Drilling at Bethany Beach, DE (38°32´53''N, 75°03´45''W; elevation = 4.6 ft [1.4 m]; Bethany Beach quadrangle, Sussex County) began in May 2000. Drilling operations were superintended by Gene Cobbs, USGS Eastern Earth Surface Processes Team (EESPT; Don Queen, Head Driller; Jean Self-Trail, Drilling Coordinator); Gene Cobbs III was the driller and Manuel Canabal and Matthew Smith were the assistant drillers. The Delaware National Guard (DNG) provided space, water, and electricity at the Bethany Beach Training Site (Lt. Colonel Rhoads, DNG Commander, CWO4 Perry, Post Administrator). On 12 May 2000, the EESPT drillers arrived onsite and began rigging up, testing the water well onsite, and connecting electrical and water hookups. On 12 May, B. Cramer (Rutgers) and P. McLaughlin (DGS) moved equipment onsite and set up a field laboratory in an Allied trailer. A Kodak DC260 digital zoom camera (38.4-115.2 mm lens; 1536 x 1024 megapixel resolution), Macintosh Power 7200, and photography stand were set up to photograph 2-ft (0.61 m) core segments. Camera default settings (including flash) with wide-angle lens (38.4 mm) were used, following procedures established at Ocean View, NJ (Miller et al., Chap. 2, this volume).
All core measurements are given in feet, and depths refer to feet below land. We follow the ODP convention of top justifying depths for intervals with incomplete core recovery, with core depths assigned based on the depth of the top of the coring run plus distance below the top of the core.
The first core was obtained on 12 May using a Christensen 94-mm (HQ) system with a Christensen 4.25-in. bit. For unconsolidated sands, an extended ("snout") shoe was used to contact the sample 1.5-2.5 in (3.8-6.4 cm) ahead of the bit; core diameter is 2.4 in (6.1 cm) with a rock shoe and 2.1 in (5.3 cm) with the snout shoe. Approximately 2 ft (0.61 m) of large-diameter (12 in) surface casing was set; the large diameter was designed to catch cuttings from reaming a 5-in (12.7 cm) hole for casing targeted at 200 ft (61 m). The top 5 ft (1.52 m) was drilled but not cored; coring commenced with rapid recovery of six cores (28.6 ft [8.72 m] recovered between 5 and 50 ft [1.52 and 15.24 m]; recovery = 63.5%).
On 13 May, coring runs were shortened and the mud was thickened from 8.5 to 9 lb to try to improve recovery. Recovery was fair (~50%) on runs 7 through 11 (50-75 ft; 15.24-22.86 m). No core was recovered on run 12 (75-80 ft; 22.86-24.38 m), and run 13 (80-85 ft; 24.38-25.91 m) only recovered 1 ft (0.30 m) after penetrating a layer that turned the mud yellow green. Run 13A redrilled this section, recovering 1 ft (0.30 m) of sand and clay that was left in the outer barrel (logged as 81-82 ft; 24.69-24.99 m). The day ended by pulling the rods and unplugging the inner core barrel, with 14.05 ft (4.28 m) recovered from 35 ft (10.67 m) drilled (recovery = 40.1%).
On 14 May, the drillers circulated between runs to clear caving sands and extended the shoe farther out of the barrel. Run 16 recovered 2 ft between 90 and 91 ft (27.43 and 27.74 m). The bottom of the hole (BOH) collapsed on the next run. Run 17 (91-94 ft; 27.74-28.65 m) recovered 2 ft (0.61 m). The BOH collapsed again. The rods were pulled, the core barrel was rinsed, the water swivel was replaced, and the section was cored to 105 ft (32.00 m) on runs 18-20. Despite these setbacks, recovery was much improved for the day (15.9 ft [4.85 m] recovered between 85 and 105 ft [25.91 and 32.00 m]; recovery = 79.5%).
Coring recovery and rate improved on 15 May as we penetrated more consolidated sands on runs 21-30 (105-155 ft; 32.00-47.24). Much of run 24 (120-125 ft; 36.58-38.10 m) slipped out of the barrel, and run 25 (125-130 ft; 38.10-39.62 m) recovered 5.9 ft (1.80 m), including some from the previous run. Only 1.4 ft (0.43 m) was recovered on run 30 (150-155 ft; 45.72-47.24 m), but recovery was otherwise good for the day (34.65 ft [10.56 m] recovered between 105 and 155 ft [32.00 and 47.24 m]; recovery = 69.3%).
Coring proceeded smoothly on 16 May on runs 31-39 with good recovery (41.42 ft [12.93 m] recovered between 155 and 205 ft [47.24-62.48 m]; recovery = 82%). We penetrated a silty clay (193.5-197.55 ft; 58.98-60.21 m) suitable for setting polyvinyl chloride (PVC) casing.
On 17 May run 40 (205-210 ft; 62.48-64.01 m) was obtained to finish the rod, and the hole was prepped for logging. Nine logging runs were done from surface to 205 ft (62.48 m) with no operational problems. All logging was performed using Century Geophysical Corporation tools. The natural gamma ray tool was run downhole and uphole in the rods. The following tools were then run up- and downhole on formation: multitool (electric logs including spontaneous potential [SP], short normal resistivity [16N], long normal resistivity [64N], point resistivity, and lateral), sonic, and induction (conductivity, calculated resistivity). A caliper log was obtained uphole. The drillers reamed the hole to 43 ft (13.11 m) using an 8-in (20.3 cm) drag bit. On 18 May, the BOH collapsed and the hole was reamed from 23 to 193 ft (7.01 to 58.83 m); 5 in (12.7 cm) PVC (schedule 4) casing was run to 192.5 ft (58.67 m) to be removed on completion. The casing became stuck at ~25 ft (~7.62 m) in the first Omar Formation clay and had to be worked hard to penetrate; the bottom 20 ft (6.10 m) of casing was pushed in with considerable effort.
Coring resumed on 19 May (runs 41-45). Coring was delayed because sand inside the casing made it difficult to equalize mud pressure. On run 41 (210-215 ft; 64.01-65.53 m), the inner core barrel was difficult to extrude from the outer barrel because the shoe came unscrewed; no core was recovered. The casing was pushed to 194 ft (59.13 m) to make sure the sands were cased off. Coring continued to 240 ft (73.15 m), recovering 17.75 ft (5.41 m; recovery = 59.2% for the day).
On 20 May, drillers again had problems with equalizing mud pressure; the mud was thickened to ~9 lb. The drillers were concerned that sands were getting by the casing, with hydraulic pressure from the Ocean City aquifer (part of the Bethany formation) either forcing the casing off bottom or blowing out the confining bed. Recovery was poor for the day (runs 46-52), due to caving sands (9.15 ft [2.79 m] recovered from 240 to 270 ft [73.15 to 82.30 m]; recovery = 30.5%).
On 21 May, we had better recovery in the sand by making shorter runs on runs 53-60 (i.e., 2-3 ft vs. 5-7 ft; 0.6-0.9 vs. 1.5-2.1 m). Drilling pressure was better; the hole stayed open below the casing, and caving sands were no longer a problem. The caving sands apparently were making their way around the casing; these sands apparently had bridged off at the casing point. A clay layer was anticipated at 265 ft (80.77 m) where the casing could be reset, but it was never encountered. The drillers penetrated a gravelly sand at the bottom of Core 58 (292-294 ft; 89.00-89.61 m) that caused chattering; Core 59 (294-297 ft; 89.61-90.53 m) recovered 0.7 ft (0.21 m) of gravel at the top that was caved from 293.8 to 294 ft (89.55 to 89.61 m). In general, recovery was improved for the short runs, but the loss of run 53 (270-275 ft; 82.30-83.82 m) and most of run 60 (297-300 ft; 90.53-91.44 m) resulted in poor recovery for the day (10.45 ft [3.19 m] recovered between 270 and 300 ft [82.30 and 91.44 m]; recovery = 34.8%).
On 22 May, heavy rains slowed drilling, but recovery dramatically improved with penetration of uniform fine-medium sands on runs 61-67. Anticipating a fining of the section downhole, we extended run 67 (330-340 ft; 100.58-103.63 m) to 10 ft (3.05 m), recovering 4.75 ft (1.45 m) of sands that represent at least 6 to 7 ft (1.83 to 2.13 m) of recovery. Not accounting for this compression, we ended the day with 27.82 ft (8.48 m) recovered between 300 and 340 ft (91.44 and 103.63 m; recovery = 69.6%).
On 23 May, the hole was open and clear in the morning, caving had ceased, and the drillers went for 10 ft (3.05 m) on run 68 (340-350 ft; 103.63-106.68 m). Caved pebbles jammed the ball on the quad latch, allowing drilling mud to wash through the inner core barrel; no core was recovered. Recovery was good on run 69 (350-355 ft; 106.68-108.20 m) with 3.55 ft (1.08 m) of soupy aquifer sands probably representing nearly full recovery. Good recovery of sands continued on runs 70 through 75 (355-380 ft; 108.20-115.82 m), including excellent recovery of a thick shelly interval (380-400 ft; 115.82-121.92 m). At the end of the day, 40 ft (12.19 m) of rods were pulled and the hole was conditioned with 300 gallons of mud. A total of 42.35 ft (12.91 m) was recovered between 340 and 400 ft (103.63 and 121.92 m; recovery = 70.6%) for runs 68-78.
The weather on 24 May was beautiful, providing excellent coring conditions. Recovery was good on 5-ft (1.52 m) runs 79 through 84 (400-430 ft; 121.92-131.06 m), and we decided to switch to the 10-ft (3.05 m) barrel in the afternoon beginning at 430 ft (131.06 m). Excellent recovery continued in the fine-grained sediments below 450 ft (137.16 m). Run 88 (460-470 ft; 140.21-143.26 m) had 67% recovery because the soft clays stopped moving into the barrel, resulting in 3.5 ft (1.07 m) of liquefied core and drilling mud on top of the core. The day ended on run 89 with 70.45 ft (21.47 m) recovered between 400 and 480 ft (121.92 and 146.30 m; recovery = 88.6%).
Coring operations on 25 May yielded excellent recovery in silty clay on runs 90 and 91 (480-485 and 485-490 ft [146.30-147.83 and 147.83-149.35 m], respectively). On runs 92 through 94 (490-516 ft; 149.35-157.28 m), a switch was made to 10-ft (3.05 m) runs, with excellent recovery. Run 95 (516-520 ft; 157.28-158.50 m) recovered only 0.2 ft (0.06 m) of an indurated zone that blocked the barrel. In the afternoon, drilling was briefly suspended for logging. A gamma log was obtained from within the rods to 505 ft (153.92 m). When drilling resumed, run 96 (520-523 ft; 158.50-159.41 m) was stopped after 3 ft (0.91 m) by a lithified zone. The lithified zone and 6 ft (1.83 m) of underlying clay were recovered on run 97 (523-530 ft; 159.41-161.54 m). The day ended with 46.72 ft (14.24 m) recovered between 480 and 530 ft (146.30 and 161.54 m; recovery = 93.44%).
Coring started on 26 May with excellent weather conditions and outstanding recovery on runs 98 and 99 (530-550 ft; 161.54-167.64 m). Run 100 (550-558.5 ft; 167.64-170.23 m) was cut short. In the afternoon, shell beds began to slow drilling because the shells would not allow core to fill the barrel. Runs 101 through 106 (558.5-588 ft; 170.23-179.22 m) could not penetrate the full 10 ft (3.05 m) and had to be shortened. The day ended with 53.7 ft (16.37 m) recovered between 530 and 588 ft (161.54 and 179.22 m; recovery = 92.6%).
On 27 May, drilling on runs 107-115 mainly encountered soft sands with a few large shells and some thin cemented zones. These cemented zones blocked the barrel, and soft sands could not push through. Most core runs had to be stopped short of the full 10 ft (3.05 m) to prevent blowing away the sands; full penetration was only achieved on runs 109 (600-610 ft; 182.88-185.93 m) and 113 (620-630 ft; 188.98-192.02 m). Recovery was excellent despite the alternations of hard cemented and soft sand zones. The soft nature of these sediments made it difficult to wash off drilling mud without destroying sedimentary structures. Loose drilling mud was gently washed away using a hose with a misting spray head. The remaining "rind" of smeared sand and mud was removed by shaving a thin layer off of the outside of the core using a sharp kitchen knife (for the clays) or a putty knife (for the sands) and rinsing away any remaining rind with a mist. This not only left the cores free of drilling mud, but also helped accentuate clay laminae and other physical structures, clay-filled burrows, and general bioturbation in what may originally appeared to be featureless sands. The day ended on run 115 with the bottom of the hole at 645 ft (196.60 m). We recovered 50.11 ft (15.27 m) between 588 and 645 ft (179.22 and 196.60 m; recovery = 88.9%).
On 28 May, we once again drilled through soft sands and silts with occasional indurated layers (runs 116-125). These indurated layers blocked run 119 (660-670 ft; 201.17-204.22 m), preventing the sands below from entering the inner core barrel. The sands and silts were quickly cored, and no mechanical problems were encountered with the rig. Run 122 (690-692 ft; 210.31-210.92 m) recovered 4.75 ft (1.45 m) from a 2-ft (0.61 m) run. The drillers believe that the upper 3 ft (0.91 m) recovered was core that had been left in the hole from the bottom of the previous run and that the lower 1.75 ft (0.53 m) represented the cored interval. Run 123 recovered only 2.1 ft (0.64 m) from an 8-ft (2.44 m) run (692-700 ft; 210.92-213.36 m), due to blockage by indurated layers. The day ended with recovery of 57.95 ft (17.66 m) between 645 and 720 ft (196.60 and 219.46 m; recovery = 77.3%).
We drilled runs 126-133 without major problems on 29 May. As has been the case every day since we penetrated the Choptank Formation at 575.2 ft (175.32 m), occasional indurated layers blocked the barrel and either cut runs short (run 126 [720-726 ft; 219.46-221.28 m] and run 132 [770-776.5 ft; 234.70-236.67 m]) or caused loss of the lower part of a run (run 128 [734-740 ft; 223.72-225.55 m] and run 133 [776.5-780; 236.68-237.74 m]). The day ended with the bottom of the hole at 780 ft (237.74 m). We recovered 56.35 ft (17.18 m) between 720 and 780 ft (219.46 and 237.74 m; recovery = 93.9%).
Indurated layers slowed coring on 30 May. Run 134 (780-790 ft; 237.74-240.79 m) recovered several thin (~0.1-0.2 ft; 3-6 cm), hard layers, but run 135 (790-792 ft; 240.79-241.40 m) was stopped by an indurated layer. Run 136 (792-792.5 ft; 241.40-241.55 m) was stopped 0.5 ft (0.15 m) into the run, recovering an indurated shelly interval. Run 137 (792.5-800 ft; 241.55-243.84 m) recovered 1.0 ft (0.30 m) of indurated material and 2.6 ft (0.79 m) of underlying soft sand. Recovery of these soft sands below the hard rock was made feasible by modification of the Christensen rock shoe, cutting uphole-directed teeth into the shoe. Run 138 (800-805 ft; 243.84-245.36 m) was shortened to 5 ft (1.52 m), attaining nearly full recovery in sands. Run 139 (805-807 ft; 245.36-245.97 m) was stopped short by an indurated layer that damaged the shoe. Run 140 (807-810 ft; 245.97-246.89 m) recovered indurated zones at the top and base, with soft sand in between; recovery was still only 1.1 ft (0.33 m), presumably losing sands from the lower part of the interval. Slow drilling of hard rock and interbedded sand on run 141 was stopped at 819 ft (249.63 m). The day ended with 26.95 ft (8.21 m) recovered between 780 and 819 ft (237.74 and 249.63 m; recovery = 69.1%).
On 31 May, runs 142 (819-829.25 ft; 249.63-252.76 m), 143 (829.25-839.5 ft; 252.76-255.88 m), and 144 (839.5-849.75 ft; 255.88-259.00 m) were drilled an extra 0.25 ft (0.08 m) to force the core into the barrel; recovery was 6.1, 8.7, and 10.35 ft (1.86, 2.65, and 3.15 m), respectively on these runs. Run 145 (849.75-851.75 ft; 259.00-259.61 m) was stopped short by an indurated layer. Run 146 (851.75-860 ft; 259.61-262.13 m) drilled easily and had >9 ft (2.74 m) of recovery; the driller pulled up 2 ft (0.61 m) from the BOH and recored the bottom 2 ft (0.61 m). About 1 ft (0.30 m) of chewed-up core was discarded below 6 ft (1.83 m) into the run; most of the remaining core from 6 to 8.4 ft (1.83 to 2.56 m) in the run is solid, though a few layers are probably a mixture of chewed-up core and drilling mud. Run 147 (860-870 ft; 262.13-265.18) recovered 10 ft (3.05 m) of core, with brecciation due to drilling disturbance at 7.3-8.6 ft (2.23-2.62 m). Run 148 (870-880 ft; 265.18-268.22 m) recovered 10.17 ft (3.10 m). The day ended with 55.73 ft (16.99 m) recovered between 819 and 880 ft (249.63 and 268.22 m; recovery = 91.36%).
On 1 June, the drillers repaired a pump, delaying the first run of the day. Runs 149 (880-889 ft; 268.22-270.97 m) and 150 (889-899 ft; 270.97-274.02 m) recovered 8.7 and 9.85 ft (2.65 and 3.00 m), respectively. Run 151 recovered 1.2 ft (0.37 m) of core from a 1-ft interval (899-900 ft; 274.02-274.32 m), returning core runs to 10-ft (3.05 m) depth intervals. Run 152 (900-910 ft; 274.32-277.37 m) hit indurated layers and difficult drilling at 902.5 ft (275.08 m); 5.85 ft (1.78 m) of core was recovered. The core had a moderate odor of kerosene. Run 153 (910-911.35; 277.37-277.78 m) hit a hard layer that stopped drilling at 911.35 ft (277.78 m) and ripped up the cutting shoe. Run 154 (911.35-920 ft; 277.78-280.42 m) recovered 2.65 ft (0.81 m). The day ended with 29.0 ft (8.84 m) recovered between 880 and 920 ft (268.22 and 280.42 m; recovery = 72.5%).
On 2 June, runs 155 (920-930 ft; 280.42-283.46 m), 156 (930-940 ft; 283.46-286.51 m), 157 (940-945 ft; 286.51-288.04 m), and 158 (945-953.5 ft; 288.04-290.63 m) recovered 7.5, 2.4, 4.5, and 7.6 ft (2.29, 0.73, 1.37, and 2.32 m), respectively. Run 159 (953.5-960 ft; 290.63-292.61 m) recovered 4.95 ft (1.51 m); a stick clogged the pump for the water hose, delaying core extrusion from the core barrel. Runs 160 (960-970 ft; 292.61-295.66 m) and 161 (970-980 ft; 295.66-298.70 m) recovered 9.8 and 7.4 ft (2.99 and 2.56 m), respectively. The day ended with 44.15 ft (13.46 m) recovered between 920 and 980 ft (280.42 and 298.70 m; recovery = 73.6% recovery).
On 3 June, run 162 (980-982 ft; 298.70-299.31 m) was stopped by a cemented layer at 2 ft (0.61 m) and recovered 1.5 ft (0.46 m). Runs 163 (982-990 ft; 299.31-301.75 m), 164 (990-1000 ft; 301.75-304.80 m), 165 (1000-1010 ft; 304.80-307.85 m), 166 (1010-1020 ft; 307.85-310.90 m), 167 (1020-1030 ft; 310.90-313.94 m), and 168 (1030-1040 ft; 313.94-316.99 m) recovered 6.4, 6.55, 7.4, 9.8, 9.05, and 8.1 ft (1.95, 2.00, 2.56, 2.99, 2.76, and 2.47 m), respectively. Run 168 became stuck in the core barrel; the pump malfunctioned, causing the core to over-run the tray. Pieces of core fell on the ground but were reconstructed. A cup in the mud pump cylinder wore out and was replaced at the end of the day. Total core recovered for the day was 48.8 ft (14.87 m) between 980 and 1040 ft (298.70 and 316.99 m; recovery = 81.33%).
On 4 June, run 169 (1040-1047.5 ft; 316.99-319.28 m) recovered 7.2 ft (2.19 m); drillers stopped at 1047.5 ft (319.28 m) because drilling was "acting strange." Run 170 (1047.5-1055 ft; 319.28-321.64 m) recovered 7.95 ft (2.42 m); mud pressure picked up in the last 2-3 ft (0.61-0.91 m). Run 171 (1055-1057 ft; 321.56-322.17 m) hit a rock at 1057 ft (322.17 m) and recovered 1.35 ft (0.41 m) of core. Run 172 (1057-1060 ft; 322.17-323.09 m) recovered 3.7 ft (1.13 m) of core. The drillers noted that the top of the core had a wear ring on it from the drilling of the previous run. The extra 0.7 ft (0.21 m) recovered on run 172 is most likely from the bottom of run 171 and should be placed with core from run 171. Run 173 (1060-1070 ft; 323.09-326.14 m) recovered 5.2 ft (1.58 m). Run 174 (1070-1077 ft; 326.14-328.27 m) recovered 6.7 ft (2.04 m) and stopped when the shoe became plugged. Total core recovered for the day was 32.15 ft (9.80 m) between 1040 and 1077 ft (316.99 and 328.27 m; recovery = 87%).
At the end of 4 June, the drillers pulled the rods; the rods were difficult to pull, possibly because of an uncentered, irregular hole. The HQ drilling was completed with 811.75 ft (247.42 m) recovered from 1072 ft (326.75 m) cored (recovery = 75.7%); 670.43 ft (204.35 m) was recovered in the 872 ft (265.79 m) cored below casing (recovery = 76.9%). The drillers returned to Reston, VA, on 5 June to pick up NQ rods, returning on the evening of 9 June.
After a 5-day pause to switch from HQ to NQ rods, drilling resumed on 10 June as the drillers began to run NQ rods. Beginning at 208 ft (63.40 m; at the base of casing), numerous sand bridges slowed reentry of the hole, requiring extensive flushing. One zone from 540 to 555 ft (164.59 to 169.16 m) required redrilling. The next 200 ft (60.96 m) was reentered more easily, and 780 ft (237.74 m) had been reentered by the end of 11 June. On 12 June, with the uneventful addition of the bottom 300 ft (91.44 m) of rod, coring resumed using a Christensen CNWL (NQ) system. The NQ system produces a 3.162-in (8.03 cm) hole diameter, cutting cores of 1.875-in (4.76 cm) diameter core with a rock shoe and 1.67-in (4.24 cm) diameter with extended shoes. Smooth coring and excellent recovery occurred on runs 175 (1077-1080 ft; 328.27-329.18 m), 176 (1080-1090 ft; 329.18-332.23 m), 177 (1090-1100 ft; 332.23-335.28 m), and 178 (1100-1110 ft; 335.28-338.33 m), recovering 2.9 ft (0.88 m), 9.95 ft (3.03 m), 10.3 ft (3.14 m), and 10.5 ft (3.20 m), respectively. Total recovery for the day was 33.7 ft (10.27 m) from 33 ft drilled (10.06 m; recovery = 102.1%).
On June 13, smooth coring proceeded on runs 179-182 (1110-1150 ft; 338.33-350.52 m) with slightly >100% recovery due to core expansion. Run 183 (1150-1153.5 ft; 350.52-351.59 m) was stopped short by a large shell that bent the shoe, recovering 2.55 ft (0.78 m). The next run (run 184; 1153.5-1160 ft; 351.59-353.57 m) used the rock shoe, recovering 2.85 ft (0.87 m) from the top part of the run. Total recovery for the day was 47.3 ft (14.42 m) from 50 ft (15.24 m) drilled (recovery = 94.6%).
Sands slowed drilling and hindered recovery on 14 June. Run 185 (1160-1165 ft; 353.57-355.09 m) stopped 5 ft (1.52 m) into the run when the drillers noted that the bit was grinding; the barrel had not latched in and only 0.15 ft (0.06 m) was recovered. The core slipped out and blocked the outer core barrel. After washing the blockage from the outer core barrel, run 186 (1165-1170 ft; 355.09-356.62 m) had nearly full recovery. Run 187 (1170-1175 ft; 356.62-358.14 m) was pulled up short as sands clogged the barrel; run 188 (1175-1180 ft; 358.14-359.66 m) finished the rod. The lower 2.5 ft (0.76 m) of run 189 (1180-1190 ft; 359.66-362.71 m) was ground up during drilling. Total recovery for the day was 19.05 ft (5.81 m) between 1160 and 1190 ft (353.57 and 362.71 m; recovery = 63.5%).
On 15 June, poor recovery on runs 190 (1190-1200 ft [362.71-365.76 m]; 0 ft [0 m] recovery), 191 (1200-1201 ft [365.76-366.06 m]; 4.3 ft [1.31 m] recovery) and 192 (1201-1210 ft [366.06-368.81 m]; 0 ft [0 m] recovery) was probably due to grinding of coarse-grained sand beds containing thin beds and burrows of silt and clay. Recovery was excellent on runs 193, 194, and 195 (1210-1220, 1220-1230, and 1230-1237.5 ft [368.81-371.86, 371.86-374.90, 374.90-377.19 m]; recovery = 94% for these three runs) because the sand fraction disappeared. Run 195 was cut short at the top of an indurated interval. Total recovery for the day was 30.25 ft (9.22 m) between 1190 and 1237.5 ft (362.71-377.19 m; recovery = 63.7%).
On 16 June drillers switched to a rock shoe for run 196 (1237.5-1240; 377.19-377.95 m) and finished the rod with full recovery of 0.7 ft (0.21 m) of indurated silt and 1.8 ft (0.55 m) of silt. Recovery was excellent all day drilling through sandy silts. Drillers reported high mud pressures during runs 197-201 (1240-1290 ft; 377.95-393.19 m). High mud pressures likely caused extensive drilling disturbance in runs 197 and 199; the core was infiltrated by the drilling mud, creating a thick rind of core material mixed with mud. This soft core material was easily split off the inner hard core, and the core was wrapped and photographed with the softer material pushed to the side. Total recovery for the day was 52.6 ft (16.03 m) between 1237.5 and 1290 ft (377.19-393.19 m; recovery = 100.2%).
On 17 June, the first run (run 202; 1290-1300 ft; 393.19-396.24 m) had no recovery; the drillers redrilled the same interval and retrieved 10.4 ft (3.17 m) of core. Although the run was drilled past 1300 ft (396.24 m) in order to retrieve the core, the run was logged as 1290-1300 ft (393.19-396.24 m) with 104% recovery. Complete recovery was obtained for run 203 (1300-1310 ft [396.24-399.29 m]; 10.55 ft [3.22 m] recovery). Run 204 (1310-1320; 399.29-402.34 m) recovered 8.9 ft (2.71 m), including a cemented zone at the base. Run 205 (1320-1320.3 ft; 402.34-402.43 m) was stopped after only 0.3 ft (0.09 m) when rock was encountered. Drillers switched to a rock shoe for run 206 and completed the 10-ft rod (1320.3-1330 ft; 402.43-405.38 m) with 5.6 ft (1.71 m) recovered. The day ended with 35.75 ft (10.90 m) recovered between 1290 and 1330 ft (393.19-405.38 m; recovery = 89.4%).
On 18 June, the drillers achieved high recovery rates on runs 207-212, recovering 61.75 ft (18.82 m) between 1330 and 1390 ft (405.38-423.67 m; recovery = 102.9%). Excellent recovery continued on the first three runs on 19 June, runs 213-215 (1390-1420 ft; 423.67-432.82 m). On run 216 (1420-1429 ft; 432.82-435.56 m), drilling was stopped short at 9 ft (2.74 m). Slow drilling continued during run 217 (1429-1437 ft; 435.56-438.00 m), with high mud pressures. The run was stopped because the mud pump blew; one rod was pulled to prevent sticking the rods in the clay penetrated during run 216. The day ended with 46.50 ft (14.17 m) recovered between 1390 and 1437 ft (423.67-438.00 m; recovery = 98.94%).
On 20 June, the first run, run 218 (1437-1440 ft; 438.00-438.91 m), had no recovery; the core had apparently slipped out of the core catcher. The drillers ran 5 ft (1.52 m) on run 219 (1440-1445 ft; 438.91-440.44 m), hoping to catch the lost core, but only recovered 3.75 ft (1.14 m). Run 220 (1445-1450 ft; 440.44-441.96 m) recovered 6.5 ft (1.98 m); the top 1.3 ft (0.40 m) appeared recored, indicating it was from the previous run. Thus, 10.25 ft (3.12 m) was recovered from a cored interval of 1440-1450 ft (438.91-441.96 m; recovery = 103%); we presume that the entire section from 1437 to 1440 ft (438.00 to 438.91 m) was lost. Field notes describe core from the interval 1445-1450 ft (440.44-441.96 m) as recovering 6.5 ft (1.98 m), though the top 1.3 ft (0.40 m) should be 1443.7-1450 ft (440.04-441.96 m). Run 221 (1450-1454 ft; 441.96-443.18 m) was stopped when the rate of penetration dropped significantly, due to a hard layer or spalling of glauconite sands on the bit. Run 222 (1454-1460 ft; 443.18-445.01 m) encountered hard drilling at the top and easier drilling in the lower part, with 6.2 ft (1.89 m) recovered. The last run (run 223; 1460-1470 ft; 445.01-448.06 m) recovered 7.95 ft (2.42 m), yielding 27.85 ft (8.49 m) recovered between 1437 and 1470 ft (438.00-448.06 m; recovery = 84.4%).
Logging was conducted on 20 and 21 June by P. McLaughlin and S. Baxter of the DGS and S. Curtin of the USGS WRD Annapolis using the DGS's Century logging tools and the USGS's logging truck and winch. On June 20 after the drillers reached the 1470-ft (448.06 m) total depth of the hole, the drill string was pulled up off the BOH and gamma logs were recorded from within the drill rods. Logs were obtained in both the up and down travel directions to the bottom of the drill string (1458 ft; 444.40 m). On 21 June, open-hole logging was conducted after the drill string was pulled from the hole. The multitool was run to the BOH (1470 ft; 448.06 m) in both the up and down directions, collecting gamma, spontaneous potential, long-normal resistivity, short-normal resistivity, and point resistivity logs. The induction tool was also run to the BOH, providing gamma and conductivity logs to the bottom of the hole. An attempt to run a full-wave sonic log was unsuccessful, due to malfunctions in the tool. The hole was grouted with cement, plugged, and abandoned on 22 and 23 June.
Total recovery at Bethany Beach was 1166.5 ft (355.55 m) from a total depth of 1470 ft (448.06 m) drilled and 1465 ft (446.53 m) cored, for an overall recovery of 79.62%; median recovery of the drilling runs was 86%. Lithologies were described onsite and later reexamined in more detail at the Rutgers core facility; these descriptions form the basis for the preliminary lithologic descriptions. Cores were cut into 2-ft (0.61 m) sections, labeled at top and bottom of each section, placed into split PVC pipe (3 in [7.62 cm] diameter), wrapped in plastic sheeting, and stored in 2-ft (0.61 m) NQ wax boxes. One hundred and sixty four core boxes were moved to permanent storage at the Rutgers University core library for further study. Cores were sampled at ~5-ft (1.52 m) intervals for planktonic foraminiferal, calcareous nannofossil, palynology, dinocyst, and diatom biostratigraphy and coarse-fraction lithologic studies at the Rutgers core library.