Quaternary Coasts of the United States: Marine and Lacustrine Systems
Quaternary Coasts of the United States: Marine and Lacustrine Systems Project #274 Quaternary Coastal Evolution - This Special Publication represents the major cumulative contribution of the Working Group of the United States of America to IGCP Project 274. The primary aims of Project 274 are to: (1) document and explain local to global variations in coastal and continental-shelf evolution, incorporating knowledge of coastal and shelf processes and environment with geodynamic, climatic, oceanographic and other data to produce local and regional models, ranging from descriptive to numerical, leading to a better understanding of interactive forces responsible for past, present and future changes to the coasts of the world; and (2) promote specified thematic studies, which are necessary to solve problems of coastal change affecting human occupation of the coastal zone. The volume contains sections on Atlantic, Pacific, Gulf and Lacustrine shorelines, covering both Holocene and Pleistocene deposits, representing a summary of decades of research into coastal and continental-shelf evolution of North America.
Chronology and Deformation of Quaternary Marine Shorelines, San Diego County, California
-
Published:January 01, 1992
Abstract
A series of 16 marine terraces and associated landforms and sedimentary deposits provides a record of Quaternary paleo-geographic and tectonic history of coastal San Diego County, California. The width of individual terrace platforms varies dramatically, from several kilometers in places where the platforms are cut into poorly lithified sedimentary strata, to a few meters or tens of meters where the platforms are cut in more resistant rocks. Beach ridges formed of dune sands lie just landward of most of the terrace shorelines. Radiometric ages and amino-acid racemization ratios, together with shoreline elevations, have been used to calculate average rate of uplift and to construct a chronology of the 16 shorelines, which range in age from 80 ka to perhaps as old as 1.29 ma. Shoreline-angle elevations suggest that nearly the entire length of coastal San Diego County has been uplifted at a rate of 0.13 to 0.14 m/ka during the Quaternary. Both higher and lower rates are recorded in areas deformed by the Rose Canyon fault zone. Changes in configuration of successive shorelines indicate that rocks on one side of the fault have been rising through middle and late Quaternary time and that the Rose Canyon fault has been active for at least the past 1 my.
- absolute age
- beach ridges
- C-14
- California
- carbon
- Cenozoic
- chronology
- dates
- deformation
- dunes
- IGCP
- Invertebrata
- isotopes
- marine environment
- Mollusca
- platforms
- Quaternary
- racemization
- radioactive isotopes
- San Diego County California
- sedimentation
- shore features
- shorelines
- terraces
- United States
- Rose Canyon Fault