Seismic geomorphology and growth architecture of a Miocene barrier reef, Browse Basin, NW-Australia
Seismic geomorphology and growth architecture of a Miocene barrier reef, Browse Basin, NW-Australia
复制标题
DOI：
10.1016/j.marpetgeo.2010.11.001
复制
发表时间：
2012
影响因子：
4.2
通讯作者：
B. Rosleff-Soerensen;L. Reuning;S. Back;P. Kukla
中科院分区：
文献类型：
--
作者：
B. Rosleff-Soerensen;L. Reuning;S. Back;P. Kukla
Browse盆地的新生代层序以碳酸盐岩体系为特征，从始新世-早中新世的非热带斜坡发展到中新世中期的热带边缘台地。通过对中新世中期热带生物礁系统的地震地貌和钻孔资料的解释，揭示了该台地的演化过程。第一个礁构造发育于早中新世中期，为相对于陆架走向倾斜的狭窄线性礁带。随后，它们向台地边缘移动，形成了一个最小长度为40公里的堡礁。大堡礁本身由三个明显的山脊组成，山脊之间被横向台阶隔开。第二个和第三个步骤是分开的岩溶地平线，这是解释为代表全球海平面下降前不久的Serravallian/Tortonian边界。随后的第三脊形成于海平面低水位和海侵初始阶段的一个略下降的位置。在托托阶早期，海平面进一步上升，首先淹没了堡礁系统，随后淹没了在台地内部后退位置建立的补丁礁和遗迹环礁。浏览盆地生物礁系统和其他同生碳酸盐系统的类似演化表明海平面变化的强烈影响。在研究区相对较大的沉降率可能增加了海平面上升的托顿，因此有助于溺水的珊瑚礁系统。然而，珊瑚礁系统的开始和最终消亡也受到全球和区域气候变化的影响。第一批地震定义的珊瑚礁同时发育，印度尼西亚贯流的输送能力达到最大值，将温暖的低盐度沃茨水带到西北大陆架。珊瑚礁溺水是在靠近中新世中期至早期边界的这条海道受到限制之后发生的。印度尼西亚海道的关闭可能导致全球中新世中后期冷却趋势的区域放大，并阻碍了珊瑚礁系统跟上海平面上升的潜力。
The Cenozoic succession of Browse Basin is characterized by a carbonate system, that developed from a non-tropical ramp in Eocene-lower Miocene times to a tropical rimmed platform in the middle Miocene. The evolution of the platform was unraveled through the interpretation of the seismic geomorphology and borehole data of the middle Miocene tropical reef system. The first reef structures developed during the early middle Miocene as narrow linear reef belts with an oblique orientation with respect to shelf strike direction. Subsequently, they prograded toward the platform margin to form a barrier reef with a minimum length of 40 km. The barrier reef itself comprises three distinct ridges separated by progradational steps. The second and third step are separated by a karstified horizon, which is interpreted to represent the global sea-level fall shortly before the Serravallian/Tortonian boundary. The following third ridge formed in a slightly downstepped position during the sea-level lowstand and initial transgressive phase. Further sea-level rise during the early Tortonian first drowned the barrier-reef system and subsequently also the patch reefs and relic atolls that had established in a backstepped position in the platform interior. The similar evolution of the Browse Basin reef system and other contemporaneous carbonate systems indicates a strong impact of eustatic sea-level changes. Relatively large subsidence rates in the study area possibly augmented the eustatic sea-level rise in the Tortonian and hence contributed to the drowning of the reef system. However, the initiation and final demise of the reef system was also governed by global and regional climate variations. The first seismically-defined reefs developed simultaneous to a maximum in the transport capacity of the Indonesian throughflow, which brings warm low-salinity waters to the North-West Shelf. Reef drowning followed the restriction of this seaway close to the middle to early Miocene boundary. This near closure of the Indonesian seaway possibly led to a regional amplification of the global middle to late Miocene cooling trend and hampered the potential of the reef system to keep up with the rising sea-level.