Combined U-Pb zircon data of granitic, dioritic, and gabbroic suites reveal development of arc-related magmatism in South Borneo throughout the Late Mesozoic but dominantly in the Cretaceous (144–72 Ma). Cretaceous igneous suites constitute the Schwaner-Singkawang, Kuching-LongPahangai, and Meratus-West Java magmatic arc zones. Arc-related felsic suites are low-K tholeiitic, and calc-alkaline to high-K calc-alkaline. Most of them are metaluminous (A/CNK 0.7–1.1), I-type, and have high large-ion lithophile element (LILE) contents, low high-field strength element (HFSE) contents, and low crystallization temperatures (688–769 °C). A few rocks have adakite characteristics, such as high Sr/Y and low Y. Late Cretaceous granitic suites from South Schwaner, which evolved at elevated temperature (761–852 °C), have diverse compositions that range from I-type transitional to A-type. The highly fractionated chemistry of these samples is attributed to an intraplate stretching tectonic setting. This regime is consistent with tectonic controls of the synchronous tholeiitic suites within North Schwaner. Two subduction systems beneath Sundaland converged and interacted during the Cretaceous. The Paleo-Pacific subduction in the north built arc-trench architectures, as shown by the Early Cretaceous Lupar Line mélange, the Schwaner to Singkawang magmatic arc, and the Late Cretaceous Lupar Line mélange and Kuching-LongPahangai arc. The Meso-Tethys subduction in the southeast produced the Cretaceous Schwaner-Singkawang magmatic arc, Meratus to Luk-Ulo mélanges, and Meratus-West Java magmatic arc. When entered into Late Cretaceous, slab rollback led to crustal stretching in the Schwaner to Singkawang regions, with the production of A-type transitional and tholeiitic suites. Though debatable, we infer the SW Borneo block to be a Sundaland continuation; Semitau shows an affinity for South Cathaysia. Both of the terranes would accrete onto Sundaland during the Indosinian orogeny.

花岗岩、闪长岩和辉长岩组合的 U-Pb 锆石数据揭示了南婆罗洲在整个晚中生代期间发育与弧相关的岩浆作用，但主要在白垩纪（144-72 Ma）。白垩纪的火成岩套构成了施瓦纳-山口洋、古晋-隆彭盖和梅拉图斯-西爪哇岩浆弧带。与弧相关的长英质套件是低钾拉斑沸石，钙碱性至高钾钙碱性。大多为金属铝质（A/CNK 0.7-1.1），I型，大离子亲石元素（LILE）含量高，高场强元素（HFSE）含量低，结晶温度低（688-769 ℃）。少数岩石具有埃达克岩特征，如高 Sr/Y 和低 Y。 来自南施瓦纳的晚白垩世花岗岩组，在高温（761-852 °C）下演化，具有多种成分，从 I 型过渡到 A 型。这些样品的高度分馏化学归因于板内拉伸构造环境。这一制度与北施瓦纳内同步拉斑斑岩组的构造控制一致。巽他大陆下的两个俯冲系统在白垩纪期间会聚并相互作用。北部的古太平洋俯冲形成了弧沟构造，如早白垩世卢帕尔线混杂岩、施瓦纳至山口洋岩浆弧、晚白垩世卢帕尔线混杂岩和古晋-隆帕汉盖弧。东南部的中特提斯俯冲产生了白垩纪施瓦纳-山口洋岩浆弧、梅拉图斯至卢克-乌洛混杂岩和梅拉图斯-西爪哇岩浆弧。进入晚白垩纪时，板片回滚导致施瓦纳到山口洋地区的地壳伸展，产生了 A 型过渡和拉斑岩组。虽然值得商榷，但我们推断西南婆罗洲地块是巽他大陆的延续；Semitau 显示出对南华夏的亲和力。在印支造山运动期间，这两个地体都将增生到巽他大陆上。