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Miami Circle - Artifacts - Radiocarbon Dates

Radiocarbon Dates

University of Houston archaeologist Randolph Widmer obtained 18 radiocarbon dates from clam shells recovered from various contexts in the 2000 field school excavations at the Miami Circle. Many of these shell samples were removed from cut hole features. Widmer combined these with earlier radiocarbon dates and proposed five prehistoric chronological phases for the site. The dates confirm that the site deposits are primarily from around 750 B.C. to A.D. 550, called by archaeologists the Glades I early period. The major break in dates comes between Widmer’s Phases IV and V, with the last phase representing a much later occupation around A.D. 1330-1680.

Radiocarbon dates from the Miami Ciricle at Brickell Poin site
OP# FS# Lab#(Beta-) Material Context Conventional Radocarbon Age 2 Sigma Calibrated Age Phase
3 558 166858 Lucina Shell Cut-hole 2770 +/- 70 BP Cal 760 - 370 BC I
3 343 146939 Lucina Shell Cut-hole 2720 +/- 70 BP Cal 740 - 340 BC I
3 395 166850 Lucina Shell Cut-hole 2720 +/- 70 BP Cal 740 - 370 BC I
3 274 146938 Lucina Shell Cut-hole 2710 +/- 70 BP Cal 730 - 340 BC I
SHC1 690 02452 Charcoal ? 2350 +/- 50 BP2 Cal 520 - 370 BC I
3 395 Lucina Shell Cut-hole 2650 +/- 100 BP3 Cal 500 - 300 BC II
SHC 700D 1675 Lucina Shell ? 2700 +/- 110 BP Cal 760 - 170 BP II
3 355 146940 Lucina Shell Cut-hole 2600 +/- 40 BP Cal 400 - 230 BC II
3 395 146941 Lucina Shell Cut-Shell 2570 +/- 70 BP Cal 400 - 230 BC II
3 434 166851 Lucina Shell Cut-hole 2570 +/- 70 BP Cal 410 - 135 BC II
3 493 166856 Lucina shell Cut-hole 2560 +/- 60 BP Cal 400 - 150 BC II
3 778 165684 Lucina Shell Cut-hole Cal 2580 +/- 60 BP Cal 400 - 160 BC II
3 883 165685 Lucina shell Basin 2520 +/- 70 BP Cal 350 - 50 BC II
3 615 165681 Lucina shell Cut-hole 2470 +/- 60 BP Cal 350 - 30 BP II
3 529 166857 Lucina shell Cut-hole 2460 +/- 70 BP Cal 360 BC-AD 10 II
3 685 165682 Lucina shell Cut-hole 2390 +/- 70 BP Cal 160 BC-AD 10 III
3 732 165683 Lucina shell Cut-hole 2280 +/- 80 BP Cal 150 BC-AD 240 III
3 481 166854 Lucina shell Cut-hole 2270 +/- 70 BP Cal 100 BC-AD 240 III
3 487 166855 Lucina shell Cut-hole 2770 +/- 70 BP Cal 100 BC-AD 240 III
SHC 689 02451 Charcoal ? 2080 +/- 50 BP Cal 200 BC-AD 30 III
1 514 128477 charcoal ? 1950 +/- 150 BP Cal 365 BC-AD 415 III
1 515 128478 charcoal ? 1920 +/- 70 BP Cal 45 BC-AD 245 III
3 473 166853 Lucina shell Cut-hole 2020 +/- 70 BP Cal AD 180-530 IV
1 807-B 134546 bone collagen sea turtle bone Midden 2040 +/- 40 BP Cal AD 250-440 IV
SHC 700+ 1674 shell columnella ? 1980 +/- 70 BP Cal AD 250-580 IV
SHC 667 02449 charcoal ? 1710 +/- 60 BP Cal AD 250-580 IV
1 585-A 134544 charcoal ? 1600 +/- 40 BP Cal AD 390-550 IV
1 1028 charcoal Feature "A" turtle Carapace 420 +/- 80 BP Cal AD 1330-1650 V
1 495 bone collagen Feature 218 Dolphin Skull 690 +/- 40 BP Cal AD 1550-1680 V
1 519 134544 bone collagen Feature 234 Shark Interment 670 +/- 30 BP Cal AD 1560-1680 V
1 SHC dates from Carr and Ricisak 2000:267, Table 1, OP#1 dates from Carr and Ricisak 2000:282, Table 2).
2 SHC FS# 690 has an early appearing date range due to flatness in the calibration curve at this point.
3 This date represents the average of two combined C14 dates on the same sample.