Questions for Brett et al. (1998)
  1. What does 'allocyclic' mean and how is it related to eustatic sea level change?

    2. 'Allocyclic' refers to those changes to sedimentation that come from outside the depositional basin. As opposed to 'autocyclic', which come from inside the depositional basin and include earthquakes, tectonic uplift, tempestites etc. Allocyclic change as assumed to be global in extent and include sea level changes forced by changes in insolation and/or global ice volume.

  2. How do tectonic forces complicate the interpretation of eustatic sea level change in the Appalachian foreland basin (AFB)?

    3. Thrusting along the eastern margin of the basin shifts the load on the continental plate causing the line of flexure (uplift) west of the orogen to move westward and eastward through the Silurian. This does not happen at a regular period, but does change facies indications of relative sea level, thus complicating any regular, repeating changes induced by insolation-forced variations in eustatic sea-level. That is, autocyclic process create noise in the allocyclic signal.

  3. Describe lithological changes associated with the 4th and 5th order cycles in the Sequence V (a third-order cycle) and their relationship to relative sea level trends.

    4. There are two 4th order cycles in Sequence V. The first deepens through the Irondequoit Limestone into the middle of the Lewiston Member of the Rochester Shale and then shoals to the top of the member. The second 4th order cycle begins with an abrupt deepening at the base of the Burleigh Hill Member and then a shoaling to the top of the Rochester Shale. Several 5th order cycles are discernible in the deepening half of the first 4th order cycle. They are apparent as cm-scale alternations between limestone and shale layers. See Fig. 14.

  4. Where are condensed beds found in Silurian sections and what cause them to be "time-rich"?

    5. The condensed beds are periods of slow sediment accumulation at sea level maxima. Sources of sediment are most distant from the center of the basin during these intervals. Much time is present in these intervals because of the slow rate of sediment accumulation.

  5. At what order of cyclicity should the modulation of the strength of the monsoon begin to be apparent. (This is a tough question; just go with your intuition and don't worry about being right or wrong.)

The primary period of the monsoon is that of precession (20 kyr) and the modulation of the primary period is that of eccentricity (100 and 400 kyr), which are the scale of the 5th and perhaps the 4th order cycles of Brett et al.