. Relazione annuale del consiglio di amministrazione di Regents dello Smithsonian Institution. Smithsonian Institution; Smithsonian Institution. Archivi; scoperte nel campo della scienza. Tempo geologico. 333 Archenn o torta-Algonkiaii tempo non ho alcuna stima basata su uno studio di strati Archean da offrire. Se si suppone di Houghton stima di 33 per cento per il periodo Azoico e 07 per cento per le rocce sedimentaiy, tempo Archoan wouhl l)e rappresentato dal periodo di anni 22,250,000. Nella stima per la Archean, Houghton inchided una grande serie di strati che vengono ora posti in Algonkian del Proterozoic di U. S. Geolo

• Collaboratore: Library Book Collection / Alamy Foto Stock
• ID dell’immagine: RM5271
• Dimensioni dei file: 7,2 MB (156,2 KB Download compresso)
• Liberatorie: Modello - no | Proprietà - no
• Dimensioni: 2429 x 1029 px | 41,1 x 17,4 cm | 16,2 x 6,9 inches | 150dpi

Altre informazioni

Questa foto è un'immagine di pubblico dominio, il che significa che il copyright è scaduto o che il titolare del copyright ha rinunciato a tale diritto. Alamy addebita un costo per l'accesso alla copia ad alta risoluzione dell'immagine.

Questa immagine potrebbe avere delle imperfezioni perché è storica o di reportage.

. Annual report of the Board of Regents of the Smithsonian Institution. Smithsonian Institution; Smithsonian Institution. Archives; Discoveries in science. GEOLOGIC TIME. 333 Archenn or pie-Algonkiaii time I have no estimate based on a study of Archean strata to offer. If we assume Houghton's estimate of 33 per cent for the Azoic period and 07 per cent for the sedimentaiy rocks, Archoan time wouhl l)e represented by the period of 22, 250, 000 years. In estimating for the Archean, Houghton inchided a large series of strata that are now placed in the Algonkian of the Proterozoic of the U. S. Geological Survey; and T think that his estimate is more than one-half too large; if so, 10, 000, 000 years would be a fair estimate, or rather conjecture, for Archean time.. It is easy to vary these results by assuming different values for area and rate of denudation, the rateof deposition of carbonate of lime, etc.; but there remains after each attempt I have made that was based on any reliable facts of thickness, extent, and character of strata, a result that does not pass below 25, 000, 000 to 30, 000, 000 years as a mininnim and 60, 000, 000 to 70, 000, 000 years as a maximum for post-Archean geo- logic time. I have not referred to the rate of developmeni, of life, as that is virtually controlled by conditions of environment. In conclnsion, geologic time is of great but not of indertnite ; it is not improbable that daring Ordo- viciau or Silurian time a sea may have conuecited the two latter seas.. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.. Smithsonian Institution. Board of Regents; United States National Museum. Report of the U. S. National Museum; Smithsonian Institution. Report of the Secretary. Washington : Smithsonian Institution

Parole chiave associate all'immagine

• bookcentury1800
• bookdecade1840