Ideas start to form…

Cordilleras -“I feel sure they formerly consisted of a chain of Volcanoes from which enormous streams of Lava were poured forth at the bottom of the sea…these Volcanoes must have formed Islands.” Burkhardt 46

http://pages.britishlibrary.net/charles.darwin2/beagle_images/pl60.jpg

The Theory -

Shallow vs. Deep

Rocky vs. Sediment

Uplift vs. Subsidence

Mapping

Three Distinct Forms

Structure and Distribution of Coral Reefs

Uplifted Coral Reef in Solomon Islands

http://www.iris.edu/about/ENO/iows/6_2004a.htm

Structure and Distribution of Coral Reefs

Structure and Distribution of Coral Reefs, Darwin, http://www.uwgb.edu/dutchs/geophoto/coastal/TAHITI.jpg

The Atoll

Structure and Distribution of Coral Reefs, Darwin, http://www.youconnect.co.uk/english/2003-10/images/earth/eye.gif

Maps

Structure and Distribution of Coral Reefs, Darwin

Distribution of Reefs

Structure and Distribution of Coral Reefs, Darwin

Bright Blue – Atolls or Lagoon Islands

Pale Blue – Barrier Reefs

Red – Fringing Reefs

Darwin’s Success

“I think my book will be popular to a certain extent…why I think so is because I have found in conversation so great and surprising interest amongst such men and some o-scientific men on subject; and all my chapters are not nearly so dry and dull as that which you have read on Geographical Distribution.” Buckhardt 201