EXPLANATION FOR THE CAMP MAP by J. Gregory McHone

    The base map is modified from Klitgord and Schouten (1986), which still has the best pre-Atlantic reconstruction I know of.  The paleo-equator and a couple other pieces are from Olsen (1997).  Pangaea moved northward during the early Mesozoic, causing many published plume locations to be improbable (a fact conveniently overlooked).  The SDR wedge basalt location is from Holbrook and Kelemen (1993).  Dikes, sills and basalts in Africa are mainly as shown by Deckart et al. (1997), and much of that is probably from earlier papers by Herve Bertrand and his colleagues. CAMP features in South America were collected mainly from Marzoli et al. (1999), Baksi and Archibald (1997), Montes-Lauar et al. (1994), and Oliveira et al. (1990).  Other location data are referenced below. Dikes as shown are generalized; do not use this map for detailed examination of dike trends, sizes, etc. There are many more that actually exist on the ground.

    The western boundary of CAMP is the eastern highland border (orogenic axis) of the Appalachian Mountains, as was pointed out long ago by King (1961).  This must represent crustal or lithospheric control, perhaps where there was a thickness change at the Grenville craton border as in the model of King and Anderson (1998).  The boundary continues under the coastal plain of the southern USA.  The other borders are simply an outline of CAMP dikes, sills, and basaltic lavas. There is a rumor of CAMP in southern and western Texas, and within the buried Mesozoic basin of the eastern Yucatan Peninsula (Mexico), for which I am seeking a good reference.  In fact, CAMP basalts MAY also exist farther south, east, and north of the border as shown on the map. The total CAMP area, as shown, is probably between 10 and 11 million square kilometers.  The map scale is approximate only for the middle of the map, as the great area is large enough to be distorted by the map projection.

    Huge areas are shown as sills in west Africa (esp. Mali) and the Amazon Basin.  The sills occur mainly within Proterozoic and Paleozoic terranes, but there is no obvious reason why lava flows may not also be present.  In the eastern USA, sills and lavas are common within the Mesozoic basins but not in the surrounding metamorphic basement regions.  Originally, lavas should have covered those basement surfaces, however.  Certainly, some of the Mali descriptions of cumulate pyroxenites etc. are typical of large sills.  But, given the difficulties of mapping in Africa and South America, perhaps some of the "sills" are actually portions of basaltic lavas that remain in place upon the much older basement rock surfaces.

Labels (most are only on the small version)

WA = West Armoricain dike swarm, France (Caroff et al., 1995)
ME = Messejana dike, Portugal and Spain (Schermerhorn et al., 1978)
A = Avalon dike, Newfoundland (Papezik and Hodych, 1980)
C = Caraquet dike, New Brunswick and Maine (Greenough and Papezik, 1986)
S = Shelburne dike, Nova Scotia (Papezik and Barr, 1981)
X = Christmas Cove dike, Maine (McHone et al., manuscript)
H = Higganum-Holden-Onway dike system, Connecticut-Massachusetts-New Hampshire (Philpotts and Martello, 1986)
FZ = Foum Zguid dike, Morocco (Bertrand, 1991)
KK = Ksi-Ksou dike, Algeria (Bertrand, 1991)
CE = Ceara alkali basalt, northern Brazil (Marzoli et al., 1999)
MA = Maranhao dikes and basalts, Brazil (Fodor et al., 1990)
MO = Mosquito basalt, western part of the Maranhao province (Baksi and Archibald, 1997)
RO = Roraima dike swarm, Brazil (Marzoli et al., 1999)
AM = Amazon Basin sill province (Marzoli et al., 1999)
AN = Anari basalt, western Brazil (Montes-Lauar et al., 1994)
TP = Tapirapua basalt, western Brazil (Montes-Lauar et al., 1994)
BP = Blake Plateau area, western Atlantic
FL = Florida, southern USA
SGR = South Georgia Rift terrane (basalts described by Sundeen, 1989; Gohn et al., 1978; Arthur, 1988; McBride, 1991)
MS = Mississippi Embayment (basalt dated by Baksi, 1997)