The Indonesian Archipelago is located in the Equatorial area between longitude 94º and 141º N and latitude 8º N and 13º S, comprised more than 17 000 islands with a total land area of > 1.9 million sq km and a sea area of > 5.8 million sq km or 25% and 75% of the total territory respectively. The Archipelago is situated on a crossroad between two eceans, the Indian and Pacific, and bridges two continents, the Asia and Australian. The stable platforms, the Sundaland in the northwest and the Sahul Shelf in the southeast are interwined with a complex zone comprising island arcs, volcanic arcs, continental terrains, oceanic terrains and submarine trenchs. Within the complex zone there are regular features shown by the intimate relationship between volcanicity, belts of earthquake foci and the belts of gravity negative anomalies.
The importance of a stratigraphic lexicon to geoscientists has long been resalized by us. It has become a kind of a preliminary guidebook to the understanding of the geology of an area to be studied. Through a lexicon, also known as nomenclature, earth scientists can find all the existing lithostratigaphic terminologies of their respective countries. It is therefore important to update the Stratigraphic Lexicon of Indonesia compiled by Marks (1957), and the result is as presented in this volume.
Like most stratigraphic lexicon, the present one also contains information on the lithostratigaphic units which are available in the literature, either formal or informal ones, accompanied by name of unit, age, nomenclature, type locality, description, fossil content, thickness, distibution, environment, tectonic setting, economic aspect, remark, and reference.
Sediment (usually shale or limestone) in which hydrocarbons originate; it contains more than 5% organic matter and has the potential to generate petroleum.See Map
Any porous rock in which oil, gas, or water may accumulate; usually sandstone, limestone, or dolomite, but sometimes fractured igneous or metamorphic rock.See Map