Reasons to Believe

New Date for First Aussies

Australia, do we have a problem?

It may seem so, or at least it did a few years ago. The RTB creation model places the creation of humanity at roughly 50,000 years ago, with the spread of peoples and civilization outward from Mesopotamia some time after that, but probably no earlier than 30,000 years ago.1 Research findings published in 1996 claimed that aborigines inhabited Australia as early as 50,000-75,000 years ago.2 RTB’s scenario appeared to contradict the data. Time to go back to the drawing board?

The answer lies in a place called the “Jinmium rock shelter” in northern Australia. Archeologists have been working there for many years. Circular engravings in the rock walls drew them to investigate the site. Initially, they applied thermoluminescence dating methods to determine the age of those engravings.

This technique simply measures the time elapsed since quartz minerals in the sand associated with the engraving process last received exposure to sunlight. The assumption is that all mineral samples were well exposed to sunlight before they were buried by winds and debris of time.

The strengths and weaknesses of thermoluminescence dating can be illustrated by familiar “glow-in-the-dark” plastics. When my sons were very young, I stuck glow-in-the-dark stars on their bedroom ceiling to teach them how to find the North Star. When I turned out the lights at bedtime, the stars would glow above their heads. A few hours later, when I’d check to see if their eyes were finally closed and their covers somewhere nearby, the stars had vanished from sight (unless, of course, the lights had been on in the interim).

In principle, I could have come into their room at any time during those few hours, measured the intensity of light emitted by the stars, and thus determined how much time had passed since the lights that eradiated them went out. Certain variables would have complicated the situation though—how much light the stars had absorbed and over what span of time, for instance.

Questions such as these drew eleven researchers back to the Jinmium site to apply more tests.3 Among them was the lead scientist from the group that published the 1996 results. This second team performed optically stimulated luminiscence tests (subtly different from thermoluminescence) on the quartz grains and made radiocarbon measurements on charcoal fragments (from human activity) in the same sediment layer.

Quartz found near the top of the sediment appears to be 2,200 years old while grains found at the maximum burial depth (two meters) measured roughly 22,000 years old.4 Dates obtained (by radiocarbon methods) from the charcoal samples ranged from 100 to 3,900 years ago.5 In the very layer that produced the 60,000-year thermoluminescence date, the radiometric tests showed the charcoal to be 1,000 to 3,000 years old. The team’s conclusion: the dates published in 1996 were off by “more than an order magnitude.”6

This reassessment does NOT rule out human occupation in Australia before three or four thousand years ago. Other sites in Australia where both radiocarbon dating and atomic mass spectrometry have been applied yield dates somewhere in the neighborhood of 30,000 years.7 Such timing is not inconsistent with the earliest dates for human occupation of other regions of the eastern hemisphere outside Mesopotamia.8 These dates correspond with RTB’s biblical creation model to a sufficient degree that no major revision seems necessary at this time.

SIDEBAR

What about other dates for humanity that appear to challenge the Genesis chronology for creation and the spread of civilization? One comes from the Mount Carmel region of Israel, where indicators suggest the presence of “homo sapiens” as early as 100,000 years ago.9 Another comes from Brazil, where a structure has been dated at 35,000 years.

As it turns out, both dates are based on thermoluminescence, which can only be trusted to provide upper limits. Further testing may show both the Israeli and Brazilian remains are much younger than thermoluminescence tests suggest. At this time, no substantial discrepancy exists between these findings and the Genesis creation chronology for humanity. I might add that in developing a creation chronology for The Genesis Question I used only measurements that are currently undisputed or uncontested.

Subjects: Early Human Migration, Human Origins and the Bible, Origin of Agriculture/Human Civilization, Radiometric Dating Techniques, TCM - Human Origins

Dr. Hugh Ross

Reasons to Believe emerged from my passion to research, develop, and proclaim the most powerful new reasons to believe in Christ as Creator, Lord, and Savior and to use those new reasons to reach people for Christ. Read more about Dr. Hugh Ross.

References:

  1. Hugh Ross, The Genesis Question, 2d ed. (Colorado Springs, CO: NavPress, 2001), 107-15, 119-25, 173-87.
  2. R. L. K. Fullagar, D. M. Price, and L. M. Head, “Early Human Occupation of Northern Australia: Archeology and Thermoluminescence Dating of Jinmium Rock Shelter, Northern Territory,” Antiquity 70 (1996): 751-73.
  3. Richard Roberts et al., “Optical and Radiocarbon Dating at Jinmium Rock Shelter in Northern Australia,” Nature 393 (1998): 358-62.
  4. Roberts et al., 361.
  5. Roberts et al., 360-61.
  6. Roberts et al., 362.
  7. David B. Roberts, R. Tuniz, C. Jones, and R. & J. Head, “New Optical and Radiocarbon Dates from Ngarrabullgan Cave, a Pleistocene Archeological Site in Australia: Implications for the Comparability of Time Clocks and for the Human Colonization of Australia,” Antiquity 71 (1997): 183-88.
  8. Tim Appenzeller, “Art: Evolution or Revolution,” Science 282 (1998): 1451-54.
  9. Anthropologists dispute whether the Mount Carmel specimens are modern humans (homo sapiens sapiens) or archaic homo sapiens.