GEOL 101 Lecture Notes - Lecture 8: Foraminifera, Trace Fossil, Crinoid
Document Summary
Inchnofacies indicate a particular sedimentary facies and can be identified on the basis of its trace fossil assemblage. Caco3 shells and skeletal structure of plants and animals. Tend to form in reefs and as the tests of a single cell plankton that rain down on the seafloor after. Grain size classification, lithification, porosity, permeability, compaction, grading, bedding, lamination. Most foraminifers construct tests (shells) covering the cell body. Fossil foraminifera are the remains of their tests (shells). Fossils can be microscopic or a few centimeters long. Fully grown individuals range in size from about 200 micrometers to 20 centimeters long. Some of the earliest life forms were blue-green algae that deposited some of the first limestone as stromatolites as bulbs of laminated limestone. Limestones form in the photic zone of the ocean. At calcium carbonate compensation depth, caco3 dissolves- no limestone from plankton is formed at depths in the oceans below 4500 meters.
