7. Early Mesozoic pre-rift configuration of the continents .......... ........................ 21
8. Mafic index plotted versus TiO2 showing fields of circum-Atlantic tholeiite ................... 22
9a. Plot of TiO2 versus MgO for selected ENA tholeiites ............ ........................ 23
9b. Plot of TiO2 versus MgO for circum-Atlantic tholeiites ........... ........................ 24
10. Plot of Ti versus Zr for circum-Atlantic tholeiites ............. ...........................26
PART II
11. Lithology of the pre-Middle Jurassic Florida basement surface ............................ 35
12. Florida basement (pre-Middle Jurassic) tectonic features ........... ..................... 36
TABLES
PART I Page 1. Reported radiometric age determinations for Florida tholeiite .......... .................... 2
2. Magma types recognized by Weigand and Ragland (1970) ........... ..................... 3
3. Major element compositions and normative mineralogy of Florida tholeiite reported by Milton and Grasty (1969) and Mueller and Porch (1983) ............. ..............................4
4. Florida deep well data for diabase and basalt .............. .............................6
5. Sample location data .................................... ...............11
6. Major and trace element compositions and normative mineralogy for Florida tholeiite .......... 13
7. Petrogenetic model for Florida tholeiite showing calculated compositions and norm ative m ineralogy .............. .........................................18
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