PRE-CAMBRIAN FORMATIONS. 354 PRECEDENCE. and an upper series, the Huronian, which corre- sponds to the present Algoukian. The Pre-Canibrian rocks are widelj- distributed and form a :^cries of disconnected areas, some of them of coH'^iderable extent. Tlieir exposure at tlie sTirface may be due to their liaving remained uncovered since early geologic times, or because the overlying sediments and other rocks of later date have been worn away. The more important Pre-Cambrian areas found in North America are the following: (1) Laurentian area of Canada, consisting of a basement complex or Arclutan system known as the Ottawa gpeiss, which grades up into the Grenville scries of Algonkian age. (2) The Hastings district southwest of Ottawa. (3) The original Huronian area bordering the north channel of Lake Huron and extending west to Lake Superior. Botli the Archtean and Al- gonkian are recognizable here, the latter being subdivided into an upper and lower Huronian. (4) Adirondack area of eastern Xew York. (5) The Lake Superior region. Probalily a greater amount of work has been done in this area than any other of Pre-Cambrian age and the strati- graphic details have been most carefully worked out. (C) Eastern United States; a belt extend- ing from Elaine tlirough New Hampshire, ilassa- chusetts. Connecticut. New York. New .Jersey, Pennsylvania, ilaryland, Georgia, North Caro- lina to Alabama, and consisting of a complex series of semi-crystalline and holocrvstalline rocks. (7) Black Hills area. (8) Southeast Missouri area. (9) Central Texas. (10) Scat- tered areas in the Cordilleran region. Pre-Cam- brian rocks are also known in Great Britain, Scandinavia, Central Europe, China, India, and Australasia. The Pre-Cambrian rocks are rich in mineral deposits. Almost inexhaustible supplies of iron ore are found in the Lake Superior region, and important deposits of the same met^al are kno'n in New York and New .Jersey. !Many valuable quarries of building stone are located within the Pre-Cambrian areas, while the other economic minerals include graphite, garnet, apatite, talc, emery, feldspar, gohl, copper, and nickel. BiBUOGBAPHY. Van Hise. "Principles of Pre- Cambrian N(n-th American Geologv," Sixteenth Annual Report United States Geological Survey (Washington, 1896); Geikie. Text-Book of Ge- ology (London. 189.3) ; Van Hise. '"The Iron Ore Deposits of the Lake Superior Region," Tirenty- first Annual Rcimrt United States Geological Surve-y (Washington. 1901): Adams. "On the Typical Laurentian Area of Canada," Journal of Geology (Chicago. 1893): Adams, "Origin and Relations of the Grenville and Hastings series in the Canadian Laurentian." American Journal of Science. 4th series, vol. iii. (New Haven. 1897) ; ^latthew, "The Effusive and Dike Rocks Near Saint John, New Brunswick." Xeic York Academy of Sciences Transactions, vol. xiv. (New York, 189.5) ; Kemp. "Pre-Cambrian Sediments in the Adirondacks." Science, vol. xii. (ib.. 1900) ; Kemp. "Crystalline Limestones. Ophicalcites. and Associated Schists of the Eastern Adirondacks," Geological Society of America Bulletin, vol. vi. (Rochester, 189.5) : Van Hise, "Correlation Papers. Archtean and Algonkian." United States Geological Surrey. Bulletin Vo. S6 (Washington, 1892) ; Leith. "Reviews of Pre-Cambrian Litera- ture." Journal of Geology, from vol. i. to date (Chicago). See AKCH.i;AN System j Algonkiait System ; Lauke>-tiax System; etc PRECEDENCE (ML. prwcedentia, from Lat. prwccderc, to go before, from prce, before -|- cedcre, to go, yield; connected with cadere, Skt. ^ad, to fall). The order in which individuals are entitled to follow one another in a state pro- cession or on other public occasions. In former days questions of this sort were considered of great importance; thus the memoirs of Saint- Simon are largelj- occupied with minute histories of acrid controversies on these points. In mod- ern times, with the gradual diminution of court ceremonial, less interest attaches to them ; but they are still minutely regulated in some coun- tries, either by statute law, by royal letters patent, or by ancient usage. The order of prece- dence among different countries is in modern practice reduced, as in the signing of treaties by several powers, to the alphabetical order of their names. Precedence among the diplomatic repre- sentatives accredited to any government depends upon the date of the presentation of their creden- tials, ambassadors, however, ranking envoys and ministers plenipotentiary. Precedence involves the right to be presented, or to pass into a room, first; but in processions, especially those of ecclesiastical dignitaries, the persons of highest rank regularly come last. In the United States the only positive pre- cedence is that given by official position ; ami in the settling of uncertain questions arising luider this sy.stem, there is no final authority, different administrations having acted in different ways. The position of foreign ambassadors, for example, is questionable. It has been claimed for them that as the personal representatives of sovereign powers, accredited to the Executive, they should come next to the President, and before the Vice- President, who is only, so to speak, an heir apparent. There has been no official settlement of the question. It is also contended by some that the Governors of sovereign States of the Union should precede the General of the Army and the Admiral of the Navy, who are officers subordinate to tl>e Federal Executive. A question has also been raised as to the position to be assigned to a United States ambassador when on leave at home. He is the personal representative of the Federal Government, and it may be held that he should have higher rank tlian the General of the Army or Admiral of the Navy. Great ini- certaiuty, however, has prevailed in the usage of Wasliington on similar points. The most generally accepted order of official precedence at the na- tional capital is as follows: The President ; the Vice-President and Presi- dent of the .Senate; Ambassadors in their order; the Chief .Justice of the United States ; Senators ; the Speaker of the House; Representatives in Congress : Associate Justices of the Supreme Court ; the Secretary of State, members of the diplomatic corps other than ambassadors, and foreign members of international commissions; the Secretary of the Treasury; the Secretary of War ; the Attorney-General ; the Postmaster- General : the Secretary of the Navy ; the Secre- tary of the Interior; the Secretary of Agricul- ture ; the Secretary of Commerce and Labor : the General of the Army and the Admiral of the Navy; the Governors'of States; the Chief Justice and Associates of the Court of Claims : Circuit
