CIRCULATION IN LARGE ANCIENT EPICONTINENTAL SEAS: WHAT WAS DIFFERENT AND WHY?

摘要: At times in the geological past, vast epicontinental seas flooded continents. Almost everything we know about pre-Jurassic (200 million years ago) marine life and environmental change originates from such settings. Most of truly oceanic sediments deposited before this time have either been subsequently subducted or metamorphosed (Allison Briggs, 1993). An understanding ancient is clearly essential to our interpretation past ecological change. Epicontinental seas, however, really no suitably scaled modern counterparts. They were typically shallow, on order 10 200 m deep, but extent, covering areas up ∼106 km2 (Wells et al., 2005a, 2005b). Such as Baltic are similar depths considerably smaller. Without analogues these important water bodies handicapped. Since depth scale seaways makes them so different, their response storm tidal waves has questioned (Hallam, 1975). Specifically, it argued that wave energy was attenuated by large distances traveled (Keulegan Krumbein, 1949; Shaw, 1964; Irwin, 1965). This contention can be rejected case wind basis height data isolated seas. Wind affected fetch, duration, intensity (e.g., see Jonsson 2002, 2005). Substantial regularly documented even small today. Wave heights—crest-to-trough height—of larger than 6 Sea almost annually. result strong winds (15–20 m/s) blowing over deep for at least hours. Annual storms generate wavelengths 80 m, leading sediment reworking down 40 …