HOWEVER WE MUST BE ABLE TO PUT THEM IN THE RIGHT SEQUENCE OR THE STORY THEY TELL DOESN T MAKE SENSE, JUST LIKE A BOOK WITH ITS PAGES OUT OF ORDER

HOWEVER WE MUST BE ABLE TO PUT THEM IN THE RIGHT SEQUENCE OR THE STORY THEY TELL DOESN T MAKE SENSE, JUST LIKE A BOOK WITH ITS PAGES OUT OF ORDER DOESN T MAKE SENSE: ACCURATE DATING METHODS ARE ESSENTIAL TO THIS PROCESS

SOME INITIAL DEFINITIONS: FOSSIL: THE REMAINS OF PLANT/ANIMAL SKELETAL STRUCTURE CAN BE AN IMPRESSION OR THE REAL THING

IF STRUCTURE EXISTS, IT S MADE OF MINERAL/STONE, NOT BONE!

ARTIFACT: OBJECTS OR MATERIALS MADE OR MODIFIED FOR USE BY HOMINIDS

CONTEXT THE RELATIONSHIP BETWEEN AND AMONG ARTIFACTS AND OTHER MATERIALS THIS CONCEPT IS CRITICAL TO THE EXAMINATION AND UNDERSTANDING OF FOSSILS AND ARTIFACTS W/O CONTEXT, ARCHAEOLOGICAL DISCOVERIES DON T HAVE MUCH MEANING

DATING METHODS RELATIVE DATING PROCEDURES: STRATIGRAPHY: THE LAYERING OF DIRT, ROCK FORMATIONS, AND FOSSILS THE LOWER THE DEPTH THE OLDER THE AGE

TAPHONOMY STUDY OF PROCESSES OF SITE DISTURBANCE AND DESTRUCTION

CHEMICAL DATING: MEASURES FLUORINE, URANIUM, & NITROGEN IN TEETH & BONES SAMPLES MUST BE FOUND IN GROUNDWATER AND IN CLOSE PROXIMITY SITES

HOW IT OPERATES: AS TIME GOES BY: FLOURIDE AND URANIUM= INCREASES IN SAMPLE NITROGEN= DECREASES URANIUM DOESN T DESTROY SAMPLE,SO PREFERRED METHOD

ALL ELEMENTS FOUND IN NATURE

PALEOMAGNITISM: INVOLVES PERIODIC PAST REVERSALS OF EARTH S MAGNETIC POLES

ROCK FORMATIONS (ESP. LAVA) RETAIN EARTH S MAGNETIC FIELD WHEN LAID DOWN

LAVA BONES INDIRECTLY MEASURED BY POLARITY DATES

BIOSTRATIGRAPHY LOOKS AT FAUNA/FLORA FOSSILS OF SHORT-LIVED SPECIES IN PARTICULAR REGION

TONS OF CHARTS & STUDIES

PIGS ESP. HELPFUL IN AFRICA

CHRONOMETRIC (ie. ABSOLUTE) DATING METHODS DENDROCHRONOLOGY: LOOKS AT TREE RINGS NEED SENSITIVE TREES OVER COMPLACENT TREES THEY RESPOND TO PRECIPITATION, HEAT, ETC

BEST WHERE WOOD IS PRESERVED (IE. ARID AMERICAN S.W.) CLIMATE VARIATIONS ARE CRITICAL CAN GO BACK 10,000 YA BUT SHAKY (7500 YA BETTER) BRISTLE CONE PINE IS BEST TREE B/C THERE ARE THE WORLD S OLDEST TREES

THE METHUSALA TREE : 4,800 YEARS OLD, CALIFORNIA

VARVES: LAKE SEDIMENTS DEPOSITED BY ANNUAL GLACIER MELTS FROM LAST ICE AGE SUMMER CLIMATE VARIATIONS TRACKED GOOD UP TO 20,000 YA (BEST 10,000-15,000); USED IN DATING SITES IN N. AMERICA; N. EUROPE

EXAMPLES OF VARVES

THERMOLUMINESCENCE: MEASURES LIGHT EMITED FROM SAMPLES PREVIOUSLY HEATED IN PREHISTORIC TIMES EXAMINES RADIOACTIVE PROPERTIES EXCELLENT UP TO ABOUT 10,000 YA (BUT BEEN USED TO 70,000 YA) EX S: CAMPFIRE STONES, BURNT POTSHARDS, FLINT

ELECTRON SPIN RESONANCE DATING LIKE THERMO, MEASURES TRAPPED ELECTRONS SPINS MATERIAL W/IN MAGNETIC FIELDS AND MEASURES MICROWAVES/RADIATION

NO HEAT INVOLVED: GOOD FOR BONE AND SHELL

CARBON-14: MEASURES AMOUNT OF RADIOACTIVE CARBON ISOTOPE C- 14 DEAD FAUNA/FLORA DECLINES AT CONSTANT RATE AFTER DEATH GOOD UP TO 40,000-50,000 YA WHICH IS WHEN H. sapiens ENTER EUROPE

C-14 PHIALS AND MACHINE

SHROUD OF TURIN: C-14 TESTING 1988 U. OF OXFORD, U. OF ARIZONA, SWISS FEDERAL INSTITUTE OF TECHNOLOGY

RESULTS: DATED BETWEEN 1260-1390 AD (MIDDLE AGES) 3 PEER-REVIEWED ARTICLES DISPUTE RESULTS BASED ON: SITE OF SHROUD SAMPLES POSSIBILITY REPAIRS OR CONTAMINATION AFFECT DATES

POTASSIUM-ARGON (K-Ar): INVOLVES STEADY DECAY OF K-40 INTO Ar-39 POT-40 S ½ LIFE IS 1250 MILLION YEARS DECAYS INTO ARGON BLAST SAMPLE W/ NEUTRON BEAM, MEASURE TRAPPED ARGON

DATES P-RICH ROCK SURROUNDING FOSSILS, NOT FOSSILS THEMSELVES EXTREMELY VALUABLE IN E. AFRICA MIOCENE (5-22 MILLION YA BUT CAN GO BACK 3+BILLION YA)

V. SCIENTIFIC: THOUSANDS OF DOLLARS A SAMPLE, WEEKS FOR RESULTS

FISSION TRACKING: COUNTS TRACKS ACROSS SAMPLE BY DISINTEGRATING URANIUM ATOMS (U-238) ACCURATE FROM 20 YEARS TO 5 BILLION YA

NEED ELECTRON MICROSCOPE AND COMPUTER TO COUNT TRACKS

CROSS-REFERENCING: COMBINING ABOVE METHODS HELPS ELIMINATE ERRORS K-AR DATING W/ FISSION TRACKING IS VERY ACCURATE USUALLY COSTS DETERMINE DATING METHOD