The on-site scientific team provided preliminary descriptions of sedimentary texture, structure, color, fossil content, identification of lithostratigraphic units (NJGS Information Circular 1, 1990), and lithologic contacts (Table T1; Figs. F2, F3, F4, F5, F6, F7, F8, F9). Subsequent studies integrated preliminary descriptions with additional descriptions, biostratigraphy, biofacies studies, isotopic stratigraphy, and the downhole gamma-ray log. Unconformities were identified on the basis of physical stratigraphy, including irregular contacts, reworking, bioturbation, major facies changes, and gamma-ray peaks. Paraconformities were inferred from biostratigraphic breaks. Core photographs (Figs. F10, F11, F12; see also "Visual Core Descriptions") illustrate sequence-bounding unconformities (Figs. F10, F11) and facies variation within sequences (Figs. F10, F11, F12).
For the nonmarine and nearshore sections (primarily the Miocene and younger section), lithofacies interpretations provide the primary means of recognizing unconformities and interpreting paleoenvironments and systems tracts. For the neritic sections (primarily the Paleogene), biostratigraphic and biofacies studies provide an additional means of recognizing unconformities and the primary means of interpreting paleoenvironments and systems tracts. Benthic foraminiferal biofacies were used to recognize inner (0-30 m), middle (30-100 m), and outer (100-200 m) neritic and upper bathyal (200-600 m) paleodepths. Cumulative percentages of the sediment grain size were computed from samples washed for paleontological analysis. Each sample was dried and weighed before washing and the dry weight was used to compute the percentage of sand. This differs from the method used in previous New Jersey coastal plain cores (Bass River, Island Beach, Atlantic City, and Cape May) in which the samples were not dried before washing.
Facies changes within onshore sequences generally follow repetitive transgressive-regressive patterns (Sugarman et al., 1993, 1995) that consist of (1) a basal transgressive glauconite (particularly Paleogene sections) or quartz sands (particularly Miocene sections) equivalent to the transgressive systems tract (TST) of Posamentier et al. (1988) and (2) a coarsening-upward succession of regressive medial silts and upper quartz sands equivalent to the highstand systems tracts (HST) of Posamentier et al. (1988). Lowstand systems tracts (LSTs) are usually absent in the coastal plain and the TSTs are generally thin. Because the TSTs are thin, maximum flooding surfaces (MFSs) are difficult to differentiate from unconformities. Both can be marked by shell beds and gamma-ray peaks. Flooding surfaces, particularly MFSs, may be differentiated from sequence boundaries by the association of erosion and rip-up clasts at the latter, lithofacies successions, and benthic foraminiferal changes. The transgressive surface (TS) marking the top of the LST represents a change from generally regressive to transgressive facies; because LSTs are generally absent, these surfaces are generally merged with the sequence boundaries. Where present, LSTs are recognized as generally thin, regressive, fluvial-estuarine sediments underlying TSTs and overlying sequence-bounding unconformities.
The upper 16.1 ft (4.9 m) at Ocean View consists of sands and well-rounded pebbly gravels; the base of the gravels was recovered in Hole B, but not in Hole A (Fig. F2). The gravels represent reworked fluvial sediments deposited in nearshore environments and may constitute an unnamed member of the Cape May Formation. This gravel comprises the terrace on which the Garden State Parkway was built. Elsewhere, the terrace has been correlated with marine isotope Stage 5 (Ashley et al., 1991) and the Cape May Formation (Sheridan et al., 2000; W. Newell, pers. comm., 1999). Well-sorted yellow very fine to medium quartz sands underlie the gravels (16.1-35 ft; 4.9-10.7 m). A dark gray slightly sandy clay was missed in Hole A but recovered in Hole B (19.4-22.7 ft; 59-6.9 m); this clay is well expressed in the gamma log (Fig. F2). The sands bracketing the clay show several fining-upward patterns on the 1-ft scale (e.g., near 28 ft; 8.5 m). Alternating thin beds of gravelly sands, poorly sorted sands, and thin clay drapes (35-78.75 ft; 10.7-24.0 m) represent dynamic nearshore environments (?tidal delta/barrier complex). These sands and gravelly sands comprise an unconfined aquifer; the interval from 64 to 84 ft (19.5 to 25.6 m) was screened at the adjacent Ocean View Service Area #2 water well. The lower part of the Cape May Formation (78.5-107.5 ft; 24.0-32.8 m) (Fig. F2) is characterized by coarsening-upward successions (typically 0.2-1.0 ft [6-30 cm] thick) from fine quartz sands to very coarse sands with occasional reddish yellow gravels, iron-stained layers, and iron concretions. The contact between the Cape May and Cohansey Formations was placed at 107.5 ft (32.8 m) at a sharp, burrowed surface. This contact is probably a sequence boundary separating ?Pleistocene sediments above from ?upper Miocene (probably upper Miocene Zone DN6, although possibly middle Miocene Zone DN8) (see "Biostratigraphy") sediments below. This lower part of the Cape May Formation was deposited in nearshore environments, interpreted as nearshore barrier island/tidal inlet complexes.
A sharp contact at 107.5 ft (32.8 m) separates reddish yellow medium to coarse quartz sand from underlying very dark gray, burrowed silty fine quartz sand. This contact is interpreted as a sequence boundary (Fig. F2). We assign the section above 107.5 ft (32.8 m) to the Cape May Formation, in part because of the gravel contained throughout. Dark gray silty fine quartz sand characterizes the interval from 107.5 to 120 ft (32.8 to 36.6 m) (Fig. F2). Below an interval of no recovery (120-130 ft; 36.6-39.6 m), clayey fine sand to silty sandy clay (130-135.2 ft; 39.6-41.2 m) overlies a mottled clay containing granules (135.2-141.9 ft; 41.2-43.3 m). In the field, the clay surface was mottled with brown iron-stained oxidized patches; the clay weathered to a thick yellow Fe-oxidized rind with a strong sulfur odor. This granular clay facies is unusual for New Jersey Coastal Plain cores but could represent fluvial, estuarine, or possibly lagoonal/tidal deltaic environments. Given the marine sands above and below and the lack of a visible contact separating facies, we eliminate a fluvial interpretation. Given the bimodal grain size (clay and granules), we favor an estuarine interpretation.
A sharp contact (141.9 ft; 43.3 m) separates the clay from very coarse pebbly quartz sand below (141.9-146.2 ft; 43.3-44.6 m). We tentatively interpret this sharp facies change as a sequence boundary and the overlying succession as a classic Miocene sequence of lower HST clays and upper HST sands (Sugarman et al., 1993). However, due to the nearshore depositional setting, it is possible that this facies change merely reflects a lateral environmental shift.
A coarsening- (shoaling) upward succession is observed from 141.9 to 151.8 ft (43.3 to 46.3 m), consisting of very coarse quartz sand at the top fining downward to silty fine sand near the base (Fig. F2). This coarsening-upward succession constitutes the upper HST of a sequence; the sands were deposited in nearshore environments (i.e., the section contains dinoflagellates) (see "Biostratigraphy"). Below an interval of no recovery (151.8-155.0 ft; 46.27-47.24 m), variegated clays with thin sand laminae and sand beds (155.0-159.8 ft; 47.2-48.71 m) comprising the lower HST were probably deposited in an estuarine environment (Fig. F2). A possible sequence boundary occurs at a burrowed contact at 159.8 ft (48.71 m), separating the clays above from clayey sand below (Fig. F2). Again, considering the nearshore/estuarine depositional setting, this change may only reflect a facies shift and not a sequence boundary. Burrowed, clayey silty quartz sand extends from 159.8 to 165.6 ft (48.71 to 50.47 m) (Fig. F2), although the section from 160 to 164 ft (48.77 to 49.99 m) suffers from coring disturbance. These clayey sands were probably deposited in nearshore or estuarine environments. There is a contact zone between 166.7 and 167.3 ft (50.81 and 50.99 m), with clayey sand burrowed into lighter gray massive sand. Massive medium quartz sand is found below the contact zone (167.3-172.5 ft; 50.99-52.58 m). We tentatively place a sequence boundary at the base of the burrowed clayey sands (166.7 ft; 50.81 m) (Fig. F2). Sands found from 166.7 to 220.55 ft (50.81 to 67.22 m) comprise the HST of a sequence (Fig. F2). Below an interval of no recovery (172.5-180 ft; 52.58-54.86 m), the sands are medium-coarse grained (180-213.5 ft; 54.86-65.07 m). They show several thin fining-upward successions (e.g., 191-191.2 ft [58.22-58.28 m], 191.2-192.0 ft [58.28-58.52 m]), faint cross beds, occasional pebbles, thin heavy mineral laminae, and mud chips (207.1-208 ft; 63.12-63.40 m). The sands were probably deposited in offshore bars. A sharp change to slightly sandy kaolinitic silty clay (213.5-213.6 ft; 65.07-65.11 m) could be interpreted as a sequence boundary; however, the absence of obvious erosion on this surface suggests that it is a facies change. Below an interval of no recovery (213.6-220 ft; 65.11-67.06 m) associated with a gamma-log peak (Fig. F2), a massive sandy clayey silt extends to 220.55 ft (67.22 m), where there is a distinct irregular surface. The clayey silt is coarser and less kaolinitic than the clay above and differs from the underlying cross-bedded sands by the lack of common organic matter. The sequence stratigraphic placement of this silt is uncertain. We favor interpreting the surface at 220.55 ft (67.22 m) as a sequence boundary, based primarily on the gamma-log kick. Below the sequence boundary, cross-bedded organic-rich fine-medium dark sands deposited in delta-front environments are assigned to the Kirkwood Formation.
The formational assignment of the gray sands, yellow sands, and clays from 107.5 to 166 ft (32.77 to 50.60 m) is uncertain. We provisionally place them in the Cohansey Formation, although is it possible that they represent a distinct lithostratigraphic unit (even as unnamed sands and clays between 140 and 357 ft [42.67 and 108.81 m] at the Leg 150X Cape May borehole were not assignable to the Cohansey, Beaverdam, or Manokin Formations) (Miller et al., 1996a). The section from 166 to 220.55 ft (50.60 to 67.22 m) is similar in lithology and sedimentary structure to the Cohansey Sand found in outcrop, and we firmly assign this section to the Cohansey Formation. Initial correlation with the Cape May borehole suggests that the sequences bracketed by basal unconformities at 141.9, 159.8/166.7, and 220.55 ft (43.25, 48.71/50.81, and 67.22 m) may correspond with Sequences Ch4, Ch3, and Ch2 of de Verteuil (1997). The entire section from 107.5 to 220.55 ft (32.77 to 67.22 m) is upper middle to lower upper Miocene (dinocyst Zones DN6 or DN8) (see "Biostratigraphy"), consistent with the age of the Cohansey Formation elsewhere.
Well-sorted fine-medium peaty, very dark gray quartz sands of the Kirkwood Formation underly the sequence boundary at 220.55 ft (67.22 m) (Fig. F3). The sands are heavily burrowed, are generally massive with occasional cross beds and laminae, were deposited on a marine shelf influenced by a delta, and comprise the upper HST of a sequence. Between 220.55 and 246.8 ft (67.22 and 75.22 m), the section alternates between very dark gray, laminated, very organic-rich sand (e.g., 220-224 and 231-233 ft; 67.01-68.28 and 70.41-71.02 m) and gray, cross-bedded to massive, moderately organic-rich to organic-poor sand. The gray beds became stained yellow during archiving as a result of Fe-rich pore waters. Below 246.8 ft (75.22 m), silts grade down to a silty clay with occasional cross beds of clayey silt (Fig. F3). The silty clays are occasionally lignitic and laminated and continue to just above an interval of no recovery (267-270 ft; 81.38-82.30 m); they were deposited in a prodelta environment of the lower HST. The basal 0.25 ft (0.08 m) of the sequence consists of clayey sands with rip-up clasts that appear to be a contact zone. This zone is associated with a gamma-log kick, and we infer that there is a sequence boundary at 267 ft (81.38 m) (Fig. F3). Sands from 270 to 284.8 ft (82.30 to 86.81 m) comprise the upper HST of the underlying sequence (Fig. F3). From 270 to 280 ft (82.30 to 85.34 m), the section is predominantly silty, massive (extensively bioturbated), fine sand with some medium sand and traces of lignite. These sands were deposited on a shallow shelf. The section becomes siltier from 280 to 284.8 ft (85.34 to 86.81 m). Silty clays (290-327.1 ft; 88.39-99.70 m) comprising the lower HST appear below an interval of no recovery (284.8-290 ft; 86.81-88.39 m) associated with a gamma-log kick (Fig. F3). These silty clays are lignitic and shelly throughout, with shell hashes (including whole gastropod shells and pectinid fragments) at 308-308.8, 312-312.2, and 312.7-312.8 ft (93.88-94.12, 95.91-95.16, and 95.31-95.34 m). Silty clays grade downsection to TST silty fine sands (324.5-326.5 ft; 98.91-99.52 m) and an indurated shell bed (326.5 ft-327.1 ft; 99.52-99.70 m). A silty fine sand occurs (327.1-327.2 ft; 99.70-99.73 m) at the top of an interval of no recovery (327.2-330.0 ft; 99.70-100.58 m). We place a sequence boundary at the base of the shell bed (327.1 ft; 99.70 m). Age control for the two sequences between 220.55 and 327.1 ft (67.22 and 99.70 m) is equivocal. No Sr-isotopic age control is available for the sequence between 220.55 and 267 ft (67.22 and 81.3 m). Sr-isotopic ages from the sequence from 267 to 327.2 ft (81.38 to 99.70 m) appear to be reworked (Fig. F8), though an age of 12.4 Ma appears to be a maximum age (see "Strontium Isotopic Stratigraphy"). Dinocysts tentatively assign both sequences to upper middle Miocene Zone DN6 or lower upper Miocene Zone DN8) (see "Biostratigraphy"). We tentatively correlate both sequences with the Kw-Cohansey sequence of Miller et al. (1996a, 1997).
Shelly silty fine sand (327.1-352.2 ft; 99.70-107.35 m) occurs at the top of the underlying sequence (Fig. F3) with several thin shelly beds (331.5-331.8, 335.8, 337.9, 351.0, and 351.5 ft; 101.04-101.13, 102.35, 102.99, 106.98, and 107.14 m). The shelly sands are heavily bioturbated, finely micaceous, and contain sporadic clay laminae and finely disseminated lignite; we interpret the sands as the upper HST, probably deposited in a delta-front environment (Fig. F3). Toward the base of this interval, yellowish silty sands are interbedded with gray very silty sands as the section fines down. An irregular surface (352.2-352.5 ft; 107.35-107.44 m) marks the top of a fine-grained unit comprised of a laminated gray clay (352.5-360 ft; 107.44-109.73 m), greenish shelly silty clay (360-368.8 ft; 109.73-112.41 m), sandy silty clay (368.8-369.5 ft; 112.41-112.62 m), shell hash (369.5-369.6 ft; 112.62-112.65 m), and slightly silty clay (370-409.75 ft; 112.78-124.89 m). Shell debris increases below 398.6 ft (121.49 m) with several concentrations down to 409.75 ft (124.89 m). We interpret this fine-grained unit as the lower HST deposited in prodelta environments (Fig. F3). A subtle contact at 410.05 ft (124.98 m) separates clays above from poorly sorted, clayey, medium-coarse sand below. A gamma-ray peak and a change in Sr-isotopic ages (~15.9 Ma below; ~14.1 Ma above) (see "Strontium Isotopic Stratigraphy") mark this contact (Fig. F3). The sands immediately below the contact contain black phosphate, typical of sands in the upper Kw2b Sequence elsewhere in New Jersey (e.g., the ACGS #4 borehole) (Owens et al., 1988). Thus, we interpret the subtle contact at 410.05 ft (124.98 m) as a sequence boundary. Based on Sr-isotopic ages of ~12.4-14.1 Ma (using the Oslick et al. [1994] age calibration) (see "Strontium Isotopic Stratigraphy"), we correlate the sequence above (327.1-410.05 ft; 99.07-124.98 m) with Sequence Kw3 of Sugarman et al. (1993) (Fig. F3).
Below the unconformity, a poorly sorted clayey medium-coarse sand (410.05-413.4 ft; 124.98-126.00 m) overlies a slightly shelly silty fine sand (413.4-417.1 ft; 126.00-127.13 m) and shelly silty fine sand (420-433.25 ft; 128.02-132.05 m) with shell hashes (shell hashes occur at 421.6-421.7, 422.9, 425.7-426.1, 427.1, 427.65, 427.9-428.1, 431.2-431.6, and 431.9-432.1 ft; 128.50-128.53, 128.90, 129.75-129.88, 130.18, 130.35, 130.42-130.48, 131.43-131.55, and 131.64-131.70 m) (Fig. F4). An irregular heavily burrowed contact at 433.25 ft (132.05 m) separates shelly sands above from slightly shelly clayey silts below (Fig. F4). We interpret this surface as an MFS, with identical Sr-isotopic ages above and below (Fig. F4). The sands above are interpreted as an upper HST deposited on a muddy deltaic influenced shelf (Fig. F4). Slightly shelly clayey laminated silts (433.25-441.5 ft; 132.05-134.57 m) with thin sand laminae overlie massive fine sands (450-459.2 ft; 137.16-139.96 m) and interbedded clays and burrowed sands (460-464.5 ft; 140.21-141.58 m). These complex deposits indicate the influence of a delta (delta-front or proximal prodelta environments) on a shelf; the section from 462.1 to 464 ft (140.85 to 141.43 m) is predominantly silty clay with sand interbeds and is interpreted as prodelta (Fig. F4). A facies shift between prodelta silty clays above with medium to very coarse quartz delta-front sands below occurs at 464.0 ft (141.43 m), with a core break between 464.5 and 465.0 ft (141.58 and 141.73 m). We interpret the contact at 464.0 ft (141.43 m) as a sequence boundary. Phosphate pellets occur at 464.3-464.5 ft (141.52-141.58 m), consistent with placing of a sequence boundary at 464 ft (141.43 m). Sr-isotopes indicate that the sequence from 410.05 to 464.5 ft (124.98 to 141.58 m; 15.6-16.0 Ma) (Fig. F4) correlates with Sequence Kw2b of Sugarman et al. (1993), and a 0.9-m.y. hiatus occurs between this sequence and the sequence below (~16.9 Ma).
The entire section from 464.5 to 636.35 ft (141.43 to 193.96 m) correlates with the Kw2a Sequence of Sugarman et al. (1993), with Sr-isotopic ages of 16.9-17.9 Ma (Fig. F4) (cf. ages of 16.7-17.8 Ma at Atlantic City and 16.5-17.5 Ma at Cape May) (Miller et al., 1997). At Ocean View, this thick sequence can be subdivided into three distinct higher-order sequences, with basal unconformities (503.8, 531.6, and 636.35 ft; 153.56, 162.03, and 193.96 m), lower silty clays/clayey silts, and upper shelly sands (Fig. F4).
The first higher-order Kw2a sequence occurs from 464.5 to 503.8 ft (141.43 to 153.56 m); we term this the Kw2a3 sequence (Fig. F4). Shelly medium to very coarse quartz sand (465-477.1 ft; 141.73-145.39 m) displays several fining-upward successions consisting of basal very coarse quartz sand with shelly concentrations grading up to medium sands. These sands are lignitic with occasional lignitic cross beds. Interbeds of clay occur from 470.4 to 472.1 ft (143.38 to 143.90 m) (Fig. F4). The sands sharply overlie a uniform cross-bedded shelly silt (477.1-495.0 ft; 145.42-150.88 m) and shelly silty clay (495.0-502.4 ft; 150.88-153.13 m) (Fig. F4). The silts and silty clays represent prodelta environments, whereas the sand above represents delta-front environments (Fig. F4). Shell beds (502.4-503.0 ft [153.13-153.31 m] and 503.6-503.8 ft [153.50-153.56 m]) are located between silty clay shell hashes and overlie a shelly clayey sand. These sediments are interpreted as a TST with a sequence boundary at 503.8 ft (153.56 m) (Fig. F4).
We interpret the sands (465-477.1 ft; 141.73-145.42 m) as the upper HST and the silts and clays as the lower HST (Fig. F4). However, it may be possible to interpret the sands as the LST, the sharp contact at 477.1 ft (145.42 m) as a sequence boundary and the contact at 465 ft (141.73 m) as a transgressive surface. Sr-isotopes are ambiguous on which interpretation is correct. The age of 16.9 Ma at 465.1 ft (141.76 m) is consistent with the interpretation of a sequence boundary 465 ft (141.73 m), although an age of 16.4 Ma at 475 ft (144.78 m) is consistent with 477.1 ft (145.42 m) as a sequence boundary. However, repetitions of sand/clay contacts continue below 477.1 ft (145.42 m) (e.g., 480.3 ft; 146.40 m), suggesting that the sharp contact at 477.1 ft (145.42 m) is a facies change.
The second higher-order Kw2a sequence occurs from 503.8 to 531.6 ft (153.56 to 162.03 m); we term this the Kw2a2 sequence (Fig. F4). The interval from 503.8 to 524.75 ft (153.56 to 159.94 m) is dominated by shelly medium sands, although the bottom few feet are clayey shelly sands (Fig. F4). These sands coarsen upsection, indicating a shallowing-upward HST; the shelly sands were deposited in inner neritic environments (Fig. F4). There is a facies contact at 524.75 ft (159.94 m), separating shelf facies above from prodelta facies below. From 524.75 to 531.1 ft (159.94 to 161.88 m), laminated clay-silt with few shell beds was deposited in prodelta environments (Fig. F4). The silts become shelly (531.3-531.6 ft; 161.94-162.03 m), interpreted as a thin TST. There is a sharp, though bioturbated contact (531.6 ft; 162.03 m) with silty fine sand below. This contact is interpreted as a sequence boundary (Fig. F4).
The third higher-order Kw2a sequence occurs from 531.6 to 636.35 ft (162.03 to 193.96 m); we term this the Kw2a1 sequence (Fig. F4). Fine-grained, slightly micaceous sands from 531.6 to 533.1 ft (162.03 to 162.49 m) with clayey silt interbeds comprise a thin upper HST deposited in delta-front or proximal prodelta environments (Fig. F4). Silts and sands deposited in proximal prodelta environments alternate from 533.1 to 538 ft (162.03 to 163.98 m): thin-bedded clay-silt (534-535 ft; 162.76-163.07 m), silts with thinner interbeds of silty fine-sand (535-536 ft; 163.07-163.37 m), laminated clayey silts (536-537.1 ft; 163.37-163.71 m), and thin-bedded fine micaceous sands with thinner silt laminae (537.1-538.0 ft; 163.71-163.98 m). Laminated slightly micaceous, slightly sandy, clayey silts dominate from 538.0 to 580 ft (163.98 to 176.78 m), representing deposition in prodelta environments (Fig. F4). Clay increases slightly downsection below 580 ft (176.78 m), with alternating beds of silty clays and clayey silts continuing to 620.65 ft (189.17 m). These alternating beds overlie a heavily burrowed silty sand (620.65-625.5 ft; 189.17-190.65 m) that becomes increasingly shelly toward the base and, in turn, overlies a spectacular shell bed (625.5-626.7 ft; 190.65-191.02 m). A tight clay with rip-up clasts (626.7-627.0 ft; 191.02-191.11 m) lies immediately above an indurated zone of calcareous claystone (627.0-627.45 ft; 191.11-191.25 m). The section from 625.5 to 627.45 ft (190.65 to 191.25 m) comprises the MFS, and the section from 533.1 to 625.5 ft (162.49 to 190.65 m) is interpreted as the lower HST (Fig. F4). Sandy shelly silty clay (627.45-631.2 ft; 191.25-192.39 m) and clayey fine sand (632.2-634.3 ft; 192.69-193.33 m) grade down to clayey medium to coarse to very coarse quartz sand (to 635.95 ft; 193.84 m), suggesting deepening upsection between 627.45 and 635.95 ft (191.25 and 193.84 m) (Fig. F12).
Placement of the sequence boundary is uncertain. An indurated calcarenite (635.95-636.35 ft; 193.84-193.96 m) (Fig. F12) could mark the sequence boundary, but we prefer the following interpretation. A deepening-upward section from 627.45 to 636.35 ft (191.25 to 193.96 m) is interpreted as the TST deposited in nearshore to inner-shelf environments (Figs. F4, F12). Below this (636.35-640.0 ft; 193.96-195.07 m), the facies consist of dark peaty, slightly micaceous silty clays (Fig. F12) with laminae and thin beds of fine sands showing decreasing sand downsection. These facies were deposited in lagoonal/estuarine/marsh environments (Fig. F4). The section from 640 to 640.4 ft (195.07 to 195.19 m) consists of medium to coarse sand deposited in shoreface setting. Thus, the section from 636.35 to 640.4 ft (193.96 to 195.19 m) shallows upsection, consistent with interpretation of this section as a prograding LST (Fig. F4). A sharp contact occurs at 640.4 ft (195.19 m), with shelly fine-medium shelf sand below (641.4-641.55 ft; 195.50-195.54 m); these sands are identical to shelly shelf sands found below an interval of no recovery (641.6-650 ft; 195.56-198.12 m). We interpret this sharp facies shift (640.4 ft; 195.19 m) as a sequence boundary. The bottom of the recovered interval consists of a return to shoreface sands (641.55-641.65 ft; 195.54-195.56 m) that we attribute to bioturbation of shoreface sands downsection below the sequence boundary. However, we cannot exclude the possibility that the shelly fine-medium shelf sand (641.4-641.55 ft; 195.50-195.54 m) was burrowed up and that the sequence boundary lies in the interval of no recovery (641.6-650 ft; 195.56-198.12 m).
Shelly fine-medium sands (650-670 ft; 198.12-204.22 m) grade down to shelly medium-coarse sands (670-675 ft; 204.22-205.74 m) and alternations of fine, medium, coarse-very coarse sand (675-680 ft; 205.74-207.26 m) with clay interbeds from 681.5 to 687.5 ft (207.72 to 209.55 m). We interpret the sands as reflecting nearshore/shoreface deposition and the clays as indicating the influence of a delta (delta-front sands and clays) (Fig. F5). The sands (650-680 ft; 198.12-207.26 m) comprise an aquifer unit that may correlate to the upper part of the Atlantic City 800-foot sand aquifer. The lithology gradually fines downcore as shown on the gamma-ray log (Fig. F5), alternating between fine to medium quartz sands and micaceous clays and silts (680-713 ft; 207.26-217.32 m). The clayey silts are laminated to burrowed and infilled with micaceous fine sands. These interbedded sands and clayey silts were deposited in a delta-front setting, though it appears that the delta front was prograding onto a storm-dominated shelf. Between 713 and 716.8 ft (217.32 and 218.48 m), the lithology consists of clayey micaceous fine sand with minor amounts of glauconite sand, representing deposition on a shelf. A major facies change occurs below 716.8 ft (218.48 m), with shells and pebbles within a sandy clay matrix (716.8-716.95 ft; 218.48-218.53 m), a massive shell bed (716.95-718.4 ft; 218.53-218.97 m), and a sequence boundary (718.4 ft; 218.97 m) (Fig. F11).
The interval between 640.4 and 718.4 ft (195.19 and 218.97 m) is interpreted as a sequence: the shell bed is the transgressive lag (716.8-718.4 ft; 218.53-218.97 m), the glauconitic unit is the thin TST (713-716.95 ft; 217.32-218.53 m), and the coarsening-upward succession is the HST (636.35-713 ft; 193.96-217.32 m) (Fig. F5). Based on Sr-isotopic ages of ~19.9-20.6 Ma, this sequence correlates with Sequence Kw1b of Sugarman et al. (1993). The spectacular sequence boundary at 718.4 ft (218.97 m) (Fig. F11) thus correlates with a sequence boundary at 666 ft (203.00 m) at the Leg 150X Atlantic City borehole (Fig. F5). The Kw1c sequence found downdip at Cape May (Miller et al., 1997) apparently has been cut out at both Ocean View and Atlantic City (Miller et al., 1997).
The entire section from ~718.4 to 891.65 ft (~218.97 to 271.88 m), with Sr-isotopic ages ranging between 20.4 and 21.5 Ma (Fig. F8), correlates with the Kw1a sequence of Sugarman et al. (1993) (Fig. F5). Like the Kw2a sequence above, it is possible to subdivide this thick sequence into several higher-order sequences (Fig. F5), with basal unconformities at ?740, 775.9/780, and 891.65 ft (?225.55, 236.49/237.74, and 271.88 m). From the top down, we term these higher-order sequences as Kw1a3, Kw1a2, and Kw1a1 (Fig. F5).
Lignitic medium to coarse quartz sands with occasional shell fragments (720-730 ft; 219.46-222.50 m) appear at 718.4-720 ft (218.97-219.46 m). These sands represent the upper HST of a sequence (Fig. F5); the environment of deposition of these organic-rich shelly sands may have been delta front. The sands grade down to interbeds of shelly fine-medium sand and silty clay (730-738.2 ft; 222.50-225.00 m), with predominantly peaty silty clay at 738.8-740 ft (225.19-225.55 m). These clays are lower HST deposits from a prodelta or delta-front environment (Fig. F5). There is a facies boundary between shelly sands and clays (delta-front/prodelta interface) and cross-bedded medium-coarse sands below ~740 ft (~225.55 m) (nearshore environments, though with a deltaic influence). This facies shift from lower HST silts and clays above to upper HST sands below could be interpreted as a higher-order sequence or facies shift due to autocyclical processes (e.g., lobe switching). We tentatively interpret the section from 718.4 to 740 ft (218.97 to 225.55 m) as a sequence and term it Sequence Kw1a3 (Fig. F5).
Organic-rich micaceous fine-medium-coarse sands return from 740 to 766.2 ft (225.55 to 233.54 m), comprising the upper HST of a sequence deposited in nearshore/delta-front environments (Fig. F5). Occasional silty drapes appear at 750 ft (228.60 m) and are interbedded with the sands to 766.2 ft (233.54 m). Interbeds of micaceous silty clay appear at 770.2-770.4, 770.7-771.0, and 774.3-775.2 ft (234.76-234.82, 234.91-235.00, and 236.01-236.28 m); although the section is predominantly sand, the gamma log shows an interval of high radiation from 770 to 777 ft (234.70 to 236.83 m) (Fig. F5). These interbedded silty clays and sands probably mark delta-front/prodelta environments and the lower HST of a sequence (Fig. F5); the sequence boundary may be in an interval of no recovery between 775.9 and 780.0 ft (236.49 and 237.74 m). We term the tentative sequence between 740 and 775.9/780 ft (225.55 and 236.49/237.74 m) as Sequence Kw1a2 (Fig. F5). The strong deltaic influence on Sequences Kw1a3 and Kw1a2 explains the great thickness of the Kw1a sequence(s) at this site. The greater thickness of this section is consistent either with autocyclical shifts or the preservation of two higher-order sequences due to higher sediment supply and accommodation space provided by loading.
Cross-bedded to massive micaceous fine-medium sands with common opaque minerals are found from 780 to 810 ft (237.74 to 246.89 m), marking an upper HST (Figs. F5, F12). Occasional silty clay laminae differentiate these sands from their temporal Kw1a equivalents at Cape May and Atlantic City (Miller et al., 1997); at those boreholes, the Kw1a sands were deposited in neritic environments. At Ocean View, there is a clear deltaic influence on these sands, although extensive bioturbation and dominance of burrowed sands still suggest deposition on a storm-dominated shelf. The sands from 718.4 to 810.0 ft (218.97 to 246.89 m) comprise an aquifer that correlates with the lower part of the Atlantic City 800-foot sand aquifer (Fig. F5), with the section from 780 to 810 ft (237.74 to 246.89 m) providing the best potential aquifer based on the lithology.
Laminated micaceous silty fine sands with interbedded darker laminated silty clays and thin sand laminae characterize the sediments from 810 to 863.8 ft (246.89 to 263.29 m). These proximal prodelta/distal delta-front deposits represent the lower HST (Figs. F5, F12). The silty clays contain more sand than is typical of prodelta deposits in the Kw1 sequence(s) elsewhere in New Jersey, reflecting closer proximity to source. The section from 862 to 863.8 ft (262.74 to 263.29 m) is a more uniform silty clay. A facies change to a fine sandy glauconitic silt containing abundant shells (870-872.1 ft; 265.18-265.82 m) marks the transition to deeper water facies of the TST; this level is associated with a distinct gamma-ray peak that we interpret as the MFS (Fig. F5). These deeper-water (shelf) deposits continue downsection with a shelly silty clay (872.1 ft-879.1 ft; 265.82-267395 m) and massive silty micaceous shelly clay (880-889.6 ft; 268.22-271.15 m). These sediments are either very distal prodelta or very muddy shelf deposits (Fig. F5). Below the shelly sands, there is a spectacular bioturbated gray clay from 890.7 to 892.3 ft (271.49 to 271.97 m) (Fig. F5). The top of the clay is a sharp though heavily bioturbated contact with sand burrowed down into the clay. This contact (890.7 ft; 271.49 m) lacks evidence for erosion (e.g., rip-up clasts or an irregular contact), and we interpret it as a transgressive surface and the section from 890.7 to 891.65 ft (271.49 to 271.77 m) as an LST (Fig. F5). A sequence boundary marked by a minor gamma-ray peak (Fig. F5) at 891.65 ft (271.77 m) separates clay from clayey sands below. We correlate the sequence between 718.4 and 891.65 ft (218.97 and 271.88 m) with the Kw1a sequence of Sugarman et al. (1993) and Miller et al. (1997) and the sequence below this with Sequence Kw0 of Miller et al. (1997).
A clayey, slightly glauconitic, slightly micaceous fine sand between 891.65 and 895.3 ft (271.77 and 272.89 m) gradually becomes clayier near its base, as evinced by a minor gamma-log peak (Fig. F5). A sequence boundary occurs at the base of a contact zone between 895.3 and 895.55 ft (272.89 and 272.96 m). The contact zone consists of reworked sandy glauconitic clay with shells and pebbles. It is slightly cemented and has common phosphorite pellets in the contact zone that are burrowed upsection. Sr-isotopic age estimates available for this thin sequence indicate ages of 21.3-23.8 Ma, thus correlating with the Kw0 sequence. This entire sequence is illustrated in Figure F10.
Below the contact at 895.55 ft (272.96 m) is a dark greenish gray, slightly silty, heavily bioturbated, glauconitic, medium quartz sand (895.55-950 ft; 272.96-289.56 m) (Fig. F6). Scattered shells are found from 895.8 to 905.7 ft (273.04 to 276.06 m). Shells are rare in these sands from 906 to 920 ft (276.15 to 280.42 m) and become notable again below 920 ft (280.42 m). These sands were deposited on the shelf in inner-middle neritic environments. Sr-isotopes indicate that these sands are uppermost Oligocene (24.9-25.3 Ma), correlating with Sequence O6 of Pekar et al. (1997a) (Fig. F6). Green sands above 950 ft (289.56 m) are distinct from clayey brown sands below; we interpret the brown sands below as an HST and the green sands above as a TST (Fig. F6). Thus, a sequence boundary should occur near 950 ft (289.56 m). Sr-isotopes indicate that the brown sands are clearly older (26.4-26.7 Ma) than the green sands above (25.3 Ma). The green sands between 895.55 and 950 ft (272.96 and 289.56 m) correlate with Sequence O6 of Pekar et al. (1997a), and the brown sands below 950 ft (289.56 m) correlate with Sequence O5 of Pekar et al. (1997a). However, there is no physical surface indicative of a sequence boundary near 950 ft (289.56 m), unless is it in a coring gap (949.9-950.0 ft; 289.53-289.56 m).
The interval from 950 to 960 ft (289.56 to 292.61 m) contains a silty medium-to-coarse quartz-glauconite sand interbedded with brown fine-sandy clay layers and thin indurated zones (Fig. F6). From 960 to 970 ft (292.61 to 295.66 m), the sediments are slightly clayey (~25% clay), massive (bioturbated), quartzose medium-to-coarse glauconite sands that are lithologically distinct from the interbedded clayey sands above (950-960 ft; 289.56-292.61 m). The section from 950 to 970 ft (289.56 to 292.61 m) is interpreted as an upper HST deposited on a shelf (Fig. F6). From 970 to 980 ft (295.66 to 298.70 m), the section generally coarsens downsection with clay and silt content decreasing and the sand-sized fraction becoming coarser and very glauconite rich (<20% quartz). Below this coarse interval, clay increases and coarse sand decreases downsection (980-1000 ft; 298.70-304.8 m) (Fig. F6). Shells appear at ~992 ft (~302.36 m) and increase in abundance to a maximum between 1000 and 1002 ft (304.8 and 305.41 m). The section from ~970 to 996 ft (~295.66 to 303.58 m) is interpreted as the lower HST; the shelly interval (996-1002 ft; 303.58-305.41 m) is interpreted as the MFS, based on the highest abundance of shells (Fig. F6). Below 1002.8 ft (305.65 m), shells are absent and very coarse glauconite and goethite predominate. The goethite component consists of brown pellets of weathered glauconite interpreted as reworked from older strata. The peak in glauconite/goe-thite abundance at 1005 ft (306.32 m) is associated with a gamma-log kick that could be interpreted as the MFS, although common reworked glauconite (goethite) at this level suggests that the MFS is slightly higher. The sediments become slightly clayey with minor coarse quartz sand between 1005 and 1014 ft (306.32 and 309.07 m). An indurated interval between 1015.3 and 1015.8 ft (309.46 and 309.62 m) separates clayey coarse glauconite/goethite (~50% glauconite, ~50% ?goethite) with interbedded glauconitic clay (1014.5-1015.4 ft; 309.22-309.49 m) above from very coarse glauconite sand with very little clay and minor goethite below. This indurated interval marks a sequence boundary at 1015.8 ft (309.62 m), separating Sequence O5 (based on a Sr-isotopic age of 26.7 Ma) (Fig. F6) of Pekar et al. (1997a) above from Sequence O3/4 below (based on a Sr-isotopic age of 28.3 Ma) (Fig. F6).
Very coarse glauconite sand with very little clay and minor goethite (1015.8-1035 ft; 309.62-315.47 m) encompasses an interval of poor recovery (Fig. F6), probably due to alternation of indurated zones (which clog the core catcher) and friable glauconite sands. These very coarse sands comprise the upper HST of the sequence. Shells become abundant in the interval from 1033 to 1040 ft (314.86 to 316.99 m), with a concentration of shells at 1035.6-1035.7 ft (315.65-315.68 m) (Fig. F6). The sands become gravelly with little shell debris (1040-1043.3 ft; 316.99-318.00 m) and give way to glauconitic sandy clay (1045-1050.5 ft; 318.52-320.19 m), indicative of the contact of the lower HST with the TST (Fig. F6). A surface at 1050.5 ft (320.19 m) (Fig. F11) separates glauconitic sandy clay above from pebbly, slightly clayey coarse glauconitic quartz sand below. We interpret this surface as a sequence boundary and the underling glauconitic quartz sand as the HST of the underlying sequence (Fig. F6). Only one Sr-isotopic age estimate (28.1 Ma at 1031.0 ft [314.25 m]) is available for the sequence between 1015.8 and 1050.5 ft (309.62 and 320.19 m), correlating it with Sequence O3 of Pekar et al. (1997a). Sequence O4 may be cut out at Ocean View. Alternatively, a thin cemented zone at 1031.7-1031.75 ft (314.46-314.48 m) overlain by a thin clay (1031.4-1031.7 ft; 314.37-314.46 m) may be a sequence boundary separating Sequence O3 from O4 below. If so, the interval between 1015.8 and 1031.7 ft (309.62 and 314.46 m) could be assigned to Sequence O4. Note that this interpretation requires the Sr age estimate at 1031.00 ft (314.25 m) to be from a reworked shell.
Sands from 1050.5 to 1077.6 ft (320.19 to 328.45 m) are massive silty glauconitic medium-to-coarse quartz sand (Fig. F6). This unit was deposited as the upper HST and was deposited on a marine shelf (Fig. F6). The glauconite is rounded to ovoid and dominated by brown reworked grains (goethite). The sediments from 1060 to 1070 ft (323.09 to 326.14 m) contain granules to pebbles in the sand fraction. Interspersed very weathered thin shells occur in the lower part of the section, with occasional thin highly weathered shell concentrations (e.g., 1064.8-1064.9 ft; 324.55-324.58 m). The interval from 1077.6 to 1080 ft (328.45 to 329.18 m) consists of slightly quartzose, slightly glauconitic silty clay deposited as the lower HST on a marine shelf (Fig. F6). Sediments from 1080.0 to 1086.4 ft (329.18 to 331.13 m) consist of slightly quartzose clayey glauconite sands interbedded with glauconitic clay. Glauconite in this interval consists of black, primarily unweathered grains, representing the TST and basal part of the sequence (Fig. F6). A sequence boundary occurs in an unrecovered interval between 1086.4 and 1090 ft (311.13 and 332.23 m), probably at the level of a sharp gamma-log spike at 1090 ft (332.23 m) (Fig. F6). An indurated zone at 1090.4 ft (332.35 m) may mark the boundary (Fig. F6), although the major facies change occurs within the coring gap. Based on Sr-isotope ages of 30.1 and 30.4 Ma at 1076 and 1080.6 ft (327.96 and 329.18 m), respectively, we correlate the sequence between 1050.5 and 1090 ft (320.19 and 332.23 m) with Sequence O2 of Pekar et al. (1997a).
We assign the glauconitic quartz and quartzose glauconite sands (895.55-1086.4/1090 ft; 272.96-331.13/332.23 m) to the Oligocene Atlantic City Formation of Pekar et al. (1997b) (Fig. F6). It might be possible to place the formational boundary at 1000 ft (304.80 m) at the base of consistent quartzose sands or at 1086.4/1090 ft (331.13/332.23 m) at the base of quartzose sands. We favor the lower placement, because brown weathered glauconite, typical of the Atlantic City Formation, is common above 1090 ft (332.23 m).
Clayey, slightly quartzose fine-grained glauconite sand is found throughout the interval from 1090 to 1126.3 ft (332.23 to 343.30 m) (Fig. F6). The entire section from 1090 to 1126.3 ft (332.23 to 343.30 m) was deposited on an inner to middle neritic shelf. The upper part of this interval (1090-1110 ft; 332.23-338.33 m) consists primarily of green unweathered glauconite that is typical of TSTs in New Jersey. From 1110 to 1126.3 ft (338.33 to 343.30 m), brown, weathered, abraded glauconite is common to predominant in clayey glauconite sands. This facies succession is unusual because such brown weathered glauconite is typical of upper HSTs. These weathered glauconite sands have a sharp contact with a brown clay at 1126.3 ft (343.30 m). The section below 1126 ft was drilled with smaller-diameter NQ rods (see "Operations") and the Oligocene NQ cores were covered in a thick rind of drilling mud and formational sands that obscures structures and lithologies. Only by cutting the cores in half could the original lithology be determined, although in some sections is was not clear if clay interbeds represent drilling disturbance or original strata. Clays with interbedded quartzose glauconite sands continue to 1140.2 ft (347.53 m) (Fig. F6). The sequence stratigraphy of the entire section from 1090 to 1140.2 ft (332.23 to 347.53 m) is enigmatic. Gamma-ray logs show a large increase from 1124 to 1127 ft (342.60 to 343.51 m) (Fig. F6), whereas Sr-isotopes suggest a break between 1096.0 and 1135.7 ft (334.06 and 346.16 m; 31.0 and 32.9 Ma). We reconcile these observations as follows: the section below 1140.2 ft (347.53 m) was deposited as nearshore sands, with the clays (1126.3-1140.2 ft; 343.30-347.53 m) also deposited in nearshore setting. A sequence boundary occurs at 1126.3 ft (343.30 m) in association with a gamma-ray peak; Sr-isotopes indicate that the sequence below correlates with Sequence O1 and the sequence above with Sequence O2 of Pekar et al. (1997a). The facies successions from brown, primarily transported glauconite (1110-1126.3 ft; 338.33-343.30 m) to in situ glauconite (1090-1110 ft; 332.23-338.33 m) represents a transgressive deposit, with the HST missing due to truncation.
Clays with interbedded quartzose glauconite sands (1126.3-1140.2 ft; 347.53-343.30 m) overlie heavily bioturbated (?Ophiomorpha burrows), slightly clayey ("gummy") quartzose glauconite sands with thin clay interbeds/laminae (1140.1-1151.1 ft; 347.50-350.86 m) (Fig. F6). The glauconite is primarily brown, weathered, and cracked, degrading easily to clay and was reworked in shallow shelf/nearshore environments. Green glauconite increases downsection from trace amounts at 1141 ft (347.78 m) to >5% at 1149 ft (350.22 m). The section becomes slightly shelly (1150-1551.1 ft; 350.6-472.9 m) and then grades down from clayey sand (1151.1-1152 ft; 350.9-351.2 m) to shelly sandy clay (1152-1155 ft; 351.2-352.1 m). The section above this is clearly regressive, shallowing upsection from middle-?outer neritic glauconite clays to nearshore reworked glauconite sands. Sandy interbeds generally increase downsection beginning at 1155-1158 ft (352.04-352.96 m) to an indurated sandstone at 1158-1158.2 ft (352.96-353.02 m). This sandstone may mark the MFS; alternatively, the MFS may occur within the shelliest of the glauconitic clays (1153 ft; 351.52 m). Below 1158 ft (352.96 m), the section is clearly transgressive and is assigned to the TST (Fig. F6). Quartzose clayey glauconite sand (1160-1163.0 ft; 353.57-354.48 m) with green unweathered glauconite becomes shelly at the base of the sequence (1170-1171.5 ft; 356.62-357.07 m). Coring gaps (1158.2-1160 ft [353.02-353.57 m] and 1163-1170 ft [354.48-356.62 m]) otherwise limit interpretation of this section (Fig. F6). We recovered a spectacular sequence boundary at 1171.5 ft (356.98 m), separating Oligocene from Eocene strata.
Based on Sr-isotopic ages, we correlate the section from 1126.0 to 1171.5 ft (343.20 to 357.07 m) to the O1 sequence of Pekar et al. (1997a) (Fig. F6). However, one Sr-isotopic age of 33.3 Ma at 1151 ft (350.82 m) suggests that perhaps the Mays Landing (ML) basal Oligocene sequence is represented at Ocean View (Fig. F6). If this is true, then a sequence boundary separating O1 from ML may occur at a contact between slightly shelly clayey glauconite sand (1150-1151.1 ft; 350.52-350.89 m) and a clayey sand (1151.1-1152 ft; 350.86-351.13 m). However, the contact appears gradual and we prefer interpretation of one lowermost Oligocene (1126.0-1171.5 ft; 343.20-357.07 m) sequence correlated with Sequence O1 of Pekar et al. (1997a).
Laminated micaceous greenish gray clays to slightly silty clays appear below a spectacular sequence boundary at 1171.5 ft (357.07 m) (Figs. F7, F11). The sequence boundary consists of basal shelly quartzose glauconite clay (1170.0-1170.9 ft; 356.62-356.89 m), an interval with pods of reworked greenish clay within a matrix of glauconite sands (1170.9-1171.5 ft; 356.89-357.07 m), and a sharp contact at 1171.5 ft (357.07 m). Glauconite (1%-2%) is found in the sequence below, starting at 1176.2 ft (358.51 m) and continuing downsection to a possible sequence boundary at 1180.3 ft (359.76 m) (Fig. F7). The 1180.3-ft (359.76 m) contact is burrowed with lighter green clays below burrowed up into brown clays above. The uniform silty clay lithology below 1171.5 ft (357.07 m) is assigned to the Absecon Inlet Formation of Browning et al. (1997a), which is upper Eocene where previously dated. Benthic foraminiferal assemblages at Ocean View are similar to those in the Absecon Inlet Formation at Cape May and Atlantic City: Siphonina tenuicarinata, Siphonina claibornensis, Melonis barleeanum, Hanzawaia blanpiedi, Cibicidoides ?speciousus, Uvigerina multistriata, Ceratobulimina sp., Spiroplectammina mississippiensis, Osangularia sp., Fursenkoina, and common dentilinids. These assemblages indicate deposition in middle to outer neritic paleodepths (probably the Siphonina or Cibicidoides biofacies of Browning et al., 1997a) (~75- to 100-m paleodepth). Planktonic foraminifers indicate that the section below 1172.1 ft (357.26 m) is upper Eocene, based on the highest occurrence (HO) of Hantkenina alabamensis at this level (Fig. F7). Nannofossils indicate that the section from 1174.2 to 1198 ft (358.01 to 365.27 m) belongs to Zone NP21, which spans the Eocene/Oligocene boundary, consistent with previous correlations of the upper Absecon Inlet Formation (Browning et al., 1997a). Thus, the sequence from 1171.7 to 1180.3 ft (357.13 to 359.76 m) is uppermost Eocene (i.e., the portion of Zone NP21 within the range of Hantkenina) and corresponds to Sequence E11 of Browning et al. (1997a).
Clays and silty clays below the 1180.3-ft (359.76 m) sequence boundary become slightly siltier below 1190 ft (362.71 m) (Fig. F7). Below 1210 ft (368.81 m), the sediments become clayier with slightly glauconitic burrows and thin shell layers. Glauconite increases (usually in burrows) from 1220 to 1242.25 ft (371.86 to 381.30 m), and occasional pyrite nodules are found. A very slightly sandy (~15% quartz sand) section at 1231-1255.8 ft (375.21-382.77 m) may mark the top of a shallowing-upward succession with a minor flooding at ~1231 ft (375.21 m) (Fig. F7). An increase in the abundance of planktonic foraminifers and benthic foraminiferal assemblages between 1241 and 1251 ft (378.26 and 381.30 m) may mark a minor flooding event (see "Biostratigraphy"); alternatively, it may be possible to interpret a sequence boundary at ~1241-1251 ft (~378.26-381.30 m) (see "Biostratigraphy"). However, physical evidence for a sequence boundary is minimal. The similarity in size and abundance of glauconite and quartz sand components through this interval (1231-1255.8 ft; 375.21-381.30 m) is evidence that the glauconite is reworked and the faunal change near 1251 ft (381.30 m) represents a change from an upper HST to a lower HST (Fig. F7). From 1260 ft to 1330 ft (384.05 to 405.38 m), the lithology consists of slightly glauconitic shelly pyritic clay (Fig. F7). Shells become common below 1272 ft (387.71 m). Glauconitic burrows increase from 1329.6 to 1338.65 ft (405.26 to 408.02 m). Glauconite is rare, and the clay alternates with silty clay from 1340 to 1371.4 ft (408.43 to 418.00 m); these alternations of silty clay and clay have a typical thickness of ~2 cm. Some "clays" noted from ~1358 to 1370 ft (413.92 to 417.58 m) may represent intrusion of drilling mud into fractures of silty clay-clay, though most appear to be in situ silty clay-clay couplets. The cause of the cyclicity is unclear, although it is certainly on the centennial-millennial scale.
Glauconite appears in trace abundance at ~1370 ft (417.58 m), becoming slightly glauconitic silty clay at 1370.75 ft (417.80 m) with glauconite lenses (Fig. F7). A change occurs at 1371.4 ft (418.00 m) from brownish silty clay above to greenish glauconitic clay to silty clay that continues down to 1373.2 ft (418.55 m). From 1373.2 to 1374.4 ft (418.55 to 418.92 m), there is a glauconitic silty clay with dispersed shell fragments. A clayey, heavily burrowed glauconite sand occurs from 1374.4 to 1374.8 ft (418.92 to 419.04 m). Glauconite increases to an irregular bioturbated surface at 1375.0 ft (419.10 m), which represents a major sequence boundary (Fig. F7). The facies shifts from transgressive glauconitic clays to regressive silty clays (i.e., changes at 1371.4 and 1374.4 ft [418.00 and 418.92 m] may represent flooding surfaces associated with parasequences.
The sequence from 1180.3 to 1375.0 ft (359.76 to 419.10 m) correlates with Sequence E10 of Browning et al. (1997a). Sediments between 1375.0 and 1376.85 ft (419.10 and 419.66 m) appear to represent a very thin sequence. A surface at 1376.85 ft (419.66 m) is erosional with clay rip-up clasts from the section below; above this, the sequence fines upsection from clayey glauconite sand to slightly glauconitic silty clay. Below the sequence boundary at 1376.85 ft (419.66 m), slightly glauconitic olive gray, slightly shelly silty clay (1376.85-1379.62 ft; 419.66-420.51 m) overlies heavily burrowed very light green clay to silty clay (1379.62-1400 ft; 420.51-426.72 m). A facies change at 1393.5 ft (424.74 m) from dark brown clays above to light green clays below may mark the MFS, with the brown clays above representing the HST. Glauconite and shells increase downward to a sequence boundary at 1402.9 ft (427.60 m) (Fig. F11). We tentatively correlate the sequence from 1376.85 to 1402.9 ft (419.66 to 427.60 m) with sediments between 770.7 and 840.1 ft (234.91 and 256.06 m) at Bass River and between ~1330 and 1352 ft (~405.38 and 412.09 m) at Atlantic City. This previously unnamed sequence is here termed Sequence E10a. The lithologic assignment of the section between 1374.4 and 1402.9 ft (418.92 and 427.60 m) is equivocal (Fig. F7). The section contains variable facies that have aspects both of the silty clays of the Absecon Inlet Formation and the glauconitic clays and yellow clays of the underlying Shark River Formation. Coarse-grained facies (fine-to-medium quartz sands) that mark the upper Shark River Formation elsewhere in New Jersey are absent at Ocean View because of its downdip position, further complicating placement of the Absecon Inlet/Shark River Formational boundary. We tentatively place the formational boundary at the top of slightly coarser-grained (slightly sandy) yellow clays at 1402.9 ft (427.60 m) (Fig. F11). This is consistent with sequence stratigraphic and biostratigraphic correlations among boreholes.
Below the 1402.9-ft (427.60 m) sequence boundary (Fig. F11), extremely dry, green, slightly glauconitic shelly silty clays (upper HST?) grade down to green clays (lower HST?) (Fig. F7). Glauconite increases downsection below 1422.3 ft (433.52 m) from slightly glauconitic clay to clayey glauconite sand from 1434.1 to 1434.4 ft (437.11 to 437.21 m); this section is interpreted as a TST (Fig. F7). A distinct sequence boundary at 1434.4 ft (437.21 m) separates clayey glauconite sand above from slightly glauconitic clay below. We tentatively correlate the sequence from 1402.9 to 1434.4 ft (427.60 to 437.21 m) with Sequence E9 of Browning et al. (1997b). In other boreholes on the coastal plain, Sequence E9 contains a mix of middle Eocene foraminifers and upper Eocene calcareous nannoplankton. This sequence contains Acarinina, indicative of the middle Eocene and upper Eocene calcareous nannoplankton indicative of Zone NP18 (Fig. F7), requiring reworking of the middle Eocene foraminifers. This sequence is much finer grained at this site than it is in updip boreholes.
Below the 1434.4-ft (437.21 m) sequence boundary, slightly glauconitic (typically 2%), foraminifer-rich (typically 20%-25%), slightly clayey silt grades down to foraminiferal silty clay at 1465 ft (446.53 m) (Fig. F7). No core was recovered between 1465 and 1484 ft (446.53 and 452.32 m). A sharp gamma ray-log peak occurs at 1473.8 ft (449.21 m), suggesting a sequence boundary (Fig. F7). Porcellanitic Eocene clays ("ash colored marls") of the lower Shark River Formation are found below the gamma-log kick at 1474 ft (449.28 m) (Fig. F7). The clays above 1474 ft (449.28 m) contain more glauconite and are distinctly browner in color than clays below 1474 ft (449.28 m). Because of poor recovery, it is not possible to be certain that a sequence boundary was penetrated. Nevertheless, the character of the clay between 1434.4 and ~1474 ft (437.21 and ~449.28 m) suggest that it is equivalent to Sequence E8 of Browning et al. (1997b) and the section below 1474 ft (449.28 m) is assigned to Sequence E7 of Browning et al. (1997b) (Fig. F7). The inferred sequence between 1434.4 and 1473.8 ft (437.21 and 449.21 m) is assigned to planktonic foraminiferal Zone P12 and the upper part to Zone NP17 (see "Biostratigraphy"), indicating that it correlates with Sequence E8 of Browning et al. (1997b).
The clays below 1474 ft (449.28 m) contain alternations of slightly glauconitic porcellanitic foraminiferal clay with beds of clayey porcellanite at 1487.2-1487.9 and 1488.9-1489.8 ft (453.30-453.51 and 453.82-454.09 m) (Fig. F7). A strong petroleum odor was noted on the cores from 1484 to 1486 ft (452.32 to 452.93 m). From 1490 to 1543.3 ft (454.15 to 470.40 m), the clays display large- (centimeter) and small-scale (millimeter) burrows that break up laminations; these distinctive burrows are reminiscent of the lower middle Eocene section at the ACGS #4 borehole and deep-water bioturbation (Miller et al., 1990). Field samples from 1488 and 1490 ft (453.54 and 454.15 m) contain common Cibicidoides subspiratus and Cibicidoides eocanus and occasional Alabamina wilcoxensis, Anomalinoides acuta, Cibicidoides praemundulus, Gyroidinoides sp., and sparse plankton; this benthic fauna appears similar to biofacies G of Browning et al. (1997b), which is found in the lower Shark River Formation at Allaire, Island Beach, ACGS #4, and Atlantic City. Planktonic foraminifers are sparse and poorly preserved and include primarily Acarinina spp.; tentative identification of Acarinina primitiva and Acarinina soldadoensis are consistent with an uppermost lower to lowermost middle Eocene assignment. The section between 1501 and 1521 ft (457.50 and 463.60 m) is largely indurated and foraminifers were difficult to process. There is a small percentage (1%-2%) of glauconite throughout this section, with the amount becoming greater (2%-3%) between 1515 and 1517 ft (461.77 and 462.38 m) (Fig. F7). The section from 1521 ft (463.60 m) and below contains an interesting mix of lower Eocene planktonic foraminifers (Zones P6b/P7) (Morozovella formosa, Morozovella gracilis, and various acarininids) and middle Eocene nannofossils (Zone NP15) and planktonic foraminifers (Zone P10 or younger) (Globigerinatheka subconglobata, Subbotina frontosa, and Hantkenina nuttalli). This biostratigraphic discrepancy engendered considerable debate as to the assignment of this section to the middle or lower Eocene. Based on the following criteria, we interpret the section from 1521 ft (463.60 m) to TD as middle Eocene.
Uniform porcellanitic foraminiferal clays continue from 1521 to 1543.3 ft (463.60 to 470.40 m), where glauconite increases from trace (<2%) above to up to 7% at 1550 ft (472.44 m) (Fig. F7). Glauconite increases to a sequence boundary at 1559.0 ft (475.18 m) (Fig. F7). Based on assignment of this sequence to nannofossil Subzone NP15b, we correlate the sequence between 1474 and 1559.0 ft (449.28 and 475.18 m) with Sequence E7 of Browning et al. (1997b).
Uniform indurated, porcellanitic, slightly glauconitic foraminiferal clay returns from 1559 ft (475.18 m) to the bottom of the hole (Fig. F7). A slightly glauconitic interval with rip-up clasts occurs at ~1571 ft (478.84 m), wheras the shoe at 1573.3-1573.5 ft (479.54-479.60 m) (i.e., the lowest sample recovered) contains common glauconite and mud chips, perhaps indicating that a sequence boundary was penetrated at the BOH (i.e., 1571-1573.5 ft; 479-479.7 m). Based on assignment to Subzone NP15a, we tentatively correlate the sequence between 1559.0 ft (475.18 m) and TD with Sequence E6 of Browning et al. (1997b) (lower Eocene) (Fig. F7). If one or more sequence boundaries are located at 1571-1573 ft (478.84-479.60 m), then it would predict that the BOH correlates with Sequence E5 of Browning et al. (1997b), which is assigned to Subzone NP14a at other locations. Further nannofossil studies will test this correlation.