1,100 1,200 1,300 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3 1.4 1,000 900 0 0 1 KILOMETER 1 MILE 1,300 1,200 1,100 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3 1.4 1,000 900 800 700 600 500 400 300 800 500 400 300 600 700 200 100 100 200 Tck Tmb (Tcm) Tlmo Tck (Tex) (QTu) Tcm Tlmo Calvert Formation Crystalline basement rocks Raised rim Quaternary to upper Miocene deposits, undifferentiated Fractured, faulted and (or) brecciated crystalline basement rock Melt zone ? Exmore tsunami-breccia deposits VERTICAL EXAGGERATION X2 Northwest D Horizontal distances keyed to shot points (1,300 to 100) along the navigation track Southeast D´ SECTION A–A´ Inner rim faults Compaction faults Annular trough Two-way traveltime, in seconds Inner rim Compaction faults Compaction faults Inner basin CHESAPEAKE BAY SEISMIC PROFILE (D–D´) AND GEOLOGIC INTERPRETATION 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 2,250 2,150 2,050 2,200 0 0 1 MILE 1 KILOMETER 2,100 2,000 1,950 2,250 2,150 2,200 2,100 2,000 1,950 (Kp) Tcm Tck (Tex) Tmb (QTu) Tlmo Disruption boundary Potomac Formation Crystalline basement rocks Quaternary to upper Miocene deposits undifferentiated Exmore tsunami-breccia deposits Horizontal distances keyed to shotpoints (2,250 to 1,950) along the navigation track Northwest C Two-way traveltime, in seconds Southeast C' faults Outer rim VERTICAL EXAGGERATION X2 Compaction faults Outer rim Annular trough YORK RIVER SEISMIC PROFILE (C–C´) AND GEOLOGIC INTERPRETATION (57F8) (58F127) (58F82) 59 73 69 86 (55F20) (56F16) (57F7) (58F38) (59F2) (58F57) (56G73) 93 49 53 55 57 64 67 84 50 corehole 65, 66 47 (60E3) Kiptopeke corehole (63F50) 88 Jamestown (58F50, 58F67) Newport News Park 1 and 2 coreholes 125 FEET SEA LEVEL -250 -500 -750 -1,000 -1,250 -1,500 -1,750 -2,000 Te Tsm Ty Qt Te To Qt Tcl Tpp (Tn) Ty Qt Ty Tcm Qt (Ta) (Te) (Tsm) (Ty) Tcr (Tck) To (Tex) To (Tcl) (Tcm) (Tmb) Tmb Tmb Tex Tck Tcl (Tck) (Tex) (Kp) (Tm) (Qt) Marlboro Clay Nanjemoy Formation Aquia Formation Bottom of NNP2 Disruption boundary Potomac Formation Crystalline basement rocks St. Marys Formation Eastover Formation Yorktown Formation Quaternary deposits Eastville paleochannel Calvert Formation (lower Miocene) Chesapeake Bay impact crater megablock beds Exmore tsunami-breccia deposits Chickahominy Formation Calvert Formation (middle Miocene) Exmore tsunami-breccia deposits Chickahominy Formation James River James River James River Chesapeake Bay Atlantic Ocean Inner basin Annular trough Annular trough Claremont Lower York-James Peninsula Outer rim of crater Approximate location of (C–C') seismic profile Approximate location of (D–D') seismic profile VERTICAL EXAGGERATION X 166.6 HORIZONTAL SCALE 1:250,000 West B East B' STRATIGRAPHIC CROSS SECTION B–B´ SCALE 1:250 000 Locations of cross section B–B' and profiles C–C' and D–D'; also shown on plate 1 C B D D´ B´ C´ Fractured, faulted and (or) brecciated crystalline basement rock Crystalline basement rocks Aquia Formation (upper Paleocene) Potomac Formation (Lower Cretaceous) Marlboro Clay (Eocene and Paleocene?) Nanjemoy Formation (lower Eocene) Chesapeake Bay impact crater megablock beds (upper Eocene?) Exmore tsunami-breccia deposits (upper Eocene) Quaternary to upper Miocene deposits, undifferentiated Chickahominy Formation (upper Eocene) Calvert Formation (middle Miocene) Newport News unit of Calvert Formation (lower Miocene) St. Marys Formation (upper Miocene) Eastover Formation (upper Miocene) Quaternary deposits, undifferentiated Chowan River Formation (upper Pliocene) Yorktown Formation (upper and lower Pliocene) Piney Point Formation (middle Eocene) 59 (57F8) Borehole or continous corehole — Number keyed to plate 1; number in parentheses refers to local number shown in appendix 1A; altitudes of tops of stratigraphic units are shown in appendix 1B; boreholes and coreholes projected into the line of section on plate 1 Newport News unit of Calvert Formation (lower Miocene), Old Church Formation (upper Oligocene), and Delmarva beds (lower Oligocene), undivided Old Church Formation (upper Oligocene) and Delmarva beds (lower Oligocene), undivided Qt Te Tsm Tcm Tcl To Tck QTu Tlmo Tex Tmb Ty Tpp Tn Tm Ta Kp Tcr EXPLANATION INTERIOR—GEOLOGICAL SURVEY, RESTON, VIRGINIA—1999 SECTION B–B' AND SEISMIC PROFILES FROM YORK RIVER (C–C´) AND CHESAPEAKE BAY (D–D´) By David S. Powars and T. Scott Bruce 1999