Post-Paleozoic activity - Lamont-Doherty Earth Observatory ...

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330 W. Manspeizer and Others USGS LINE 28 NORFOLK BASIN ^00 500 600 700 800 900 1000 1100 1200 " Figure 9. Seismic record of part of USGS line 28 showing buried Norfolk basin (shotpoints 500 to 1,000). Diffractions obscure some of the deeper reflectors. Upper limit of northwestdipping units in basin is truncated by the postrift unwnformity (PRU). Caption and figures from Klitgord and Hutchin- son 91985). northwest-southeast extensional strain increased, new northeast- trending faults (with evidence for dip slip and oblique slip) devel- oped. These later faults were reactivated by sinistral strike slip following emplacement of lava flows in the Early Jurassic. Dip- slip motion in all cases preceded strike-slip and oblique-slip; and in most cases, northeast, north-northeast, and east-northeast faults cut north-south faults. Normal faulting resumed in the late phases of basin formation and was followed by Cretaceous(?) compres- sion, in which the region was alternately deformed by northeast- southwest and northwest-southeast compressive forces. The general homoclinal character of synrift strata within the exposed basins thus belies their complicated structural histories. TERTIARY 1 Although each basin has unique features, they share a core of stratigraphic and structural elements that allow us to model, for example, the Newark basin (Fig. 6) of New Jersey and Pennsyl- vania, which geologically is the best known of these basins. By analogy with the Atlantis and Long Island basins (Figs. 7, 8), the Norfolk and Franklin basins (Figs. 9 and lo), the Hartford-Deerfield basin (Ando and others, 1984), the Rich- mond and Taylorsville basins (Ressetar and Taylor, 1988), and the Culpeper basin (Costain and others, this chapter), we model the Newark basin as a half graben with west-dipping strata and with listric normal border faults that sole into east-facing detach- ment surfaces of thrust-imbricated Precambrian and Paleozoic n
Post-Paleozoic activity USGS LINES 1 /IA FRANKLIN RIFT BASIN SP I000 800 600 400 \2\ 200 d w si NNW GULF OF MAINE GEORGES BANK SSE Â¥*LIN IA 1 LINE I* SPIOOO 800 600 400 121 200 I I I I 0 eP i5 - - - - --- >ST RI~T~IMENTARY ROCK- \^ S~;*=~- SI - l - , --- ---- - //- -, Bud- -Ã -- 0 =\ -
Page 1 and 2: The Geology of North America Vol. F
Page 3 and 4: Post-Paleozoic activity SIBERIAN Fi
Page 5 and 6: DETRITAL BASINS :'->: SALT BASINS 0
Page 7 and 8: similar orientations and/or lie alo
Page 9 and 10: Post-Paleozoic activity NEWARK BASI
Page 11: Strata within these Mesozoic basins
Page 15 and 16: sic marine tongue was speculated to
Page 17 and 18: contours in red are over Jurassic d
Page 19 and 20: crust. A pronounced north-northeast
Page 21 and 22: for relative contributions from iso
Page 23 and 24: Post-Paleozoic activity CULPEPER LI
Page 25 and 26: the basins and also corresponding w
Page 27 and 28: tons (1963), Thayer and others (197
Page 29 and 30: ank 0 6 I I Post-Paleozoic activity
Page 31 and 32: the north side of the basin. Accord
Page 33 and 34: - 46' - 42O Post-Paleozoic activity
Page 35 and 36: activity was initiated. The initial
Page 37 and 38: percent pyroxene (chiefly augite),
Page 39 and 40: have formed under higher conditions
Page 41 and 42: lines an elongated north-south patt
Page 43 and 44: Several studies of the intrusions w
Page 45 and 46: 0 100 200 300 Miles ^ Figure 27. Ma
Page 47 and 48: tomac Formation. They also report t
Page 49 and 50: REFERENCES CITED ' Post-Paleozoic a
Page 51 and 52: Galton, P. M., 1976, Prosauropod di
Page 53 and 54: - , 1988, Triassic-Jurassic rifting
Page 55 and 56: Bulletin, v. 95, p. 1176-1 187. Res

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