Cryptic (geology)
The Cryptic era is an informal term for the earliest geologic evolution of the Earth and Moon. It is the oldest (informal) era of the Hadean eon, and it is commonly accepted to have begun close to 4533 million (about 4.533 billion) years ago when the Earth and Moon formed. No samples exist to date the transition between the Cryptic era and the following Basin Groups era for the Moon (see also Pre-Nectarian), though sometimes it is stated that this era ended 4150 million years ago for one or both of these bodies. Neither this time period, nor any other Hadean subdivision, has been officially recognized by the International Commission on Stratigraphy.
Haida argillite carvings
Duff's first period dates between the years 1800–1835. This is a "non-sense" period which is characterized by a lack of logical compositions of traditional Haida images or themes. According to Duff, these illogical representations in argillite are due to an unwillingness on the Haida's behalf to allow important elements of their culture to be owned by Europeans and Americans. Duff's second period is called "White Man’s Non-sense" and takes place between 1830 and 1865. This period is filled with argillite carvings depicting Europeans or Americans which are often carved using a more Western influenced style. This movement towards more Western styles and themes is potentially due to an increase in contact between the two cultures. There were also many mixed images and visual punning carried out during Duff's "Non-Sense" period. This "non-sense" theme is therefore also indicative of the Haida's ridicule of Western culture's seeming lack of rationality.
The depictions of Western culture increased and grew more detailed and elaborate during this period. By 1865 there are conventions in Haida depictions of Western style clothing, and a merging of traditional and Western methods of figure representation. The third period existed between 1865 and 1910. This "Haida sense" period represents a movement back to strongly traditional themes in argillite carving, most likely due to the population and culture decrease happening throughout Haida society at the time. Meaning is suddenly apparent in argillite carving, as are important Haida figures such as chiefs and shamans and sacred or religious themes. Haida myths begin to be represented in the carvings, the Bear-Mother myth being one of the most common myth themes that appear in this period. Duff sees this period as being an attempt by the Haida to record elements of their culture that were quickly being forgotten because of religious conversion or because of death. By 1910 the art of argillite carving was beginning to decline in conjunction with the continued loss of Haida individuals and culture. Duff's fourth period is composed of two phases and added to Kaufmann's original chronology. This period is entitled "Haida-Sense II" and existed between the years 1910–1981, making it the longest period in Duff's model. Many of the great Haida artists producing carvings in the third period died during the early years of the fourth period causing a lack of skilled carvers and a stall in the production of argillite carvings. This first phase of period four is what Duff calls "The Plateau Era". The plateau era is ended by a nationwide revitalization in the 1960s which occurred throughout Native American communities in order to revitalize the practice of traditional cultures. Aspiring argillite carvers looked to remaining older carvers, academia, museums and galleries for information on how to carve.