Indian Ledge. Contains one of the finest and most complete stratigraphic records of Lower Devonian earth history anywhere in the world. During the Silurian period, 434 million years ago, large glacial formations melted as the world’s climate warmed following a short ice age. The melted glacial water contributed to a substantial and significant rise [400 feet]in the levels of major seas, creating many new marine habitats including the Helderberg Sea of eastern New York. At this time New York, along with much of North America, Greenland, Ireland, Scotland, and parts of Russia, belonged to the paleocontinent called Laurentia. Laurentia was located within 30° north and south of the paleoequator. The south shore of New York’s Hudson Bay lay at the center of Laurentia, placing most of New York state within 10° south of the equator. Thus during the Late Silurian, New York was very warm and moist – a tropical/subtropical environment. Fossils of stromatoporoid corals, tabulate corals, and small solitary rugose corals found in the Coeymans and Manlius formations (LaPorte 1969: 107) of the Helderberg escarpment are evidence of this warm climate. Corals require shallow, clear water in which the temperature remains above 18° C (65° F). Most of the corals alive today are located within 30° north or south of the equator and live at or close to sea level. To speculate about the past, the presence of coral fossils supports the idea that eastern New York state was once part of a shallow sea located close to the equator.
There are many books and interpretations of The I Ching. It is a subject that has led many individuals to make the study of it their life's work. These writings have interested me since I was a teenager. I do not pretend to be a knowledgeable source of information on this subject. This short list will provide you with some good background if you would like to pursue it.