Page 3 - Maldonado_Stanley_1976

Contents

P age
Introduction l
Generai ......................................................................... . l
Acknowledgments ............................................................... . l
Structurai-Stratigraphic Framework ............................................... . 3
Hydrography .................................................................... . 4
Methodology .................................................................... . 7
Defining the Major Strait Environments ............................................. . 8
Generai ......................................................................... . 8
Environments ................................................................... . 11
Slope (Environment l) ......................................................... . Il
Neritic-Bathyal Borderland (Environments 2, 3, 4, 5) ............................. . 11
Basin (Environments 6, 7) ...................................................... . 18
Shallow Platform (Environment 8) .............................................. . 18
Marked Topographic High (Environment 9) ..................................... . 19
Canyon (Environment 10) ...................................................... . 20
The Strait Narrows (Environment Il) .......................................... . 20
Sediment Types in the Strait of Sicily . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .......... . 21
General Distribution of Sediment Types .......................................... . 21
Definition of Major Sediment Types in Cores ..................................... . 22
Coarse Calcareous Sand ........................................................ . 23
Sand-Silt Size Sediments ....................................................... . 23
Volcanic Ash .................................................................. . 24
Muds .......................................................... · ............... . 24
Sapropel and Organic Ooze .................................................... . 24
Sand Fraction Composition ......................................................... . 25
Generai ......................................................................... . 25
Coarse Calcareous Sand Type ..................................................... . 25
Sand-Silt Sediment Type ......................................................... . 29
Voicanic Ash Type .............................................................. . 29
Shallow Water Mud Type ........................................................ . 29
Hemipelagic Mud Type .......................................................... . 30
Turbiditic Mud Type ........................................................... . 30
Sapropel Type .................................................................. . 30
Organic Ooze Type .............................................................. . 31
Bryozoan Content ............................................................... . 31
SEM Analysis of the Lutite Fraction ................................................ . 31
Sea-Floor Photography ............................................................. . 36
Structures Observed in X-Radiographs and Split Cores ............................... . 37
Definition of Sequences ............................................................ . 44
Generai ......................................................................... . 44
Upward-Fining and Upward-Coarsening Sequences ................................. . 46
Uniform Sequence ............................................................... . 47
Turbiditic Sequence ............................................................. . 48
Sapropel Sequence ............................................................... . 51
Sedimentation and Stratigraphy in the Strait Environments ........................... . 51
Regional Distribution of Sequences ............................................... . 51
Environmental Factors Controlling the Strait Sedimentation ........................ . 55
Bioturbation as an Environmental Indicator ....................................... . 59
Rates of Sedimentation .......................................................... . 61
Implications of Strait Sedimentation to Current Reversais .......................... . 65
Summary .......................................................................... . 66
Literature Cited ................................................................... . 69
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