2003 Annual Science Report
Arizona State University Reporting | JUL 2002 – JUN 2003
This year we published 3 papers. One dealt with isotopic variations in caliche developed on basalt and stressed implications for the search for past life on Mars as well as a new suggestion for the origin of carbonate in ALH 84001. We claim that isotopic variations in such caliche are actual isotope biosignatures independent of knowledge of past or present isotopic reservoirs. A second paper presented O isotope data for cherts in Archean cherts and argued that the Earth 3.5 billion years ago had climatic temperatures on the order of 50-70 degrees C. The 3rd paper dealt with the early hydrosphere of Mars and argued that remnant brines should still be present in the megaregolith if Mars indeed had a “warm, wet, early period”. A test using remote geophysical prospecting was suggested.
A new manuscript that describes the geologic context of the 1.2 Ga palekarst that hosts the world’s oldest onland microfossils was written and submitted. An additional manuscript is in preparation describing cave deposits associated with the paleokarst and presents evidence for microfossils entombed in these deposits.
A survey for entombed microfossils and organic materials in modern caliche in basalts is being concluded. This is to demonstrate the potential of caliche on basalt as a host medium for possible microfossils in caliche on Mars (which must be present if Mars indeed had a warm, wet early period).
PROJECT INVESTIGATORS:L Knauth
PROJECT MEMBERS:Donald Burt
RELATED OBJECTIVES:Objective 2.1
Earth's early biosphere
Biosignatures to be sought in Solar System materials