Deep‐Time Perspectives on Miocene Isolated Carbonate Platforms of Southeast Asia

Abstract

Although the biota, facies, stacking patterns, sequence stratigraphy, and diagenesis of numerous isolated carbonate platforms have been described and interpreted, trends in the genesis, evolution, and sizes among Phanerozoic examples remain poorly quantified. To provide broad perspectives on Miocene isolated platforms of Central Luconia and Southeast Asia (the focus of this volume), this study summarizes the results of qualitative review of the literature and a quantitative analysis of a relational database of attributes in initiation, growth, character, and demise of more than 850 Phanerozoic isolated platforms. The data and comparisons among parameters reveal numerous trends, including observations that (1) syndepositional tectonics has been interpreted to play an important role in initiation, growth, or demise of more than 44% of isolated platforms; (2) tectonically active platforms are more likely to have higher aspect ratios (more elongate in plan-view and more squat in cross section); (3) stratal geometries are not distributed randomly in time (by era, p = 0.00, and by system, p = 0.04), although aggradational isolated platforms are most common within and among all eras (63% of all platforms); (4) sizes (area, long axis length), thicknesses, and aspect ratios (long axis:short axis; long axis:thickness) of isolated platforms are distinct among Phanerozoic platforms of different eras and systems; (5) although individual platforms steepen as they grow taller, syndepositional relief is not correlated (R2 = 0.04) with depositional gradient among isolated platforms across the Phanerozoic; (6) causes of isolated platform termination vary nonrandomly through the Phanerozoic (by era, p = 0.00, and by system, p = 0.00). Of all eras, Cenozoic platforms are most likely to drown (68%), in some instances through an association with clastic influx (19%). Subaerial exposure more commonly contributed to the demise of Mesozoic (45%) and Paleozoic (37%) platforms than to that of Cenozoic (13%) platforms. These results, supplemented by more granular comparison of numerous individual platforms, compliment earlier syntheses that focus on the nature of secular changes. The insights suggest that although each platform is unique in many ways, Phanerozoic isolated carbonate platforms include numerous themes that are persistent across ages, sizes, settings, and component biota.