. Bulletin of the Geological Society of America. Geology. EXPLANATION OF DIAGRAMMATIC SUMMARY 431 Explanation of Figure 2 Conventions used in diagram. —Time is represented in sequence from left to right. As the total lapse of ages represented by the record is un- known and the relative durations of successive ages are indeterm- inate, there is no definite time scale; but that portion of pre- Franciscan time represented was probably much longer than post- Franciscan time. The time scale is therefore much smaller at the left than at the right of the diagram. Vertical ordinates represent posi- ti
. Bulletin of the Geological Society of America. Geology. EXPLANATION OF DIAGRAMMATIC SUMMARY 431 Explanation of Figure 2 Conventions used in diagram. —Time is represented in sequence from left to right. As the total lapse of ages represented by the record is un- known and the relative durations of successive ages are indeterm- inate, there is no definite time scale; but that portion of pre- Franciscan time represented was probably much longer than post- Franciscan time. The time scale is therefore much smaller at the left than at the right of the diagram. Vertical ordinates represent posi- tions in the earth's superficial crust from a mile above sealevel to 6 miles below sealevel. Sealevel is arbitra- rily taken as a fixed datum. /Sequence of sea and land.—The upper curve represents from age to age the varying relation of the rock surface to sealevel in the chosen locality. BelowT sealevel the posi- tion of this line results from the amount of subsidence, less the thickness of deposits. Above sea- level its position is determined by the amount of uplift, less the effect of erosion. The values indicated are to be taken qualitatively, not quantitatively. The following is the interpretation of the several lettered sections: a-b. Submergence; sedimentation corresponding to the strata of the Coast complex; com- prising epochs probably of great duration and of com- plex physical changes; probably closed by orogenic movements that resulted in folding of the Coast com- plex in the zone of defor- mation by flow, and were connected with granitic in- 3 2 ^ c ® O o o a, a o o c 5 H •5" ^ o W " — o << CD Present. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Geological Society of America. [New York : The Society]
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectgeology, bookyear1890
