b west east - usgsjames river james river james river chesapeake bay atlantic ocean annular trough...
TRANSCRIPT
1,1001,2001,3000.0
0.10.2
0.3
0.40.5
0.60.7
0.80.9
1.0
1.11.2
1.3
1.4
1,000 900
0
0 1 KILOMETER
1 MILE
1,300 1,200 1,1000.00.10.2
0.3
0.40.50.60.7
0.8
0.91.0
1.11.2
1.31.4
1,000 900
800 700 600 500 400 300
800 500 400 300600700
200 100
100200
TckTmb
(Tcm)
Tlmo
Tck
(Tex)
(QTu)
TcmTlmo
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´
SEC
TIO
NA–
A´
Inner rim faultsCompaction faults
Annular trough
Tw
o-w
ay tr
avel
time,
in s
econ
ds
Inner rim
Compaction faults Compaction faultsInner 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 2,0502,200
0
0
1 MILE
1 KILOMETER
2,100 2,000 1,950
2,250 2,1502,200 2,100 2,000 1,950
(Kp)
Tcm
Tck
(Tex)
Tmb
(QTu)
Tlmo
Disruptionboundary
PotomacFormation
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
Tw
o-w
ay tr
avel
time,
in s
econ
ds
Southeast
C'
faults
Outer rim
VERTICAL EXAGGERATION X2
Compaction faultsOuter rim
Annular trough
YORK RIVER SEISMIC PROFILE (C–C´) AND GEOLOGIC INTERPRETATION
(57F8)(58F127) (58F82)59
73 6986
(55F20) (56F16)(57F7) (58F38)
(59F2)
(58F57)
(56G73)9349
5355
57 64 67
8450corehole
65, 66
47(60E3)
Kiptopekecorehole
(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
TeTsm
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 FormationAquia Formation
Bottom ofNNP2
Disruptionboundary
Potomac Formation
Crystalline basement rocks
St. Marys Formation
Eastover Formation
Yorktown Formation
Quaternary depositsEastville
paleochannel
Calvert Formation (lower Miocene)
Chesapeake Bayimpact crater
megablock beds
Exmore tsunami-brecciadeposits
ChickahominyFormation
Calvert Formation(middle Miocene)
Exmore tsunami-brecciadeposits
Chickahominy Formation
Jam
es R
iver
Jam
es R
iver
Jam
es R
iver
Chesapeake BayAtlanticOcean
Inner basin Annular troughAnnular 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 166.6HORIZONTAL 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
2F
1DS
10M
88K
131
EM
133H
134CM 135JB
128E
127W
55JN 65, 66
15A
G
F
CB
A´
D
D´ B´
A
G´
E´F´
E
C´
VirginiaBeach
Norfolk
NewportNews
Hampton
Williamsburg
Gloucester Point
Jamestown
Reedville
Exmore
Chincoteague
CapeCharles
Tappahannock
WestPoint
Claremont
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 ChurchFormation (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 Bruce1999