioturbated. Also recovered were numerous rock clasts. The greenish-gray mud was observed in Core U1420A-80R (758.9–768.6 mbsf) and it contained diatom, radiolarian, and foraminifera fossils. The biostratigraphy of these groups imply that the sediment is between 0 and 0.3 Ma in age. The paleomagnetic inclination of the sediment is normal and is within the Brunhes Chron. The sediment velocities are ~2000 m/s for Cores U1420A-50R to ‑60R and decrease to ~1700 m/s in Cores U1420A-61R to ‑70R. The salinity of the interstitial water samples is 22 and methane concentrations are between 3,000 to 15,000 ppm.

Daily Science Report for 17 July 2013

LOCATION: Hole U14120A (59°41.3399′N, 143°12.0599′W, 248.2 m water depth)

SCIENCE UPDATE: Cores U1420A-63R to ‑78R (594.0–749.2 mbsf) were cut. Core recovery increased to 36% for Cores U1420A-63R to ‑69R (594.0–661.9 mbsf). It then decreased to 6% from Cores U1420A-70R to ‑78R (661.9–749.2 mbsf).

The major lithology of the sediments recovered is a dark gray, sandy, clast-rich diamict with intervals of sandy mud. Several rock clasts of diverse composition have also been retrieved. The P-wave velocity of the diamict intevals is over 2000 m/s. Paleomagnetics indicate that the sediment is of normal polarity. The sediment contains forams, but diatoms and radiolarians are barren. No biostratigraphic age datums were observed. Methane concentrations are between 4,000–10,000 ppm and the salinity of the interstitial waters is 22.

Daily Science Report for 16 July 2013

LOCATION: Hole U14120A (59°41.3399′N, 143°12.0599′W, 248.2 m water depth)

SCIENCE UPDATE: Cores U1420A-45R to ‑62R (419.4–594.0 mbsf) were cut using the RCB system. Core recovery continues to be low, with many rock clasts recovered. In addition to the rock clasts, 1–4 m intervals of dark gray clayey clast-rich diamict and sandy mud were recovered in Cores U1420A-50R, ‑52R, and ‑58R. The diamict in Core U1420A-52R contains dispersed volcanic ash. Foraminifera are present in the recovered sediment intervals, but diatoms and radiolarians are barren. The paleomagnetics indicate that the sediment is of normal polarity. Five interstitial water (IW) samples and 8 headspace gas samples were taken over the past day. The IW samples have very low salinity (22) relative to seawater and methane concentrations are 10,000–30,000 ppm.

Daily Science Report for 15 July 2013

LOCATION: Hole U14120A (59°41.3399′N, 143°12.0599′W, 248.2 m water depth)

SCIENCE UPDATE: Cores U1420A-22R to ‑44R (196.3–419.4 mbsf) were cut using the RCB system. Core recovery continues to be ~4% and the cores consist of rock clasts. These clasts are of diverse composition, with sedimentary, igneous, and metamorphic rocks all represented. Occasionally small intervals of dark gray, clast-rich diamict are retrieved. The science labs are finishing analyzing data from U1419 and working on site reports.

Daily Science Report for 14 July 2013

LOCATION: Site U14120 (59°41.3399′N, 143°12.0599′W, 248.2 m water depth)

SCIENCE UPDATE: Hole U1420A was spudded at 1045 h. Cores U1420A-1R to ‑21R (0–196.3 mbsf) have been cut using the RCB coring system. Coring conditions have been difficult and core recovery is ~4%. The majority of what has been recovered is rock clasts derived from the surrounding mountains. Many of these rocks were larger than the RCB bit. It appears that most of the surrounding sediment was washed away during the coring process.

The rocks recovered in Hole U1420A are dominantly siltstones, granites, greenstones, and diorite. Small intervals (~10 cm) of diamict were recovered, but it makes up a small portion of the total recovery. Two interstitial water (IW) samples and three gas head-space samples were taken from Hole U1420A. The IW samples from Cores U1420A-2R and ‑5R have very low salinities compared to the seawater (22 and 16, respectively). Methane concentrations are <10 ppm. Cores from Hole U1419E are being run on the cryogenic magnetometer and overall Site U1419 displays highly variable magnetic properties. Core-log-seismic integration is ongoing for Site U1418.

Daily Science Report for 13 July 2013

LOCATION: Site U14120 (59°41.34′N, 143°12.06′W, ~259 m water depth)

SCIENCE UPDATE: Hole U1419E was cored to fill in coring gaps. After a 9.0 m wash-down, Cores U1419E-2H to ‑12H (9.0–69.0 mbsf) were recovered with three advance without recovery intervals (29.5–36.0 mbsf, 39.3–46.0 mbsf, and 50.9–51.9 mbsf). Cores U1419E-13H to ‑19H (69.0–98.7 mbsf) were taken with the half-length APC system. Hole U1419E ended at 2315 h. The ship transited 30 nm to Site U1420 (proposed site GOAL-15C). A seafloor survey using the VIT camera system took place the morning of 14 July and Hole U1420A will be spudded shortly.

All of the cores from Hole U1419D and Cores U1419E-2H to ‑17H (9.0–92.5 mbsf) were split and described. The lithology is the same as Holes U1419A–U1419C. The upper part of the Holes is gray mud, diatom ooze, biosiliceous ooze, and sand. Farther down core diamict, interbedded mud and diamict, and clasts are observed. The clasts are interpreted to be ice rafted debris (IRD) and range in size from sand to cobbles that fill the entire core liner. Many cores from Hole U1419E appear to be highly disturbed.

Daily Science Report for 12 July 2013

LOCATION: Hole U1419D (59°31.9200′N, 144°08.0515′W, 687.3 m water depth)

SCIENCE UPDATE: Cores U1419C-17H to ‑20H (97.3–109.1 mbsf) were recovered using the half-length APC system. Hole U1419C ended at 1425 h. Hole U1419D was spudded at 1720 h and washed down to 5.5 mbsf. Cores U1419D-2H to ‑14H (5.5–80.1 mbsf) were recovered using the APC system and Cores U1419D-15H to ‑24H (80.1–114.2 mbsf) were recovered using the half-length APC system. Hole U1419D is complete and coring is about to commence on Hole U1419E to fill in coring gaps.

The lithologies observed in Hole U1419C are the same as those documented in Holes U1419A and U1419B. The upper part of Hole U1419C contains gray mud, diatom ooze, biosiliceous ooze, and sand. Farther down core diamict, interstratified diamict, interbedded mud and diamict, and clasts are observed. The clasts are interpreted to be ice rafted debris (IRD) and range in size from sand to cobbles that fill the entire core liner. The composition of the IRD is very diverse and a large cobble of marble was retrieved. In addition, small, articulated bivalves are present. Stratigraphic correlation between Holes U1419A, U1419B, U1419C, and U1419D has been successful, but coring Hole U1419E is necessary to fill in the apparent coring gaps. All of the geochemical analyses for Hole U1419A are complete and the results show that the sulfate-methane transition occurs at ~20 mbsf and there is a broad increase in silica downcore. The downhole logging data for Hole U1418F has been processed and is being interpreted with regard to lithologic changes.

Daily Science Report for 11 July 2013

LOCATION: Hole U1419C (59°31.9204′N, 144°08.0079′W, 685.8 m water depth)

SCIENCE UPDATE: Cores U1419B-6H to ‑10H (46.5–81.8 mbsf) were recovered using the APC system. After Core U1419B-10H, the half-length APC system was deployed and Cores U1419B-11H to ‑19H (81.8–114.0 mbsf) were recovered. Hole U1419B included a 1-meter advance without coring from 109.6 to 110.6 mbsf. Total recovery for Hole U1419B is 88%. Hole U1419B ended at 1940 h. Hole U1419C was spudded at 2105 h and washed down two meters before coring. Cores U1419C-2H to ‑16H (2.0–97.3 mbsf) have been recovered so far.

The lithologies observed in Hole U1419B are identical to those of Hole U1419A. The upper part of Hole U1419B contains gray mud, diatom ooze, biosiliceous ooze, and sand. Farther down core diamict, interbedded mud and diamict, and clasts are observed. The clasts are interpreted to be ice rafted debris (IRD) and range in size from sand to cobbles that fill the entire core liner. The composition of the IRD is very diverse.

Daily Science Report for 10 July 2013

LOCATION: Hole U1419B (59°31.93′N, 144°08.03′W, 687.1 m water depth)

SCIENCE UPDATE: Cores U1419A-10H to ‑13H (75.0–98.4 mbsf) were cored using the full APC system. At Core U1419A-14H, the half-length APC coring system was deployed and Cores U1419A-14H to ‑20H (98.4–118.6 mbsf) were retrieved. After Core U1419A-20H, the XCB coring system was deployed and Cores U1419A-21X to ‑29X (118.6–193.0 mbsf) were recovered. Total core recovery for Hole U1419A was 58%. Hole U1419B was spudded early morning of 11 July and thus far Cores U1419B-1H to ‑5H (0–50.4 mbsf) were retrieved.

The cores from Hole U1419A contain a wide range of lithologies. The upper part of the Hole contains gray mud, biosiliceous ooze, and sand. Farther down core diamict, interbedded mud and diamict, and clasts are observed. The clasts are interpreted to be ice rafted debris (IRD) and range in size from sand to cobbles that fill the entire core liner. The composition of the IRD is very diverse. Foraminifera preservation is good and the benthic forams suggest changes in bottom water oxygenation. Radiolarians and diatoms are present in the upper section of the Hole, but radiolarians are barren below Core U1419A-15H and diatoms are barren below Core U1419A-12H. The radiolarian biostratigraphy indicates that Cores U1419A-1H to ‑15H are 0–0.3 Ma in age. Analysis of the interstitial water samples is almost complete.

Daily Science Report for 9 July 2013

LOCATION: Hole U1419A (59°31.9297′N, 144°08.0282′W, 687.4 m water depth)

SCIENCE UPDATE: Hole U1418F was terminated at 1605 h. The transit to Site U1419 took ~5 hours. Hole U1419A was spudded early morning of 10 July. Thus far, Cores U1419A-1H to ‑9H were recovered (0–75.0 mbsf).

The lab groups have been working on their Site U1418 reports. Interstitial water whole rounds and gas headspace samples are being taken on every core for Hole U1419A and rhizon sampling is proceeding on Cores U1419A-1H to ‑3H. Methane concentrations are ~20,000 ppm for Cores U1419A-4H to ‑9H (26.4–75.0 mbsf).

Daily Science Report for 8 July 2013

LOCATION: Hole U1418F (58°46.5883′N, 144°29.5986′W, 3667.0 m water depth)

SCIENCE UPDATE: The VSI tool string was run at Hole U1418F to a depth of ~250 mbsf. An obstruction in the hole prevented the tool string from descending any farther. Following the VSI, the FMS Sonic tool string was run to a depth of ~600 mbsf, where it encountered an obstruction. The drill string will be pulled out of the hole and the ship will transit to Site U1419 (KB-2A) this afternoon.

The science lab teams are finishing their Site U1418 reports. A few core sections were re-run on the cryogenic magnetometer and the paleomagnetic data continues to be processed. Almost all of the geochemical samples have been run for Site U1418.

Daily Science Report for 7 July 2013

LOCATION: Hole U1418F (58°46.5883′N, 144°29.5986′W, 3667.0 m water depth)

SCIENCE UPDATE: The triple combo downhole logging tool string was run in hole at 1950 h. The tool was able to descend to ~600 mbsf before encountering an obstruction. Due to issues with the logging winch, the triple combo was pulled out of the hole after the single run and rigged down. Currently the VSI tool string is being prepared for deployment.

All of the cores for Site U1418 have been run through the labs and the scientists are compiling and analyzing data as well as constructing Site Reports. All of the interstitial water samples have been run and the CHN samples for Hole U1418F are being prepared for analysis.

Daily Science Report for 6 July 2013

LOCATION: Hole U1418F (58°46.5883′N, 144°29.5986′W, 3667.0 m water depth)

SCIENCE UPDATE: The decision was made to continue coring past the estimated 850 mbsf target depth to ensure that the interpreted mass transport deposit observed on seismic reflection lines was retrieved. Coring continued to 948.7 mbsf with Cores U1418F-62R to ‑72R (842.0–948.7 mbsf) recovered. The hole is currently being conditioned for downhole logging and the triple combo tool string will be run this afternoon.

Cores U1418F-57R to ‑69R (793.5–919.6 mbsf) contain greenish gray mud interbedded with silt. Cores U1418F-70R to ‑72R (919.6–948.7 mbsf) contain dark greenish gray mud, silty mud, sand, and diamict. The beds are highly deformed and display evidence of flow and folding. These three cores are interpreted as the mass transport deposit. The top of the Jaramillo Subchronzone (0.988 Ma) was found in Core U1418F-58R and the base (1.072 Ma) in Core U1418F-63R.

Daily Science Report for 5 July 2013

LOCATION: Hole U1418F (58°46.5883′N, 144°29.5986′W, 3667.0 m water depth)

SCIENCE UPDATE: Cores U1418F-50R to ‑61R (725.6–842.0 mbsf) were retrieved with 83% recovery. Coring in Hole U1418F will be completed today and downhole logging will commence this evening.

Cores U1418F-45R to ‑56R (677.1–793.5 mbsf) are comprised of dark greenish gray laminated and massive mud with thin (mm-scale) cemented beds. There is evidence of slumping in certain intervals. The sediment P-wave velocities are ~1800 m/s. The Bruhnes-Matuyama reversal (0.78 Ma) was observed in Core U1418F-43R (657.7–667.4 mbsf) and part of the transition was recovered. Foraminifera are present but the sediments are barren of siliceous microfossils. IC and ICP analyses are complete for Hole U1418D and the upper part of Hole U1418F.

Daily Science Report for 4 July 2013

LOCATION: Hole U1418F (58°46.5883′N, 144°29.5986′W, 3667.0 m water depth)

SCIENCE UPDATE: Cores U1418F-37R to ‑49R (599.5–725.6 mbsf) were recovered (81% recovery). The radiolarian biostratigraphy suggests that the sediments are in the Stylatractus universus Zone (0.5–1.3 Ma).

The lithology of Cores U1418F-30R to ‑44R (531.6–677.1 mbsf) consists of repeating intervals of dark greenish gray to dark gray laminated mud, massive mud, and diamict. The sediment displays varying intensities of bioturbation and contains clasts and extensional faults. The geochemical analyses for Hole U1418D have been completed. Foraminifera are present in the cores, but siliceous microfossils are mostly barren.

Daily Science Report for 3 July 2013

LOCATION: Hole U1418F (58°46.5883′N, 144°29.5986′W, 3667.0 m water depth)

SCIENCE UPDATE: Cores U1418F-23R to ‑36R (463.7–599.5 mbsf) were recovered (85% recovery). Radiolarian biostratigraphy indicates that Core U1418F-27R is ~0.5 Ma in age.

Cores U1418F-17R to ‑29R (405.5–531.6 mbsf) consist of two distinct lithologic facies. The first facies is a dark gray, laminated mud with intervals of diamict, and dispersed clasts. The second facies is a dark greenish gray mud with heavy bioturbation; few clasts are observed. The abundance of all microfossils is low, and the sediments are mostly barren of siliceous fossils. Geochemical analysis of pore water and sediment is ongoing.

Daily Science Report for 2 July 2013

LOCATION: Hole U1418F (58°46.5883′N, 144°29.5986′W, 3667.0 m water depth)

SCIENCE UPDATE: Cores U1418F-9R to ‑22R (327.9–463.7 mbsf) have been recovered (89% recovery). Diatom and radiolarian biostratigraphy indicate that the age of the sediments is between 0.3 and 1.0 Ma.

Cores U1418F-6R to ‑16R (298.8–405.5 mbsf) contain intervals of laminated mud with silt that are bounded by thin beds of diamict. Large clasts of diverse composition are present and are interpreted as being ice rafted debris. The top of diatom zone NPD 11 (0.3 Ma) was identified in Sample U1418F-9R-CC and the last occurrence of the radiolarian S. acquilonium (>0.4 Ma) was identified in Sample U1418F-17R-CC. Interstitial water and head space samples continue to be taken in Hole U1418F.

Daily Science Report for 1 July 2013

LOCATION: Hole U1418F (58°46.5883′N, 144°29.5986′W, 3667.0 m water depth)

SCIENCE UPDATE: Hole U1418F was spudded at 0450 h and drilled down without recovery to 260.0 mbsf. Cores U1418F-2R and ‑3R yielded no recovery using the RCB system. The deplugger was deployed to clear the drill bit of any obstruction. Cores U1418F-4R to ‑8R (279.4–327.9 mbsf) were cut and 30.74 m of sediment was recovered.

Cores U1418F-4R and ‑5R are a dark gray muddy diamict that is predominantly clast-poor. Larger clasts of greenstone and granitoids are observed. Foraminifera are present and the diatom biostratigraphy indicates that the sediments are in zone NPD 12 (0–300 kyr). A continuous depth splice for Site U1418 was constructed to 220 mbsf.